From 7fc1a7f3af4931100bea1697f65133df24f47a28 Mon Sep 17 00:00:00 2001
From: William Petit <wpetit@cadoles.com>
Date: Fri, 11 Sep 2020 09:19:18 +0200
Subject: [PATCH] feat(ui+backend): base of data persistence

---
 Makefile                                      |   2 +-
 .../components/DashboardPage/ItemPanel.tsx    |   4 +-
 .../DashboardPage/ProjectModelPanel.tsx       |   3 +-
 .../components/DashboardPage/ProjectPanel.tsx |  10 +-
 .../components/ProjectPage/EstimationTab.tsx  |  14 +-
 ...ancielPreview.tsx => FinancialPreview.tsx} |   2 +-
 .../components/ProjectPage/ProjectPage.tsx    |  31 ++-
 .../ProjectPage/RepartitionPreview.tsx        |   2 +-
 .../ProjectPage/TaskCategorieTable.tsx        |   2 +-
 .../src/components/ProjectPage/TasksTable.tsx |  41 +--
 client/src/gql/fragments/project.ts           |  34 +++
 client/src/gql/mutations/project.tsx          |  69 +++++
 client/src/gql/queries/helper.ts              |   4 +-
 client/src/gql/queries/project.ts             |  49 ++++
 client/src/hooks/useProjectReducer.sagas.ts   |  95 +++++++
 client/src/hooks/useProjectReducer.ts         | 222 ++++++++++-----
 client/src/hooks/useReducerAndSaga.ts         |  24 ++
 client/src/types/params.ts                    |  38 +--
 client/src/types/project.ts                   |  80 +++---
 client/src/types/task.ts                      |  17 +-
 client/src/util/uuid.ts                       |  35 +++
 cmd/server/migration.go                       |  43 ++-
 internal/config/config.go                     |   2 +-
 internal/gqlgen.yml                           |   3 -
 internal/graph/estimation_handler.go          |  49 ++++
 internal/graph/mutation.graphql               |  20 ++
 internal/graph/mutation.resolvers.go          |  18 +-
 internal/graph/project_handler.go             |  96 +++++++
 internal/graph/query.graphql                  |  54 ++++
 internal/graph/query.resolvers.go             |  12 +
 internal/graph/user_handler.go                |   2 +-
 internal/model/base.go                        |  21 ++
 internal/model/project.go                     | 123 +++++++++
 internal/model/project_repository.go          | 261 ++++++++++++++++++
 internal/model/user.go                        |   3 +-
 .../postgres/initdb.d/init-databases.sh       |   2 +
 modd.conf                                     |   6 +-
 37 files changed, 1298 insertions(+), 195 deletions(-)
 rename client/src/components/ProjectPage/{FinancielPreview.tsx => FinancialPreview.tsx} (97%)
 create mode 100644 client/src/gql/fragments/project.ts
 create mode 100644 client/src/gql/mutations/project.tsx
 create mode 100644 client/src/gql/queries/project.ts
 create mode 100644 client/src/hooks/useProjectReducer.sagas.ts
 create mode 100644 client/src/hooks/useReducerAndSaga.ts
 create mode 100644 client/src/util/uuid.ts
 create mode 100644 internal/graph/estimation_handler.go
 create mode 100644 internal/graph/project_handler.go
 create mode 100644 internal/model/base.go
 create mode 100644 internal/model/project.go
 create mode 100644 internal/model/project_repository.go

diff --git a/Makefile b/Makefile
index 3dea2b9..99a9760 100644
--- a/Makefile
+++ b/Makefile
@@ -28,7 +28,7 @@ down:
 	docker-compose down -v --remove-orphans
 
 db-shell:
-	docker-compose exec postgres psql -Udaddy
+	docker-compose exec postgres psql -Uguesstimate
 
 migrate: build-server
 	( set -o allexport && source .env && set +o allexport && bin/server -workdir "./cmd/server" -config ../../data/config.yml -migrate $(MIGRATE) )
diff --git a/client/src/components/DashboardPage/ItemPanel.tsx b/client/src/components/DashboardPage/ItemPanel.tsx
index 4335c68..f4c0598 100644
--- a/client/src/components/DashboardPage/ItemPanel.tsx
+++ b/client/src/components/DashboardPage/ItemPanel.tsx
@@ -3,7 +3,7 @@ import { Link } from "react-router-dom";
 import { WithLoader } from "../WithLoader";
 
 export interface Item {
-  id: string
+  id: string|number
   [propName: string]: any;
 }
 
@@ -21,7 +21,7 @@ export interface ItemPanelProps {
   isLoading?: boolean
   items: Item[]
   tabs?: TabDefinition[],
-  itemKey: (item: Item, index: number) => string
+  itemKey: (item: Item, index: number) => string|number
   itemLabel: (item: Item, index: number) => string
   itemUrl: (item: Item, index: number) => string
 }
diff --git a/client/src/components/DashboardPage/ProjectModelPanel.tsx b/client/src/components/DashboardPage/ProjectModelPanel.tsx
index 8bd9498..36d3048 100644
--- a/client/src/components/DashboardPage/ProjectModelPanel.tsx
+++ b/client/src/components/DashboardPage/ProjectModelPanel.tsx
@@ -1,5 +1,6 @@
 import React, { FunctionComponent } from "react";
 import { ItemPanel } from "./ItemPanel";
+import { useProjects } from "../../gql/queries/project";
 
 export interface ProjectModelPanelProps {
 
@@ -13,7 +14,7 @@ export const ProjectModelPanel: FunctionComponent<ProjectModelPanelProps> = () =
       newItemUrl="/models/new"
       items={[]}
       itemKey={(item) => { return item.id }}
-      itemLabel={(item) => { return item.id }}
+      itemLabel={(item) => { return `${item.id}` }}
       itemUrl={(item) => { return `/models/${item.id}` }}
     />
   );
diff --git a/client/src/components/DashboardPage/ProjectPanel.tsx b/client/src/components/DashboardPage/ProjectPanel.tsx
index df5f69e..d1cd01c 100644
--- a/client/src/components/DashboardPage/ProjectPanel.tsx
+++ b/client/src/components/DashboardPage/ProjectPanel.tsx
@@ -1,19 +1,25 @@
 import React, { FunctionComponent } from "react";
 import { ItemPanel } from "./ItemPanel";
+import { useProjects } from "../../gql/queries/project";
 
 export interface ProjectPanelProps {
 
 }
 
 export const ProjectPanel: FunctionComponent<ProjectPanelProps> = () => {
+  const { projects } = useProjects({
+    fetchPolicy: 'cache-and-network',
+  });
+
   return (
     <ItemPanel
       title="Mes projets"
       className="is-primary"
       newItemUrl="/projects/new"
-      items={[]}
+      items={projects}
+      itemIconClassName="fa fa-file"
       itemKey={(item) => { return item.id }}
-      itemLabel={(item) => { return item.id }}
+      itemLabel={(item) => { return `#${item.id} - ${item.title ? item.title : 'Projet sans nom'}` }}
       itemUrl={(item) => { return `/projects/${item.id}` }}
     />
   );
diff --git a/client/src/components/ProjectPage/EstimationTab.tsx b/client/src/components/ProjectPage/EstimationTab.tsx
index d169067..2317410 100644
--- a/client/src/components/ProjectPage/EstimationTab.tsx
+++ b/client/src/components/ProjectPage/EstimationTab.tsx
@@ -2,7 +2,7 @@ import React, { FunctionComponent, Fragment } from "react";
 import { Project } from "../../types/project";
 import TaskTable from "./TasksTable";
 import { TimePreview } from "./TimePreview";
-import FinancialPreview from "./FinancielPreview";
+import FinancialPreview from "./FinancialPreview";
 import { addTask, updateTaskEstimation, removeTask, updateTaskLabel, ProjectReducerActions } from "../../hooks/useProjectReducer";
 import { Task, TaskID, EstimationConfidence } from "../../types/task";
 import RepartitionPreview from "./RepartitionPreview";
@@ -18,16 +18,16 @@ const EstimationTab: FunctionComponent<EstimationTabProps> = ({ project, dispatc
         dispatch(addTask(task));
     };
 
-    const onTaskRemove = (taskId: TaskID) => {
-        dispatch(removeTask(taskId));
+    const onTaskRemove = (id: number) => {
+        dispatch(removeTask(id));
     }
 
-    const onTaskLabelUpdate = (taskId: TaskID, label: string) => {
-        dispatch(updateTaskLabel(taskId, label));
+    const onTaskLabelUpdate = (id: number, label: string) => {
+        dispatch(updateTaskLabel(id, label));
     }
 
-    const onEstimationChange = (taskId: TaskID, confidence: EstimationConfidence, value: number) => {
-        dispatch(updateTaskEstimation(taskId, confidence, value));
+    const onEstimationChange = (id: number, confidence: EstimationConfidence, value: number) => {
+        dispatch(updateTaskEstimation(id, confidence, value));
     };
 
     return (
diff --git a/client/src/components/ProjectPage/FinancielPreview.tsx b/client/src/components/ProjectPage/FinancialPreview.tsx
similarity index 97%
rename from client/src/components/ProjectPage/FinancielPreview.tsx
rename to client/src/components/ProjectPage/FinancialPreview.tsx
index 5300733..bf4e4c2 100644
--- a/client/src/components/ProjectPage/FinancielPreview.tsx
+++ b/client/src/components/ProjectPage/FinancialPreview.tsx
@@ -64,7 +64,7 @@ export const CostDetails:FunctionComponent<CostDetailsProps> = ({ project, cost,
         <tbody>
         {
           Object.keys(cost.details).map(taskCategoryId => {
-            const taskCategory = project.params.taskCategories[taskCategoryId];
+            const taskCategory = project.taskCategories[parseInt(taskCategoryId)];
             const details = cost.details[taskCategoryId];
             return (
               <tr key={`task-category-cost-${taskCategory.id}`}>
diff --git a/client/src/components/ProjectPage/ProjectPage.tsx b/client/src/components/ProjectPage/ProjectPage.tsx
index f3a5f8a..3379eb9 100644
--- a/client/src/components/ProjectPage/ProjectPage.tsx
+++ b/client/src/components/ProjectPage/ProjectPage.tsx
@@ -1,14 +1,15 @@
 import React, { FunctionComponent, useEffect } from "react";
 import style from "./style.module.css";
 import { newProject, Project } from "../../types/project";
-import { useProjectReducer, updateProjectLabel } from "../../hooks/useProjectReducer";
+import { useProjectReducer, updateProjectTitle, resetProject } from "../../hooks/useProjectReducer";
 import EditableText from "../EditableText/EditableText";
 import Tabs from "../../components/Tabs/Tabs";
 import EstimationTab from "./EstimationTab";
 import ParamsTab from "./ParamsTab";
 import ExportTab from "./ExportTab";
-import { useParams } from "react-router";
+import { useParams, useHistory } from "react-router";
 import { Page } from "../Page";
+import { useProjects } from "../../gql/queries/project";
 
 export interface ProjectProps {
   projectId: string
@@ -16,10 +17,24 @@ export interface ProjectProps {
 
 export const ProjectPage: FunctionComponent<ProjectProps> = () => {
   const { id } = useParams();
-  const [ project, dispatch ] = useProjectReducer(newProject());
-  
-  const onProjectLabelChange = (projectLabel: string) => {
-    dispatch(updateProjectLabel(projectLabel));
+  const isNew = id === 'new';
+  const projectId = isNew ? undefined : parseInt(id);
+  const { projects } = useProjects({ variables: { filter: {ids: projectId !== undefined ? [projectId] : undefined} }});
+  const [ project, dispatch ] = useProjectReducer(newProject(projectId));
+  const history = useHistory();
+
+  useEffect(() => {
+    history.push(`/projects/${project.id}`);
+  }, [project.id])
+
+  useEffect(() => {
+    if (isNew || projects.length === 0) return;
+    dispatch(resetProject(projects[0]));
+  }, [projects.length]);
+
+  const onProjectTitleChange = (projectTitle: string) => {
+    if (project.title === projectTitle) return;
+    dispatch(updateProjectTitle(projectTitle));
   };
   
   return (
@@ -30,8 +45,8 @@ export const ProjectPage: FunctionComponent<ProjectProps> = () => {
             <EditableText
               editIconClass="is-size-4"
               render={(value) => (<h2 className="is-size-3">{value}</h2>)}
-              onChange={onProjectLabelChange}
-              value={project.label ? project.label : "Projet sans nom"} 
+              onChange={onProjectTitleChange}
+              value={project.title ? project.title : "Projet sans nom"} 
             />
             <div className={`box mt-3 ${style.tabContainer}`}>
               <Tabs items={[
diff --git a/client/src/components/ProjectPage/RepartitionPreview.tsx b/client/src/components/ProjectPage/RepartitionPreview.tsx
index caacc2c..1322ab4 100644
--- a/client/src/components/ProjectPage/RepartitionPreview.tsx
+++ b/client/src/components/ProjectPage/RepartitionPreview.tsx
@@ -21,7 +21,7 @@ const RepartitionPreview: FunctionComponent<RepartitionPreviewProps> = ({ projec
         </thead>
         <tbody>
           {
-            Object.values(project.params.taskCategories).map(tc => {
+            Object.values(project.taskCategories).map(tc => {
               let percent = (repartition[tc.id] * 100).toFixed(0);
               return (
                 <tr key={`task-category-${tc.id}`}>
diff --git a/client/src/components/ProjectPage/TaskCategorieTable.tsx b/client/src/components/ProjectPage/TaskCategorieTable.tsx
index 9f10b65..9eaf813 100644
--- a/client/src/components/ProjectPage/TaskCategorieTable.tsx
+++ b/client/src/components/ProjectPage/TaskCategorieTable.tsx
@@ -55,7 +55,7 @@ const TaskCategoriesTable: FunctionComponent<TaskCategoriesTableProps> = ({ proj
         </thead>
         <tbody>
         {
-          Object.values(project.params.taskCategories).map(tc => {
+          Object.values(project.taskCategories).map(tc => {
             return (
               <tr key={`task-category-${tc.id}`}>
                 <td>
diff --git a/client/src/components/ProjectPage/TasksTable.tsx b/client/src/components/ProjectPage/TasksTable.tsx
index 708eb1b..005e942 100644
--- a/client/src/components/ProjectPage/TasksTable.tsx
+++ b/client/src/components/ProjectPage/TasksTable.tsx
@@ -9,22 +9,25 @@ import ProjectTimeUnit from "../ProjectTimeUnit";
 export interface TaskTableProps {
   project: Project
   onTaskAdd: (task: Task) => void
-  onTaskRemove: (taskId: TaskID) => void
-  onEstimationChange: (taskId: TaskID, confidence: EstimationConfidence, value: number) => void
-  onTaskLabelUpdate: (taskId: TaskID, label: string) => void
+  onTaskRemove: (taskId: number) => void
+  onEstimationChange: (taskId: number, confidence: EstimationConfidence, value: number) => void
+  onTaskLabelUpdate: (taskId: number, label: string) => void
 }
 
 export type EstimationTotals = { [confidence in EstimationConfidence]: number }
 
 const TaskTable: FunctionComponent<TaskTableProps> = ({ project, onTaskAdd, onEstimationChange, onTaskRemove, onTaskLabelUpdate }) => {
-  
-  const defaultTaskCategory = Object.keys(project.params.taskCategories)[0];
-  const [ task, setTask ] = useState(newTask("", defaultTaskCategory));
+  const [ task, setTask ] = useState(newTask("", null));
   const [ totals, setTotals ] = useState({
     [EstimationConfidence.Optimistic]: 0,
     [EstimationConfidence.Likely]: 0,
     [EstimationConfidence.Pessimistic]: 0,
   } as EstimationTotals);
+
+  useEffect(() => {
+    if (project.taskCategories.length === 0) return;
+    setTask({...task, category: project.taskCategories[0]});
+  }, [project.taskCategories]);
   
   const isPrint = usePrintMediaQuery();
   
@@ -33,7 +36,7 @@ const TaskTable: FunctionComponent<TaskTableProps> = ({ project, onTaskAdd, onEs
     let likely = 0;
     let pessimistic = 0;
     
-    Object.values(project.tasks).forEach(t => {
+    project.tasks.forEach(t => {
       optimistic += t.estimations.optimistic;
       likely += t.estimations.likely;
       pessimistic += t.estimations.pessimistic;
@@ -49,26 +52,28 @@ const TaskTable: FunctionComponent<TaskTableProps> = ({ project, onTaskAdd, onEs
   
   const onNewTaskCategoryChange = (evt: ChangeEvent) => {
     const value = (evt.currentTarget as HTMLInputElement).value;
-    setTask({...task, category: value});
+    const taskCategoryId = parseInt(value);
+    const category = project.taskCategories.find(tc => tc.id === taskCategoryId);
+    setTask({...task, category });
   };
   
-  const onTaskLabelChange = (taskId: TaskID, value: string) => {
+  const onTaskLabelChange = (taskId: number, value: string) => {
     onTaskLabelUpdate(taskId, value);
   };
   
   const onAddTaskClick = (evt: MouseEvent) => {
     onTaskAdd(task);
-    setTask(newTask("", defaultTaskCategory));
+    setTask(newTask("", project.taskCategories[0]));
   };
   
-  const onTaskRemoveClick = (taskId: TaskID, evt: MouseEvent) => {
+  const onTaskRemoveClick = (taskId: number, evt: MouseEvent) => {
     onTaskRemove(taskId);
   };
   
-  const withEstimationChange = (confidence: EstimationConfidence, taskID: TaskID, evt: ChangeEvent) => {
+  const withEstimationChange = (confidence: EstimationConfidence, taskId: number, evt: ChangeEvent) => {
     const textValue = (evt.currentTarget as HTMLInputElement).value;
     const value = parseFloat(textValue);
-    onEstimationChange(taskID, confidence, value);
+    onEstimationChange(taskId, confidence, value);
   };
   
   const onOptimisticChange = withEstimationChange.bind(null, EstimationConfidence.Optimistic);
@@ -93,11 +98,11 @@ const TaskTable: FunctionComponent<TaskTableProps> = ({ project, onTaskAdd, onEs
     </thead>
     <tbody>
     {
-      Object.values(project.tasks).map(t => {
-        const category = project.params.taskCategories[t.category];
+      project.tasks.map((t,i) => {
+        const category = project.taskCategories.find(tc => tc.id === t.category.id);
         const categoryLabel = category ? category.label : '???';
         return (
-          <tr key={`taks-${t.id}`}>
+          <tr key={`tasks-${t.id}-${i}`}>
           <td className={`is-narrow noPrint`}>
           <button
           onClick={onTaskRemoveClick.bind(null, t.id)}
@@ -163,9 +168,9 @@ const TaskTable: FunctionComponent<TaskTableProps> = ({ project, onTaskAdd, onEs
       </p>
       <p className="control">
       <span className="select">
-      <select onChange={onNewTaskCategoryChange} value={task.category}>
+      <select onChange={onNewTaskCategoryChange} value={task.category ? task.category.id : -1}>
       {
-        Object.values(project.params.taskCategories).map(tc => {
+        Object.values(project.taskCategories).map(tc => {
           return (
             <option key={`task-category-${tc.id}`} value={tc.id}>{tc.label}</option>
             );
diff --git a/client/src/gql/fragments/project.ts b/client/src/gql/fragments/project.ts
new file mode 100644
index 0000000..73641c7
--- /dev/null
+++ b/client/src/gql/fragments/project.ts
@@ -0,0 +1,34 @@
+import { gql } from '@apollo/client';
+
+export const FRAGMENT_FULL_PROJECT = gql`
+fragment FullProject on Project {
+  id
+  title
+  taskCategories {
+    id
+    label
+    costPerTimeUnit
+  }
+  tasks {
+    id
+    label
+    category {
+      id
+      label
+    }
+    estimations {
+      optimistic
+      likely
+      pessimistic
+    }
+  }
+  params {
+    timeUnit {
+      label
+      acronym
+    }
+    currency
+    hideFinancialPreviewOnPrint
+  }
+}
+`
\ No newline at end of file
diff --git a/client/src/gql/mutations/project.tsx b/client/src/gql/mutations/project.tsx
new file mode 100644
index 0000000..2006fee
--- /dev/null
+++ b/client/src/gql/mutations/project.tsx
@@ -0,0 +1,69 @@
+import { gql, useMutation, PureQueryOptions } from '@apollo/client';
+import { FRAGMENT_FULL_PROJECT } from '../fragments/project';
+import { QUERY_PROJECTS } from '../queries/project';
+
+export const MUTATION_CREATE_PROJECT = gql`
+mutation createProject($changes: CreateProjectChanges!) {
+  createProject(changes: $changes) {
+    ...FullProject
+  }
+}
+${FRAGMENT_FULL_PROJECT}
+`;
+
+export function useProjectCreateMutation() {
+  return useMutation(MUTATION_CREATE_PROJECT);
+}
+
+export const MUTATION_UPDATE_PROJECT_TITLE = gql`
+mutation updateProjectTitle($projectId: ID!, $title: String!) {
+  updateProjectTitle(projectId: $projectId, title: $title) {
+    ...FullProject
+  }
+}
+${FRAGMENT_FULL_PROJECT}
+`;
+
+export function useUpdateProjectTitleMutation() {
+  return useMutation(MUTATION_UPDATE_PROJECT_TITLE, {
+    refetchQueries: ({ variables }: PureQueryOptions) => {
+      return [
+        { query: QUERY_PROJECTS, variables: { filters: { ids: [ variables.projectId ] } }},
+      ];
+    }
+  });
+}
+
+export const MUTATION_ADD_PROJECT_TASK = gql`
+mutation addProjectTask($projectId: ID!, $changes: ProjectTaskChanges!) {
+  addProjectTask(projectId: $projectId, changes: $changes) {
+    id
+  }
+}
+`;
+
+export function useAddProjectTaskMutation() {
+  return useMutation(MUTATION_ADD_PROJECT_TASK);
+}
+
+export const MUTATION_UPDATE_PROJECT_TASK = gql`
+mutation updateProjectTask($projectId: ID!, $taskId: ID!, $changes: ProjectTaskChanges!) {
+  updateProjectTask(projectId: $projectId, taskId: $taskId, changes: $changes) {
+    id
+  }
+}
+`;
+
+export function useUpdateProjectTaskMutation() {
+  return useMutation(MUTATION_UPDATE_PROJECT_TASK);
+}
+
+export const MUTATION_REMOVE_PROJECT_TASK = gql`
+mutation removeProjectTask($projectId: ID!, $taskId: ID!) {
+  removeProjectTask(projectId: $projectId, taskId: $taskId)
+}
+`;
+
+export function useRemoveProjectTaskMutation() {
+  return useMutation(MUTATION_REMOVE_PROJECT_TASK);
+}
diff --git a/client/src/gql/queries/helper.ts b/client/src/gql/queries/helper.ts
index 586791a..0a42fb4 100644
--- a/client/src/gql/queries/helper.ts
+++ b/client/src/gql/queries/helper.ts
@@ -1,7 +1,7 @@
-import { useQuery, DocumentNode } from "@apollo/client";
+import { useQuery, DocumentNode, QueryHookOptions } from "@apollo/client";
 import { useState, useEffect } from "react";
 
-export function useGraphQLData<T>(q: DocumentNode, key: string, defaultValue: T, options = {}) {
+export function useGraphQLData<T, A = any, R = Record<string, any>>(q: DocumentNode, key: string, defaultValue: T, options: QueryHookOptions<A, R> = {}) {
   const query = useQuery(q, options);
   const [ data, setData ] = useState<T>(defaultValue);
   useEffect(() => {
diff --git a/client/src/gql/queries/project.ts b/client/src/gql/queries/project.ts
new file mode 100644
index 0000000..c7ac205
--- /dev/null
+++ b/client/src/gql/queries/project.ts
@@ -0,0 +1,49 @@
+import { gql, useQuery, QueryHookOptions } from '@apollo/client';
+import { User } from '../../types/user';
+import { useGraphQLData } from './helper';
+import { Project } from '../../types/project';
+
+export const QUERY_PROJECTS = gql`
+query projects($filter: ProjectsFilter) {
+  projects(filter: $filter) {
+    id
+    title
+    taskCategories {
+      id
+      label
+      costPerTimeUnit
+    }
+    tasks {
+      id
+      label
+      category {
+        id
+        label
+      }
+      estimations {
+        optimistic
+        likely
+        pessimistic
+      }
+    }
+    params {
+      timeUnit {
+        label
+        acronym
+      }
+      currency
+      hideFinancialPreviewOnPrint
+    }
+  }
+}`;
+
+export function useProjectsQuery() {
+  return useQuery(QUERY_PROJECTS);
+}
+
+export function useProjects<A = any, R = Record<string, any>>(options: QueryHookOptions<A, R> = {}) {
+  const { data, loading, error } = useGraphQLData<Project[]>(
+    QUERY_PROJECTS, 'projects', [], options
+  );
+  return { projects: data, loading, error };
+}
\ No newline at end of file
diff --git a/client/src/hooks/useProjectReducer.sagas.ts b/client/src/hooks/useProjectReducer.sagas.ts
new file mode 100644
index 0000000..2427555
--- /dev/null
+++ b/client/src/hooks/useProjectReducer.sagas.ts
@@ -0,0 +1,95 @@
+import { all, select, takeLatest, put, delay } from "redux-saga/effects";
+import { client } from '../gql/client';
+import { MUTATION_CREATE_PROJECT, MUTATION_UPDATE_PROJECT_TITLE, MUTATION_ADD_PROJECT_TASK, MUTATION_REMOVE_PROJECT_TASK } from "../gql/mutations/project";
+import { UPDATE_PROJECT_TITLE, resetProject, ADD_TASK, taskSaved, AddTask, taskAdded, taskRemoved, RemoveTask, REMOVE_TASK } from "./useProjectReducer";
+import { Project } from "../types/project";
+
+export function* rootSaga() {
+  yield all([
+    createProjectSaga(),
+    takeLatest(UPDATE_PROJECT_TITLE, updateProjectTitleSaga),
+    takeLatest(ADD_TASK, addTaskSaga),
+    takeLatest(REMOVE_TASK, removeTaskSaga),
+  ]);
+}
+
+export function* updateProjectTitleSaga() {
+  yield delay(500);
+
+  let project = yield select();
+
+  if (project.id === undefined) {
+    project = yield createProjectSaga();
+  }
+
+  yield client.mutate({
+    mutation: MUTATION_UPDATE_PROJECT_TITLE,
+    variables: {
+      projectId: project.id,
+      title: project.title,
+    }
+  });
+}
+
+export function* createProjectSaga() {
+  const project: Project = yield select();
+
+  if (project.id !== undefined) return;
+  
+  const { data } = yield client.mutate({
+    mutation: MUTATION_CREATE_PROJECT,
+    variables: {
+      changes: {
+        title: project.title,
+      }
+    }
+  });
+
+  yield put(resetProject(data.createProject));
+
+  return yield select();
+}
+
+export function* addTaskSaga({ task }: AddTask) {
+  let project: Project = yield select();
+
+  if (project.id === undefined) {
+    project = yield createProjectSaga();
+  }
+  
+  const { data } = yield client.mutate({
+    mutation: MUTATION_ADD_PROJECT_TASK,
+    variables: {
+      projectId: project.id,
+      changes: {
+        label: task.label,
+        categoryId: task.category ? task.category.id : -1,
+        estimations: {
+          optimistic: task.estimations.optimistic,
+          likely: task.estimations.likely,
+          pessimistic: task.estimations.pessimistic,
+        }
+      }
+    }
+  });
+
+  yield put(taskAdded({ ...task, ...data.addProjectTask }));
+}
+
+export function* removeTaskSaga({ id }: RemoveTask) {
+  let project: Project = yield select();
+
+  if (project.id === undefined) {
+    project = yield createProjectSaga();
+  }
+  
+  yield client.mutate({
+    mutation: MUTATION_REMOVE_PROJECT_TASK,
+    variables: {
+      projectId: project.id,
+      taskId: id,
+    }
+  });
+
+  yield put(taskRemoved(id));
+}
\ No newline at end of file
diff --git a/client/src/hooks/useProjectReducer.ts b/client/src/hooks/useProjectReducer.ts
index e795308..c6d23d8 100644
--- a/client/src/hooks/useProjectReducer.ts
+++ b/client/src/hooks/useProjectReducer.ts
@@ -1,6 +1,8 @@
 import { Project } from "../types/project";
 import { Task, TaskID, EstimationConfidence, TaskCategoryID, TaskCategory } from "../types/task";
-import { useReducer } from "react";
+import { useReducerAndSaga } from "./useReducerAndSaga";
+import { rootSaga } from "./useProjectReducer.sagas";
+import { uuid } from "../util/uuid";
 
 export interface Action {
   type: string
@@ -8,34 +10,41 @@ export interface Action {
 
 export type ProjectReducerActions =
 AddTask |
+TaskSaved |
 RemoveTask |
+TaskRemoved |
 UpdateTaskEstimation |
-UpdateProjectLabel |
+UpdateProjectTitle |
 UpdateTaskLabel |
 UpdateParam |
 UpdateTaskCategoryLabel |
 UpdateTaskCategoryCost |
 AddTaskCategory |
-RemoveTaskCategory
+RemoveTaskCategory |
+ResetProject
 
 export function useProjectReducer(project: Project) {
-  return useReducer(projectReducer, project);
+  return useReducerAndSaga<Project>(projectReducer, project, rootSaga);
 }
 
 export function projectReducer(project: Project, action: ProjectReducerActions): Project {
   console.log(action);
+
   switch(action.type) {
-    case ADD_TASK:
-    return handleAddTask(project, action as AddTask);
+    case TASK_ADDED:
+    return handleTaskAdded(project, action as TaskAdded);
+
+    case TASK_SAVED:
+    return handleTaskSaved(project, action as TaskSaved);
     
-    case REMOVE_TASK:
-    return handleRemoveTask(project, action as RemoveTask);
+    case TASK_REMOVED:
+    return handleTaskRemoved(project, action as RemoveTask);
     
     case UPDATE_TASK_ESTIMATION:
     return handleUpdateTaskEstimation(project, action as UpdateTaskEstimation);
     
-    case UPDATE_PROJECT_LABEL:
-    return handleUpdateProjectLabel(project, action as UpdateProjectLabel);
+    case UPDATE_PROJECT_TITLE:
+    return handleUpdateProjectTitle(project, action as UpdateProjectTitle);
     
     case UPDATE_TASK_LABEL:
     return handleUpdateTaskLabel(project, action as UpdateTaskLabel);
@@ -54,6 +63,9 @@ export function projectReducer(project: Project, action: ProjectReducerActions):
     
     case UPDATE_TASK_CATEGORY_COST:
     return handleUpdateTaskCategoryCost(project, action as UpdateTaskCategoryCost);
+
+    case RESET_PROJECT:
+    return handleResetProject(project, action as ResetProject);
     
   }
   
@@ -70,30 +82,74 @@ export function addTask(task: Task): AddTask {
   return { type: ADD_TASK, task };
 }
 
-export function handleAddTask(project: Project, action: AddTask): Project {
+export interface TaskAdded extends Action {
+  task: Task
+}
+
+export const TASK_ADDED = "TASK_ADDED";
+
+export function taskAdded(task: Task): TaskAdded {
+  return { type: TASK_ADDED, task };
+}
+
+export function handleTaskAdded(project: Project, action: TaskAdded): Project {
   const task = { ...action.task };
   return {
     ...project,
-    tasks: {
+    tasks: [
       ...project.tasks,
-      [task.id]: task,
-    }
+      task,
+    ]
+  };
+};
+
+export const TASK_SAVED = "TASK_SAVED";
+
+export interface TaskSaved extends Action {
+  task: Task
+}
+
+export function taskSaved(task: Task): TaskSaved {
+  return { type: TASK_SAVED, task };
+}
+
+export function handleTaskSaved(project: Project, action: TaskSaved): Project {
+  const taskIndex = project.tasks.findIndex(t => t.id === action.task.id);
+  if (taskIndex === -1) return project;
+  const tasks = [ ...project.tasks ];
+  tasks[taskIndex] = { ...tasks[taskIndex], ...action.task };
+  return {
+    ...project,
+    tasks
   };
 }
 
 export interface RemoveTask extends Action {
-  id: TaskID
+  id: number
 }
 
 export const REMOVE_TASK = "REMOVE_TASK";
 
-export function removeTask(id: TaskID): RemoveTask {
+export function removeTask(id: number): RemoveTask {
   return { type: REMOVE_TASK, id };
 }
 
-export function handleRemoveTask(project: Project, action: RemoveTask): Project {
-  const tasks = { ...project.tasks };
-  delete tasks[action.id];
+export interface TaskRemoved extends Action {
+  id: number
+}
+
+export const TASK_REMOVED = "TASK_REMOVED";
+
+export function taskRemoved(id: number): TaskRemoved {
+  return { type: TASK_REMOVED, id };
+}
+
+
+export function handleTaskRemoved(project: Project, action: TaskRemoved): Project {
+  const tasks = [...project.tasks];
+  const taskIndex = project.tasks.findIndex(t => t.id === action.id);
+  if (taskIndex === -1) return project;
+  tasks.splice(taskIndex, 1);
   return {
     ...project,
     tasks
@@ -101,20 +157,24 @@ export function handleRemoveTask(project: Project, action: RemoveTask): Project
 }
 
 export interface UpdateTaskEstimation extends Action {
-  id: TaskID
+  id: number
   confidence: string
   value: number
 }
 
 export const UPDATE_TASK_ESTIMATION = "UPDATE_TASK_ESTIMATION";
 
-export function updateTaskEstimation(id: TaskID, confidence: EstimationConfidence, value: number): UpdateTaskEstimation {
+export function updateTaskEstimation(id: number, confidence: EstimationConfidence, value: number): UpdateTaskEstimation {
   return { type: UPDATE_TASK_ESTIMATION, id, confidence, value };
 }
 
 export function handleUpdateTaskEstimation(project: Project, action: UpdateTaskEstimation): Project {
+  const tasks = [...project.tasks];
+  const taskIndex = project.tasks.findIndex(t => t.id === action.id);
+  if (taskIndex === -1) return project;
+  
   const estimations = {
-    ...project.tasks[action.id].estimations,
+    ...project.tasks[taskIndex].estimations,
     [action.confidence]: action.value
   };
   
@@ -125,58 +185,54 @@ export function handleUpdateTaskEstimation(project: Project, action: UpdateTaskE
   if (estimations.pessimistic < estimations.likely) {
     estimations.pessimistic = estimations.likely;
   }
+
+  project.tasks[taskIndex] = { ...project.tasks[taskIndex], estimations };
   
   return {
     ...project,
-    tasks: {
-      ...project.tasks,
-      [action.id]: {
-        ...project.tasks[action.id],
-        estimations: estimations,
-      }
-    }
+    tasks
   };
 }
 
 
-export interface UpdateProjectLabel extends Action {
-  label: string
+export interface UpdateProjectTitle extends Action {
+  title: string
 }
 
-export const UPDATE_PROJECT_LABEL = "UPDATE_PROJECT_LABEL";
+export const UPDATE_PROJECT_TITLE = "UPDATE_PROJECT_TITLE";
 
-export function updateProjectLabel(label: string): UpdateProjectLabel {
-  return { type: UPDATE_PROJECT_LABEL, label };
+export function updateProjectTitle(title: string): UpdateProjectTitle {
+  return { type: UPDATE_PROJECT_TITLE, title };
 }
 
-export function handleUpdateProjectLabel(project: Project, action: UpdateProjectLabel): Project {
+export function handleUpdateProjectTitle(project: Project, action: UpdateProjectTitle): Project {
   return {
     ...project,
-    label: action.label
+    title: action.title
   };
 }
 
 export interface UpdateTaskLabel extends Action {
-  id: TaskID
+  id: number
   label: string
 }
 
 export const UPDATE_TASK_LABEL = "UPDATE_TASK_LABEL";
 
-export function updateTaskLabel(id: TaskID, label: string): UpdateTaskLabel {
+export function updateTaskLabel(id: number, label: string): UpdateTaskLabel {
   return { type: UPDATE_TASK_LABEL, id, label };
 }
 
 export function handleUpdateTaskLabel(project: Project, action: UpdateTaskLabel): Project {
+  const tasks = [...project.tasks];
+  const taskIndex = project.tasks.findIndex(t => t.id === action.id);
+  if (taskIndex === -1) return project;
+
+  tasks[taskIndex] = { ...tasks[taskIndex], label: action.label };
+  
   return {
     ...project,
-    tasks: {
-      ...project.tasks,
-      [action.id]: {
-        ...project.tasks[action.id],
-        label: action.label,
-      }
-    }
+    tasks
   };
 }
 
@@ -215,15 +271,12 @@ export function updateTaskCategoryLabel(categoryId: TaskCategoryID, label: strin
 export function handleUpdateTaskCategoryLabel(project: Project, action: UpdateTaskCategoryLabel): Project {
   return {
     ...project,
-    params: {
-      ...project.params,
-      taskCategories: {
-        ...project.params.taskCategories,
-        [action.categoryId]: {
-          ...project.params.taskCategories[action.categoryId],
-          label: action.label
-        },
-      }
+    taskCategories: {
+      ...project.taskCategories,
+      [action.categoryId]: {
+        ...project.taskCategories[action.categoryId],
+        label: action.label
+      },
     }
   };
 }
@@ -242,15 +295,12 @@ export function updateTaskCategoryCost(categoryId: TaskCategoryID, costPerTimeUn
 export function handleUpdateTaskCategoryCost(project: Project, action: UpdateTaskCategoryCost): Project {
   return {
     ...project,
-    params: {
-      ...project.params,
-      taskCategories: {
-        ...project.params.taskCategories,
-        [action.categoryId]: {
-          ...project.params.taskCategories[action.categoryId],
-          costPerTimeUnit: action.costPerTimeUnit
-        },
-      }
+    taskCategories: {
+      ...project.taskCategories,
+      [action.categoryId]: {
+        ...project.taskCategories[action.categoryId],
+        costPerTimeUnit: action.costPerTimeUnit
+      },
     }
   };
 }
@@ -269,12 +319,9 @@ export function handleAddTaskCategory(project: Project, action: AddTaskCategory)
   const taskCategory = { ...action.taskCategory };
   return {
     ...project,
-    params: {
-      ...project.params,
-      taskCategories: {
-        ...project.params.taskCategories,
-        [taskCategory.id]: taskCategory,
-      }
+    taskCategories: {
+      ...project.taskCategories,
+      [taskCategory.id]: taskCategory,
     }
   };
 }
@@ -290,13 +337,40 @@ export function removeTaskCategory(taskCategoryId: TaskCategoryID): RemoveTaskCa
 }
 
 export function handleRemoveTaskCategory(project: Project, action: RemoveTaskCategory): Project {
-  const taskCategories = { ...project.params.taskCategories };
+  const taskCategories = { ...project.taskCategories };
   delete taskCategories[action.taskCategoryId];
   return {
     ...project,
-    params: {
-      ...project.params,
-      taskCategories
+    taskCategories: {
+      ...project.taskCategories,
+      ...taskCategories
     }
   };
-}
\ No newline at end of file
+}
+
+export interface ResetProject extends Action {
+  project: Project
+}
+
+export const RESET_PROJECT = "RESET_PROJECT";
+
+export function resetProject(project: Project): ResetProject {
+  const newProject = JSON.parse(JSON.stringify(project));
+  
+  newProject.tasks.forEach(t => {
+    if (!t.localId) t.localId = uuid();
+  });
+
+  newProject.taskCategories.forEach(tc => {
+    if (!tc.localId) tc.localId = uuid();
+  });
+
+  return { type: RESET_PROJECT, project: newProject };
+}
+
+export function handleResetProject(project: Project, action: ResetProject): Project {
+  return {
+    ...project,
+    ...action.project,
+  };
+}
diff --git a/client/src/hooks/useReducerAndSaga.ts b/client/src/hooks/useReducerAndSaga.ts
new file mode 100644
index 0000000..163952f
--- /dev/null
+++ b/client/src/hooks/useReducerAndSaga.ts
@@ -0,0 +1,24 @@
+import { useReducer, useRef, useMemo, useCallback, useEffect } from "react"
+import { runSaga, stdChannel } from 'redux-saga'
+
+export function useReducerAndSaga<T>(reducer: React.Reducer<any, any>, initialState, rootSaga): [T, (a: any) => void] {
+  const [state, reactDispatch] = useReducer(reducer, initialState)
+  
+  const env = useRef(state)
+  env.current = state
+  
+  const channel = useMemo(() => stdChannel(), [])
+  const dispatch = useCallback((a) => {
+    setImmediate(channel.put, a)
+    reactDispatch(a)
+  }, [])
+  
+  const getState = useCallback(() => env.current, [])
+
+  useEffect(() => {
+    const task = runSaga({ channel, dispatch, getState }, rootSaga)
+    return () => task.cancel()
+  }, [])
+
+  return [state, dispatch]
+}
\ No newline at end of file
diff --git a/client/src/types/params.ts b/client/src/types/params.ts
index a28ea01..722e3d7 100644
--- a/client/src/types/params.ts
+++ b/client/src/types/params.ts
@@ -11,7 +11,6 @@ export interface TimeUnit {
 }
 
 export interface Params {
-  taskCategories: TaskCategoriesIndex
   timeUnit: TimeUnit
   currency: string
   roundUpEstimations: boolean
@@ -19,53 +18,38 @@ export interface Params {
 }
 
 export const defaults = {
-    taskCategories: {
-        "RQ15CD3iX1Ey2f9kat7tfLGZmUx9GGc15nS6A7fYtZv76SnS4": { 
-            id: "RQ15CD3iX1Ey2f9kat7tfLGZmUx9GGc15nS6A7fYtZv76SnS4", 
-            label: "Développement",
-            costPerTimeUnit: 500,
-        },
-        "QRdGS5Pr5si9SSjU84WAq19cjxQ3rUL71jKh8oHSMZSY4bBH9": { 
-            id: "QRdGS5Pr5si9SSjU84WAq19cjxQ3rUL71jKh8oHSMZSY4bBH9", 
-            label: "Conduite de projet",
-            costPerTimeUnit: 500,
-        },
-        "RPcqFMLdQrgBSomv7Sao7EQSb7on6rtjfDQK5JZNhNSg9DwEo": { 
-            id: "RPcqFMLdQrgBSomv7Sao7EQSb7on6rtjfDQK5JZNhNSg9DwEo", 
-            label: "Recette",
-            costPerTimeUnit: 500,
-        },
-    },
+  params: {
     timeUnit: {
-        label: "jour/homme",
-        acronym: "j/h",
+      label: "jour/homme",
+      acronym: "j/h",
     },
     roundUpEstimations: true,
     currency: "€ H.T.",
     costPerTimeUnit: 500,
     hideFinancialPreviewOnPrint: false,
+  }
 }
 
 export function getTimeUnit(project: Project): TimeUnit {
-    return project.params.timeUnit ? project.params.timeUnit : defaults.timeUnit;
+    return project.params.timeUnit ? project.params.timeUnit : defaults.params.timeUnit;
 }
 
 export function getRoundUpEstimations(project: Project): boolean {
-    return project.params.hasOwnProperty("roundUpEstimations") ? project.params.roundUpEstimations : defaults.roundUpEstimations;
+    return project.params.hasOwnProperty("roundUpEstimations") ? project.params.roundUpEstimations : defaults.params.roundUpEstimations;
 }
 
 export function getCurrency(project: Project): string {
-    return project.params.currency ? project.params.currency : defaults.currency;
+    return project.params.currency ? project.params.currency : defaults.params.currency;
 }
 
-export function getTaskCategories(project: Project): TaskCategoriesIndex {
-    return project.params.taskCategories ? project.params.taskCategories : defaults.taskCategories;
+export function getTaskCategories(project: Project): TaskCategory[] {
+    return project.taskCategories ? project.taskCategories : [];
 }
 
 export function getTaskCategoryCost(taskCategory: TaskCategory): number {
-    return taskCategory.hasOwnProperty("costPerTimeUnit") ? taskCategory.costPerTimeUnit : defaults.costPerTimeUnit;
+    return taskCategory.hasOwnProperty("costPerTimeUnit") ? taskCategory.costPerTimeUnit : defaults.params.costPerTimeUnit;
 }
 
 export function getHideFinancialPreviewOnPrint(project: Project): boolean {
-  return project.params.hasOwnProperty("hideFinancialPreviewOnPrint") ? project.params.hideFinancialPreviewOnPrint : defaults.hideFinancialPreviewOnPrint;
+  return project.params.hasOwnProperty("hideFinancialPreviewOnPrint") ? project.params.hideFinancialPreviewOnPrint : defaults.params.hideFinancialPreviewOnPrint;
 }
\ No newline at end of file
diff --git a/client/src/types/project.ts b/client/src/types/project.ts
index 50cf101..effc659 100644
--- a/client/src/types/project.ts
+++ b/client/src/types/project.ts
@@ -1,29 +1,27 @@
 import { Task, TaskCategory, TaskID, getTaskWeightedMean, TaskCategoryID, getTaskStandardDeviation } from './task';
-import { Params, defaults, getTaskCategoryCost } from "./params";
+import { Params, defaults, getTaskCategoryCost, TaskCategoriesIndex } from "./params";
 import { Estimation } from '../hooks/useProjectEstimations';
 
-export type ProjectID = string;
+export type ProjectID = number;
 
 export interface Project {
   id: ProjectID
-  label: string
+  title: string
   description: string
-  tasks: Tasks
+  taskCategories: TaskCategory[]
+  tasks: Task[]
   params: Params
 }
 
-export interface Tasks {
-  [id: string]: Task
-}
-
-export function newProject(): Project {
+export function newProject(id: number|undefined = undefined): Project {
   return {
-    id: "",
-    label: "",
+    id: id,
+    title: "",
     description: "",
-    tasks: {},
+    tasks: [],
+    taskCategories: [],
     params: {
-      ...defaults
+      ...defaults.params
     },
   };
 }
@@ -36,7 +34,7 @@ export function getProjectWeightedMean(p : Project): number {
 }
 
 export function getTaskCategoryWeightedMean(taskCategoryId: TaskCategoryID, p : Project): number {
-  return Object.values(p.tasks).filter(t => t.category === taskCategoryId).reduce((sum: number, t: Task) => {
+  return Object.values(p.tasks).filter(t => t.category && t.category.id === taskCategoryId).reduce((sum: number, t: Task) => {
     sum += getTaskWeightedMean(t);
     return sum;
   }, 0);
@@ -58,7 +56,7 @@ export function getTaskCategoriesMeanRepartition(project: Project): MeanRepartit
 
   const repartition: MeanRepartition = {};
   
-  Object.values(project.params.taskCategories).forEach(tc => {
+  Object.values(project.taskCategories).forEach(tc => {
     repartition[tc.id] = getTaskCategoryWeightedMean(tc.id, project) / projectMean;
     if (Number.isNaN(repartition[tc.id])) repartition[tc.id] = 0;
   });
@@ -74,34 +72,54 @@ export interface MinMaxCost {
 export interface Cost {
   totalCost: number
   totalTime: number
-  details: { [taskCategoryId: string]: { time: number, cost: number } }
+  details: CostDetails[]
+}
+
+export interface CostDetails {
+  time: number
+  cost: number
+  taskCategoryId: TaskCategoryID
 }
 
 export function getMinMaxCosts(project: Project, estimation: Estimation): MinMaxCost {
-  const max: Cost = {totalCost: 0, totalTime: 0, details: {}};
-  const min: Cost = {totalCost: 0, totalTime: 0, details: {}};
+  const max: Cost = {totalCost: 0, totalTime: 0, details: []};
+  const min: Cost = {totalCost: 0, totalTime: 0, details: []};
 
   const repartition = getTaskCategoriesMeanRepartition(project);
 
-  Object.values(project.params.taskCategories).forEach(tc => {
+  Object.values(project.taskCategories).forEach(tc => {
     const cost = getTaskCategoryCost(tc);
 
     const maxTime = Math.round((estimation.e + estimation.sd) * repartition[tc.id]);
-    max.details[tc.id] = {
-      time: maxTime,
-      cost: Math.ceil(maxTime) * cost,
-    };
-    max.totalTime += max.details[tc.id].time;
-    max.totalCost += max.details[tc.id].cost;
+    let maxDetails = getDetailsForTaskCategory(max.details, tc.id);
+    if (!maxDetails) {
+      maxDetails = { taskCategoryId: tc.id, time: 0, cost: 0 };
+      max.details.push(maxDetails);
+    }
+
+    maxDetails.time = maxTime;
+    maxDetails.cost = Math.ceil(maxTime) * cost;
+
+    max.totalTime += maxDetails.time;
+    max.totalCost += maxDetails.cost;
 
     const minTime = Math.round((estimation.e - estimation.sd) * repartition[tc.id]);
-    min.details[tc.id] = {
-      time: minTime,
-      cost: Math.ceil(minTime) * cost,
-    };
-    min.totalTime += min.details[tc.id].time;
-    min.totalCost += min.details[tc.id].cost;
+    let minDetails = getDetailsForTaskCategory(min.details, tc.id);
+    if (!minDetails) {
+      minDetails = { taskCategoryId: tc.id, time: 0, cost: 0 };
+      min.details.push(minDetails);
+    }
+    minDetails.time = minTime;
+    minDetails.cost = Math.ceil(minTime) * cost;
+    min.totalTime += minDetails.time;
+    min.totalCost += minDetails.cost;
   });
 
   return { max, min };
+}
+
+function getDetailsForTaskCategory(details: CostDetails[], id: TaskCategoryID): CostDetails|void {
+  for (let d, i = 0; (d = details[i]); ++i) {
+    if (d.taskCategoryId === id) return d;
+  }
 }
\ No newline at end of file
diff --git a/client/src/types/task.ts b/client/src/types/task.ts
index 672196c..8175673 100644
--- a/client/src/types/task.ts
+++ b/client/src/types/task.ts
@@ -1,6 +1,7 @@
 import { defaults } from "./params";
+import { uuid } from "../util/uuid";
 
-export type TaskID = string
+export type TaskID = number
 
 export enum EstimationConfidence {
   Optimistic = "optimistic",
@@ -11,21 +12,21 @@ export enum EstimationConfidence {
 export interface Task {
   id: TaskID
   label: string
-  category: TaskCategoryID
+  category: TaskCategory
   estimations: { [confidence in EstimationConfidence]: number }
 }
 
-export type TaskCategoryID = string
+export type TaskCategoryID = number
 
 export interface TaskCategory {
-  id: TaskCategoryID
+  id: number
   label: string
   costPerTimeUnit: number
 }
 
-export function newTask(label: string, category: TaskCategoryID): Task {
+export function newTask(label: string, category: TaskCategory): Task {
   return {
-    id: '',
+    id: null,
     label,
     category,
     estimations: {
@@ -38,8 +39,8 @@ export function newTask(label: string, category: TaskCategoryID): Task {
 
 export function createTaskCategory(): TaskCategory {
   return {
-    id: '',
-    costPerTimeUnit: defaults.costPerTimeUnit,
+    id: null,
+    costPerTimeUnit: defaults.params.costPerTimeUnit,
     label: ""
   };
 }
diff --git a/client/src/util/uuid.ts b/client/src/util/uuid.ts
new file mode 100644
index 0000000..b7cf239
--- /dev/null
+++ b/client/src/util/uuid.ts
@@ -0,0 +1,35 @@
+const hex: string[] = [];
+
+for (var i = 0; i < 256; i++) {
+  hex[i] = (i < 16 ? '0' : '') + (i).toString(16);
+}
+
+export function uuid(): string {
+  const r = crypto.getRandomValues(new Uint8Array(16));
+  
+  r[6] = r[6] & 0x0f | 0x40;
+  r[8] = r[8] & 0x3f | 0x80;
+  
+  return (
+    hex[r[0]] +
+    hex[r[1]] +
+    hex[r[2]] +
+    hex[r[3]] +
+    "-" +
+    hex[r[4]] +
+    hex[r[5]] +
+    "-" +
+    hex[r[6]] +
+    hex[r[7]] +
+    "-" +
+    hex[r[8]] +
+    hex[r[9]] +
+    "-" +
+    hex[r[10]] +
+    hex[r[11]] +
+    hex[r[12]] +
+    hex[r[13]] +
+    hex[r[14]] +
+    hex[r[15]]
+  );
+}
\ No newline at end of file
diff --git a/cmd/server/migration.go b/cmd/server/migration.go
index 235b62a..0418ce7 100644
--- a/cmd/server/migration.go
+++ b/cmd/server/migration.go
@@ -79,6 +79,10 @@ func applyMigration(ctx context.Context, ctn *service.Container) error {
 // nolint: gochecknoglobals
 var initialModels = []interface{}{
 	&model.User{},
+	&model.Project{},
+	&model.Access{},
+	&model.TaskCategory{},
+	&model.Task{},
 }
 
 func m000initialSchema() orm.Migration {
@@ -91,15 +95,50 @@ func m000initialSchema() orm.Migration {
 				}
 			}
 
+			// Create foreign keys indexes
+			err := tx.Model(&model.Access{}).
+				AddForeignKey("user_id", "users(id)", "CASCADE", "CASCADE").Error
+			if err != nil {
+				return errors.WithStack(err)
+			}
+
+			err = tx.Model(&model.TaskCategory{}).
+				AddForeignKey("project_id", "projects(id)", "CASCADE", "CASCADE").Error
+			if err != nil {
+				return errors.WithStack(err)
+			}
+
+			err = tx.Model(&model.Access{}).
+				AddForeignKey("project_id", "projects(id)", "CASCADE", "CASCADE").Error
+			if err != nil {
+				return errors.WithStack(err)
+			}
+
+			err = tx.Model(&model.Access{}).
+				AddForeignKey("user_id", "users(id)", "CASCADE", "CASCADE").Error
+			if err != nil {
+				return errors.WithStack(err)
+			}
+
+			err = tx.Model(&model.Task{}).
+				AddForeignKey("category_id", "task_categories(id)", "CASCADE", "CASCADE").Error
+			if err != nil {
+				return errors.WithStack(err)
+			}
+
 			return nil
 		},
 		func(ctx context.Context, tx *gorm.DB) error {
-			for _, m := range initialModels {
-				if err := tx.DropTableIfExists(m).Error; err != nil {
+			for i := len(initialModels) - 1; i >= 0; i-- {
+				if err := tx.DropTableIfExists(initialModels[i]).Error; err != nil {
 					return errors.WithStack(err)
 				}
 			}
 
+			if err := tx.DropTableIfExists("sessions").Error; err != nil {
+				return errors.WithStack(err)
+			}
+
 			return nil
 		},
 	)
diff --git a/internal/config/config.go b/internal/config/config.go
index 73c94cd..b35ec46 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -90,7 +90,7 @@ func NewDefault() *Config {
 			Address:                 ":8081",
 			CookieAuthenticationKey: "",
 			CookieEncryptionKey:     "",
-			CookieMaxAge:            int((time.Hour * 1).Seconds()), // 1 hour
+			CookieMaxAge:            int((time.Hour * 24).Seconds()), // 24 hour
 			TemplateDir:             "template",
 			PublicDir:               "public",
 			FrontendURL:             "http://localhost:8080",
diff --git a/internal/gqlgen.yml b/internal/gqlgen.yml
index 826d129..8e26274 100644
--- a/internal/gqlgen.yml
+++ b/internal/gqlgen.yml
@@ -45,10 +45,7 @@ autobind:
 models:
   ID:
     model:
-      - github.com/99designs/gqlgen/graphql.ID
-      - github.com/99designs/gqlgen/graphql.Int
       - github.com/99designs/gqlgen/graphql.Int64
-      - github.com/99designs/gqlgen/graphql.Int32
   Int:
     model:
       - github.com/99designs/gqlgen/graphql.Int
diff --git a/internal/graph/estimation_handler.go b/internal/graph/estimation_handler.go
new file mode 100644
index 0000000..31f7f3d
--- /dev/null
+++ b/internal/graph/estimation_handler.go
@@ -0,0 +1,49 @@
+package graph
+
+import (
+	"context"
+	"strconv"
+
+	"forge.cadoles.com/Cadoles/guesstimate/internal/model"
+	"github.com/pkg/errors"
+)
+
+func handleEstimations(ctx context.Context, task *model.Task) (*model.Estimations, error) {
+	estimations := &model.Estimations{}
+
+	if task.Estimations == nil {
+		return estimations, nil
+	}
+
+	rawOptimistic, exists := task.Estimations[model.EstimationOptimistic]
+	if exists && rawOptimistic != nil {
+		optimistic, err := strconv.ParseFloat(*rawOptimistic, 64)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		estimations.Optimistic = optimistic
+	}
+
+	rawLikely, exists := task.Estimations[model.EstimationLikely]
+	if exists && rawLikely != nil {
+		likely, err := strconv.ParseFloat(*rawLikely, 64)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		estimations.Likely = likely
+	}
+
+	rawPessimistic, exists := task.Estimations[model.EstimationPessimistic]
+	if exists && rawPessimistic != nil {
+		pessimistic, err := strconv.ParseFloat(*rawPessimistic, 64)
+		if err != nil {
+			return nil, errors.WithStack(err)
+		}
+
+		estimations.Pessimistic = pessimistic
+	}
+
+	return estimations, nil
+}
diff --git a/internal/graph/mutation.graphql b/internal/graph/mutation.graphql
index 73d565f..fe9179a 100644
--- a/internal/graph/mutation.graphql
+++ b/internal/graph/mutation.graphql
@@ -2,6 +2,26 @@ input UserChanges {
   name: String
 }
 
+input CreateProjectChanges {
+  title: String!
+}
+
+input ProjectTaskChanges {
+  label: String
+  categoryId: ID
+  estimations: ProjectTaskEstimationsChanges
+}
+
+input ProjectTaskEstimationsChanges {
+  optimistic: Float
+  likely: Float
+  pessimistic: Float
+}
+
 type Mutation {
   updateUser(id: ID!, changes: UserChanges!): User!
+  createProject(changes: CreateProjectChanges!): Project!
+  updateProjectTitle(projectId: ID!, title: String!): Project!
+  addProjectTask(projectId: ID!, changes: ProjectTaskChanges): Task!
+  removeProjectTask(projectId: ID!, taskId: ID!): Boolean!
 }
\ No newline at end of file
diff --git a/internal/graph/mutation.resolvers.go b/internal/graph/mutation.resolvers.go
index 18b88bc..d707451 100644
--- a/internal/graph/mutation.resolvers.go
+++ b/internal/graph/mutation.resolvers.go
@@ -10,10 +10,26 @@ import (
 	"forge.cadoles.com/Cadoles/guesstimate/internal/model"
 )
 
-func (r *mutationResolver) UpdateUser(ctx context.Context, id string, changes model.UserChanges) (*model.User, error) {
+func (r *mutationResolver) UpdateUser(ctx context.Context, id int64, changes model.UserChanges) (*model.User, error) {
 	return handleUpdateUser(ctx, id, changes)
 }
 
+func (r *mutationResolver) CreateProject(ctx context.Context, changes model.CreateProjectChanges) (*model.Project, error) {
+	return handleCreateProject(ctx, changes)
+}
+
+func (r *mutationResolver) UpdateProjectTitle(ctx context.Context, projectID int64, title string) (*model.Project, error) {
+	return handleUpdateProjectTitle(ctx, projectID, title)
+}
+
+func (r *mutationResolver) AddProjectTask(ctx context.Context, projectID int64, changes *model.ProjectTaskChanges) (*model.Task, error) {
+	return handleAddProjectTask(ctx, projectID, changes)
+}
+
+func (r *mutationResolver) RemoveProjectTask(ctx context.Context, projectID int64, taskID int64) (bool, error) {
+	return handleRemoveProjectTask(ctx, projectID, taskID)
+}
+
 // Mutation returns generated.MutationResolver implementation.
 func (r *Resolver) Mutation() generated.MutationResolver { return &mutationResolver{r} }
 
diff --git a/internal/graph/project_handler.go b/internal/graph/project_handler.go
new file mode 100644
index 0000000..a33296b
--- /dev/null
+++ b/internal/graph/project_handler.go
@@ -0,0 +1,96 @@
+package graph
+
+import (
+	"context"
+
+	"forge.cadoles.com/Cadoles/guesstimate/internal/model"
+	model1 "forge.cadoles.com/Cadoles/guesstimate/internal/model"
+	"github.com/pkg/errors"
+)
+
+func handleProjects(ctx context.Context, filter *model1.ProjectsFilter) ([]*model1.Project, error) {
+	user, db, err := getSessionUser(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	repo := model.NewProjectRepository(db)
+
+	if filter == nil {
+		filter = &model1.ProjectsFilter{
+			OwnerIds: make([]int64, 0, 1),
+		}
+	}
+
+	filter.OwnerIds = append(filter.OwnerIds, user.ID)
+
+	projects, err := repo.Search(ctx, filter)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return projects, nil
+}
+
+func handleCreateProject(ctx context.Context, input model.CreateProjectChanges) (*model.Project, error) {
+	user, db, err := getSessionUser(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	repo := model.NewProjectRepository(db)
+
+	project, err := repo.Create(ctx, input.Title, user.ID)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return project, nil
+}
+
+func handleUpdateProjectTitle(ctx context.Context, projectID int64, title string) (*model.Project, error) {
+	db, err := getDB(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	repo := model.NewProjectRepository(db)
+
+	project, err := repo.UpdateTitle(ctx, projectID, title)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return project, nil
+}
+
+func handleAddProjectTask(ctx context.Context, projectID int64, changes *model.ProjectTaskChanges) (*model.Task, error) {
+	db, err := getDB(ctx)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	repo := model.NewProjectRepository(db)
+
+	task, err := repo.AddTask(ctx, projectID, changes)
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return task, nil
+}
+
+func handleRemoveProjectTask(ctx context.Context, projectID int64, taskID int64) (bool, error) {
+	db, err := getDB(ctx)
+	if err != nil {
+		return false, errors.WithStack(err)
+	}
+
+	repo := model.NewProjectRepository(db)
+
+	if err := repo.RemoveTask(ctx, projectID, taskID); err != nil {
+		return false, errors.WithStack(err)
+	}
+
+	return true, nil
+}
diff --git a/internal/graph/query.graphql b/internal/graph/query.graphql
index d2423e1..a96a16d 100644
--- a/internal/graph/query.graphql
+++ b/internal/graph/query.graphql
@@ -8,6 +8,60 @@ type User {
   createdAt: Time!
 }
 
+type Project {
+  id: ID!
+  title: String!
+  tasks: [Task]!
+  params: ProjectParams!
+  acl: [Access]!
+  taskCategories: [TaskCategory]!
+}
+
+type Task {
+  id: ID!
+  label: String
+  category: TaskCategory
+  estimations: Estimations
+}
+
+type TaskCategory {
+  id: ID!
+  label: String!
+	costPerTimeUnit: Float!
+}
+
+type Access {
+  id: ID!
+  user: User!
+  level: String!
+}
+
+type ProjectParams {
+  timeUnit: TimeUnit
+  currency: String!
+  roundUpEstimations: Boolean!
+  hideFinancialPreviewOnPrint: Boolean!
+}
+
+type TimeUnit {
+  label: String!
+  acronym: String!
+}
+
+type Estimations {
+  optimistic: Float!
+  likely: Float!
+  pessimistic: Float!
+}
+
+input ProjectsFilter {
+  ids: [ID]
+  limit: Int
+  offset: Int
+  search: String
+}
+
 type Query {
   currentUser: User
+  projects(filter: ProjectsFilter): [Project]
 }
diff --git a/internal/graph/query.resolvers.go b/internal/graph/query.resolvers.go
index cd11ce9..73073dc 100644
--- a/internal/graph/query.resolvers.go
+++ b/internal/graph/query.resolvers.go
@@ -14,7 +14,19 @@ func (r *queryResolver) CurrentUser(ctx context.Context) (*model1.User, error) {
 	return handleCurrentUser(ctx)
 }
 
+func (r *queryResolver) Projects(ctx context.Context, filter *model1.ProjectsFilter) ([]*model1.Project, error) {
+	return handleProjects(ctx, filter)
+}
+
+func (r *taskResolver) Estimations(ctx context.Context, obj *model1.Task) (*model1.Estimations, error) {
+	return handleEstimations(ctx, obj)
+}
+
 // Query returns generated.QueryResolver implementation.
 func (r *Resolver) Query() generated.QueryResolver { return &queryResolver{r} }
 
+// Task returns generated.TaskResolver implementation.
+func (r *Resolver) Task() generated.TaskResolver { return &taskResolver{r} }
+
 type queryResolver struct{ *Resolver }
+type taskResolver struct{ *Resolver }
diff --git a/internal/graph/user_handler.go b/internal/graph/user_handler.go
index 475936f..c214d9d 100644
--- a/internal/graph/user_handler.go
+++ b/internal/graph/user_handler.go
@@ -19,7 +19,7 @@ func handleCurrentUser(ctx context.Context) (*model.User, error) {
 	return user, nil
 }
 
-func handleUpdateUser(ctx context.Context, id string, changes model.UserChanges) (*model.User, error) {
+func handleUpdateUser(ctx context.Context, id int64, changes model.UserChanges) (*model.User, error) {
 	user, db, err := getSessionUser(ctx)
 	if err != nil {
 		return nil, errors.WithStack(err)
diff --git a/internal/model/base.go b/internal/model/base.go
new file mode 100644
index 0000000..289533f
--- /dev/null
+++ b/internal/model/base.go
@@ -0,0 +1,21 @@
+package model
+
+import "time"
+
+type Base struct {
+	ID        int64 `gorm:"primary_key,AUTO_INCREMENT" json:"id"`
+	CreatedAt time.Time
+	UpdatedAt time.Time
+}
+
+func (b *Base) BeforeSave() (err error) {
+	now := time.Now()
+
+	if b.CreatedAt.IsZero() {
+		b.CreatedAt = now
+	}
+
+	b.UpdatedAt = now
+
+	return nil
+}
diff --git a/internal/model/project.go b/internal/model/project.go
new file mode 100644
index 0000000..1738c9b
--- /dev/null
+++ b/internal/model/project.go
@@ -0,0 +1,123 @@
+package model
+
+import (
+	"encoding/json"
+
+	"github.com/jinzhu/gorm/dialects/postgres"
+	"github.com/pkg/errors"
+)
+
+type Project struct {
+	Base
+	Title          *string         `json:"title"`
+	Tasks          []*Task         `json:"tasks"`
+	Params         *ProjectParams  `gorm:"-" json:"params"`
+	ParamsJSON     postgres.Jsonb  `json:"-" gorm:"column:params;"`
+	TaskCategories []*TaskCategory `json:"taskCategories"`
+	ACL            []*Access       `json:"acl"`
+}
+
+func (p *Project) BeforeSave() error {
+	data, err := json.Marshal(p.Params)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	p.ParamsJSON = postgres.Jsonb{RawMessage: data}
+
+	return nil
+}
+
+func (p *Project) AfterFind() error {
+	params := &ProjectParams{}
+	if err := json.Unmarshal(p.ParamsJSON.RawMessage, params); err != nil {
+		return errors.WithStack(err)
+	}
+
+	p.Params = params
+
+	return nil
+}
+
+type ProjectParams struct {
+	TimeUnit                    *TimeUnit `json:"timeUnit"`
+	Currency                    string    `json:"currency"`
+	RoundUpEstimations          bool      `json:"roundUpEstimations"`
+	HideFinancialPreviewOnPrint bool      `json:"hideFinancialPreviewOnPrint"`
+}
+
+func NewDefaultProjectParams() *ProjectParams {
+	return &ProjectParams{
+		Currency: "€ H.T.",
+		TimeUnit: &TimeUnit{
+			Acronym: "J/H",
+			Label:   "Jour/Homme",
+		},
+		RoundUpEstimations:          false,
+		HideFinancialPreviewOnPrint: false,
+	}
+}
+
+func NewDefaultTaskCategories() []*TaskCategory {
+	return []*TaskCategory{
+		&TaskCategory{
+			Label:           "Développement",
+			CostPerTimeUnit: 500,
+		},
+		&TaskCategory{
+			Label:           "Conduite de projet",
+			CostPerTimeUnit: 500,
+		},
+		&TaskCategory{
+			Label:           "Recette",
+			CostPerTimeUnit: 500,
+		},
+	}
+}
+
+const (
+	LevelOwner       = "owner"
+	LevelReadOnly    = "readonly"
+	LevelContributor = "contributor"
+)
+
+type Access struct {
+	Base
+	ProjectID int64
+	Project   *Project `json:"-"`
+	UserID    int64
+	User      *User  `json:"user"`
+	Level     string `json:"level"`
+}
+
+const (
+	EstimationPessimistic = "pessimistic"
+	EstimationLikely      = "likely"
+	EstimationOptimistic  = "optimistic"
+)
+
+type Task struct {
+	Base
+	ProjectID   int64           `json:"-"`
+	Project     *Project        `json:"-"`
+	Label       *string         `json:"label"`
+	CategoryID  int64           `json:"-"`
+	Category    *TaskCategory   `json:"category"`
+	Estimations postgres.Hstore `json:"estimations"`
+}
+
+type TaskCategory struct {
+	Base
+	ProjectID       int64    `json:"-"`
+	Project         *Project `json:"-"`
+	Label           string   `json:"label"`
+	CostPerTimeUnit float64  `json:"costPerTimeUnit"`
+}
+
+type ProjectsFilter struct {
+	Ids      []*int64 `json:"ids"`
+	Limit    *int     `json:"limit"`
+	Offset   *int     `json:"offset"`
+	Search   *string  `json:"search"`
+	OwnerIds []int64  `json:"-"`
+}
diff --git a/internal/model/project_repository.go b/internal/model/project_repository.go
new file mode 100644
index 0000000..81d4048
--- /dev/null
+++ b/internal/model/project_repository.go
@@ -0,0 +1,261 @@
+package model
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+
+	"github.com/jinzhu/gorm/dialects/postgres"
+
+	"forge.cadoles.com/Cadoles/guesstimate/internal/orm"
+	"github.com/jinzhu/gorm"
+	"github.com/pkg/errors"
+)
+
+type ProjectRepository struct {
+	db *gorm.DB
+}
+
+func (r *ProjectRepository) Create(ctx context.Context, title string, ownerID int64) (*Project, error) {
+	project := &Project{
+		Title:          &title,
+		Tasks:          make([]*Task, 0),
+		TaskCategories: NewDefaultTaskCategories(),
+		Params:         NewDefaultProjectParams(),
+	}
+
+	err := orm.WithTx(ctx, r.db, func(ctx context.Context, tx *gorm.DB) error {
+		if err := tx.Save(project).Error; err != nil {
+			return errors.WithStack(err)
+		}
+
+		err := tx.Model(project).Association("ACL").Append(&Access{
+			Level:  LevelOwner,
+			UserID: ownerID,
+		}).Error
+
+		if err != nil {
+			return errors.WithStack(err)
+		}
+
+		err = tx.Model(project).
+			Preload("ACL").
+			Preload("ACL.User").
+			Preload("Tasks").
+			Preload("Tasks.Category").
+			Preload("TaskCategories").
+			Find(project).
+			Error
+
+		if err != nil {
+			return errors.WithStack(err)
+		}
+
+		return nil
+	})
+	if err != nil {
+		return nil, errors.Wrap(err, "could not create user")
+	}
+
+	return project, nil
+}
+
+func (r *ProjectRepository) UpdateTitle(ctx context.Context, projectID int64, title string) (*Project, error) {
+	project := &Project{}
+	project.ID = projectID
+
+	err := r.db.Transaction(func(tx *gorm.DB) error {
+		if err := tx.Model(project).Update("title", title).Error; err != nil {
+			return errors.WithStack(err)
+		}
+
+		err := tx.Model(project).
+			Preload("ACL").
+			Preload("ACL.User").
+			Preload("Tasks").
+			Preload("Tasks.Category").
+			Preload("TaskCategories").
+			First(project, "id = ?", projectID).
+			Error
+		if err != nil {
+			return errors.WithStack(err)
+		}
+
+		return nil
+	})
+	if err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return project, nil
+}
+
+func (r *ProjectRepository) Search(ctx context.Context, filter *ProjectsFilter) ([]*Project, error) {
+	projects := make([]*Project, 0)
+
+	projectTableName := r.db.NewScope(&Project{}).TableName()
+
+	query := r.db.Table(projectTableName).
+		Preload("ACL").
+		Preload("ACL.User").
+		Preload("Tasks").
+		Preload("Tasks.Category").
+		Preload("TaskCategories")
+
+	if filter != nil {
+		if len(filter.Ids) > 0 {
+			query = query.Where(fmt.Sprintf("%s.id in (?)", projectTableName), filter.Ids)
+		}
+
+		if len(filter.OwnerIds) > 0 {
+			accessTableName := r.db.NewScope(&Access{}).TableName()
+
+			query = query.
+				Joins(
+					fmt.Sprintf(
+						"left join %s on %s.project_id = %s.id",
+						accessTableName, accessTableName, projectTableName,
+					),
+				).
+				Where(fmt.Sprintf("%s.level = ?", accessTableName), LevelOwner).
+				Where(fmt.Sprintf("%s.user_id IN (?)", accessTableName), filter.OwnerIds)
+		}
+
+		if filter.Limit != nil {
+			query = query.Limit(*filter.Limit)
+		}
+
+		if filter.Offset != nil {
+			query = query.Offset(*filter.Offset)
+		}
+	}
+
+	if err := query.Find(&projects).Error; err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return projects, nil
+}
+
+func (r *ProjectRepository) AddTask(ctx context.Context, projectID int64, changes *ProjectTaskChanges) (*Task, error) {
+	project := &Project{}
+	project.ID = projectID
+	task := &Task{}
+
+	if changes == nil {
+		return nil, errors.Errorf("changes should not be nil")
+	}
+
+	err := r.db.Transaction(func(tx *gorm.DB) error {
+		if changes.Label != nil {
+			task.Label = changes.Label
+		}
+
+		if changes.CategoryID != nil {
+			taskCategory := &TaskCategory{}
+			taskCategory.ID = *changes.CategoryID
+			task.Category = taskCategory
+		}
+
+		if changes.Estimations != nil {
+			if task.Estimations == nil {
+				task.Estimations = postgres.Hstore{}
+			}
+
+			if changes.Estimations.Pessimistic != nil {
+				pessimistic := strconv.FormatFloat(*changes.Estimations.Pessimistic, 'f', 12, 64)
+				task.Estimations[EstimationPessimistic] = &pessimistic
+			}
+
+			if changes.Estimations.Likely != nil {
+				likely := strconv.FormatFloat(*changes.Estimations.Likely, 'f', 12, 64)
+				task.Estimations[EstimationLikely] = &likely
+			}
+
+			if changes.Estimations.Optimistic != nil {
+				optimistic := strconv.FormatFloat(*changes.Estimations.Optimistic, 'f', 12, 64)
+				task.Estimations[EstimationOptimistic] = &optimistic
+			}
+
+			if changes.CategoryID != nil {
+				taskCategory := &TaskCategory{}
+				if err := tx.Find(taskCategory, "id = ?", *changes.CategoryID).Error; err != nil {
+					return errors.Wrap(err, "could not find task category")
+				}
+
+				task.Category = taskCategory
+			}
+		}
+
+		if err := tx.Save(task).Error; err != nil {
+			return errors.Wrap(err, "could not create task")
+		}
+
+		err := tx.Model(project).Association("Tasks").Append(task).Error
+		if err != nil {
+			return errors.Wrap(err, "could not add task")
+		}
+
+		return nil
+	})
+
+	if err != nil {
+		return nil, errors.Wrap(err, "could not add task")
+	}
+
+	return task, nil
+}
+
+func (r *ProjectRepository) RemoveTask(ctx context.Context, projectID int64, taskID int64) error {
+	project := &Project{}
+	project.ID = projectID
+
+	err := r.db.Transaction(func(tx *gorm.DB) error {
+		task := &Task{}
+		task.ID = taskID
+
+		err := tx.Model(project).Association("Tasks").Delete(task).Error
+		if err != nil {
+			return errors.Wrap(err, "could not remove task relationship")
+		}
+
+		err = tx.Delete(task, "id = ?", taskID).Error
+		if err != nil {
+			return errors.Wrap(err, "could not delete task")
+		}
+
+		return nil
+	})
+	if err != nil {
+		return errors.Wrap(err, "could not remove task")
+	}
+
+	return nil
+}
+
+func (r *ProjectRepository) UpdateTaskEstimation(ctx context.Context, projectID, taskID int64, estimation string, value float64) (*Task, error) {
+	err := r.db.Transaction(func(tx *gorm.DB) error {
+		task := &Task{}
+		if err := tx.First(task, "id = ?", taskID).Error; err != nil {
+			return errors.WithStack(err)
+		}
+
+		strValue := strconv.FormatFloat(value, 'f', 12, 64)
+		task.Estimations[estimation] = &strValue
+
+		if err := tx.Save(task).Error; err != nil {
+			return errors.WithStack(err)
+		}
+
+		return nil
+	})
+	if err != nil {
+		return nil, errors.Wrap(err, "could not update task")
+	}
+
+	return nil, nil
+}
+
+func NewProjectRepository(db *gorm.DB) *ProjectRepository {
+	return &ProjectRepository{db}
+}
diff --git a/internal/model/user.go b/internal/model/user.go
index da37466..62e68cc 100644
--- a/internal/model/user.go
+++ b/internal/model/user.go
@@ -5,11 +5,10 @@ import (
 )
 
 type User struct {
-	ID          string    `json:"id"`
+	Base
 	Name        *string   `json:"name"`
 	Email       string    `json:"email"`
 	ConnectedAt time.Time `json:"connectedAt"`
-	CreatedAt   time.Time `json:"createdAt"`
 }
 
 type UserChanges struct {
diff --git a/misc/containers/postgres/initdb.d/init-databases.sh b/misc/containers/postgres/initdb.d/init-databases.sh
index 84d73b7..ca981d7 100644
--- a/misc/containers/postgres/initdb.d/init-databases.sh
+++ b/misc/containers/postgres/initdb.d/init-databases.sh
@@ -2,6 +2,8 @@
 
 set -e
 
+psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" template1 -c 'CREATE EXTENSION hstore;'
+
 psql -v ON_ERROR_STOP=1 --username "$POSTGRES_USER" --dbname "$POSTGRES_DB" <<-EOSQL
     CREATE USER hydra WITH ENCRYPTED PASSWORD 'hydra';
     CREATE DATABASE hydra;
diff --git a/modd.conf b/modd.conf
index 172b1bb..576dcf5 100644
--- a/modd.conf
+++ b/modd.conf
@@ -11,10 +11,14 @@ modd.conf {
   prep: make build
   prep: [ -e data/config.yml ] || ( mkdir -p data && bin/server -dump-config > data/config.yml )
   prep: [ -e .env ] || ( cp .env.dist .env )
-  prep:  make migrate-latest
   daemon: ( set -o allexport && source .env && set +o allexport && bin/server -workdir "./cmd/server" -config ../../data/config.yml )
 }
 
+cmd/server/migration.go {
+  prep: make migrate-down
+  prep: make migrate-latest
+}
+
 **/*.go {
   prep: make test
 }