guesstimate/src/hooks/use-project-reducer.ts

import { Project } from "../models/project";
import { Task, TaskID, EstimationConfidence } from "../models/task";
import { useReducer } from "preact/hooks";

export interface Action {
    type: string
}

export type ProjectReducerActions =
    AddTask |
    RemoveTask |
    UpdateTaskEstimation |
    UpdateProjectLabel |
    UpdateTaskLabel

export function useProjectReducer(project: Project) {
    return useReducer(projectReducer, project);
}

export function projectReducer(project: Project, action: ProjectReducerActions): Project {
    switch(action.type) {
        case ADD_TASK:
            return handleAddTask(project, action as AddTask);

        case REMOVE_TASK:
            return handleRemoveTask(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_TASK_LABEL:
            return handleUpdateTaskLabel(project, action as UpdateTaskLabel);
    }

    return project;
}

export interface AddTask extends Action {
    task: Task
}

export const ADD_TASK = "ADD_TASK";

export function addTask(task: Task): AddTask {
    return { type: ADD_TASK, task };
}

export function handleAddTask(project: Project, action: AddTask): Project {
    const task = { ...action.task };
    return {
        ...project,
        tasks: {
            ...project.tasks,
            [task.id]: task,
        }
    };
}

export interface RemoveTask extends Action {
    id: TaskID
}

export const REMOVE_TASK = "REMOVE_TASK";

export function removeTask(id: TaskID): RemoveTask {
    return { type: REMOVE_TASK, id };
}

export function handleRemoveTask(project: Project, action: RemoveTask): Project {
    const tasks = { ...project.tasks };
    delete tasks[action.id];
    return {
        ...project,
        tasks
    };
}

export interface UpdateTaskEstimation extends Action {
    id: TaskID
    confidence: string
    value: number
}

export const UPDATE_TASK_ESTIMATION = "UPDATE_TASK_ESTIMATION";

export function updateTaskEstimation(id: TaskID, confidence: EstimationConfidence, value: number): UpdateTaskEstimation {
    return { type: UPDATE_TASK_ESTIMATION, id, confidence, value };
}

export function handleUpdateTaskEstimation(project: Project, action: UpdateTaskEstimation): Project {
    const estimations = {
        ...project.tasks[action.id].estimations,
        [action.confidence]: action.value
    };

    if (estimations.likely <= estimations.optimistic) {
        estimations.likely = estimations.optimistic + 1;
    }

    if (estimations.pessimistic <= estimations.likely) {
        estimations.pessimistic = estimations.likely + 1;
    }

    return {
        ...project,
        tasks: {
            ...project.tasks,
            [action.id]: {
                ...project.tasks[action.id],
                estimations: estimations,
            }
        }
    };
}


export interface UpdateProjectLabel extends Action {
    label: string
}

export const UPDATE_PROJECT_LABEL = "UPDATE_PROJECT_LABEL";

export function updateProjectLabel(label: string): UpdateProjectLabel {
    return { type: UPDATE_PROJECT_LABEL, label };
}

export function handleUpdateProjectLabel(project: Project, action: UpdateProjectLabel): Project {
    return {
        ...project,
        label: action.label
    };
}

export interface UpdateTaskLabel extends Action {
    id: TaskID
    label: string
}

export const UPDATE_TASK_LABEL = "UPDATE_TASK_LABEL";

export function updateTaskLabel(id: TaskID, label: string): UpdateTaskLabel {
    return { type: UPDATE_TASK_LABEL, id, label };
}

export function handleUpdateTaskLabel(project: Project, action: UpdateTaskLabel): Project {
    return {
        ...project,
        tasks: {
            ...project.tasks,
            [action.id]: {
                ...project.tasks[action.id],
                label: action.label,
            }
        }
    };
}