package module

import (
	"fmt"

	"forge.cadoles.com/arcad/edge/pkg/app"
	"forge.cadoles.com/arcad/edge/pkg/storage"
	"forge.cadoles.com/arcad/edge/pkg/storage/filter"
	"github.com/dop251/goja"
	"github.com/mitchellh/mapstructure"
	"github.com/pkg/errors"
)

type StoreModule struct {
	server *app.Server
	store  storage.DocumentStore
}

func (m *StoreModule) Name() string {
	return "store"
}

func (m *StoreModule) Export(export *goja.Object) {
	if err := export.Set("upsert", m.upsert); err != nil {
		panic(errors.Wrap(err, "could not set 'upsert' function"))
	}

	if err := export.Set("get", m.get); err != nil {
		panic(errors.Wrap(err, "could not set 'get' function"))
	}

	if err := export.Set("query", m.query); err != nil {
		panic(errors.Wrap(err, "could not set 'query' function"))
	}

	if err := export.Set("delete", m.delete); err != nil {
		panic(errors.Wrap(err, "could not set 'delete' function"))
	}
}

func (m *StoreModule) upsert(call goja.FunctionCall, rt *goja.Runtime) goja.Value {
	ctx := assertContext(call.Argument(0), rt)
	collection := m.assertCollection(call.Argument(1), rt)
	document := m.assertDocument(call.Argument(2), rt)

	document, err := m.store.Upsert(ctx, collection, document)
	if err != nil {
		panic(errors.Wrapf(err, "error while upserting document in collection '%s'", collection))
	}

	return rt.ToValue(map[string]interface{}(document))
}

func (m *StoreModule) get(call goja.FunctionCall, rt *goja.Runtime) goja.Value {
	ctx := assertContext(call.Argument(0), rt)
	collection := m.assertCollection(call.Argument(1), rt)
	documentID := m.assertDocumentID(call.Argument(2), rt)

	document, err := m.store.Get(ctx, collection, documentID)
	if err != nil {
		if errors.Is(err, storage.ErrDocumentNotFound) {
			return nil
		}

		panic(errors.Wrapf(err, "error while getting document '%s' in collection '%s'", documentID, collection))
	}

	return rt.ToValue(map[string]interface{}(document))
}

type queryOptions struct {
	Limit          *int    `mapstructure:"limit"`
	Offset         *int    `mapstructure:"offset"`
	OrderBy        *string `mapstructure:"orderBy"`
	OrderDirection *string `mapstructure:"orderDirection"`
}

func (m *StoreModule) query(call goja.FunctionCall, rt *goja.Runtime) goja.Value {
	ctx := assertContext(call.Argument(0), rt)
	collection := m.assertCollection(call.Argument(1), rt)
	filter := m.assertFilter(call.Argument(2), rt)
	queryOptions := m.assertQueryOptions(call.Argument(3), rt)

	queryOptionsFuncs := make([]storage.QueryOptionFunc, 0)

	if queryOptions.Limit != nil {
		queryOptionsFuncs = append(queryOptionsFuncs, storage.WithLimit(*queryOptions.Limit))
	}

	if queryOptions.OrderBy != nil {
		queryOptionsFuncs = append(queryOptionsFuncs, storage.WithOrderBy(*queryOptions.OrderBy))
	}

	if queryOptions.Offset != nil {
		queryOptionsFuncs = append(queryOptionsFuncs, storage.WithOffset(*queryOptions.Limit))
	}

	if queryOptions.OrderDirection != nil {
		queryOptionsFuncs = append(queryOptionsFuncs, storage.WithOrderDirection(
			storage.OrderDirection(*queryOptions.OrderDirection),
		))
	}

	documents, err := m.store.Query(ctx, collection, filter, queryOptionsFuncs...)
	if err != nil {
		panic(errors.Wrapf(err, "error while querying documents in collection '%s'", collection))
	}

	rawDocuments := make([]map[string]interface{}, len(documents))
	for idx, doc := range documents {
		rawDocuments[idx] = map[string]interface{}(doc)
	}

	return rt.ToValue(rawDocuments)
}

func (m *StoreModule) delete(call goja.FunctionCall, rt *goja.Runtime) goja.Value {
	ctx := assertContext(call.Argument(0), rt)
	collection := m.assertCollection(call.Argument(1), rt)
	documentID := m.assertDocumentID(call.Argument(2), rt)

	if err := m.store.Delete(ctx, collection, documentID); err != nil {
		panic(errors.Wrapf(err, "error while deleting document '%s' in collection '%s'", documentID, collection))
	}

	return nil
}

func (m *StoreModule) assertCollection(value goja.Value, rt *goja.Runtime) string {
	collection, ok := value.Export().(string)
	if !ok {
		panic(rt.NewTypeError(fmt.Sprintf("collection  must be a string, got '%T'", value.Export())))
	}

	return collection
}

func (m *StoreModule) assertFilter(value goja.Value, rt *goja.Runtime) *filter.Filter {
	rawFilter, ok := value.Export().(map[string]interface{})
	if !ok {
		panic(rt.NewTypeError(fmt.Sprintf("filter  must be an object, got '%T'", value.Export())))
	}

	filter, err := filter.NewFrom(rawFilter)
	if err != nil {
		panic(errors.Wrap(err, "could not convert object to filter"))
	}

	return filter
}

func (m *StoreModule) assertDocumentID(value goja.Value, rt *goja.Runtime) storage.DocumentID {
	documentID, ok := value.Export().(storage.DocumentID)
	if !ok {
		rawDocumentID, ok := value.Export().(string)
		if !ok {
			panic(rt.NewTypeError(fmt.Sprintf("document id  must be a documentid or a string, got '%T'", value.Export())))
		}

		documentID = storage.DocumentID(rawDocumentID)
	}

	return documentID
}

func (m *StoreModule) assertQueryOptions(value goja.Value, rt *goja.Runtime) *queryOptions {
	rawQueryOptions, ok := value.Export().(map[string]interface{})
	if !ok {
		panic(rt.NewTypeError(fmt.Sprintf("query options  must be an object, got '%T'", value.Export())))
	}

	queryOptions := &queryOptions{}

	if err := mapstructure.Decode(rawQueryOptions, queryOptions); err != nil {
		panic(errors.Wrap(err, "could not convert object to query options"))
	}

	return queryOptions
}

func (m *StoreModule) assertDocument(value goja.Value, rt *goja.Runtime) storage.Document {
	document, ok := value.Export().(map[string]interface{})
	if !ok {
		panic(rt.NewTypeError("document must be an object"))
	}

	return document
}

func StoreModuleFactory(store storage.DocumentStore) app.ServerModuleFactory {
	return func(server *app.Server) app.ServerModule {
		return &StoreModule{
			server: server,
			store:  store,
		}
	}
}