package repositoryimp

import (
	"context"
	"errors"
	"fmt"

	"github.com/tech/sendico/pkg/db/repository/builder"
	rd "github.com/tech/sendico/pkg/db/repository/decoder"
	"github.com/tech/sendico/pkg/db/storable"
	"github.com/tech/sendico/pkg/merrors"
	"github.com/tech/sendico/pkg/model"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

type MongoRepository struct {
	collectionName string
	collection     *mongo.Collection
}

func idFilter(id primitive.ObjectID) bson.D {
	return bson.D{
		{Key: storable.IDField, Value: id},
	}
}

func NewMongoRepository(db *mongo.Database, collection string) *MongoRepository {
	return &MongoRepository{
		collectionName: collection,
		collection:     db.Collection(collection),
	}
}

func (r *MongoRepository) Collection() string {
	return r.collectionName
}

func (r *MongoRepository) Insert(ctx context.Context, obj storable.Storable, getFilter builder.Query) error {
	if (obj.GetID() == nil) || (obj.GetID().IsZero()) {
		obj.SetID(primitive.NewObjectID())
	}
	obj.Update()
	_, err := r.collection.InsertOne(ctx, obj)
	if mongo.IsDuplicateKeyError(err) {
		if getFilter != nil {
			if err = r.FindOneByFilter(ctx, getFilter, obj); err != nil {
				return err
			}
		}
		return merrors.DataConflict("duplicate_key")
	}
	return err
}

func (r *MongoRepository) InsertMany(ctx context.Context, objects []storable.Storable) error {
	if len(objects) == 0 {
		return nil
	}

	docs := make([]interface{}, len(objects))
	for i, obj := range objects {
		if (obj.GetID() == nil) || (obj.GetID().IsZero()) {
			obj.SetID(primitive.NewObjectID())
		}
		obj.Update()
		docs[i] = obj
	}

	_, err := r.collection.InsertMany(ctx, docs)
	return err
}

func (r *MongoRepository) findOneByFilterImp(ctx context.Context, filter bson.D, errMessage string, result storable.Storable) error {
	err := r.collection.FindOne(ctx, filter).Decode(result)
	if errors.Is(err, mongo.ErrNoDocuments) {
		return merrors.NoData(errMessage)
	}
	return err
}

func (r *MongoRepository) Get(ctx context.Context, id primitive.ObjectID, result storable.Storable) error {
	if id.IsZero() {
		return merrors.InvalidArgument("zero id provided while fetching "+result.Collection(), "id")
	}
	return r.findOneByFilterImp(ctx, idFilter(id), fmt.Sprintf("%s with ID = %s not found", result.Collection(), id.Hex()), result)
}

type QueryFunc func(ctx context.Context, collection *mongo.Collection) (*mongo.Cursor, error)

func (r *MongoRepository) executeQuery(ctx context.Context, queryFunc QueryFunc, decoder rd.DecodingFunc) error {
	cursor, err := queryFunc(ctx, r.collection)
	if errors.Is(err, mongo.ErrNoDocuments) {
		return merrors.NoData("no_items_in_array")
	}
	if err != nil {
		return err
	}
	defer cursor.Close(ctx)

	for cursor.Next(ctx) {
		if err = decoder(cursor); err != nil {
			return err
		}
	}

	return nil
}

func (r *MongoRepository) Aggregate(ctx context.Context, pipeline builder.Pipeline, decoder rd.DecodingFunc) error {
	queryFunc := func(ctx context.Context, collection *mongo.Collection) (*mongo.Cursor, error) {
		return collection.Aggregate(ctx, pipeline.Build())
	}
	return r.executeQuery(ctx, queryFunc, decoder)
}

func (r *MongoRepository) FindManyByFilter(ctx context.Context, query builder.Query, decoder rd.DecodingFunc) error {
	queryFunc := func(ctx context.Context, collection *mongo.Collection) (*mongo.Cursor, error) {
		return collection.Find(ctx, query.BuildQuery(), query.BuildOptions())
	}
	return r.executeQuery(ctx, queryFunc, decoder)
}

func (r *MongoRepository) FindOneByFilter(ctx context.Context, query builder.Query, result storable.Storable) error {
	return r.findOneByFilterImp(ctx, query.BuildQuery(), result.Collection()+" not found by filter", result)
}

func (r *MongoRepository) Update(ctx context.Context, obj storable.Storable) error {
	obj.Update()
	return r.collection.FindOneAndReplace(ctx, idFilter(*obj.GetID()), obj).Err()
}

func (r *MongoRepository) Patch(ctx context.Context, id primitive.ObjectID, patch builder.Patch) error {
	if id.IsZero() {
		return merrors.InvalidArgument("zero id provided while patching", "id")
	}
	_, err := r.collection.UpdateByID(ctx, id, patch.Build())
	return err
}

func (r *MongoRepository) PatchMany(ctx context.Context, query builder.Query, patch builder.Patch) (int, error) {
	result, err := r.collection.UpdateMany(ctx, query.BuildQuery(), patch.Build())
	if err != nil {
		return 0, err
	}
	return int(result.ModifiedCount), nil
}

func (r *MongoRepository) ListIDs(ctx context.Context, query builder.Query) ([]primitive.ObjectID, error) {
	filter := query.BuildQuery()
	findOptions := options.Find().SetProjection(bson.M{storable.IDField: 1})

	cursor, err := r.collection.Find(ctx, filter, findOptions)
	if err != nil {
		return nil, err
	}
	defer cursor.Close(ctx)

	var ids []primitive.ObjectID
	for cursor.Next(ctx) {
		var doc struct {
			ID primitive.ObjectID `bson:"_id"`
		}
		if err := cursor.Decode(&doc); err != nil {
			return nil, err
		}
		ids = append(ids, doc.ID)
	}
	if err := cursor.Err(); err != nil {
		return nil, err
	}

	return ids, nil
}

func (r *MongoRepository) ListPermissionBound(ctx context.Context, query builder.Query) ([]model.PermissionBoundStorable, error) {
	filter := query.BuildQuery()
	findOptions := options.Find().SetProjection(bson.M{
		storable.IDField:              1,
		storable.PermissionRefField:   1,
		storable.OrganizationRefField: 1,
	})

	cursor, err := r.collection.Find(ctx, filter, findOptions)
	if err != nil {
		return nil, err
	}
	defer cursor.Close(ctx)

	result := make([]model.PermissionBoundStorable, 0)

	for cursor.Next(ctx) {
		var doc model.PermissionBound
		if err := cursor.Decode(&doc); err != nil {
			return nil, err
		}
		result = append(result, &doc)
	}
	if err := cursor.Err(); err != nil {
		return nil, err
	}

	return result, nil
}

func (r *MongoRepository) ListAccountBound(ctx context.Context, query builder.Query) ([]model.AccountBoundStorable, error) {
	filter := query.BuildQuery()
	findOptions := options.Find().SetProjection(bson.M{
		storable.IDField:           1,
		model.AccountRefField:      1,
		model.OrganizationRefField: 1,
	})

	cursor, err := r.collection.Find(ctx, filter, findOptions)
	if err != nil {
		return nil, err
	}
	defer cursor.Close(ctx)

	result := make([]model.AccountBoundStorable, 0)

	for cursor.Next(ctx) {
		var doc model.AccountBoundBase
		if err := cursor.Decode(&doc); err != nil {
			return nil, err
		}
		result = append(result, &doc)
	}
	if err := cursor.Err(); err != nil {
		return nil, err
	}

	return result, nil
}

func (r *MongoRepository) Delete(ctx context.Context, id primitive.ObjectID) error {
	_, err := r.collection.DeleteOne(ctx, idFilter(id))
	return err
}

func (r *MongoRepository) DeleteMany(ctx context.Context, query builder.Query) error {
	_, err := r.collection.DeleteMany(ctx, query.BuildQuery())
	return err
}

func (r *MongoRepository) Name() string {
	return r.collection.Name()
}