package repository

import (
	"context"
	"strings"

	app "haixun-backend/internal/library/errors"
	"haixun-backend/internal/library/errors/code"
	"haixun-backend/internal/model/style_preset/domain/entity"
	domrepo "haixun-backend/internal/model/style_preset/domain/repository"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

type mongoRepository struct {
	collection *mongo.Collection
}

func NewMongoRepository(db *mongo.Database) domrepo.Repository {
	if db == nil {
		return &mongoRepository{}
	}
	return &mongoRepository{collection: db.Collection(entity.CollectionName)}
}

func (r *mongoRepository) EnsureIndexes(ctx context.Context) error {
	if r.collection == nil {
		return nil
	}
	_, err := r.collection.Indexes().CreateMany(ctx, []mongo.IndexModel{
		{Keys: bson.D{{Key: "tenant_id", Value: 1}, {Key: "owner_uid", Value: 1}, {Key: "persona_id", Value: 1}, {Key: "create_at", Value: -1}}},
	})
	return err
}

func (r *mongoRepository) List(ctx context.Context, tenantID, ownerUID, personaID string) ([]entity.Preset, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	cur, err := r.collection.Find(ctx, personaFilter(tenantID, ownerUID, personaID), options.Find().SetSort(bson.D{{Key: "update_at", Value: -1}}))
	if err != nil {
		return nil, err
	}
	defer cur.Close(ctx)
	var out []entity.Preset
	if err := cur.All(ctx, &out); err != nil {
		return nil, err
	}
	return out, nil
}

func (r *mongoRepository) Get(ctx context.Context, tenantID, ownerUID, personaID, presetID string) (*entity.Preset, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	filter := personaFilter(tenantID, ownerUID, personaID)
	filter["_id"] = strings.TrimSpace(presetID)
	var out entity.Preset
	err := r.collection.FindOne(ctx, filter).Decode(&out)
	if err != nil {
		if err == mongo.ErrNoDocuments {
			return nil, app.For(code.Persona).ResNotFound("style preset not found")
		}
		return nil, err
	}
	return &out, nil
}

func (r *mongoRepository) Upsert(ctx context.Context, preset *entity.Preset) (*entity.Preset, error) {
	if r.collection == nil {
		return nil, app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	if preset == nil {
		return nil, app.For(code.Persona).InputMissingRequired("preset is required")
	}
	filter := personaFilter(preset.TenantID, preset.OwnerUID, preset.PersonaID)
	filter["_id"] = preset.ID
	_, err := r.collection.ReplaceOne(ctx, filter, preset, options.Replace().SetUpsert(true))
	if err != nil {
		return nil, err
	}
	return preset, nil
}

func (r *mongoRepository) Delete(ctx context.Context, tenantID, ownerUID, personaID, presetID string) error {
	if r.collection == nil {
		return app.For(code.Persona).DBUnavailable("Mongo is not configured")
	}
	filter := personaFilter(tenantID, ownerUID, personaID)
	filter["_id"] = strings.TrimSpace(presetID)
	res, err := r.collection.DeleteOne(ctx, filter)
	if err != nil {
		return err
	}
	if res.DeletedCount == 0 {
		return app.For(code.Persona).ResNotFound("style preset not found")
	}
	return nil
}

func personaFilter(tenantID, ownerUID, personaID string) bson.M {
	return bson.M{
		"tenant_id":  strings.TrimSpace(tenantID),
		"owner_uid":  strings.TrimSpace(ownerUID),
		"persona_id": strings.TrimSpace(personaID),
	}
}