package storage

import (
	"context"
	"errors"
	"fmt"

	"github.com/spf13/viper"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

type MongoDBStorage struct {
	*mongo.Client
	DbName      string
	Collections map[string]string
}

func NewMongoDBStorage(cfg *viper.Viper) (MongoDBStorage, error) {
	var (
		mongodb_host   = cfg.GetString("storage.db.mongodb.host")
		mongodb_port   = cfg.GetString("storage.db.mongodb.port")
		mongodb_dbname = cfg.GetString("storage.db.mongodb.db_name")
		mongodb_groups = cfg.GetString("storage.db.mongodb.collections.groups")
	)

	client, err := mongo.NewClient(options.Client().ApplyURI("mongodb://" + mongodb_host + ":" + mongodb_port))
	if err != nil {
		return MongoDBStorage{}, err
	}

	err = client.Connect(context.TODO())

	if err != nil {
		return MongoDBStorage{}, err
	}

	storage := MongoDBStorage{
		Client: client,
		DbName: mongodb_dbname,
		Collections: map[string]string{
			"groups": mongodb_groups,
		},
	}
	//TODO Indexes
	return storage, err
}

func (s MongoDBStorage) CreateGroup(group Group) error {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["groups"])
	if _, err := collection.InsertOne(context.TODO(), group); err != nil {
		return err
	}

	return nil
}

func (s MongoDBStorage) GetGroup(id string) (*Group, error) {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["groups"])

	group := &Group{}
	if err := collection.FindOne(context.TODO(), bson.M{"_id": id}).Decode(group); err != nil {
		return nil, err
	}

	return group, nil
}

func (s MongoDBStorage) GetGroups(namespaces []string) (groups []Group, err error) {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["groups"])

	var cur *mongo.Cursor

	findOptions := options.Find()

	if len(namespaces) == 0 {
		cur, err = collection.Find(context.TODO(), bson.D{}, findOptions)
		if err != nil {
			return groups, err
		}
	} else {
		cur, err = collection.Find(context.TODO(), bson.M{"namespace": bson.M{"$in": namespaces}}, findOptions)
		if err != nil {
			return groups, err
		}
	}

	for cur.Next(context.TODO()) {
		var group Group
		var elem bson.M

		if err := cur.Decode(&elem); err != nil {
			return groups, err
		}

		bsonBytes, _ := bson.Marshal(elem)
		bson.Unmarshal(bsonBytes, &group)

		groups = append(groups, group)

	}

	return
}

func (s MongoDBStorage) GetGroupsByIds(groupids []string) (groups []Group, err error) {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["groups"])

	var cur *mongo.Cursor

	findOptions := options.Find()

	if len(groupids) == 0 {
		return groups, errors.New("no group id provided")
	} else {
		cur, err = collection.Find(context.TODO(), bson.M{"_id": bson.M{"$in": groupids}}, findOptions)
		if err != nil {
			return groups, err
		}
	}

	for cur.Next(context.TODO()) {
		var group Group
		var elem bson.M

		if err := cur.Decode(&elem); err != nil {
			return groups, err
		}

		bsonBytes, _ := bson.Marshal(elem)
		bson.Unmarshal(bsonBytes, &group)

		groups = append(groups, group)

	}

	return
}

func (s MongoDBStorage) UpdateGroup(group Group) error {
	collection := s.Client.Database(s.DbName).Collection(s.Collections["groups"])
	if _, err := collection.ReplaceOne(context.TODO(), bson.M{"_id": group.ID}, group); err != nil {
		fmt.Println(err)
		return err
	}

	return nil
}