/*
   Copyright (c) 2019 AT&T Intellectual Property.
   Copyright (c) 2018-2019 Nokia.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package sdlgoredis

import (
	"errors"
	"fmt"
	"os"

	"github.com/go-redis/redis"
)

type DB struct {
	client       *redis.Client
	redisModules bool
}

func Create() *DB {
	hostname := os.Getenv("DBAAS_SERVICE_HOST")
	if hostname == "" {
		hostname = "localhost"
	}
	port := os.Getenv("DBAAS_SERVICE_PORT")
	if port == "" {
		port = "6379"
	}
	redisAddress := hostname + ":" + port
	client := redis.NewClient(&redis.Options{
		Addr:     redisAddress,
		Password: "", // no password set
		DB:       0,  // use default DB
		PoolSize: 20,
	})

	db := DB{
		client:       client,
		redisModules: true,
	}

	commands, err := db.client.Command().Result()
	if err == nil {
		redisModuleCommands := []string{"setie", "delie"}
		for _, v := range redisModuleCommands {
			_, ok := commands[v]
			if !ok {
				db.redisModules = false
			}
		}
	} else {
		fmt.Println(err)
	}
	return &db
}

func (db *DB) CloseDB() error {
	return db.client.Close()
}

func (db *DB) MSet(pairs ...interface{}) error {
	return db.client.MSet(pairs...).Err()
}

func (db *DB) MGet(keys []string) ([]interface{}, error) {
	val, err := db.client.MGet(keys...).Result()
	return val, err
}

func (db *DB) Del(keys []string) error {
	_, err := db.client.Del(keys...).Result()
	return err
}

func (db *DB) Keys(pattern string) ([]string, error) {
	val, err := db.client.Keys(pattern).Result()
	return val, err
}

func (db *DB) SetIE(key string, oldData, newData interface{}) (bool, error) {
	if !db.redisModules {
		return false, errors.New("Redis deployment not supporting command")
	}

	result, err := db.client.Do("SETIE", key, newData, oldData).Result()
	if err != nil {
		return false, err
	}
	if result == "OK" {
		return true, nil
	} else {
		return false, nil
	}
}

func (db *DB) SetNX(key string, data interface{}) (bool, error) {
	result, err := db.client.SetNX(key, data, 0).Result()
	return result, err
}

func (db *DB) DelIE(key string, data interface{}) (bool, error) {
	if !db.redisModules {
		return false, errors.New("Redis deployment not supporting command")
	}
	result, err := db.client.Do("DELIE", key, data).Result()
	if err != nil {
		return false, err
	}
	if result == "1" {
		return true, nil
	}
	return false, nil
}