package db

import (
	"fmt"
	"github.com/go-redis/redis"
	"time"
)

const NONCE = "go-tiny-url"

type Domain string

const (
	DATA  Domain = "data"
	TOKEN Domain = "token"
)

type db redis.Client

// Returns a connected client to dataset
func Connect() *db {

	cli := redis.NewClient(&redis.Options{
		Addr:     "127.0.0.1:6379",
		Password: "",
		DB:       0,
	})

	if _, err := cli.Ping().Result(); err != nil {
		return nil
	}

	return (*db)(cli)
}

// returns value from key (nil if nothing)
func (c *db) Get(dom Domain, key string) []byte {

	// 1. Try to get
	if val, err := (*redis.Client)(c).Get(fmt.Sprintf("%s:%s:%s", NONCE, dom, key)).Result(); err != nil {
		// 2. nil if nothing found
		return nil
	} else {
		// 3. return if found
		return []byte(val)
	}

}

// stores a value for a key (success state in return)
func (c *db) Set(dom Domain, key string, value string, exp ...time.Duration) bool {

	var expiration time.Duration = 0
	if len(exp) > 0 {
		expiration = exp[0]
	}

	// 1. Try to set
	if (*redis.Client)(c).Set(fmt.Sprintf("%s:%s:%s", NONCE, dom, key), value, expiration).Err() != nil {
		// 2. failure
		return false
	}

	// 3. success
	return true

}

// deletes the value for a key (success state in return)
func (c *db) Del(dom Domain, key string) bool {

	// 1. Try to set
	if (*redis.Client)(c).Del(fmt.Sprintf("%s:%s:%s", NONCE, dom, key)).Err() != nil {
		// 2. failure
		return false
	}

	// 3. success
	return true

}