/*
* @Author: Bartuccio Antoine
* @Date:   2018-07-27 15:37:59
* @Last Modified by:   Bartuccio Antoine
* @Last Modified time: 2019-01-05 17:46:26
 */

package shared

import (
	"encoding/json"
	"fmt"
	"io/ioutil"
	"sync"
)

// General purpose chat info storage
type chatData struct {
	mutex sync.Mutex
	data  map[int64]map[string]interface{}
}

type chatDataFile struct {
	mutex sync.Mutex
	path  string
}

// ChatData manage access to stored data about a chat
var ChatData *chatData
var cdf chatDataFile

// InitChatData is meant to store infos about a chat.
func InitChatData(chatDataFilePath string) {

	cdf = chatDataFile{path: chatDataFilePath}
	ChatData = &chatData{data: make(map[int64]map[string]interface{})}

	ChatData.mutex.Lock()
	defer ChatData.mutex.Unlock()

	cdf.read()

}

// Set stores data about a chat
func (c *chatData) Set(chat int64, key string, data interface{}) {

	c.mutex.Lock()
	defer c.mutex.Unlock()

	if _, exists := c.data[chat]; !exists {
		c.data[chat] = make(map[string]interface{})
	}
	c.data[chat][key] = data
	go cdf.write()
}

// Get retrieves data about a chat
func (c *chatData) Get(chat int64, key string) (interface{}, bool) {

	c.mutex.Lock()
	defer c.mutex.Unlock()

	m, exists := c.data[chat]
	if !exists {
		return nil, false
	}
	data, ok := m[key]
	if !ok {
		return nil, false
	}
	return data, true
}

func (c *chatDataFile) read() {

	c.mutex.Lock()
	defer c.mutex.Unlock()

	data, err := ioutil.ReadFile(c.path)
	if err != nil {
		// File doesn't exist, skip import
		return
	}
	if err := json.Unmarshal(data, &ChatData.data); err != nil {
		fmt.Printf("Error while unmarshaling chat data with path %s, error : %v\n", c.path, err)
	}
}

func (c *chatDataFile) write() {

	c.mutex.Lock()
	defer c.mutex.Unlock()

	ChatData.mutex.Lock()
	defer ChatData.mutex.Unlock()

	data, err := json.Marshal(ChatData.data)
	if err != nil {
		fmt.Printf("Error while marshaling chat data file with path %s, error : %v\n", c.path, err)
		return
	}
	if err := ioutil.WriteFile(c.path, data, 0770); err != nil {
		fmt.Printf("Error writing chat data file with path %s, error %v\n", c.path, err)
	}
}