<?php
/**
 * Created by PhpStorm.
 * User: Andrey Mistulov
 * Company: Aristos
 * Date: 14.03.2017
 * Time: 15:25
 */

namespace Prowebcraft;

/**
 * Class Data
 * @package Aristos
 */
class JsonDb extends \Prowebcraft\Dot
{
    protected $db = '';
    protected $data = null;
    protected $config = [];
    // Tentative d'encodage après échec
    const MAX_JSON_ENCODE_ATTEMPTS = 5;
    // Tentative d'écriture après échec
    const MAX_FILE_WRITE_ATTEMPTS = 5;
    // Délais entre deux tentaives
    const RETRY_DELAY_SECONDS = 1;

    public function __construct($config = [])
    {
        $this->config = array_merge([
            'name' => 'data.json',
            'backup' => false,
            'dir' => getcwd()
        ], $config);
        $this->loadData();
        parent::__construct();
    }

    /**
     * Reload data from file
     * @return $this
     */
    public function reload()
    {
        $this->loadData(true);
        return $this;
    }


    /**
     * Set value or array of values to path
     *
     * @param mixed      $key   Path or array of paths and values
     * @param mixed|null $value Value to set if path is not an array
     * @param bool $save Save data to database
     * @return $this
     */
    public function set($key, $value = null, $save = true)
    {
        parent::set($key, $value);
        if ($save)
            $this->save();
        return $this;
    }

    /**
     * Add value or array of values to path
     *
     * @param mixed      $key Path or array of paths and values
     * @param mixed|null $value Value to set if path is not an array
     * @param boolean    $pop Helper to pop out last key if value is an array
     * @param bool       $save    Save data to database
     * @return $this
     */
    public function add($key, $value = null, $pop = false, $save = true)
    {
        parent::add($key, $value, $pop);
        if ($save)
            $this->save();
        return $this;
    }

    /**
     * Delete path or array of paths
     *
     * @param mixed     $key Path or array of paths to delete
     * @param bool      $save Save data to database
     * @return $thisurn $this
     */
    public function delete($key, $save = true)
    {
        parent::delete($key);
        if ($save)
            $this->save();
        return $this;
    }

    /**
     * Delete all data, data from path or array of paths and
     * optionally format path if it doesn't exist
     *
     * @param mixed|null $key Path or array of paths to clean
     * @param boolean    $format Format option
     * @param bool       $save Save data to database
     * @return $this
     */
    public function clear($key = null, $format = false, $save = true)
    {
        parent::clear($key, $format);
        if ($save)
            $this->save();
        return $this;
    }


    /**
     * Local database upload
     * @param bool $reload Reboot data?
     * @return array|mixed|null
     */
    protected function loadData($reload = false)
    {
        if ($this->data === null || $reload) {
            $this->db = $this->config['dir'] . $this->config['name'];
            if (!file_exists($this->db)) {
                return null; // Rebuild database manage by CMS
            } else {
                if ($this->config['backup']) {
                    try {
                        copy($this->config['dir'] . DIRECTORY_SEPARATOR . $this->config['name'], $this->config['dir'] . DIRECTORY_SEPARATOR . $this->config['name'] . '.backup');
                    } catch (\Exception $e) {
                        error_log('Erreur de chargement : ' . $e);
                        exit('Erreur de chargement : ' . $e);
                    }
                }
            }
            $this->data = json_decode(file_get_contents($this->db), true);
            if (!$this->data === null) {
                throw new \InvalidArgumentException('Database file ' . $this->db
                    . ' contains invalid json object. Please validate or remove file');
            }
        }
        return $this->data;
    }

    /**
     * Save database
     */
    public function save()
    {
        $jsonOptions = JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT | JSON_FORCE_OBJECT;
        $jsonData = json_encode($this->data, $jsonOptions);

        $attempts = 0;
        while ($attempts < self::MAX_JSON_ENCODE_ATTEMPTS) {
            if ($jsonData !== false) {
                break; // Sortir de la boucle si l'encodage réussit
            }
            $attempts++;
            error_log('Erreur d\'encodage JSON (tentative ' . $attempts . ') : ' . json_last_error_msg());
            $jsonData = json_encode($this->data, $jsonOptions); // Réessayer l'encodage
            sleep(self::RETRY_DELAY_SECONDS); // Attendre avant de réessayer
        }

        if ($jsonData === false) {
            error_log('Impossible d\'encoder les données en format JSON.');
            return false;
        }
        $lockHandle = fopen($this->db, 'r+');

        if (flock($lockHandle, LOCK_EX)) {
            $attempts = 0;
            $bytesWritten = false;
            while ($attempts < self::MAX_FILE_WRITE_ATTEMPTS && $bytesWritten === false) {
                ftruncate($lockHandle, 0); // Vide le fichier
                rewind($lockHandle); // Remet le pointeur au début du fichier
                $bytesWritten = fwrite($lockHandle, $jsonData);
                if ($bytesWritten === false) {
                    $attempts++;
                    error_log('Erreur d\'écriture (tentative ' . $attempts . ') : impossible de sauvegarder les données.');
                    sleep(self::RETRY_DELAY_SECONDS); // Attendre avant de réessayer
                }
            }
            flock($lockHandle, LOCK_UN); // Libérer le verrouillage
            fclose($lockHandle); // Fermer le fichier
        
            if ($bytesWritten === false || $bytesWritten != strlen($jsonData)) {
                error_log('Erreur d\'écriture, les données n\'ont pas été sauvegardées.');
                return false;
            }
        } else {
            error_log('Impossible d\'obtenir un verrouillage sur le fichier de base de données.');
            fclose($lockHandle); // Fermer le fichier
            return false;
        }
        return true;
        
        
    }
}