<?php

/**
 * Namespace for classes and functions related to the game Factorio.
 * @package NAE\Factorio
 */
namespace NAE\Factorio;

/**
 * Class for managing Factorio mods.
 * @author "Marcel Naeve" <php@naeve.info>
 * @license MIT License (http://www.opensource.org/licenses/mit)
 */
class FactorioMod {

    /**
     * @var int INIT_TYPE_PATH - Mod is initialized from a zip file.
     */
    const INIT_TYPE_PATH = 1;

    /**
     * @var int INIT_TYPE_NAME - Mod is initialized from a mod name.
     */
    const INIT_TYPE_NAME = 3;


    /**
     * @var object|null $info - Mod information from Zip file.
     */
    private $info = null;

    /**
     * @var object|null $api - Mod information from Factorio API.
     */
    private $api = null;

    /**
     * @var object|null $mod_settings - Mod settings enabled/disabled from json in mods folder.
     */
    private $mod_settings = null;

    /**
     * @var string|null $mod_folder - Path to the mods folder.
     */
    private $mod_folder = null;

    /**
     * @var string $game_folder - Path to the Factorio game folder.
     */
    private $game_folder = "factorio";


    /**
     * Reads all Mods as FactorioMod objects to an array.
     * @param string $modFolder Path to the mods folder.
     * @return array Array of FactorioMod objects.
     */
    static function readModFolder(string $modFolder) : array {

        $mods = [];

        $dh = opendir($modFolder);                      // open the directory handle

        while ( false !== ($entry = readdir($dh)) ) {   // read directory entries

            if(preg_match("/\.zip$/ui", $entry)) {      // if the file is a zip file

                $mods[] = new FactorioMod(
                    $modFolder. "/". $entry,
                    FactorioMod::INIT_TYPE_PATH
                );

            }

        }

        closedir($dh);                                  // close the directory handle

        return $mods;

    }

    /**
     * Reads mod information from info.json file in mod Zip file.
     * @param string $zipPath Path to the mod Zip file.
     * @return object|null Mod information from info.json file.
     */
    private function readInfo(string $zipPath) : ?object {

        if(!file_exists($zipPath)) {                // file does not exist?
            return null;
        }

        $za = new \ZipArchive();
        $res = $za->open($zipPath);                 // open the zip file

        if($res !== true) {                         // open the zip file failed?
            return null;
        }

        $c = null;
        for( $i = 0; $i < $za->numFiles; $i++ ){    // Iterate over all files in the zip file

            $name = $za->getNameIndex( $i );        // get the name of current file

            if(basename($name) == "info.json") {    // if the file is info.json
                $c = $za->getFromIndex($i);         // get the content of info.json
                $i = $za->numFiles;                 // break the loop by condition
                break;                              // break the loop by force (double tap)
            }

        }

        $za->close();                               // close the zip file

        return json_decode( $c, false );            // return decoded json object or null on failure

    }

    /**
     * Sends a GET request to Factorio API to get mod information.
     * @param string $name Mod name to get information from Factorio API.
     * @return object|null Mod information from Factorio API.
     */
    private function callApi(string $name="") : ?object {

        if($name === "") {              // no name given?
            if($this->info === null) {  // also no path to module for info.json?
                return null;
            }
            $name = $this->info->name;  // get name from info.json
        }

        $api = "https://mods.factorio.com/api/mods/" . $name;

        $curl = curl_init();

        curl_setopt($curl, CURLOPT_URL, $api);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);

        $response = curl_exec($curl);
        $cri = curl_getinfo($curl);

        curl_close($curl);

        if($cri["http_code"] != 200) { // request failed?
            return null;
        }

        if(trim($response) < 1) { // response body empty?
            return null;
        }

        $r = json_decode($response, false); // decode json object or null on failure

        return $r;
    }

    /**
     * Constructor.
     * @param string $init Path to the mod Zip file or mod name.
     * @param int $init_type Initialization type (FactorioMod::INIT_TYPE_PATH or FactorioMod::INIT_TYPE_NAME).
     * @param string $mod_folder Path to the mods folder.
     */
    public function __construct(string $init, int $init_type=self::INIT_TYPE_PATH, string $mod_folder="") {

        if($init_type === self::INIT_TYPE_PATH) {

            $this->info = $this->readInfo($init);
            if($this->info !== null) {
                $this->mod_folder = dirname($init);
                $this->callApi();
            }

        }

        if($init_type === self::INIT_TYPE_NAME) {

            $this->mod_folder = $mod_folder;
            $this->callApi($init);

            // TODO: look if mod is installed..

        }

    }

    /**
     * Returns last release version information of the mod.
     * @return object|null Last release version information of the mod.
     */
    public function getLastVersionInfo() : ?object {

        $target = count($this->api->releases) - 1;

        return $this->api->releases[ $target ];

    }

    /**
     * Checks if the latest release mod version is newer than the installed version.
     * @return bool True if the latest release mod version is newer, false otherwise.
     */
    public function isUpdateable() : bool {

        $lv = new \NAE\Factorio\FactorioVersion(
            $this->getLastVersionInfo()->version
        );

        $cv = new \NAE\Factorio\FactorioVersion(
            $this->info->version
        );

        return $lv->isNewer($cv);

    }

    /**
     * Deletes the mod from the mods folder file.
     * @return bool True if the mod was deleted, false otherwise.
     */
    private function delete() : bool {
        // TODO: implement
        return false;
    }

    /**
     * Downloads the latest release mod version to the mods folder.
     * @return bool True if the mod was downloaded, false otherwise.
     */
    private function download() : bool {
        
        // TODO: continue implementing.. where player-data.json..
        $player_data = json_decode(file_get_contents($this->game_folder. "/player-data.json"), true);
        $token = $player_data["service-token"];
        $username = $player_data["service-username"];

        $url = "https://mods.factorio.com" . $this->getLastVersionInfo()->download_url . "?username=$username&token=$token";

        return false;
    }

    /**
     * Uninstalls the mod from the mods folder and the settings.json file.
     * @return bool True if the mod was uninstalled, false otherwise.
     */
    public function uninstall() : bool {
        // TODO: implement
        return false;
    }

    /**
     * Installs the mod in the mods folder and adds it to the settings.json file as enabled.
     * @return bool True if the mod was installed, false otherwise.
     */
    public function install() : bool {
        // TODO: implement
        return false;
    }

    /**
     * Updates the mod to the latest release mod version.
     * @return bool True if the mod was updated, false otherwise.
     */
    public function update() : bool {
        // TODO: implement
        return false;
    }

    /**
     * Loads the mod settings for all mods (enabled/disabled) from the settings.json file.
     * @return bool True if the mod settings have been loaded successfully, false otherwise.
     */
    private function loadModSettings() : bool {
        
        $this->mod_settings = json_decode(
            file_get_contents($this->mod_folder. "/settings.json")
        );

        return false;
    }

    /**
     * Returns the mod settings for all mods (enabled/disabled) from settings.json.
     * @return object|null Mod settings for all mods.
     */
    public function getModSettings() :?object {
        return $this->mod_settings;
    }

    /**
     * Sets the path to the game folder.
     * @param string $game_folder Path to the game folder.
     * @return FactorioMod The instance of FactorioMod for chaining.
     */
    public function setGameFolder(string $game_folder) : FactorioMod {

        $this->game_folder = $game_folder;
        return $this;

    }

    /**
     * Returns the path to the game folder.
     * @return string Path to the game folder.
     */
    public function getGameFolder() : string {

        return $this->game_folder;

    }

    /**
     * Saves the changes in the mod settings for all mods (enabled/disabled) to the settings.json file.
     * @return bool True if the mod settings have been saved successfully, false otherwise.
     */
    private function saveModSettings() : bool {

        $j = json_encode($this->mod_settings);
        
        $r = file_put_contents($this->mod_folder. "/settings.json", $j);

        if($r === false) {
            return false;
        }

        return ( $r === strlen($j) );

    }

    /**
     * Sets the mod settings for all mods (enabled/disabled) in the settings.json file.
     * @param object $mod_settings Mod settings for all mods.
     * @return FactorioMod The instance of FactorioMod for chaining.
     */
    public function setModSettings(object $mod_settings) : FactorioMod {

        $this->mod_settings = $mod_settings;

        return $this;

    }

    /**
     * Checks if this mod is enabled in the settings.json.
     * @return bool True if this mod is enabled, false otherwise.
     */
    public function isEnabled() : bool {
        // TODO: implement
        return false;
    }

    /**
     * Checks if this mod is disabled in the settings.json.
     * @return bool True if this mod is disabled, false otherwise.
     */
    public function isDisabled() : bool {
        // TODO: implement
        return false;
    }

    /**
     * Sets this mod to enabled in the settings.json
     */
    public function enable() {
        // TODO: implement
    }

    /**
     * Sets this mod to disabled in the settings.json
     */
    public function disable() {
        // TODO: implement
    }

}