<?php
/**
 * @package     Awf
 * @copyright   2014 Nicholas K. Dionysopoulos / Akeeba Ltd
 * @license     GNU GPL version 3 or later
 */

namespace Awf\Text;

use \Awf\Application\Application;

/**
 * Class Text
 *
 * Internationalisation class for Awf applications
 *
 * @package Awf\Text
 */
abstract class Text
{
	/** @var   array  The cache of translation strings */
	private static $strings = array();

	/** @var   array[callable]  Callables to use to process translation strings after laoding them */
	private static $iniProcessCallbacks = array();

	/**
	 * Adds an INI process callback to the stack
	 *
	 * @param   callable $callable The processing callback to add
	 *
	 * @return  void
	 */
	public static function addIniProcessCallback($callable)
	{
		static::$iniProcessCallbacks[] = $callable;
	}

	/**
	 * Loads the language file for a specific language
	 *
	 * @param   string  $langCode     The ISO language code, e.g. en-GB, use null for automatic detection
	 * @param   string  $appName      The name of the application to load translation strings for
	 * @param   string  $suffix       The suffix of the language file, by default it's .ini
	 * @param   boolean $overwrite    Should I overwrite old language strings?
	 * @param   string  $languagePath The base path to the language files (optional)
	 *
	 * @return  void
	 */
	public static function loadLanguage($langCode = null, $appName = null, $suffix = '.ini', $overwrite = true, $languagePath = null)
	{
		if (is_null($langCode))
		{
			$langCode = self::detectLanguage($appName, $suffix, $languagePath);
		}

		if (empty($appName))
		{
			$appName = Application::getInstance()->getName();
		}

		if (empty($languagePath))
		{
			$languagePath = Application::getInstance($appName)->getContainer()->languagePath;
		}

		$fileNames = array(
			// langPath/MyApp/en-GB.ini
			$languagePath . '/' . strtolower($appName) . '/' . $langCode . $suffix,
			// langPath/MyApp/en-GB/en-GB.ini
			$languagePath . '/' . strtolower($appName) . '/' . $langCode . '/' . $langCode . $suffix,
			// langPath/en-GB.ini
			$languagePath . '/' . $langCode . $suffix,
			// langPath/en-GB/en-GB.ini
			$languagePath . '/' . $langCode . '/' . $langCode . $suffix,
		);

		$filename = null;

		foreach ($fileNames as $file)
		{
			if (@file_exists($file))
			{
				$filename = $file;
				break;
			}
		}

		if (is_null($filename))
		{
			return;
		}

		$strings = parse_ini_file($filename);

		if (!empty(static::$iniProcessCallbacks) && !empty($strings))
		{
			foreach (static::$iniProcessCallbacks as $callback)
			{
				$ret = call_user_func($callback, $filename, $strings);

				if ($ret === false)
				{
					return;
				}
				elseif (is_array($ret))
				{
					$strings = $ret;
				}
			}
		}

		if ($overwrite)
		{
			self::$strings = array_merge(self::$strings, $strings);
		}
		else
		{
			self::$strings = array_merge($strings, self::$strings);
		}
	}

	/**
	 * Automatically detect the language preferences from the browser, choosing
	 * the best fit language that exists on our system or falling back to en-GB
	 * when no preferred language exists.
	 *
	 * @param   string $appName      The application's name to load language strings for
	 * @param   string $suffix       The suffix of the language file, by default it's .ini
	 * @param   string $languagePath The base path to the language files (optional)
	 *
	 * @return  string  The language code
	 */
	public static function detectLanguage($appName = null, $suffix = '.ini', $languagePath = null)
	{
		if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE']))
		{
			$languages = strtolower($_SERVER["HTTP_ACCEPT_LANGUAGE"]);
			// $languages = ' fr-ch;q=0.3, da, en-us;q=0.8, en;q=0.5, fr;q=0.3';
			// need to remove spaces from strings to avoid error
			$languages = str_replace(' ', '', $languages);
			$languages = explode(",", $languages);

			// First we need to sort languages by their weight
			$temp = array();

			foreach ($languages as $lang)
			{
				$parts = explode(';', $lang);

				$q = 1;
				if ((count($parts) > 1) && (substr($parts[1], 0, 2) == 'q='))
				{
					$q = floatval(substr($parts[1], 2));
				}

				$temp[$parts[0]] = $q;
			}

			arsort($temp);
			$languages = $temp;

			foreach ($languages as $language => $weight)
			{
				// pull out the language, place languages into array of full and primary
				// string structure:
				$temp_array = array();
				// slice out the part before the dash, place into array
				$temp_array[0] = $language; //full language
				$parts = explode('-', $language);
				$temp_array[1] = $parts[0]; // cut out primary language

				if ((strlen($temp_array[0]) == 5) && ((substr($temp_array[0], 2, 1) == '-') || (substr($temp_array[0], 2, 1) == '_')))
				{
					$langLocation = strtoupper(substr($temp_array[0], 3, 2));
					$temp_array[0] = $temp_array[1] . '-' . $langLocation;
				}

				//place this array into main $user_languages language array
				$user_languages[] = $temp_array;
			}

			if (!isset($user_languages))
			{
				return 'en-GB';
			}

			if (empty($appName))
			{
				$appName = Application::getInstance()->getName();
			}

			if (empty($languagePath))
			{
				$languagePath = Application::getInstance($appName)->getContainer()->languagePath;
			}

			$baseName = $languagePath . '/' . strtolower($appName) . '/';

			if (!@is_dir($baseName))
			{
				$baseName = $languagePath . '/';
			}

			if (!@is_dir($baseName))
			{
				return 'en-GB';
			}

			// Look for classic file layout
			foreach ($user_languages as $languageStruct)
			{
				// Search for exact language
				$langFilename = $baseName . $languageStruct[0] . $suffix;

				if (!file_exists($langFilename))
				{
					$langFilename = '';

					if (function_exists('glob'))
					{
						$allFiles = glob($baseName . $languageStruct[1] . '-*' . $suffix);

						if (count($allFiles))
						{
							$langFilename = array_shift($allFiles);
						}
					}
				}

				if (!empty($langFilename) && file_exists($langFilename))
				{
					return basename($langFilename, $suffix);
				}
			}

			// Look for subdirectory layout
			$allFolders = array();

			try
			{
				$di = new \DirectoryIterator($baseName);
			}
			catch (\Exception $e)
			{
				return 'en-GB';
			}

			/** @var \DirectoryIterator $file */
			foreach ($di as $file)
			{
				if ($di->isDot())
				{
					continue;
				}

				if (!$di->isDir())
				{
					continue;
				}

				$allFolders[] = $file->getFilename();
			}

			foreach ($user_languages as $languageStruct)
			{
				if (array_key_exists($languageStruct[0], $allFolders))
				{
					return $languageStruct[0];
				}

				foreach ($allFolders as $folder)
				{
					if (strpos($folder, $languageStruct[1]) === 0)
					{
						return $folder;
					}
				}
			}
		}

		return 'en-GB';
	}

	/**
	 * Translate a string
	 *
	 * @param   string $key Language key
	 *
	 * @return  string  Translation
	 */
	public static function _($key)
	{
		if (empty(self::$strings))
		{
			self::loadLanguage('en-GB');
			self::loadLanguage();
		}

		$key = strtoupper($key);

		if (array_key_exists($key, self::$strings))
		{
			return self::$strings[$key];
		}
		else
		{
			return $key;
		}
	}

	/**
	 * Passes a string through a sprintf.
	 *
	 * Note that this method can take a mixed number of arguments as for the sprintf function.
	 *
	 * @param   string $string The format string.
	 *
	 * @return  string  The translated strings
	 */
	public static function sprintf($string)
	{
		$args = func_get_args();
		$count = count($args);
		if ($count > 0)
		{
			$args[0] = self::_($string);

			return call_user_func_array('sprintf', $args);
		}

		return '';
	}

	/**
	 * Does a translation key exist?
	 *
	 * @param   string $key The key to check
	 *
	 * @return  boolean
	 */
	public static function hasKey($key)
	{
		if (empty(self::$strings))
		{
			self::loadLanguage('en-GB');
			self::loadLanguage();
		}

		$key = strtoupper($key);

		return array_key_exists($key, self::$strings);
	}
}