<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Intl;

use Symfony\Component\Intl\Data\Bundle\Reader\JsonBundleReader;
use Symfony\Component\Intl\Data\Bundle\Reader\BufferedBundleReader;
use Symfony\Component\Intl\Data\Bundle\Reader\BundleEntryReader;
use Symfony\Component\Intl\Data\Bundle\Reader\BundleEntryReaderInterface;
use Symfony\Component\Intl\Data\Provider\ScriptDataProvider;
use Symfony\Component\Intl\ResourceBundle\CurrencyBundle;
use Symfony\Component\Intl\ResourceBundle\CurrencyBundleInterface;
use Symfony\Component\Intl\ResourceBundle\LanguageBundle;
use Symfony\Component\Intl\ResourceBundle\LanguageBundleInterface;
use Symfony\Component\Intl\ResourceBundle\LocaleBundle;
use Symfony\Component\Intl\ResourceBundle\LocaleBundleInterface;
use Symfony\Component\Intl\ResourceBundle\RegionBundle;
use Symfony\Component\Intl\ResourceBundle\RegionBundleInterface;

/**
 * Gives access to internationalization data.
 *
 * @author Bernhard Schussek <bschussek@gmail.com>
 */
final class Intl
{
    /**
     * The number of resource bundles to buffer. Loading the same resource
     * bundle for n locales takes up n spots in the buffer.
     */
    const BUFFER_SIZE = 10;

    /**
     * The directory name of the currency data.
     */
    const CURRENCY_DIR = 'currencies';

    /**
     * The directory name of the language data.
     */
    const LANGUAGE_DIR = 'languages';

    /**
     * The directory name of the script data.
     */
    const SCRIPT_DIR = 'scripts';

    /**
     * The directory name of the locale data.
     */
    const LOCALE_DIR = 'locales';

    /**
     * The directory name of the region data.
     */
    const REGION_DIR = 'regions';

    /**
     * @var ResourceBundle\CurrencyBundleInterface
     */
    private static $currencyBundle;

    /**
     * @var ResourceBundle\LanguageBundleInterface
     */
    private static $languageBundle;

    /**
     * @var ResourceBundle\LocaleBundleInterface
     */
    private static $localeBundle;

    /**
     * @var ResourceBundle\RegionBundleInterface
     */
    private static $regionBundle;

    /**
     * @var string|bool|null
     */
    private static $icuVersion = false;

    /**
     * @var string
     */
    private static $icuDataVersion = false;

    /**
     * @var BundleEntryReaderInterface
     */
    private static $entryReader;

    /**
     * Returns whether the intl extension is installed.
     *
     * @return bool Returns true if the intl extension is installed, false otherwise.
     */
    public static function isExtensionLoaded()
    {
        return class_exists('\ResourceBundle');
    }

    /**
     * Returns the bundle containing currency information.
     *
     * @return CurrencyBundleInterface The currency resource bundle.
     */
    public static function getCurrencyBundle()
    {
        if (null === self::$currencyBundle) {
            self::$currencyBundle = new CurrencyBundle(
                self::getDataDirectory().'/'.Intl::CURRENCY_DIR,
                self::getEntryReader(),
                self::getLocaleBundle()
            );
        }

        return self::$currencyBundle;
    }

    /**
     * Returns the bundle containing language information.
     *
     * @return LanguageBundleInterface The language resource bundle.
     */
    public static function getLanguageBundle()
    {
        if (null === self::$languageBundle) {
            self::$languageBundle = new LanguageBundle(
                self::getDataDirectory().'/'.Intl::LANGUAGE_DIR,
                self::getEntryReader(),
                self::getLocaleBundle(),
                new ScriptDataProvider(
                    self::getDataDirectory().'/'.Intl::SCRIPT_DIR,
                    self::getEntryReader()
                )
            );
        }

        return self::$languageBundle;
    }

    /**
     * Returns the bundle containing locale information.
     *
     * @return LocaleBundleInterface The locale resource bundle.
     */
    public static function getLocaleBundle()
    {
        if (null === self::$localeBundle) {
            self::$localeBundle = new LocaleBundle(
                self::getDataDirectory().'/'.Intl::LOCALE_DIR,
                self::getEntryReader()
            );
        }

        return self::$localeBundle;
    }

    /**
     * Returns the bundle containing region information.
     *
     * @return RegionBundleInterface The region resource bundle.
     */
    public static function getRegionBundle()
    {
        if (null === self::$regionBundle) {
            self::$regionBundle = new RegionBundle(
                self::getDataDirectory().'/'.Intl::REGION_DIR,
                self::getEntryReader(),
                self::getLocaleBundle()
            );
        }

        return self::$regionBundle;
    }

    /**
     * Returns the version of the installed ICU library.
     *
     * @return null|string The ICU version or NULL if it could not be determined.
     */
    public static function getIcuVersion()
    {
        if (false === self::$icuVersion) {
            if (!self::isExtensionLoaded()) {
                self::$icuVersion = self::getIcuStubVersion();
            } elseif (defined('INTL_ICU_VERSION')) {
                self::$icuVersion = INTL_ICU_VERSION;
            } else {
                try {
                    $reflector = new \ReflectionExtension('intl');
                    ob_start();
                    $reflector->info();
                    $output = strip_tags(ob_get_clean());
                    preg_match('/^ICU version (?:=>)?(.*)$/m', $output, $matches);

                    self::$icuVersion = trim($matches[1]);
                } catch (\ReflectionException $e) {
                    self::$icuVersion = null;
                }
            }
        }

        return self::$icuVersion;
    }

    /**
     * Returns the version of the installed ICU data.
     *
     * @return string The version of the installed ICU data.
     */
    public static function getIcuDataVersion()
    {
        if (false === self::$icuDataVersion) {
            self::$icuDataVersion = trim(file_get_contents(self::getDataDirectory().'/version.txt'));
        }

        return self::$icuDataVersion;
    }

    /**
     * Returns the ICU version that the stub classes mimic.
     *
     * @return string The ICU version of the stub classes.
     */
    public static function getIcuStubVersion()
    {
        return '51.2';
    }

    /**
     * Returns the absolute path to the data directory.
     *
     * @return string The absolute path to the data directory
     */
    public static function getDataDirectory()
    {
        return realpath(__DIR__.'/Resources/data');
    }

    /**
     * Returns the cached bundle entry reader.
     *
     * @return BundleEntryReaderInterface The bundle entry reader
     */
    private static function getEntryReader()
    {
        if (null === self::$entryReader) {
            self::$entryReader = new BundleEntryReader(new BufferedBundleReader(
                new JsonBundleReader(),
                self::BUFFER_SIZE
            ));
        }

        return self::$entryReader;
    }

    /**
     * Resets the internal state.
     */
    private static function reset()
    {
        self::$currencyBundle = null;
        self::$languageBundle = null;
        self::$localeBundle = null;
        self::$regionBundle = null;
        self::$icuVersion = false;
        self::$icuDataVersion = false;
        self::$entryReader = null;
    }

    /**
     * This class must not be instantiated.
     */
    private function __construct()
    {
    }
}
