Intl.php

<?php
/*
    This file is part of Erebot, a modular IRC bot written in PHP.

    Copyright © 2010 François Poirotte

    Erebot is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Erebot is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with Erebot.  If not, see <http://www.gnu.org/licenses/>.
*/

namespace Erebot;

class Intl implements \Erebot\IntlInterface
{
    const EXPIRE_CACHE = 60;

    static protected $cache = array();

    protected $locales;

    protected $component;

    public function __construct($component)
    {
        $this->locales = array();
        $categories = array(
            self::LC_CTYPE,
            self::LC_NUMERIC,
            self::LC_TIME,
            self::LC_COLLATE,
            self::LC_MONETARY,
            self::LC_MESSAGES,
            self::LC_PAPER,
            self::LC_NAME,
            self::LC_ADDRESS,
            self::LC_TELEPHONE,
            self::LC_MEASUREMENT,
            self::LC_IDENTIFICATION,
        );
        foreach ($categories as $category) {
            $this->locales[$category] = "en_US";
        }
        $this->component = $component;
    }

    public static function nameToCategory($name)
    {
        $categories = array_flip(
            array(
                self::LC_CTYPE          => 'LC_CTYPE',
                self::LC_NUMERIC        => 'LC_NUMERIC',
                self::LC_TIME           => 'LC_TIME',
                self::LC_COLLATE        => 'LC_COLLATE',
                self::LC_MONETARY       => 'LC_MONETARY',
                self::LC_MESSAGES       => 'LC_MESSAGES',
                self::LC_PAPER          => 'LC_PAPER',
                self::LC_NAME           => 'LC_NAME',
                self::LC_ADDRESS        => 'LC_ADDRESS',
                self::LC_TELEPHONE      => 'LC_TELEPHONE',
                self::LC_MEASUREMENT    => 'LC_MEASUREMENT',
                self::LC_IDENTIFICATION => 'LC_IDENTIFICATION',
            )
        );
        if (!isset($categories[$name])) {
            throw new \InvalidArgumentException('Invalid category name');
        }
        return $categories[$name];
    }

    public static function categoryToName($category)
    {
        $categories = array(
            self::LC_CTYPE          => 'LC_CTYPE',
            self::LC_NUMERIC        => 'LC_NUMERIC',
            self::LC_TIME           => 'LC_TIME',
            self::LC_COLLATE        => 'LC_COLLATE',
            self::LC_MONETARY       => 'LC_MONETARY',
            self::LC_MESSAGES       => 'LC_MESSAGES',
            self::LC_PAPER          => 'LC_PAPER',
            self::LC_NAME           => 'LC_NAME',
            self::LC_ADDRESS        => 'LC_ADDRESS',
            self::LC_TELEPHONE      => 'LC_TELEPHONE',
            self::LC_MEASUREMENT    => 'LC_MEASUREMENT',
            self::LC_IDENTIFICATION => 'LC_IDENTIFICATION',
        );
        if (!isset($categories[$category])) {
            throw new \InvalidArgumentException('Invalid category');
        }
        return $categories[$category];
    }

    public function getLocale($category)
    {
        if (!isset($this->locales[$category])) {
            throw new \InvalidArgumentException('Invalid category');
        }
        return $this->locales[$category];
    }

    private function getBaseDir($component)
    {
        $reflector = new \ReflectionClass($component);
        $parts = explode(DIRECTORY_SEPARATOR, $reflector->getFileName());
        do {
            $last = array_pop($parts);
        } while ($last !== 'src' && count($parts));
        $parts[] = 'data';
        $parts[] = 'i18n';
        $base = implode(DIRECTORY_SEPARATOR, $parts);
        return $base;
    }

    public function setLocale($category, $candidates)
    {
        $categoryName = self::categoryToName($category);
        if (!is_array($candidates)) {
            $candidates = array($candidates);
        }
        if (!count($candidates)) {
            throw new \InvalidArgumentException('Invalid locale');
        }

        $base = $this->getBaseDir($this->component);
        $newLocale = null;
        foreach ($candidates as $candidate) {
            if (!is_string($candidate)) {
                throw new \InvalidArgumentException('Invalid locale');
            }

            $locale = \Locale::parseLocale($candidate);
            if (!is_array($locale) || !isset($locale['language'])) {
                throw new \InvalidArgumentException('Invalid locale');
            }

            // For anything else than LC_MESSAGES,
            // we take the first candidate as is.
            if ($categoryName != 'LC_MESSAGES') {
                $newLocale = $candidate;
            }

            if ($newLocale !== null) {
                continue;
            }

            $catalog = str_replace('\\', '_', ltrim($this->component, '\\'));
            if (isset($locale['region'])) {
                $normLocale = $locale['language'] . '_' . $locale['region'];
                $file = $base .
                        DIRECTORY_SEPARATOR . $normLocale .
                        DIRECTORY_SEPARATOR . $categoryName .
                        DIRECTORY_SEPARATOR . $catalog;

                if (file_exists($file . '.mo')) {
                    $newLocale = $normLocale;
                    continue;
                }

                if (file_exists($file . '.po')) {
                    $newLocale = $normLocale;
                    continue;
                }
            }

            $file = $base .
                DIRECTORY_SEPARATOR . $locale['language'] .
                DIRECTORY_SEPARATOR . $categoryName .
                DIRECTORY_SEPARATOR . $catalog;

            if (file_exists($file . '.mo')) {
                $newLocale = $locale['language'];
                continue;
            }

            if (file_exists($file . '.po')) {
                $newLocale = $locale['language'];
                continue;
            }
        }

        if ($newLocale === null) {
            $newLocale = 'en_US';
        }
        $this->locales[$category] = $newLocale;
        return $newLocale;
    }

    protected function getTranslation($component, $message)
    {
        $time = time();
        $locale = $this->locales[self::LC_MESSAGES];
        if (!isset(self::$cache[$component][$locale]) ||
            $time > (self::$cache[$component][$locale]['added'] + self::EXPIRE_CACHE)) {
            if (isset(self::$cache[$component][$locale]['file'])) {
                $file = self::$cache[$component][$locale]['file'];
            } else {
                try {
                    $file = $this->getBaseDir($component);
                } catch (Exception $e) {
                    return null;
                }

                $catalog = str_replace('\\', '_', ltrim($component, '\\'));
                $file .=    DIRECTORY_SEPARATOR . $locale .
                            DIRECTORY_SEPARATOR . 'LC_MESSAGES' .
                            DIRECTORY_SEPARATOR . $catalog . '.mo';

                if (!file_exists($file)) {
                    $file = substr($file, 0, -3) . '.po';
                }

                if (!file_exists($file)) {
                    return null;
                }
            }

            $oldErrorReporting = error_reporting(E_ERROR);

            if (version_compare(PHP_VERSION, '5.3.0', '>=')) {
                clearstatcache(false, $file);
            } else {
                clearstatcache();
            }

            $mtime = false;
            if ($file !== false) {
                $mtime = filemtime($file);
            }

            if ($mtime === false) {
                // We also cache failures to avoid
                // harassing the CPU too much.
                self::$cache[$component][$locale] = array(
                    'mtime'     => $time,
                    'string'    => array(),
                    'added'     => $time,
                    'file'      => false,
                );
            } elseif (!isset(self::$cache[$component][$locale]) ||
                $mtime !== self::$cache[$component][$locale]['mtime']) {
                $parser = \File_Gettext::factory(substr($file, -2), $file);
                $parser->load();
                self::$cache[$component][$locale] = array(
                    'mtime'     => $mtime,
                    'strings'   => $parser->strings,
                    'added'     => $time,
                    'file'      => $file,
                );
            }
            error_reporting($oldErrorReporting);
        }

        if (isset(self::$cache[$component][$locale]['strings'][$message])) {
            return self::$cache[$component][$locale]['strings'][$message];
        }
        return null;
    }

    protected function reallyGetText($message, $component)
    {
        $translation = $this->getTranslation(
            $component,
            $message
        );
        return (!strlen($translation)) ? $message : $translation;
    }

    public function gettext($message)
    {
        return $this->reallyGetText($message, $this->component);
    }

    public function _($message)
    {
        return $this->reallyGetText($message, $this->component);
    }

    public static function clearCache()
    {
        self::$cache = array();
    }
}