<?php

/**
 * Represents a language and defines localizable string formatting and
 * other functions, as well as the localized messages for HTML Purifier.
 */
class HTMLPurifier_Language
{
    
    /**
     * ISO 639 language code of language. Prefers shortest possible version
     */
    public $code = 'en';
    
    /**
     * Fallback language code
     */
    public $fallback = false;
    
    /**
     * Array of localizable messages
     */
    public $messages = array();
    
    /**
     * Array of localizable error codes
     */
    public $errorNames = array();
    
    /**
     * True if no message file was found for this language, so English
     * is being used instead. Check this if you'd like to notify the
     * user that they've used a non-supported language.
     */
    public $error = false;
    
    /**
     * Has the language object been loaded yet?
     * @todo Make it private, fix usage in HTMLPurifier_LanguageTest
     */
    public $_loaded = false;
    
    /**
     * Instances of HTMLPurifier_Config and HTMLPurifier_Context
     */
    protected $config, $context;
    
    public function __construct($config, $context) {
        $this->config  = $config;
        $this->context = $context;
    }
    
    /**
     * Loads language object with necessary info from factory cache
     * @note This is a lazy loader
     */
    public function load() {
        if ($this->_loaded) return;
        $factory = HTMLPurifier_LanguageFactory::instance();
        $factory->loadLanguage($this->code);
        foreach ($factory->keys as $key) {
            $this->$key = $factory->cache[$this->code][$key];
        }
        $this->_loaded = true;
    }
    
    /**
     * Retrieves a localised message.
     * @param $key string identifier of message
     * @return string localised message
     */
    public function getMessage($key) {
        if (!$this->_loaded) $this->load();
        if (!isset($this->messages[$key])) return "[$key]";
        return $this->messages[$key];
    }
    
    /**
     * Retrieves a localised error name.
     * @param $int integer error number, corresponding to PHP's error
     *             reporting
     * @return string localised message
     */
    public function getErrorName($int) {
        if (!$this->_loaded) $this->load();
        if (!isset($this->errorNames[$int])) return "[Error: $int]";
        return $this->errorNames[$int];
    }
    
    /**
     * Converts an array list into a string readable representation
     */
    public function listify($array) {
        $sep      = $this->getMessage('Item separator');
        $sep_last = $this->getMessage('Item separator last');
        $ret = '';
        for ($i = 0, $c = count($array); $i < $c; $i++) {
            if ($i == 0) {
            } elseif ($i + 1 < $c) {
                $ret .= $sep;
            } else {
                $ret .= $sep_last;
            }
            $ret .= $array[$i];
        }
        return $ret;
    }
    
    /**
     * Formats a localised message with passed parameters
     * @param $key string identifier of message
     * @param $args Parameters to substitute in
     * @return string localised message
     * @todo Implement conditionals? Right now, some messages make
     *     reference to line numbers, but those aren't always available
     */
    public function formatMessage($key, $args = array()) {
        if (!$this->_loaded) $this->load();
        if (!isset($this->messages[$key])) return "[$key]";
        $raw = $this->messages[$key];
        $subst = array();
        $generator = false;
        foreach ($args as $i => $value) {
            if (is_object($value)) {
                if ($value instanceof HTMLPurifier_Token) {
                    // factor this out some time
                    if (!$generator) $generator = $this->context->get('Generator');
                    if (isset($value->name)) $subst['$'.$i.'.Name'] = $value->name;
                    if (isset($value->data)) $subst['$'.$i.'.Data'] = $value->data;
                    $subst['$'.$i.'.Compact'] = 
                    $subst['$'.$i.'.Serialized'] = $generator->generateFromToken($value);
                    // a more complex algorithm for compact representation
                    // could be introduced for all types of tokens. This
                    // may need to be factored out into a dedicated class
                    if (!empty($value->attr)) {
                        $stripped_token = clone $value;
                        $stripped_token->attr = array();
                        $subst['$'.$i.'.Compact'] = $generator->generateFromToken($stripped_token);
                    }
                    $subst['$'.$i.'.Line'] = $value->line ? $value->line : 'unknown';
                }
                continue;
            } elseif (is_array($value)) {
                $keys = array_keys($value);
                if (array_keys($keys) === $keys) {
                    // list
                    $subst['$'.$i] = $this->listify($value);
                } else {
                    // associative array
                    // no $i implementation yet, sorry
                    $subst['$'.$i.'.Keys'] = $this->listify($keys);
                    $subst['$'.$i.'.Values'] = $this->listify(array_values($value));
                }
                continue;
            }
            $subst['$' . $i] = $value;
        }
        return strtr($raw, $subst);
    }
    
}

