rss-bridge/lib/BridgeAbstract.php

<?php
require_once(__DIR__ . '/BridgeInterface.php');
abstract class BridgeAbstract implements BridgeInterface {

    const NAME = 'Unnamed bridge';
    const URI = '';
    const DESCRIPTION = 'No description provided';
    const MAINTAINER = 'No maintainer';
    const PARAMETERS = array();

    public $useProxy = true;

    protected $cache;
    protected $items = array();
    protected $inputs = array();
    protected $queriedContext = '';

    protected function returnError($message, $code){
        throw new \HttpException($message, $code);
    }

    protected function returnClientError($message){
        $this->returnError($message, 400);
    }

    protected function returnServerError($message){
        $this->returnError($message, 500);
    }

    /**
    * Return items stored in the bridge
    * @return mixed
    */
    public function getItems(){
        return $this->items;
    }

    protected function validateTextValue($value, $pattern = null){
        if(!is_null($pattern)){
            $filteredValue = filter_var($value, FILTER_VALIDATE_REGEXP,
                array('options' => array(
                    'regexp' => '/^' . $pattern . '$/'
                ))
            );
        } else {
            $filteredValue = filter_var($value);
        }

        if($filteredValue === false)
            return null;

        return $filteredValue;
    }

    protected function validateNumberValue($value){
        $filteredValue = filter_var($value, FILTER_VALIDATE_INT);

        if($filteredValue === false && !empty($value))
            return null;

        return $filteredValue;
    }

    protected function validateCheckboxValue($value){
        $filteredValue = filter_var($value, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE);

        if(is_null($filteredValue))
            return null;

        return $filteredValue;
    }

    protected function validateListValue($value, $expectedValues){
        $filteredValue = filter_var($value);

        if($filteredValue === false)
            return null;

        if(!in_array($filteredValue, $expectedValues)){ // Check sub-values?
            foreach($expectedValues as $subName => $subValue){
                if(is_array($subValue) && in_array($filteredValue, $subValue))
                    return $filteredValue;
            }
            return null;
        }

        return $filteredValue;
    }

    protected function validateData(&$data){
        if(!is_array($data))
            return false;

        foreach($data as $name=>$value){
            $registered = false;
            foreach(static::PARAMETERS as $context=>$set){
                if(array_key_exists($name,$set)){
                    $registered = true;
                    if(!isset($set[$name]['type'])){
                        $set[$name]['type']='text';
                    }

                    switch($set[$name]['type']){
                    case 'number':
                        $data[$name] = $this->validateNumberValue($value);
                        break;
                    case 'checkbox':
                        $data[$name] = $this->validateCheckboxValue($value);
                        break;
                    case 'list':
                        $data[$name] = $this->validateListValue($value, $set[$name]['values']);
                        break;
                    default:
                    case 'text':
                        if(isset($set[$name]['pattern'])){
                            $data[$name] = $this->validateTextValue($value, $set[$name]['pattern']);
                        } else {
                            $data[$name] = $this->validateTextValue($value);
                        }
                        break;
                    }

                    if(is_null($data[$name])){
                        echo 'Parameter \'' . $name . '\' is invalid!' . PHP_EOL;
                        return false;
                    }
                }
            }

            if(!$registered)
                return false;
        }

        return true;
    }

    protected function setInputs(array $inputs, $queriedContext){
        // Import and assign all inputs to their context
        foreach($inputs as $name => $value){
            foreach(static::PARAMETERS as $context => $set){
                if(array_key_exists($name, static::PARAMETERS[$context])){
                    $this->inputs[$context][$name]['value'] = $value;
                }
            }
        }

        // Apply default values to missing data
        $contexts = array($queriedContext);
        if(array_key_exists('global', static::PARAMETERS)){
            $contexts[] = 'global';
        }

        foreach($contexts as $context){
            foreach(static::PARAMETERS[$context] as $name => $properties){
                if(isset($this->inputs[$context][$name]['value'])){
                    continue;
                }

                $type = isset($properties['type']) ? $properties['type'] : 'text';

                switch($type){
                case 'checkbox':
                    if(!isset($properties['defaultValue'])){
                        $this->inputs[$context][$name]['value'] = false;
                    } else {
                        $this->inputs[$context][$name]['value'] = $properties['defaultValue'];
                    }
                    break;
                case 'list':
                    if(!isset($properties['defaultValue'])){
                        $firstItem = reset($properties['values']);
                        if(is_array($firstItem)){
                            $firstItem = reset($firstItem);
                        }
                        $this->inputs[$context][$name]['value'] = $firstItem;
                    } else {
                        $this->inputs[$context][$name]['value'] = $properties['defaultValue'];
                    }
                    break;
                default:
                    if(isset($properties['defaultValue'])){
                        $this->inputs[$context][$name]['value'] = $properties['defaultValue'];
                    }
                    break;
                }
            }
        }

        // Copy global parameter values to the guessed context
        if(array_key_exists('global', static::PARAMETERS)){
            foreach(static::PARAMETERS['global'] as $name => $properties){
                if(isset($inputs[$name])){
                    $value = $inputs[$name];
                } elseif (isset($properties['value'])){
                    $value = $properties['value'];
                } else {
                    continue;
                }
                $this->inputs[$queriedContext][$name]['value'] = $value;
            }
        }

        // Only keep guessed context parameters values
        if(isset($this->inputs[$queriedContext])){
            $this->inputs = array($queriedContext => $this->inputs[$queriedContext]);
        } else {
            $this->inputs = array();
        }
    }

    protected function getQueriedContext(array $inputs){
        $queriedContexts=array();
        foreach(static::PARAMETERS as $context=>$set){
            $queriedContexts[$context]=null;
            foreach($set as $id=>$properties){
                if(isset($inputs[$id]) && !empty($inputs[$id])){
                    $queriedContexts[$context]=true;
                }elseif(isset($properties['required']) &&
                    $properties['required']===true){
                    $queriedContexts[$context]=false;
                    break;
                }
            }
        }

        if(array_key_exists('global',static::PARAMETERS) &&
            $queriedContexts['global']===false){
            return null;
        }
        unset($queriedContexts['global']);

        switch(array_sum($queriedContexts)){
        case 0:
            foreach($queriedContexts as $context=>$queried){
                if (is_null($queried)){
                    return $context;
                }
            }
            return null;
        case 1: return array_search(true,$queriedContexts);
        default: return false;
        }
    }

    /**
    * Defined datas with parameters depending choose bridge
    * Note : you can define a cache with "setCache"
    * @param array array with expected bridge paramters
    */
    public function setDatas(array $inputs){
        if(!is_null($this->cache)){
            $this->cache->prepare($inputs);
            $time = $this->cache->getTime();
            if($time !== false && (time() - $this->getCacheDuration() < $time)){
                $this->items = $this->cache->loadData();
                return;
            }
        }

        if(empty(static::PARAMETERS)){
            if(!empty($inputs)){
                $this->returnClientError('Invalid parameters value(s)');
            }

            $this->collectData();
            if(!is_null($this->cache)){
                $this->cache->saveData($this->getItems());
            }
            return;
        }

        if(!$this->validateData($inputs)){
            $this->returnClientError('Invalid parameters value(s)');
        }

        // Guess the paramter context from input data
        $this->queriedContext = $this->getQueriedContext($inputs);
        if(is_null($this->queriedContext)){
            $this->returnClientError('Required parameter(s) missing');
        } elseif($this->queriedContext === false){
            $this->returnClientError('Mixed context parameters');
        }

        $this->setInputs($inputs, $this->queriedContext);

        $this->collectData();

        if(!is_null($this->cache)){
            $this->cache->saveData($this->getItems());
        }
    }

    function getInput($input){
        if(!isset($this->inputs[$this->queriedContext][$input]['value'])){
            return null;
        }
        return $this->inputs[$this->queriedContext][$input]['value'];
    }

    public function getName(){
        return static::NAME;
    }

    public function getURI(){
        return static::URI;
    }

    public function getCacheDuration(){
        return 3600;
    }

    public function setCache(\CacheAbstract $cache){
        $this->cache = $cache;
    }

    public function debugMessage($text){
        if(!file_exists('DEBUG')) {
            return;
        }

        $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 3);
        $calling = $backtrace[2];
        $message = $calling['file'] . ':'
        . $calling['line'] . ' class '
        . get_class($this) . '->'
        . $calling['function'] . ' - '
        . $text;

        error_log($message);
    }

    protected function getContents($url
    , $use_include_path = false
    , $context = null
    , $offset = 0
    , $maxlen = null){
        $contextOptions = array(
            'http' => array(
                'user_agent' => ini_get('user_agent')
            ),
        );

        if(defined('PROXY_URL') && $this->useProxy){
            $contextOptions['http']['proxy'] = PROXY_URL;
            $contextOptions['http']['request_fulluri'] = true;

            if(is_null($context)){
                $context = stream_context_create($contextOptions);
            } else {
                $prevContext=$context;
                if(!stream_context_set_option($context, $contextOptions)){
                    $context = $prevContext;
                }
            }
        }

        if(is_null($maxlen)){
            $content = @file_get_contents($url, $use_include_path, $context, $offset);
        } else {
            $content = @file_get_contents($url, $use_include_path, $context, $offset, $maxlen);
        }

        if($content === false)
            $this->debugMessage('Cant\'t download ' . $url);

        return $content;
    }

    protected function getSimpleHTMLDOM($url
    , $use_include_path = false
    , $context = null
    , $offset = 0
    , $maxLen = null
    , $lowercase = true
    , $forceTagsClosed = true
    , $target_charset = DEFAULT_TARGET_CHARSET
    , $stripRN = true
    , $defaultBRText = DEFAULT_BR_TEXT
    , $defaultSpanText = DEFAULT_SPAN_TEXT){
      $content = $this->getContents($url, $use_include_path, $context, $offset, $maxLen);
      return str_get_html($content
      , $lowercase
      , $forceTagsClosed
      , $target_charset
      , $stripRN
      , $defaultBRText
      , $defaultSpanText);
    }

    /**
     * Maintain locally cached versions of pages to avoid multiple downloads.
     * @param url url to cache
     * @param duration duration of the cache file in seconds (default: 24h/86400s)
     * @return content of the file as string
     */
    public function getSimpleHTMLDOMCached($url
    , $duration = 86400
    , $use_include_path = false
    , $context = null
    , $offset = 0
    , $maxLen = null
    , $lowercase = true
    , $forceTagsClosed = true
    , $target_charset = DEFAULT_TARGET_CHARSET
    , $stripRN = true
    , $defaultBRText = DEFAULT_BR_TEXT
    , $defaultSpanText = DEFAULT_SPAN_TEXT){
        $this->debugMessage('Caching url ' . $url . ', duration ' . $duration);

        $filepath = __DIR__ . '/../cache/pages/' . sha1($url) . '.cache';
        $this->debugMessage('Cache file ' . $filepath);

        if(file_exists($filepath) && filectime($filepath) < time() - $duration){
            unlink ($filepath);
            $this->debugMessage('Cached file deleted: ' . $filepath);
        }

        if(file_exists($filepath)){
            $this->debugMessage('Loading cached file ' . $filepath);
            touch($filepath);
            $content = file_get_contents($filepath);
        } else {
            $this->debugMessage('Caching ' . $url . ' to ' . $filepath);
            $dir = substr($filepath, 0, strrpos($filepath, '/'));

            if(!is_dir($dir)){
                $this->debugMessage('Creating directory ' . $dir);
                mkdir($dir, 0777, true);
            }

            $content = $this->getContents($url, $use_include_path, $context, $offset, $maxLen);
            if($content !== false){
                file_put_contents($filepath, $content);
            }
        }

        return str_get_html($content
        , $lowercase
        , $forceTagsClosed
        , $target_charset
        , $stripRN
        , $defaultBRText
        , $defaultSpanText);
    }
}