<?php

namespace App;

use App\Blogs\Blogs;
use App\Utils\Debug;

class Cache {

    static $pathCacheDir = [
        'feed' => __DIR__ . '/../cache/feed',
        'page' => __DIR__ . '/../cache/page',
        'home' => __DIR__ . '/../cache/page',
        'post' => __DIR__ . '/../cache/post',
        'posts' => __DIR__ . '/../cache/posts',
        'dev'  => __DIR__ . '/../cache/page'
    ];
    static $fileDir = __DIR__ . '/../datas';
    static $templateDir = '../template';

    /**
     * Checks if a cache file exists for the given request URL
     *
     * @param string $requestUrl The requested URL to check for a cached version
     * @param string $cacheDir The directory where the cache is stored, defaults to 'page'
     * @return bool Returns true if the cache file exists; otherwise, false
     */
    static function isCache(array $params): bool {
        if (file_exists(self::$pathCacheDir[$params['type']] . '/' . $params['cacheName'])) {
            return true;
        }
        return false;
    }

    /**
     * Checks if the page is valid based on the modification times of the markdown and cache files
     *
     * @param array $params An associative array
     * @return bool Returns true if the cached page is still valid; otherwise, false
     */
    static function isValidPage(array $params, string $theme): bool {
        $mdModifiedTime = 0;
        // @todo add test if file exist
        if ($params['type'] === 'home') {
            $mdModifiedTime = filemtime(self::$templateDir . '/'.$theme.'/home.php');
        } elseif ($params['type'] === 'post') {
            $postList = new Blogs($params);
            $postAttr = $postList->returnPostInfo($params['slug']);
            if (isset($postAttr['file']) && file_exists($postAttr['file'])) {
                $mdModifiedTime = filemtime($postAttr['file']);
            } else {
                return false;
            }
        } elseif ($params['type'] === 'posts') {
            $mdModifiedTime = 0;
        } elseif (file_exists(self::$fileDir . '/' . $params['type'] . 's' . $params['requestUrl'] . '.md')) {
            $mdModifiedTime = filemtime(self::$fileDir . '/' . $params['type'] . 's' . $params['requestUrl'] . '.md');
        }
        $cacheModifiedTime = filemtime(self::$pathCacheDir[$params['type']] . '/' . $params['cacheName']);

        if ($mdModifiedTime > $cacheModifiedTime) {
            return false;
        }
        return true;
    }

    /**
     * Checks if the feed is valid based on the feed's last modified timestamp 
     * and the cache file's modified time
     *
     * @param string $feedName The name of the feed
     * @param int $feedTimestamp The last modified timestamp of the feed
     * @return bool
     */
    static function isValidFeed(string $feedName, int $feedTimestamp): bool {
        $feedName = $feedName;

        if (file_exists(self::$pathCacheDir['feed'] . '/' . $feedName . '.html')) {
            $cacheModifiedTime = filemtime(self::$pathCacheDir['feed'] . '/' . $feedName . '.html');
            if ($cacheModifiedTime > $feedTimestamp) {
                return true;
            }
        }
        return false;
    }

    /**
     * Validates the API by checking if the cache file exists and if its hash
     * matches the provided API hash
     *
     * @param string $apiName The name of the API
     * @param string $apiHash Hash of the API data
     * @return bool
     */
    static function isValidApi(string $apiName, string $apiHash): bool {
        $apiName = $apiName;

        if (file_exists(self::$pathCacheDir['feed'] . '/' . $apiName . '.html')) {
            $cacheHashFile = sha1_file(self::$pathCacheDir['feed'] . '/' . $apiName . '.html');

            if ($cacheHashFile === $apiHash) {
                return true;
            }
        }
        return false;
    }

    /**
     * Validates the API by checking if the cache file exists and if its hash
     * matches the provided API hash
     *
     * @param string $apiName The name of the API
     * @param string $apiHash Hash of the API data
     * @return bool
     */
    static function isValidConfig(): bool {
        if (file_exists(__DIR__ . '/../datas/config.json')) {
            $configLastMod = filemtime(__DIR__ . '/../datas/config.json');
            if (file_exists(self::$pathCacheDir['home'] . '/home.html') && filemtime(self::$pathCacheDir['home'] . '/home.html') > $configLastMod) {
                return true;
            }
        }

        Cache::clearCache('posts');
        Cache::clearCache('post');
        Cache::clearCache('page');
        Cache::clearCache('feed');

        return false;
    }

    /**
     * Retrieves the contents of a cached file for the given request URL
     *
     * @param string $cacheName The requested URL to retrieve the cached content for
     * @param string $cacheDir The directory where the cache is stored'
     * @return string The contents of the cached file
     */
    static function getCache(string $cacheName, string $cacheDir = 'page'): ?string {
        $cacheFilename = self::$pathCacheDir[$cacheDir] . '/' . $cacheName;
        if (file_exists($cacheFilename)) {
            return file_get_contents($cacheFilename);
        }
        return null;
    }

    /**
     * Stores the given HTML content in a cache file for the specified request URL
     *
     * @param string $cacheName The requested URL
     * @param string $htmlPage The HTML content to be cached
     * @param string $cacheDir The directory where the cache will be stored
     * @return void
     */
    static function setCache(string $cacheName, string $htmlPage, string $cacheDir = 'page'): void {
        file_put_contents(self::$pathCacheDir[$cacheDir] . '/' . $cacheName, $htmlPage);
    }

    /**
     * Clears all HTML cache files in the specified cache directory
     *
     * @return void
     */
    static function clearCache($type): void {
        array_map('unlink', glob(self::$pathCacheDir[$type] . "/*.html"));
    }

    /**
     * Deletes the cache file for the specified request URL
     *
     * @param string $cacheName The URL for unvalidate cache
     * @param string $cacheDir The directory where the cache is stored
     * @return void
     */
    static function unValidateCache(string $cacheName, string $cacheDir = 'page'): void {
        if (file_exists(self::$pathCacheDir[$cacheDir] . '/' . $cacheName)) {
            unlink(self::$pathCacheDir[$cacheDir] . '/' . $cacheName);
        }
    }
}