<?php
error_reporting(E_ALL);
ini_set('display_errors', '1');

// igdb.php

require_once __DIR__ . '/igdb-settings.php';

if (!defined('WIKI_DE_API_URL')) {
    define('WIKI_DE_API_URL', 'https://de.wikipedia.org/w/api.php');
}

if (!defined('WIKI_USER_AGENT')) {
    define('WIKI_USER_AGENT', 'MultimediaFlutter/1.0 (https://windesign.at; Herwig.Birke@windesign.at)');
}

header('Content-Type: application/json; charset=utf-8');

// =====================================================
//  CORS HANDLING
// =====================================================

function origin_allowed(string $origin): bool
{
    if (!defined('IGDB_ALLOWED_ORIGINS')) {
        return false;
    }

    foreach (IGDB_ALLOWED_ORIGINS as $allowed) {

        // Wildcards verarbeiten: *.domain.tld oder localhost:*
        if (strpos($allowed, '*') !== false) {
            $pattern = '#^' . str_replace(
                ['*', '.', ':'],
                ['.*', '\.', '\:'],
                $allowed
            ) . '$#i';

            if (preg_match($pattern, $origin)) {
                return true;
            }
        } else {
            if (strcasecmp($allowed, $origin) === 0) {
                return true;
            }
        }
    }

    return false;
}

// Set CORS headers if origin matches
$origin = $_SERVER['HTTP_ORIGIN'] ?? null;
if ($origin && origin_allowed($origin)) {
    header('Access-Control-Allow-Origin: ' . $origin);
    header('Vary: Origin');
}
header('Access-Control-Allow-Methods: GET, POST, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type, Authorization, X-Requested-With');

// Preflight
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') {
    http_response_code(204);
    exit;
}

// =====================================================
//  HELPERS
// =====================================================

function respond($data, int $status = 200): void
{
    http_response_code($status);
    echo json_encode($data, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT);
    exit;
}

function error_response($msg, int $status = 400): void
{
    if (is_string($msg)) {
        $msg = ['error' => $msg];
    }
    respond($msg, $status);
}

// =====================================================
//  DATABASE
// =====================================================

function getDb(): PDO
{
    static $pdo = null;
    if ($pdo !== null) {
        return $pdo;
    }

    $dsn = sprintf(
        'mysql:host=%s;dbname=%s;charset=utf8mb4',
        DATABASE_HOST,
        DATABASE_NAME
    );

    try {
        $pdo = new PDO($dsn, DATABASE_USER, DATABASE_PASSWORD, [
            PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
            PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
        ]);
    } catch (PDOException $e) {
        error_response('DB connection failed: ' . $e->getMessage(), 500);
    }

    return $pdo;
}

// =====================================================
//  LOCALIZATION SUPPORT (Tabelle igdb_localizations)
// =====================================================

function getLocalization(int $igdbId, string $lang = 'de'): ?array
{
    $pdo = getDb();
    $stmt = $pdo->prepare(
        'SELECT * FROM igdb_localizations WHERE igdb_id = :id AND lang = :lang LIMIT 1'
    );
    $stmt->execute([
        ':id'   => $igdbId,
        ':lang' => $lang,
    ]);
    $row = $stmt->fetch();
    return $row ?: null;
}

function saveLocalization(
    int $igdbId,
    string $lang,
    ?string $title,
    ?string $summary,
    ?string $storyline,
    ?int $userId
): array {
    $pdo = getDb();

    $sql = '
        INSERT INTO igdb_localizations (igdb_id, lang, title, summary, storyline, user_id)
        VALUES (:id, :lang, :title, :summary, :storyline, :user_id)
        ON DUPLICATE KEY UPDATE
            title = VALUES(title),
            summary = VALUES(summary),
            storyline = VALUES(storyline),
            user_id = VALUES(user_id),
            updated_at = CURRENT_TIMESTAMP
    ';

    $stmt = $pdo->prepare($sql);
    $stmt->execute([
        ':id'        => $igdbId,
        ':lang'      => $lang,
        ':title'     => $title,
        ':summary'   => $summary,
        ':storyline' => $storyline,
        ':user_id'   => $userId,
    ]);

    return getLocalization($igdbId, $lang);
}

// =====================================================
//  GAMES IN MULTIMEDIAFLUTTER (Tabelle game)
// =====================================================

function saveGameStatus(
    int $igdbId,
    string $name,
    ?string $originalName,
    int $status,
    ?string $note = null
): array {
    $pdo = getDb();

    $sql = '
        INSERT INTO game (igdb_id, name, original_name, status, note)
        VALUES (:igdb_id, :name, :original_name, :status, :note)
        ON DUPLICATE KEY UPDATE
            name = VALUES(name),
            original_name = VALUES(original_name),
            status = VALUES(status),
            note = VALUES(note),
            updated_at = CURRENT_TIMESTAMP
    ';

    $stmt = $pdo->prepare($sql);
    $stmt->execute([
        ':igdb_id'      => $igdbId,
        ':name'         => $name,
        ':original_name'=> $originalName,
        ':status'       => $status,
        ':note'         => $note,
    ]);

    $stmt = $pdo->prepare('SELECT * FROM game WHERE igdb_id = :id LIMIT 1');
    $stmt->execute([':id' => $igdbId]);
    return $stmt->fetch() ?: [];
}

function getGameByIgdbId(int $igdbId): ?array
{
    $pdo = getDb();
    $stmt = $pdo->prepare('SELECT * FROM game WHERE igdb_id = :id LIMIT 1');
    $stmt->execute([':id' => $igdbId]);
    return $stmt->fetch() ?: null;
}

// =====================================================
//  IMAGE URL BUILDER
// =====================================================

function igdbImageUrl(?string $imageId, string $sizeTag = 't_cover_big'): ?string
{
    if (!$imageId) {
        return null;
    }

    return sprintf(
        'https://images.igdb.com/igdb/image/upload/%s/%s.jpg',
        $sizeTag,
        $imageId
    );
}

// =====================================================
//  TWITCH TOKEN + IGDB REQUEST
// =====================================================

function getCachedToken(): ?array
{
    if (!file_exists(IGDB_TOKEN_CACHE_FILE)) {
        return null;
    }

    $json = file_get_contents(IGDB_TOKEN_CACHE_FILE);
    $data = json_decode($json, true);

    if (!$data || time() >= ($data['expires_at'] ?? 0)) {
        return null;
    }

    return $data;
}

function saveToken(array $tokenData): void
{
    $expiresIn = (int)($tokenData['expires_in'] ?? 0);
    $tokenData['expires_at'] = time() + $expiresIn - 60; // 60s Puffer

    file_put_contents(
        IGDB_TOKEN_CACHE_FILE,
        json_encode($tokenData, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE)
    );
}

function fetchNewToken(): array
{
    $postFields = [
        'client_id'     => TWITCH_CLIENT_ID,
        'client_secret' => TWITCH_CLIENT_SECRET,
        'grant_type'    => 'client_credentials',
    ];

    $ch = curl_init();
    curl_setopt_array($ch, [
        CURLOPT_URL            => TWITCH_TOKEN_URL,
        CURLOPT_POST           => true,
        CURLOPT_POSTFIELDS     => http_build_query($postFields),
        CURLOPT_RETURNTRANSFER => true,
    ]);

    $response = curl_exec($ch);
    $status   = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    $data = json_decode($response, true);

    if ($status !== 200) {
        error_response([
            'message' => 'Failed to fetch token from Twitch',
            'status'  => $status,
            'body'    => $data,
        ], 500);
    }

    saveToken($data);
    return $data;
}

function getAccessToken(): string
{
    $cached = getCachedToken();
    if ($cached) {
        return $cached['access_token'];
    }

    $new = fetchNewToken();
    return $new['access_token'];
}

function igdbRequest(string $endpoint, string $body)
{
    $accessToken = getAccessToken();

    $ch = curl_init();
    curl_setopt_array($ch, [
        CURLOPT_URL            => IGDB_BASE_URL . $endpoint,
        CURLOPT_POST           => true,
        CURLOPT_POSTFIELDS     => $body,
        CURLOPT_HTTPHEADER     => [
            'Client-ID: ' . TWITCH_CLIENT_ID,
            'Authorization: Bearer ' . $accessToken,
            'Accept: application/json',
        ],
        CURLOPT_RETURNTRANSFER => true,
    ]);

    $response = curl_exec($ch);
    $status   = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    $data = json_decode($response, true);

    if ($status !== 200) {
        error_response([
            'message' => 'IGDB returned error',
            'status'  => $status,
            'body'    => $data,
        ], 500);
    }

    return $data;
}

/**
 * Interne Hilfsfunktion: macht einen Wikipedia-API-Call mit einem Suchstring
 * und gibt das erste Page-Objekt (inkl. extract) zurück.
 */
function wikiApiSearchWithExtract(string $searchQuery): ?array
{
    $params = [
        'action'      => 'query',
        'generator'   => 'search',
        'gsrsearch'   => $searchQuery,
        'gsrlimit'    => 1,
        'prop'        => 'extracts',
        'exintro'     => 1,
        'explaintext' => 1,
        'format'      => 'json',
        'utf8'        => 1,
    ];

    $url = WIKI_DE_API_URL . '?' . http_build_query($params, '', '&');

    $ch = curl_init();
    curl_setopt_array($ch, [
        CURLOPT_URL            => $url,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_TIMEOUT        => 5,
        CURLOPT_HTTPHEADER     => [
            'User-Agent: ' . WIKI_USER_AGENT,
        ],
    ]);

    $response = curl_exec($ch);
    if ($response === false) {
        curl_close($ch);
        return null;
    }

    $status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($status !== 200) {
        return null;
    }

    $data = json_decode($response, true);
    if (!is_array($data) || empty($data['query']['pages'])) {
        return null;
    }

    $pages = $data['query']['pages'];
    $page  = reset($pages);

    if (empty($page['extract'])) {
        return null;
    }

    // debug_url zum leichteren Debuggen
    $page['debug_url'] = $url;

    return $page;
}

/**
 * Hochwertige DE-Zusammenfassung für einen Spieltitel holen.
 *
 * - Probiert mehrere Suchvarianten (Videospiel, Computerspiel, etc.)
 * - Schneidet den Text auf ~600 Zeichen
 * - Liefert Titel, Extract, URL + debug_url
 */
function wikiFetchGermanSummaryForTitle(string $gameTitle): ?array
{
    $gameTitleTrimmed = trim($gameTitle);

    // Verschiedene Suchmuster, um Spiele sauber zu treffen
    $patterns = [
        $gameTitleTrimmed . ' (Computerspiel)',
        $gameTitleTrimmed . ' (Videospiel)',
        $gameTitleTrimmed . ' Videospiel',
        $gameTitleTrimmed, // Fallback: purer Titel
    ];

    foreach ($patterns as $pattern) {
        $page = wikiApiSearchWithExtract($pattern);
        if ($page === null || empty($page['extract'])) {
            continue;
        }

        $pageTitle = $page['title'] ?? $gameTitleTrimmed;

        // einfache Heuristik: Title ohne Klammern vergleichen
        $canonicalPageTitle = mb_strtolower(preg_replace('/\s*\(.*?\)\s*/u', '', $pageTitle), 'UTF-8');
        $canonicalGameTitle = mb_strtolower($gameTitleTrimmed, 'UTF-8');

        // Wenn der Titel gar nicht passt, nächsten Versuch → verbessert Qualität
        if (mb_strpos($canonicalPageTitle, $canonicalGameTitle) === false &&
            mb_strpos($canonicalGameTitle, $canonicalPageTitle) === false) {
            // könnte z.B. „Zelda (Band)“ sein → skip
            continue;
        }

        $extract = $page['extract'];
        $short   = mb_substr($extract, 0, 600, 'UTF-8');

        return [
            'pageid'    => (int)($page['pageid'] ?? 0),
            'title'     => $pageTitle,
            'extract'   => $short,
            'url'       => 'https://de.wikipedia.org/?curid=' . (int)($page['pageid'] ?? 0),
            'debug_url' => $page['debug_url'] ?? null,
        ];
    }

    // Keine passende Seite gefunden
    return null;
}

// =====================================================
//  ROUTING
// =====================================================

$action = $_GET['action'] ?? 'ping';

switch ($action) {

    // ---------------------------------------
    case 'ping':
        respond(['status' => 'ok']);
        break;

    // ---------------------------------------
    case 'search':
        $query = $_GET['query'] ?? '';
        $limit = (int)($_GET['limit'] ?? 10);
        $page  = (int)($_GET['page'] ?? 1);
        $lang  = $_GET['lang'] ?? 'en';

        $checkExternal = isset($_GET['check_external'])
            ? ((int)$_GET['check_external'] === 1)
            : false;

        $debug = isset($_GET['debug'])
            ? ((int)$_GET['debug'] === 1)
            : false;

        if ($query === '') {
            error_response('Missing "query"', 400);
        }

        if ($limit < 1 || $limit > 50) {
            $limit = 10;
        }
        if ($page < 1) {
            $page = 1;
        }

        $offset = ($page - 1) * $limit;

        $safeQuery = str_replace('"', '\\"', $query);
        $body = sprintf(
            'fields id,name,summary,first_release_date,cover.image_id; ' .
            'limit %d; offset %d; search "%s";',
            $limit,
            $offset,
            $safeQuery
        );

        $results = igdbRequest('/games', $body);

        foreach ($results as &$g) {
            // Cover-URL
            $g['cover_url'] = isset($g['cover']['image_id'])
                ? igdbImageUrl($g['cover']['image_id'], 't_cover_big')
                : null;

            // eigener Status aus game-Tabelle
            $localGame = getGameByIgdbId($g['id']);
            $g['my_status'] = $localGame['status'] ?? null;

            // eig. Lokalisierung aus DB (z.B. de)
            $hasLoc = false;
            if ($lang !== 'en') {
                $loc = getLocalization($g['id'], $lang);
                if ($loc !== null) {
                    $hasLoc = true;

                    if (!empty($loc['title'])) {
                        $g['name'] = $loc['title'];
                    }
                    if (!empty($loc['summary'])) {
                        $g['summary'] = $loc['summary'];
                    }
                }
            }
            $g['has_localization'] = $hasLoc;

            // Wikipedia-Felder vorbereiten
            $g['has_external_de']     = false;
            $g['external_de_source']  = null;
            $g['external_de_summary'] = null;
            $g['external_de_url']     = null;

            if ($debug) {
                $g['wiki_debug'] = [];
            }

            // Wikipedia nur bei lang=de, wenn keine eigene Lokalisierung da ist
            if ($checkExternal && $lang === 'de' && !$hasLoc) {
                $wiki = wikiFetchGermanSummaryForTitle($g['name']);

                if ($debug) {
                    $g['wiki_debug']['used_title']  = $g['name'];
                    $g['wiki_debug']['wiki_result'] = $wiki;
                }

                if ($wiki !== null && !empty($wiki['extract'])) {
                    $g['has_external_de']     = true;
                    $g['external_de_source']  = 'wikipedia';
                    $g['external_de_summary'] = $wiki['extract'];
                    $g['external_de_url']     = $wiki['url'];

                    // Direkt als Summary verwenden (Qualitäts-Boost)
                    $g['summary'] = $wiki['extract'];

                    // OPTIONAL: den Titel auf Wikipedia-Titel setzen:
                    // $g['name'] = $wiki['title'];
                }
            }
        }
        unset($g);

        respond([
            'source'        => 'igdb',
            'mode'          => 'search',
            'lang'          => $lang,
            'query'         => $query,
            'page'          => $page,
            'limit'         => $limit,
            'offset'        => $offset,
            'results_count' => count($results),
            'results'       => $results,
        ]);
        break;

    // ---------------------------------------
    case 'details':
        $idParam = $_GET['id'] ?? '';
        $lang    = $_GET['lang'] ?? 'en';

        $checkExternal = isset($_GET['check_external'])
            ? ((int)$_GET['check_external'] === 1)
            : false;

        if ($idParam === '') {
            error_response('Missing "id"', 400);
        }

        $id = (int)$idParam;
        if ($id <= 0) {
            error_response('Invalid "id"', 400);
        }

        $body = sprintf(
            'fields ' .
            'id,' .
            'name,' .
            'summary,' .
            'storyline,' .
            'first_release_date,' .
            'genres.name,' .
            'platforms.name,' .
            'cover.image_id,' .
            'screenshots.image_id,' .
            'involved_companies.company.name,' .
            'websites.url,' .
            'websites.category,' .
            'age_ratings.rating,' .
            'age_ratings.category,' .
            'language_supports.language;' .
            ' where id = %d;',
            $id
        );

        $results = igdbRequest('/games', $body);

        if (empty($results)) {
            error_response('Game not found', 404);
        }

        $game = $results[0];

        // Cover-URL
        $game['cover_url'] = isset($game['cover']['image_id'])
            ? igdbImageUrl($game['cover']['image_id'], 't_cover_big')
            : null;

        // Screenshot-URLs
        $game['screenshot_urls'] = [];
        if (!empty($game['screenshots']) && is_array($game['screenshots'])) {
            foreach ($game['screenshots'] as $s) {
                if (!empty($s['image_id'])) {
                    $game['screenshot_urls'][] =
                        igdbImageUrl($s['image_id'], 't_screenshot_big');
                }
            }
        }

        // eigener Status / Notiz
        $localGame = getGameByIgdbId($id);
        if ($localGame !== null) {
            $game['my_status'] = (int)$localGame['status'];
            $game['my_note']   = $localGame['note'];
        } else {
            $game['my_status'] = null;
            $game['my_note']   = null;
        }

        // eigene Lokalisierung (DB)
        $hasLoc = false;
        if ($lang !== 'en') {
            $loc = getLocalization($id, $lang);
            if ($loc !== null) {
                $hasLoc = true;

                if (!empty($loc['title'])) {
                    $game['name'] = $loc['title'];
                }
                if (!empty($loc['summary'])) {
                    $game['summary'] = $loc['summary'];
                }
                if (!empty($loc['storyline'])) {
                    $game['storyline'] = $loc['storyline'];
                }

                $game['localization'] = [
                    'lang'   => $lang,
                    'source' => 'custom',
                    'id'     => $loc['id'],
                ];
            }
        }
        $game['has_localization'] = $hasLoc;

        // Wikipedia-Fallback (DE), wenn keine eigene Lokalisierung existiert
        $game['has_external_de']     = false;
        $game['external_de_source']  = null;
        $game['external_de_summary'] = null;
        $game['external_de_url']     = null;

        if ($checkExternal && $lang === 'de' && !$hasLoc) {
            $wiki = wikiFetchGermanSummaryForTitle($game['name']);

            if ($wiki !== null && !empty($wiki['extract'])) {
                $game['has_external_de']     = true;
                $game['external_de_source']  = 'wikipedia';
                $game['external_de_summary'] = $wiki['extract'];
                $game['external_de_url']     = $wiki['url'];

                // Summary-Fallback auf DE-Text
                $game['summary'] = $wiki['extract'];

                // OPTIONAL: Name anpassen
                // $game['name'] = $wiki['title'];
            }
        }

        respond([
            'source' => 'igdb',
            'mode'   => 'details',
            'lang'   => $lang,
            'id'     => $id,
            'game'   => $game,
        ]);
        break;

    // ---------------------------------------
    case 'get_localization':
        $idParam = $_GET['id'] ?? '';
        $lang    = $_GET['lang'] ?? 'de';

        if ($idParam === '') {
            error_response('Missing "id"', 400);
        }

        $igdbId = (int)$idParam;
        if ($igdbId <= 0) {
            error_response('Invalid "id"', 400);
        }

        $loc = getLocalization($igdbId, $lang);

        respond([
            'found'        => (bool)$loc,
            'localization' => $loc,
        ]);
        break;

    // ---------------------------------------
    case 'submit_localization':
        if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
            error_response('Use POST', 405);
        }

        $raw  = file_get_contents('php://input');
        $data = json_decode($raw, true);
        if (!is_array($data)) {
            error_response('Invalid JSON body', 400);
        }

        $igdbId = (int)($data['igdb_id'] ?? 0);
        $lang   = trim($data['lang'] ?? 'de');
        $title  = isset($data['title']) ? trim($data['title']) : '';
        $summary= isset($data['summary']) ? trim($data['summary']) : '';
        $story  = isset($data['storyline']) ? trim($data['storyline']) : '';
        $userId = isset($data['user_id']) ? (int)$data['user_id'] : null;

        if ($igdbId <= 0) {
            error_response('Invalid "igdb_id"', 400);
        }

        if ($lang === '') {
            $lang = 'de';
        }

        $loc = saveLocalization(
            $igdbId,
            $lang,
            $title ?: null,
            $summary ?: null,
            $story ?: null,
            $userId
        );

        respond([
            'success'       => true,
            'localization'  => $loc,
        ]);
        break;

    // ---------------------------------------
    case 'set_game_status':
        if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
            error_response('Use POST', 405);
        }

        $raw  = file_get_contents('php://input');
        $data = json_decode($raw, true);
        if (!is_array($data)) {
            error_response('Invalid JSON body', 400);
        }

        $igdbId = (int)($data['igdb_id'] ?? 0);
        $name   = isset($data['name']) ? trim($data['name']) : '';
        $orig   = isset($data['original_name']) ? trim($data['original_name']) : '';
        $status = (int)($data['status'] ?? 0);
        $note   = isset($data['note']) ? trim($data['note']) : '';

        if ($igdbId <= 0) {
            error_response('Invalid "igdb_id"', 400);
        }
        if ($name === '') {
            error_response('Missing "name"', 400);
        }
        if ($status < 0 || $status > 2) {
            error_response('Invalid "status" (0, 1, 2 allowed)', 400);
        }

        $game = saveGameStatus(
            $igdbId,
            $name,
            $orig !== '' ? $orig : null,
            $status,
            $note !== '' ? $note : null
        );

        respond([
            'success' => true,
            'game'    => $game,
        ]);
        break;

    // ---------------------------------------
    case 'get_game':
        $idParam = $_GET['igdb_id'] ?? '';
        if ($idParam === '') {
            error_response('Missing "igdb_id"', 400);
        }

        $igdbId = (int)$idParam;
        if ($igdbId <= 0) {
            error_response('Invalid "igdb_id"', 400);
        }

        $game = getGameByIgdbId($igdbId);

        respond([
            'found' => (bool)$game,
            'game'  => $game,
        ]);
        break;

    case 'wiki_test':
        $title = $_GET['title'] ?? '';
        if ($title === '') {
            error_response('Missing "title"', 400);
        }

        // Wir bauen die URL sichtbar zusammen
        $params = [
            'action'      => 'query',
            'generator'   => 'search',
            'gsrsearch'   => $title . ' Videospiel',
            'gsrlimit'    => 1,
            'prop'        => 'extracts',
            'exintro'     => 1,
            'explaintext' => 1,
            'format'      => 'json',
            'utf8'        => 1,
        ];

        $url = WIKI_DE_API_URL . '?' . http_build_query($params, '', '&');

        // Wikipedia anfragen
        $ch = curl_init();
        curl_setopt_array($ch, [
            CURLOPT_URL            => $url,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 5,
            CURLOPT_HTTPHEADER     => [
                'User-Agent: ' . WIKI_USER_AGENT,
            ],
        ]);

        $response = curl_exec($ch);
        $curlErr  = curl_error($ch);
        $status   = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        // Parse versuchen
        $json = json_decode($response, true);

        respond([
            'title'            => $title,
            'used_url'         => $url,          // <- DIE WICHTIGE URL
            'http_status'      => $status,
            'curl_error'       => $curlErr,
            'raw_response'     => $response,      // <- Rohdaten
            'parsed_json'      => $json,          // <- Versuch zu decodieren
        ]);
        break;

    // ---------------------------------------
    default:
        error_response('Unknown action: ' . $action, 404);
}