/**
 * ShadowMan Telegram Bot Plugin v3.1.0
 * Telegram Bot API integration with long polling via background worker.
 *
 * Features:
 * - Background worker polling (non-blocking)
 * - Automatic LLM response forwarding to Telegram
 * - Typing indicator while LLM processes
 * - Photo/document receiving and sending
 * - File download from Telegram servers
 *
 * Requires: bot_token (secret), authorized_user_id (config)
 */

var config = shadowman.config.get();

var BOT_TOKEN = config.bot_token || shadowman.config.value('bot_token');
if (!BOT_TOKEN) {
    shadowman.log.error('bot_token not configured — plugin cannot start');
}

var AUTHORIZED_USER_ID = config.authorized_user_id || shadowman.config.value('authorized_user_id') || '';
if (!AUTHORIZED_USER_ID) {
    shadowman.log.warn('authorized_user_id not set — bot will reject all messages');
}

var POLLING_ENABLED = config.polling_enabled !== false;
var POLLING_INTERVAL = parseInt(config.polling_interval) || 2000;
var POLLING_TIMEOUT = parseInt(config.polling_timeout) || 30;
var API_BASE = 'https://api.telegram.org/bot' + BOT_TOKEN + '/';
var FILE_BASE = 'https://api.telegram.org/file/bot' + BOT_TOKEN + '/';

var lastUpdateId = shadowman.storage.get('last_update_id') || 0;

// ── Helpers ────────────────────────────────────────────────────────────

function apiCall(method, params) {
    try {
        var response = shadowman.http.post(API_BASE + method,
            JSON.stringify(params || {}),
            { headers: { 'Content-Type': 'application/json' }, timeout: 60 });
        var data = response.json();
        if (!data.ok) {
            return { success: false, error: data.description || 'Unknown error', error_code: data.error_code };
        }
        return { success: true, result: data.result };
    } catch (e) {
        return { success: false, error: e.toString() };
    }
}

function sanitizeResponse(response) {
    if (!BOT_TOKEN) return response;
    if (typeof response === 'string') {
        return response.replace(new RegExp(BOT_TOKEN, 'g'), '[REDACTED]');
    }
    if (typeof response === 'object' && response !== null) {
        var s = {};
        for (var key in response) {
            if (response.hasOwnProperty(key)) s[key] = sanitizeResponse(response[key]);
        }
        return s;
    }
    return response;
}

function isAuthorizedUser(userId) {
    return String(userId) === String(AUTHORIZED_USER_ID);
}

function getOrCreateConversationId(chatId) {
    var key = 'conv_' + String(chatId);
    var existing = shadowman.storage.get(key);
    if (existing) return existing;
    var id = shadowman.utils.uuid();
    shadowman.storage.set(key, id);
    return id;
}

/**
 * Download a file from Telegram servers by file_id.
 * Returns { success, file_path, size, data } where data is base64 content.
 */
function downloadTelegramFile(fileId) {
    var fileInfo = apiCall('getFile', { file_id: fileId });
    if (!fileInfo.success || !fileInfo.result || !fileInfo.result.file_path) {
        return { success: false, error: 'Failed to get file info' };
    }

    var filePath = fileInfo.result.file_path;
    var url = FILE_BASE + filePath;

    try {
        var response = shadowman.http.get(url, { timeout: 60 });
        if (response.status === 200) {
            return {
                success: true,
                file_path: filePath,
                size: fileInfo.result.file_size || 0,
                data: shadowman.utils.base64Encode(response.body)
            };
        }
        return { success: false, error: 'HTTP ' + response.status };
    } catch (e) {
        return { success: false, error: e.toString() };
    }
}

/**
 * Get the largest photo from a Telegram photo array.
 */
function getBestPhoto(photoArray) {
    if (!photoArray || photoArray.length === 0) return null;
    var best = photoArray[0];
    for (var i = 1; i < photoArray.length; i++) {
        if ((photoArray[i].file_size || 0) > (best.file_size || 0)) {
            best = photoArray[i];
        }
    }
    return best;
}

// ── Message processing ─────────────────────────────────────────────────

function processTelegramUpdate(update) {
    var message = update.message;
    if (!message || !message.from) return;

    var userId = message.from.id;
    var chatId = message.chat.id;
    var username = message.from.username || message.from.first_name || 'Unknown';

    if (!isAuthorizedUser(userId)) {
        shadowman.log.debug('Unauthorized message from ' + userId);
        return;
    }

    var conversationId = getOrCreateConversationId(chatId);
    var text = message.text || message.caption || '';
    var hasPhoto = message.photo && message.photo.length > 0;
    var hasDocument = message.document;

    // Handle photo messages
    if (hasPhoto) {
        var photo = getBestPhoto(message.photo);
        if (photo) {
            shadowman.log.info('Photo from @' + username + (text ? ': ' + text.substring(0, 40) : ''));
            var downloaded = downloadTelegramFile(photo.file_id);
            if (downloaded.success) {
                var filename = 'telegram_photo_' + message.message_id + '.jpg';
                var saved = shadowman.files.save(filename, downloaded.data, 'image/jpeg');
                if (saved && saved.url) {
                    // Use markdown image syntax so WebUI renders it
                    text = (text || '') + '\n\n![Photo from Telegram](' + saved.url + ')';
                } else {
                    text = text || 'Sent a photo (failed to save)';
                }
            }
        }
    }

    // Handle document messages
    if (hasDocument) {
        var doc = message.document;
        var docFilename = doc.file_name || ('telegram_file_' + message.message_id);
        var mime = doc.mime_type || 'application/octet-stream';
        shadowman.log.info('Document from @' + username + ': ' + docFilename);
        var downloaded = downloadTelegramFile(doc.file_id);
        if (downloaded.success) {
            var saved = shadowman.files.save(docFilename, downloaded.data, mime);
            if (saved && saved.url) {
                // Images as markdown, other files as links
                var isImage = mime.indexOf('image/') === 0;
                if (isImage) {
                    text = (text || '') + '\n\n![' + docFilename + '](' + saved.url + ')';
                } else {
                    text = (text || '') + '\n\n[' + docFilename + '](' + saved.url + ')';
                }
            } else {
                text = text || 'Sent a file: ' + docFilename + ' (failed to save)';
            }
        }
    }

    if (!text && !hasPhoto && !hasDocument) return;

    shadowman.log.info('Message from @' + username + ': ' + text.substring(0, 80));

    // Start typing indicator
    shadowman.state.set('typing_chat_id', chatId);

    shadowman.events.emit('message', {
        text: text,
        conversationId: conversationId,
        platform: 'Telegram',
        sender: message.from.first_name || username,
        metadata: {
            source: 'telegram',
            user_id: userId,
            username: username,
            chat_id: chatId,
            message_id: message.message_id
        }
    });
}

// ── Event handlers (main thread) ───────────────────────────────────────

shadowman.events.on('llm_response', function(data) {
    if (!data.metadata || data.metadata.source !== 'telegram') return;

    var chatId = data.metadata.chat_id;
    var text = data.text || '';

    // Stop typing indicator
    shadowman.state.set('typing_chat_id', 0);

    if (!chatId || !text) return;

    // Detect image references and send as multipart photo uploads
    var imageRegex = /!\[([^\]]*)\]\((\/files\/[^\s\)]+\.(png|jpg|jpeg|gif|webp))\)/gi;
    var imgMatch;
    var sentImages = {};

    while ((imgMatch = imageRegex.exec(text)) !== null) {
        var imgCaption = imgMatch[1] || '';
        var imgUrl = imgMatch[2];

        if (!sentImages[imgUrl]) {
            sentImages[imgUrl] = true;
            // Extract filename from URL path
            var parts = imgUrl.split('/');
            var imgFilename = parts[parts.length - 1];
            try {
                var fileData = shadowman.files.read(imgFilename);
                if (fileData && fileData.content) {
                    shadowman.log.info('Uploading photo to Telegram: ' + imgFilename);
                    shadowman.http.post(API_BASE + 'sendPhoto', null, {
                        multipart: [
                            { name: 'chat_id', value: String(chatId) },
                            { name: 'photo', filename: imgFilename, data: fileData.content, contentType: 'image/' + (imgFilename.endsWith('.png') ? 'png' : 'jpeg') },
                            { name: 'caption', value: imgCaption || '' }
                        ],
                        timeout: 60
                    });
                }
            } catch (e) {
                shadowman.log.debug('Could not send image: ' + e.toString());
            }
        }
    }

    // Send text — strip image markdown for cleaner message
    var cleanText = text.replace(/!\[[^\]]*\]\(\/files\/[^\)]+\)/g, '').trim();
    if (cleanText) {
        // Telegram 4096 char limit — split long messages
        while (cleanText.length > 0) {
            var chunk = cleanText.substring(0, 4096);
            cleanText = cleanText.substring(4096);
            apiCall('sendMessage', {
                chat_id: chatId,
                text: chunk,
                parse_mode: 'Markdown'
            });
        }
    }
});

// Handle updates from background worker
shadowman.events.on('telegram_update', function(update) {
    processTelegramUpdate(update);
    var lastId = shadowman.state.get('last_update_id');
    if (lastId > 0) {
        shadowman.storage.set('last_update_id', lastId);
    }
});

// ── Tools ──────────────────────────────────────────────────────────────

shadowman.tools.register('send_message', function(args) {
    if (!args.chat_id) return { success: false, error: 'chat_id is required' };
    if (!args.text) return { success: false, error: 'text is required' };

    var params = { chat_id: args.chat_id, text: args.text };
    if (args.parse_mode) params.parse_mode = args.parse_mode;
    if (args.disable_notification) params.disable_notification = true;
    if (args.reply_to_message_id) params.reply_to_message_id = args.reply_to_message_id;

    return sanitizeResponse(apiCall('sendMessage', params));
});

shadowman.tools.register('send_to_owner', function(args) {
    if (!args.text) return { success: false, error: 'text is required' };
    if (!AUTHORIZED_USER_ID) return { success: false, error: 'authorized_user_id not configured' };

    var params = { chat_id: AUTHORIZED_USER_ID, text: args.text };
    if (args.parse_mode) params.parse_mode = args.parse_mode;

    return sanitizeResponse(apiCall('sendMessage', params));
});

shadowman.tools.register('send_photo', function(args) {
    if (!args.chat_id) return { success: false, error: 'chat_id is required' };
    if (!args.photo) return { success: false, error: 'photo is required' };

    var params = { chat_id: args.chat_id, photo: args.photo };
    if (args.caption) params.caption = args.caption;
    if (args.parse_mode) params.parse_mode = args.parse_mode;

    return sanitizeResponse(apiCall('sendPhoto', params));
});

shadowman.tools.register('send_document', function(args) {
    if (!args.chat_id) return { success: false, error: 'chat_id is required' };
    if (!args.document) return { success: false, error: 'document is required' };

    var params = { chat_id: args.chat_id, document: args.document };
    if (args.caption) params.caption = args.caption;
    if (args.parse_mode) params.parse_mode = args.parse_mode;

    return sanitizeResponse(apiCall('sendDocument', params));
});

shadowman.tools.register('forward_message', function(args) {
    if (!args.chat_id) return { success: false, error: 'chat_id is required' };
    if (!args.from_chat_id) return { success: false, error: 'from_chat_id is required' };
    if (!args.message_id) return { success: false, error: 'message_id is required' };

    return sanitizeResponse(apiCall('forwardMessage', {
        chat_id: args.chat_id,
        from_chat_id: args.from_chat_id,
        message_id: args.message_id
    }));
});

shadowman.tools.register('get_me', function() {
    return sanitizeResponse(apiCall('getMe', {}));
});

shadowman.tools.register('get_chat', function(args) {
    if (!args.chat_id) return { success: false, error: 'chat_id is required' };
    return sanitizeResponse(apiCall('getChat', { chat_id: args.chat_id }));
});

shadowman.tools.register('set_webhook', function(args) {
    if (!args.webhook_url) return { success: false, error: 'webhook_url is required' };
    var params = { url: args.webhook_url, allowed_updates: ['message', 'edited_message', 'callback_query'] };
    if (args.secret_token) params.secret_token = args.secret_token;
    return sanitizeResponse(apiCall('setWebhook', params));
});

shadowman.tools.register('delete_webhook', function() {
    return sanitizeResponse(apiCall('deleteWebhook', {}));
});

shadowman.tools.register('get_webhook_info', function() {
    return sanitizeResponse(apiCall('getWebhookInfo', {}));
});

// ── Shared state and background workers ────────────────────────────────

shadowman.state.set('api_base', API_BASE);
shadowman.state.set('last_update_id', lastUpdateId);
shadowman.state.set('polling', POLLING_ENABLED);
shadowman.state.set('polling_timeout', POLLING_TIMEOUT);
shadowman.state.set('polling_interval', POLLING_INTERVAL);
shadowman.state.set('typing_chat_id', 0);

// Typing indicator worker — sends "typing..." every 4s while LLM processes
shadowman.background.run(function() {
    while (shadowman.state.get('polling') !== false) {
        var chatId = shadowman.state.get('typing_chat_id');
        if (chatId && chatId !== 0) {
            var base = shadowman.state.get('api_base');
            shadowman.http.post(base + 'sendChatAction', JSON.stringify({
                chat_id: chatId,
                action: 'typing'
            }), { headers: { 'Content-Type': 'application/json' }, timeout: 10 });
        }
        shadowman.utils.sleep(4000);
    }
});

// Polling worker
if (POLLING_ENABLED) {
    shadowman.background.run(function() {
        var base = shadowman.state.get('api_base');
        var timeout = shadowman.state.get('polling_timeout');
        var interval = shadowman.state.get('polling_interval');

        shadowman.http.post(base + 'deleteWebhook', '{}',
            { headers: { 'Content-Type': 'application/json' } });
        shadowman.utils.sleep(2000);
        shadowman.log.info('Polling worker started');

        while (shadowman.state.get('polling')) {
            try {
                var offset = shadowman.state.get('last_update_id');
                var result = shadowman.http.post(base + 'getUpdates', JSON.stringify({
                    offset: offset + 1,
                    timeout: timeout,
                    allowed_updates: ['message', 'edited_message', 'callback_query']
                }), {
                    headers: { 'Content-Type': 'application/json' },
                    timeout: timeout + 10
                });

                if (result.status === 200) {
                    var data = result.json();
                    if (data.ok && data.result && data.result.length > 0) {
                        for (var i = 0; i < data.result.length; i++) {
                            var update = data.result[i];
                            if (update.update_id > offset) {
                                shadowman.state.set('last_update_id', update.update_id);
                            }
                            shadowman.events.emit('telegram_update', update);
                        }
                    }
                } else {
                    shadowman.log.warn('Polling error: HTTP ' + result.status);
                    shadowman.utils.sleep(5000);
                }
            } catch (e) {
                shadowman.log.error('Polling exception: ' + e.toString());
                shadowman.utils.sleep(5000);
            }

            shadowman.utils.sleep(interval);
        }
        shadowman.log.info('Polling worker stopped');
    });
}

shadowman.log.info('Telegram plugin v3.1.0 ready (' +
    (POLLING_ENABLED ? 'polling' : 'webhook') + ' mode)');