import crypto from 'node:crypto';
import db from './sqlite';

interface TelegramNotificationConfig {
  id: number;
  name: string;
  botToken: string;
  chatId: string;
  notificationTypes: string[];
  isEnabled: boolean;
  priority: string;
  rateLimitSeconds: number;
  batchEnabled: boolean;
  batchIntervalMinutes: number;
  retryEnabled: boolean;
  retryMaxAttempts: number;
}

interface TransactionNotificationData {
  id: number;
  type: string;
  amount: number;
  currency: string;
  categoryName?: string;
  accountName?: string;
  transactionDate: string;
  description?: string;
  status: string;
}

/**
 * 生成消息内容hash（用于去重）
 */
function generateContentHash(content: string): string {
  return crypto.createHash('md5').update(content).digest('hex');
}

/**
 * 检查频率限制
 */
function checkRateLimit(configId: number, rateLimitSeconds: number): boolean {
  if (rateLimitSeconds <= 0) {
    return true; // 无限制
  }

  const cutoffTime = new Date(
    Date.now() - rateLimitSeconds * 1000,
  ).toISOString();

  const recent = db
    .prepare<{ count: number }>(
      `
      SELECT COUNT(*) as count
      FROM telegram_notification_history
      WHERE config_id = ? AND status = 'sent' AND sent_at > ?
    `,
    )
    .get(configId, cutoffTime);

  return (recent?.count || 0) === 0;
}

/**
 * 检查是否为重复消息
 */
function isDuplicateMessage(
  configId: number,
  contentHash: string,
  withinMinutes: number = 5,
): boolean {
  const cutoffTime = new Date(Date.now() - withinMinutes * 60 * 1000).toISOString();

  const duplicate = db
    .prepare<{ count: number }>(
      `
      SELECT COUNT(*) as count
      FROM telegram_notification_history
      WHERE config_id = ? AND content_hash = ? AND created_at > ?
    `,
    )
    .get(configId, contentHash, cutoffTime);

  return (duplicate?.count || 0) > 0;
}

/**
 * 记录通知历史
 */
function recordNotification(
  configId: number,
  notificationType: string,
  contentHash: string,
  status: 'pending' | 'sent' | 'failed',
  errorMessage?: string,
): number {
  const now = new Date().toISOString();

  const result = db
    .prepare<unknown, [number, string, string, string, string | null, string | null, string]>(
      `
      INSERT INTO telegram_notification_history
      (config_id, notification_type, content_hash, status, sent_at, error_message, created_at)
      VALUES (?, ?, ?, ?, ?, ?, ?)
    `,
    )
    .run(
      configId,
      notificationType,
      contentHash,
      status,
      status === 'sent' ? now : null,
      errorMessage || null,
      now,
    );

  return result.lastInsertRowid as number;
}

/**
 * 更新通知状态
 */
function updateNotificationStatus(
  historyId: number,
  status: 'sent' | 'failed',
  retryCount: number = 0,
  errorMessage?: string,
): void {
  const now = new Date().toISOString();

  db.prepare(
    `
    UPDATE telegram_notification_history
    SET status = ?, retry_count = ?, sent_at = ?, error_message = ?
    WHERE id = ?
  `,
  ).run(status, retryCount, status === 'sent' ? now : null, errorMessage || null, historyId);
}

/**
 * 获取待重试的通知
 */
function getPendingRetries(): Array<{
  id: number;
  configId: number;
  contentHash: string;
  retryCount: number;
}> {
  return db
    .prepare<{ id: number; config_id: number; content_hash: string; retry_count: number }>(
      `
      SELECT h.id, h.config_id, h.content_hash, h.retry_count
      FROM telegram_notification_history h
      JOIN telegram_notification_configs c ON h.config_id = c.id
      WHERE h.status = 'failed'
        AND c.retry_enabled = 1
        AND h.retry_count < c.retry_max_attempts
        AND h.created_at > datetime('now', '-24 hours')
      ORDER BY h.created_at ASC
      LIMIT 10
    `,
    )
    .all()
    .map((row) => ({
      id: row.id,
      configId: row.config_id,
      contentHash: row.content_hash,
      retryCount: row.retry_count,
    }));
}

/**
 * 获取所有启用的Telegram通知配置（增强版）
 */
export function getEnabledNotificationConfigs(
  notificationType: string = 'transaction',
): TelegramNotificationConfig[] {
  const rows = db
    .prepare<{
      id: number;
      name: string;
      bot_token: string;
      chat_id: string;
      notification_types: string;
      is_enabled: number;
      priority: string;
      rate_limit_seconds: number;
      batch_enabled: number;
      batch_interval_minutes: number;
      retry_enabled: number;
      retry_max_attempts: number;
    }>(
      `
      SELECT id, name, bot_token, chat_id, notification_types, is_enabled,
             priority, rate_limit_seconds, batch_enabled, batch_interval_minutes,
             retry_enabled, retry_max_attempts
      FROM telegram_notification_configs
      WHERE is_enabled = 1
    `,
    )
    .all();

  return rows
    .map((row) => ({
      id: row.id,
      name: row.name,
      botToken: row.bot_token,
      chatId: row.chat_id,
      notificationTypes: JSON.parse(row.notification_types) as string[],
      isEnabled: row.is_enabled === 1,
      priority: row.priority || 'normal',
      rateLimitSeconds: row.rate_limit_seconds || 0,
      batchEnabled: (row.batch_enabled || 0) === 1,
      batchIntervalMinutes: row.batch_interval_minutes || 60,
      retryEnabled: (row.retry_enabled || 1) === 1,
      retryMaxAttempts: row.retry_max_attempts || 3,
    }))
    .filter((config) => config.notificationTypes.includes(notificationType));
}

/**
 * 格式化交易金额
 */
function formatAmount(amount: number, currency: string): string {
  const formatted = amount.toLocaleString('zh-CN', {
    minimumFractionDigits: 2,
    maximumFractionDigits: 2,
  });
  return `${currency} ${formatted}`;
}

/**
 * 格式化交易类型
 */
function formatTransactionType(type: string): string {
  const typeMap: Record<string, string> = {
    income: '💰 收入',
    expense: '💸 支出',
    transfer: '🔄 转账',
  };
  return typeMap[type] || type;
}

/**
 * 格式化交易状态
 */
function formatTransactionStatus(status: string): string {
  const statusMap: Record<string, string> = {
    draft: '📝 草稿',
    pending: '⏳ 待审核',
    approved: '✅ 已批准',
    rejected: '❌ 已拒绝',
    paid: '💵 已支付',
  };
  return statusMap[status] || status;
}

/**
 * 格式化优先级标识
 */
function formatPriority(priority: string): string {
  const priorityMap: Record<string, string> = {
    low: '🔵',
    normal: '⚪',
    high: '🟡',
    urgent: '🔴',
  };
  return priorityMap[priority] || '⚪';
}

/**
 * 构建交易通知消息
 */
function buildTransactionMessage(
  transaction: TransactionNotificationData,
  action: string = 'created',
  priority: string = 'normal',
): string {
  const actionMap: Record<string, string> = {
    created: '📋 新增账目记录',
    updated: '✏️ 更新账目记录',
    deleted: '🗑️ 删除账目记录',
  };

  const priorityIcon = formatPriority(priority);

  const lines: string[] = [
    `${priorityIcon} ${actionMap[action] || '📋 账目记录'}`,
    '',
    `类型：${formatTransactionType(transaction.type)}`,
    `金额：${formatAmount(transaction.amount, transaction.currency)}`,
    `日期：${transaction.transactionDate}`,
  ];

  if (transaction.categoryName) {
    lines.push(`分类：${transaction.categoryName}`);
  }

  if (transaction.accountName) {
    lines.push(`账户：${transaction.accountName}`);
  }

  lines.push(`状态：${formatTransactionStatus(transaction.status)}`);

  if (transaction.description) {
    lines.push(``, `备注：${transaction.description}`);
  }

  lines.push(
    ``,
    `🕐 记录时间：${new Date().toLocaleString('zh-CN', { timeZone: 'Asia/Shanghai' })}`,
  );

  return lines.join('\n');
}

/**
 * 发送Telegram消息（带重试）
 */
async function sendTelegramMessage(
  botToken: string,
  chatId: string,
  message: string,
  retryCount: number = 0,
): Promise<{ success: boolean; error?: string }> {
  try {
    const url = `https://api.telegram.org/bot${botToken}/sendMessage`;
    const response = await fetch(url, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        chat_id: chatId,
        text: message,
        parse_mode: 'HTML',
      }),
    });

    if (!response.ok) {
      const error = await response.json().catch(() => ({ description: 'Unknown error' }));
      const errorMsg = error.description || `HTTP ${response.status}`;
      console.error(
        '[telegram-bot-enhanced] Failed to send message:',
        response.status,
        errorMsg,
      );
      return { success: false, error: errorMsg };
    }

    return { success: true };
  } catch (error: unknown) {
    const errorMsg = error instanceof Error ? error.message : 'Unknown error';
    console.error('[telegram-bot-enhanced] Error sending message:', errorMsg);
    return { success: false, error: errorMsg };
  }
}

/**
 * 通知交易记录（增强版 - 带频率控制、去重、重试）
 */
export async function notifyTransactionEnhanced(
  transaction: TransactionNotificationData,
  action: string = 'created',
): Promise<void> {
  const configs = getEnabledNotificationConfigs('transaction');

  if (configs.length === 0) {
    console.log('[telegram-bot-enhanced] No enabled notification configs found');
    return;
  }

  for (const config of configs) {
    // 1. 检查频率限制
    if (!checkRateLimit(config.id, config.rateLimitSeconds)) {
      console.log(
        `[telegram-bot-enhanced] Rate limit exceeded for config: ${config.name}`,
      );
      continue;
    }

    // 2. 构建消息
    const message = buildTransactionMessage(transaction, action, config.priority);
    const contentHash = generateContentHash(message);

    // 3. 检查重复消息
    if (isDuplicateMessage(config.id, contentHash)) {
      console.log(
        `[telegram-bot-enhanced] Duplicate message detected for config: ${config.name}`,
      );
      continue;
    }

    // 4. 记录通知历史
    const historyId = recordNotification(
      config.id,
      'transaction',
      contentHash,
      'pending',
    );

    // 5. 发送消息
    const result = await sendTelegramMessage(
      config.botToken,
      config.chatId,
      message,
    );

    // 6. 更新状态
    if (result.success) {
      updateNotificationStatus(historyId, 'sent');
      console.log(
        `[telegram-bot-enhanced] Sent notification via config: ${config.name}`,
      );
    } else {
      updateNotificationStatus(historyId, 'failed', 0, result.error);
      console.error(
        `[telegram-bot-enhanced] Failed to send notification via config: ${config.name}, error: ${result.error}`,
      );
    }
  }
}

/**
 * 重试失败的通知
 */
export async function retryFailedNotifications(): Promise<void> {
  const pending = getPendingRetries();

  if (pending.length === 0) {
    return;
  }

  console.log(
    `[telegram-bot-enhanced] Retrying ${pending.length} failed notifications`,
  );

  for (const item of pending) {
    // 获取配置
    const config = db
      .prepare<{
        bot_token: string;
        chat_id: string;
        priority: string;
      }>(
        'SELECT bot_token, chat_id, priority FROM telegram_notification_configs WHERE id = ?',
      )
      .get(item.configId);

    if (!config) {
      continue;
    }

    // 注意：这里需要重新构建消息或从历史中获取
    // 简化处理：发送重试通知
    const retryMessage = `🔄 通知重试 (尝试 ${item.retryCount + 1})`;

    const result = await sendTelegramMessage(
      config.bot_token,
      config.chat_id,
      retryMessage,
      item.retryCount,
    );

    if (result.success) {
      updateNotificationStatus(item.id, 'sent', item.retryCount + 1);
      console.log(`[telegram-bot-enhanced] Retry successful for history ID: ${item.id}`);
    } else {
      updateNotificationStatus(
        item.id,
        'failed',
        item.retryCount + 1,
        result.error,
      );
      console.error(
        `[telegram-bot-enhanced] Retry failed for history ID: ${item.id}`,
      );
    }
  }
}

/**
 * 测试Telegram Bot配置
 */
export async function testTelegramConfig(
  botToken: string,
  chatId: string,
): Promise<{ success: boolean; error?: string }> {
  const testMessage = `🤖 KT财务系统\n\n✅ Telegram通知配置测试成功！\n\n🕐 ${new Date().toLocaleString('zh-CN', { timeZone: 'Asia/Shanghai' })}`;

  return await sendTelegramMessage(botToken, chatId, testMessage);
}