import { Elysia } from 'elysia';
import * as line from '@line/bot-sdk';
import { lineConfig, lineClient } from '../lib/lineClient';
import crypto from 'crypto';

const webhookHandler = async ({ request, body, set }: { request: Request, body: any, set: any }) => {
  // 1. Verify Signature
  const signature = request.headers.get('x-line-signature');
  if (!signature) {
    set.status = 400;
    return { error: 'Missing Signature' };
  }

  // xxIn our global onParse hook, we intercepted the body and returned it as a raw text string.
  const rawBody = typeof body === 'string' ? body : JSON.stringify(body);

  if (!rawBody) {
    set.status = 400;
    return { error: 'Empty Body' };
  }

  const hash = crypto
    .createHmac('SHA256', lineConfig.channelSecret)
    .update(rawBody)
    .digest('base64');

  console.log('[LINE Webhook] Signature Check - Received:', signature, 'Calculated:', hash);

  if (hash !== signature) {
    console.error('[LINE Webhook] Invalid Signature Blocked');
    set.status = 401;
    return { error: 'Invalid Signature' };
  }

  try {
    const parsedBody = typeof body === 'string' ? JSON.parse(body) : body;
    const events: line.WebhookEvent[] = parsedBody.events || [];

    for (const event of events) {
      if (event.type === 'message' && event.message.type === 'text') {
        // Ignore verification dummy tokens
        if (event.replyToken === '00000000000000000000000000000000' || event.replyToken === 'ffffffffffffffffffffffffffffffff') {
          continue;
        }

        // Simple echo bot for now
        await lineClient.replyMessage({
          replyToken: event.replyToken,
          messages: [{
            type: 'text',
            text: `คุณส่งข้อความว่า: ${event.message.text}`
          }]
        });
      }
    }
    return { success: true };
  } catch (err) {
    console.error('[LINE Webhook] Error:', err);
    set.status = 500;
    return { error: 'Webhook processing failed' };
  }
};

export const lineRoutes = new Elysia({ prefix: '/line' })
  .post('/webhook', webhookHandler)
  .post('/webhook/', webhookHandler);