// GitLab Webhook Routes — receives issue lifecycle events from GitLab
// Used to notify users via Webex when their feedback issues are closed.

const express = require('express');
const pool = require('../db');
const { sendDirectMessage } = require('../helpers/webexBot');

const GITLAB_WEBHOOK_SECRET = process.env.GITLAB_WEBHOOK_SECRET || '';

function createWebhooksRouter() {
    const router = express.Router();

    // POST /api/webhooks/gitlab — GitLab issue webhook receiver
    router.post('/gitlab', express.json(), async (req, res) => {
        // Always return 200 — webhooks should not retry on app-level failures
        try {
            // Validate webhook secret token
            const token = req.headers['x-gitlab-token'];
            if (!GITLAB_WEBHOOK_SECRET || token !== GITLAB_WEBHOOK_SECRET) {
                console.warn('[Webhook] Invalid or missing X-Gitlab-Token');
                return res.status(200).json({ status: 'ignored', reason: 'invalid token' });
            }

            const { object_attributes } = req.body || {};

            // Only process issue close events
            if (!object_attributes || object_attributes.action !== 'close') {
                return res.status(200).json({ status: 'ignored', reason: 'not a close event' });
            }

            const issueTitle = object_attributes.title || 'Untitled';
            const issueNumber = object_attributes.iid;
            const description = object_attributes.description || '';

            // Parse submitter username from issue description
            // Format: **Submitted by:** username
            const submitterMatch = description.match(/\*\*Submitted by:\*\*\s*(\S+)/);
            if (!submitterMatch) {
                console.log('[Webhook] No submitter found in issue description — skipping DM');
                return res.status(200).json({ status: 'ignored', reason: 'no submitter in description' });
            }

            const username = submitterMatch[1];

            // Look up user email in database
            const { rows } = await pool.query(
                'SELECT email FROM users WHERE username = $1',
                [username]
            );

            if (!rows || rows.length === 0 || !rows[0].email) {
                console.log(`[Webhook] No email found for user "${username}" — skipping DM`);
                return res.status(200).json({ status: 'ignored', reason: 'user email not found' });
            }

            const email = rows[0].email;

            // Send Webex DM notification
            const message = `Hey! Your bug report **${issueTitle}** (Issue #${issueNumber}) has been resolved and deployed. — Patches O'Houlihan`;
            sendDirectMessage(email, message);

            console.log(`[Webhook] Issue #${issueNumber} closed — notified ${username} (${email})`);
            return res.status(200).json({ status: 'ok', notified: username });
        } catch (err) {
            console.error('[Webhook] Error processing GitLab webhook:', err.message);
            return res.status(200).json({ status: 'error', message: err.message });
        }
    });

    return router;
}

module.exports = createWebhooksRouter;