// Leave Requests API Routes - Pengajuan Izin/Sakit Siswa
import express from 'express';
import pool from '../db.js';
import crypto from 'crypto';
import { addToQueuePriority } from '../services/fonnteQueue.js';

const router = express.Router();

// Send WhatsApp Notification to Guru BK via Queue (prevents mass sending)
const sendWhatsAppToGuruBK = async (message) => {
    try {
        // Get all active Guru BK with phone numbers
        const [guruBKList] = await pool.query(
            "SELECT name, phone FROM staff_users WHERE role = 'GURU_BK' AND is_active = TRUE AND phone IS NOT NULL AND phone != ''"
        );

        if (guruBKList.length === 0) {
            console.log('📱 No Guru BK with phone number found');
            return;
        }

        // Get Fonnte token from settings
        const [settings] = await pool.query(
            "SELECT setting_value FROM settings WHERE setting_key = 'FONNTE_TOKEN'"
        );
        const fonnteToken = settings.length > 0 ? settings[0].setting_value : process.env.FONNTE_TOKEN;

        if (!fonnteToken) {
            console.log('📱 Fonnte token not configured');
            return;
        }

        // Add all messages to queue with HIGH priority (queue handles the delays)
        for (const guru of guruBKList) {
            addToQueuePriority(guru.phone, message, fonnteToken);
            console.log(`📱 ⚡ HIGH PRIORITY: Queued WhatsApp for Guru BK ${guru.name}: ${guru.phone}`);
        }
    } catch (error) {
        console.error('📱 WhatsApp notification error:', error.message);
    }
};

// GET /api/leave-requests - Get leave requests
router.get('/', async (req, res) => {
    try {
        const { status, studentId } = req.query;

        let query = 'SELECT * FROM leave_requests';
        const params = [];
        const conditions = [];

        if (status) {
            conditions.push('status = ?');
            params.push(status);
        }
        if (studentId) {
            conditions.push('student_id = ?');
            params.push(studentId);
        }

        if (conditions.length > 0) {
            query += ' WHERE ' + conditions.join(' AND ');
        }

        query += ' ORDER BY created_at DESC';

        const [rows] = await pool.query(query, params);

        // Map to frontend format
        const requests = rows.map(row => ({
            id: row.id,
            studentId: row.student_id,
            studentName: row.student_name,
            studentNis: row.student_nis,
            studentClass: row.student_class,
            requestType: row.request_type,
            requestDate: row.request_date,
            reason: row.reason,
            photoEvidence: row.photo_evidence,
            status: row.status,
            reviewedBy: row.reviewed_by,
            reviewedByName: row.reviewed_by_name,
            reviewedAt: row.reviewed_at,
            rejectionReason: row.rejection_reason,
            createdAt: row.created_at
        }));

        res.json(requests);
    } catch (error) {
        console.error('GET /api/leave-requests Error:', error);
        res.status(500).json({ error: error.message });
    }
});

// GET /api/leave-requests/pending-count - Get pending count for notification badge
router.get('/pending-count', async (req, res) => {
    try {
        const [rows] = await pool.query(
            "SELECT COUNT(*) as count FROM leave_requests WHERE status = 'PENDING'"
        );
        res.json({ count: rows[0].count });
    } catch (error) {
        console.error('GET /api/leave-requests/pending-count Error:', error);
        res.status(500).json({ error: error.message });
    }
});

// POST /api/leave-requests - Submit new leave request (by student)
router.post('/', async (req, res) => {
    try {
        const { studentId, studentName, studentNis, studentClass, requestType, requestDate, reason, photoEvidence } = req.body;

        if (!studentId || !requestType || !requestDate || !reason) {
            return res.status(400).json({ error: 'Data tidak lengkap. Wajib: tipe, tanggal, alasan.' });
        }

        const id = crypto.randomUUID();

        await pool.query(
            `INSERT INTO leave_requests 
             (id, student_id, student_name, student_nis, student_class, request_type, request_date, reason, photo_evidence)
             VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
            [id, studentId, studentName, studentNis, studentClass, requestType, requestDate, reason, photoEvidence || null]
        );

        console.log(`📝 New leave request from ${studentName}: ${requestType} for ${requestDate}`);

        // Send WhatsApp notification to all Guru BK
        const message = `*🔔 Pengajuan ${requestType} Baru*\n\n` +
            `Siswa: *${studentName}*\n` +
            `NIS: ${studentNis || '-'}\n` +
            `Kelas: ${studentClass || '-'}\n` +
            `Tanggal: ${requestDate}\n` +
            `Alasan: ${reason}\n\n` +
            `Silakan buka aplikasi Absensi untuk menyetujui atau menolak pengajuan ini.`;

        sendWhatsAppToGuruBK(message);

        res.json({ success: true, id, message: 'Pengajuan berhasil dikirim.' });
    } catch (error) {
        console.error('POST /api/leave-requests Error:', error);
        res.status(500).json({ error: error.message });
    }
});

// PUT /api/leave-requests/:id/approve - Approve leave request (by Guru BK)
router.put('/:id/approve', async (req, res) => {
    try {
        const { id } = req.params;
        const { reviewerId, reviewerName } = req.body;

        // Get the request first
        const [rows] = await pool.query('SELECT * FROM leave_requests WHERE id = ?', [id]);
        if (rows.length === 0) {
            return res.status(404).json({ error: 'Pengajuan tidak ditemukan.' });
        }

        const request = rows[0];

        // Update leave request status
        await pool.query(
            `UPDATE leave_requests SET status = 'APPROVED', reviewed_by = ?, reviewed_by_name = ?, reviewed_at = NOW() WHERE id = ?`,
            [reviewerId, reviewerName, id]
        );

        // Also update attendance record if exists for this date
        await pool.query(
            `UPDATE attendance SET status = ? WHERE user_id = ? AND date_str = ? AND status = 'ALFA'`,
            [request.request_type, request.student_id, request.request_date]
        );

        // If no attendance record, create one
        const [existingAttendance] = await pool.query(
            `SELECT id FROM attendance WHERE user_id = ? AND date_str = ?`,
            [request.student_id, request.request_date]
        );

        if (existingAttendance.length === 0) {
            const attendanceId = crypto.randomUUID();
            await pool.query(
                `INSERT INTO attendance (id, user_id, user_name, nis, class_name, timestamp, date_str, time_str, status, ai_verification)
                 VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`,
                [attendanceId, request.student_id, request.student_name, request.student_nis, request.student_class,
                    Date.now(), request.request_date, '00:00', request.request_type, `Disetujui oleh ${reviewerName}`]
            );
        }

        console.log(`✅ Leave request ${id} APPROVED by ${reviewerName}`);

        // Send WhatsApp notification to student/parent
        try {
            const [attendanceRows] = await pool.query(
                "SELECT parent_phone FROM attendance WHERE user_id = ? AND parent_phone IS NOT NULL AND parent_phone != '' ORDER BY timestamp DESC LIMIT 1",
                [request.student_id]
            );

            const studentPhone = attendanceRows.length > 0 ? attendanceRows[0].parent_phone : null;

            if (studentPhone) {
                const [settings] = await pool.query("SELECT setting_value FROM settings WHERE setting_key = 'FONNTE_TOKEN'");
                const fonnteToken = settings.length > 0 ? settings[0].setting_value : process.env.FONNTE_TOKEN;

                if (fonnteToken) {
                    const message = `*✅ Pengajuan ${request.request_type} Disetujui*\n\n` +
                        `Halo *${request.student_name}*,\n` +
                        `Pengajuan ${request.request_type} Anda untuk tanggal *${request.request_date}* telah *DISETUJUI* oleh ${reviewerName}.\n\n` +
                        `Terima kasih.`;

                    addToQueuePriority(studentPhone, message, fonnteToken);
                    console.log(`📱 Notified student ${request.student_name} about approval`);
                }
            }
        } catch (waErr) {
            console.error('📱 Approval WA notification error:', waErr.message);
        }

        res.json({ success: true, message: 'Pengajuan disetujui.' });
    } catch (error) {
        console.error('PUT /api/leave-requests/:id/approve Error:', error);
        res.status(500).json({ error: error.message });
    }
});

// PUT /api/leave-requests/:id/reject - Reject leave request (by Guru BK)
router.put('/:id/reject', async (req, res) => {
    try {
        const { id } = req.params;
        const { reviewerId, reviewerName, rejectionReason } = req.body;

        if (!rejectionReason) {
            return res.status(400).json({ error: 'Alasan penolakan wajib diisi.' });
        }

        await pool.query(
            `UPDATE leave_requests SET status = 'REJECTED', reviewed_by = ?, reviewed_by_name = ?, reviewed_at = NOW(), rejection_reason = ? WHERE id = ?`,
            [reviewerId, reviewerName, rejectionReason, id]
        );

        console.log(`❌ Leave request ${id} REJECTED by ${reviewerName}: ${rejectionReason}`);

        // Send WhatsApp notification to student/parent
        try {
            // Get the request again to get student info
            const [reqRows] = await pool.query('SELECT * FROM leave_requests WHERE id = ?', [id]);
            if (reqRows.length > 0) {
                const request = reqRows[0];
                const [attendanceRows] = await pool.query(
                    "SELECT parent_phone FROM attendance WHERE user_id = ? AND parent_phone IS NOT NULL AND parent_phone != '' ORDER BY timestamp DESC LIMIT 1",
                    [request.student_id]
                );

                const studentPhone = attendanceRows.length > 0 ? attendanceRows[0].parent_phone : null;

                if (studentPhone) {
                    const [settings] = await pool.query("SELECT setting_value FROM settings WHERE setting_key = 'FONNTE_TOKEN'");
                    const fonnteToken = settings.length > 0 ? settings[0].setting_value : process.env.FONNTE_TOKEN;

                    if (fonnteToken) {
                        const message = `*❌ Pengajuan ${request.request_type} Ditolak*\n\n` +
                            `Halo *${request.student_name}*,\n` +
                            `Mohon maaf, pengajuan ${request.request_type} Anda untuk tanggal *${request.request_date}* telah *DITOLAK* oleh ${reviewerName}.\n\n` +
                            `*Alasan:* ${rejectionReason}\n\n` +
                            `Silakan hubungi Guru BK jika ada pertanyaan.`;

                        addToQueuePriority(studentPhone, message, fonnteToken);
                        console.log(`📱 Notified student ${request.student_name} about rejection`);
                    }
                }
            }
        } catch (waErr) {
            console.error('📱 Rejection WA notification error:', waErr.message);
        }

        res.json({ success: true, message: 'Pengajuan ditolak.' });
    } catch (error) {
        console.error('PUT /api/leave-requests/:id/reject Error:', error);
        res.status(500).json({ error: error.message });
    }
});

// DELETE /api/leave-requests/:id - Delete leave request
router.delete('/:id', async (req, res) => {
    try {
        const { id } = req.params;
        await pool.query('DELETE FROM leave_requests WHERE id = ?', [id]);
        res.json({ success: true, message: 'Pengajuan dihapus.' });
    } catch (error) {
        console.error('DELETE /api/leave-requests Error:', error);
        res.status(500).json({ error: error.message });
    }
});

export default router;