/**
 * Import required dependencies.
 */
import express from 'express';
import Appointment from "../schemas/appointmentSchema.js";
import Booking from "../schemas/bookingSchema.js";
import {isDueDatePassed, isInputValid, isValidEmail} from "../utils.js";

/**
 * Create an Express router for handling appointment-related routes.
 */
const router = express.Router();

/**
 * Create a new appointment and associate it with a booking.
 */
router.post('/create', async function(req, res, next) {
    const { appointmentId, time, inputs } = req.body;

    if (!appointmentId || !time || !inputs) {
        console.log(appointmentId);
        console.log(time);
        console.log(inputs);
        res.status(400).json({ 'message': 'Parameters are incomplete' });
        return;
    }

    // TODO validate times

    // advanced input validation
    // get constraints from database



    try {
        const existingAppointment = await Appointment.findOne({ _id: appointmentId });
        if (!existingAppointment) {
            return res.status(404).json({ message: 'appointment does not exist' });
        }
        
        const bookingDate = new Date(Date.parse(time));

        if (!existingAppointment.times.find(input => input.date.toString() === bookingDate.toString() && input.available === true)) {
            res.status(400).json({ 'message': 'This appointment time is not available' });
            return;
        }


        if (!isInputValid(inputs, existingAppointment.inputs)) {
            res.status(400).json({ 'message': 'Custom inputs are invalid' });
            return;
        }

        if (isDueDatePassed(existingAppointment["dueDate"])) {
            return res.status(401).json({ message: 'appointment registration is closed' });
        }

        const duplicateBooking = await Booking.findOne({ appointment: appointmentId, time, inputs: inputs })
            .catch(err => {
                console.log(err);
            });

        if (duplicateBooking) {
            return res.status(404).json({ message: 'already registered' });
        }

        let times = existingAppointment.times;
        const index = times.findIndex(element => element.date.toString() === bookingDate.toString());
        if (index === -1) {
            return res.status(404).json({ message: 'registration time not found' });
        }

        times[index].available = false;

        await Appointment.updateOne(
            { _id: appointmentId },
            { $set: { times } }
        )
            .then(result => {
                if (result.modifiedCount === 1) {
                    console.log("Successfully updated the document.");
                } else {
                    console.log("Document not updated");
                    return res.status(500).json({ 'message': 'Document has not changed' });
                }
            })
            .catch(err => {
                return res.status(404).json({ 'message': 'Not found' })
            });

        const newBooking = new Booking({ appointment: appointmentId, time, inputs });

        newBooking.save()
            .then(doc => res.json({ "success": true }))
            .catch(err => res.status(500).json({ 'error': err }));

    } catch (err) {
        // Handle errors
        console.error(err);
        return res.status(500).json({ error: 'Internal Server Error' });
    }
});

/**
 * Retrieve an appointment by ID.
 */
router.get('/', function (req, res, next) {
    const {appointmentId, isUser} = req.query;
    Appointment.findOne({ _id: appointmentId })
        .then(appointment => {
            if (appointment === null) {
                res.status(404).json({'message': "Appointment not found"});
            } else {
                // Check if a registered user accesses this endpoint
                if (isDueDatePassed(appointment["dueDate"]) && !isUser) {
                    return res.status(410).json({ message: 'appointment registration is closed' });
                } else {
                    res.json(appointment);
                }
            }
        })
        .catch(err => {
            res.status(404).json({'message': "Appointment not found"});
        });
});

export { router };