// this file should contain a class that gets info from /api/showings/{id}
// and renders the seat chooser
// there may be multiple seats selected at once
// the input is a matrix with null OR a seat object

class Seat {
    constructor(id, row, col, linked, reserved) {
        this.id = id; // database id
        this.row = row;
        this.col = col;
        this.linked = linked; // linked seat
        this.reserved = reserved;
    }
}

class SeatChooser {
    constructor(showingId, container) {
        if (container.innerText === '') {
            container.innerText = 'Loading...';
        }
        this.showingId = showingId; // id of the showing
        this.container = container; // the container to render the seat chooser in

        this.seats = []; // array of nulls and Seat objects

        this.selectedSeats = []; // array of Seat objects

        this.init();
    }

    async init() {
        let showingJson = await (await fetch(`/api/showings/${this.showingId}`)).json();
        let roomMatrix = await (await fetch(`/api/showings/${this.showingId}/seatMatrix`)).json();
        // Matrix<json | null> -> Matrix<Seat | null>
        console.log("Matrix<json | null> -> Matrix<Seat | null>");
        this.seats = roomMatrix.map((row, rowIndex) => {
            return row.map((seat, colIndex) => {
                if (seat === null) {
                    return null;
                }
                return new Seat(
                    seat['seat_id'],
                    seat['seat_row'],
                    seat['seat_column'],
                    seat['seat_linked_id'],
                    seat['reserved']
                );
            });
        });
        console.log(this.seats);
        this.render();
    }

    render() {
        console.log("rendering");
        let linkedCache = false;
        // render the seat chooser
        this.container.innerHTML = '';
        // this -> row -> seat
        this.seats.forEach((row, rowIndex) => {
            let rowDiv = document.createElement('div');
            rowDiv.classList.add('row');
            row.forEach((seat, colIndex) => {
                let seatDiv = document.createElement('div');
                if (seat) {
                    seatDiv.classList.add('seat');
                    seatDiv.classList.add(seat.reserved ? 'reserved' : 'available');

                    if (seat.linked) {
                        // if cache is false, then this is the first seat in the linked pair
                        if (!linkedCache) {
                            seatDiv.classList.add('linked-left');
                            linkedCache = true;
                        } else {
                            seatDiv.classList.add('linked-right');
                            linkedCache = false;
                        }
                    } else {
                        linkedCache = false;
                    }

                    seatDiv.innerText = `${seat.row}-${seat.col}`;

                    seatDiv.dataset.id = seat.id;
                    seatDiv.dataset.row = seat.row;
                    seatDiv.dataset.col = seat.col;

                    seatDiv.addEventListener('click', (e) => {
                        this.toggleSeat(seat, e);
                    });
                } else {
                    seatDiv.classList.add('no-seat');
                }
                rowDiv.appendChild(seatDiv);
            });
            this.container.appendChild(rowDiv);
        });
    }

    toggleSeat(seat, e) {
        // toggle the seat
        // because of linked seats, we need to toggle both seats
        if (seat.reserved) return;
        e.target.classList.toggle('selected');
        if (seat.linked) {
            // beware that you can click on the left or right seat
            // the left seat has class linked-left and the right seat has class linked-right
            let leftbool = e.target.classList.contains('linked-left');
            let linkedSeat = this.seats[seat.row - 1][leftbool ? seat.col - 1 : seat.col + 1];
            if (leftbool) e.target.nextElementSibling.classList.toggle('selected');
            else e.target.previousElementSibling.classList.toggle('selected');
            if (this.selectedSeats.includes(linkedSeat)) {
                this.selectedSeats.splice(this.selectedSeats.indexOf(linkedSeat), 1);
                this.selectedSeats.splice(this.selectedSeats.indexOf(seat), 1);
            } else {
                this.selectedSeats.push(linkedSeat);
                this.selectedSeats.push(seat);
            }
        } else {
            if (this.selectedSeats.includes(seat)) {
                this.selectedSeats.splice(this.selectedSeats.indexOf(seat), 1);
            } else {
                this.selectedSeats.push(seat);
            }
        }
    }
}

let seatChooser = new SeatChooser(1, document.getElementById('seat-chooser'));