const canvas = document.getElementById('game');
const ctx = canvas.getContext('2d');

class Minesweeper {
    constructor(w, h, bombs) {
        this.size = 25;
        this.field = new Array(w);
        this.bombs = new Array(w);
        for (let x = 0; x < this.field.length; x++) {
            this.field[x] = new Array(h);
            this.bombs[x] = new Array(h);
            for (let y = 0; y < this.field.length; y++) {
                this.field[x][y] = 1;
                this.bombs[x][y] = false;
            }
        }

        for (let i = 0; i < bombs; i++) {
            let x = Math.floor(Math.random() * w);
            let y = Math.floor(Math.random() * h);
            this.bombs[x][y] ? i-- : this.bombs[x][y] = true;
        }

        this.drawField();
    }

    getNearbyBombs(x, y) {
        let counter = 0;
        for (let newX = x - 1; newX <= x + 1; newX++) {
            for (let newY = y - 1; newY <= y + 1; newY++) {
                if (newX < this.field.length && newX >= 0 && newY < this.field[0].length && newY >= 0) {
                    this.bombs[newX][newY] ? counter++ : {};
                }
            }
        }
        return counter;
    }

    checkWin() {
        for (let x = 0; x < this.field.length; x++) {
            for (let y = 0; y < this.field[x].length; y++) {
                if (this.field[x][y] != 0 && !this.bombs[x][y]) {
                    return;
                }
            }
        }
        this.drawField();
        alert("You won!");
        window.location.reload();
    }

    markSquare(x, y) {
        if (x < this.field.length && y < this.field[0].length) {
            switch (this.field[x][y]) {
                case 1:
                    this.field[x][y]++;
                    break;
                case 2:
                    this.field[x][y]++;
                    break;
                case 3:
                    this.field[x][y] = 1;
                    break;
                default:
                    break;
            }
            this.drawField();
        }
    }

    uncoverSquare(x, y) {
        if (x < this.field.length && x >= 0 && y < this.field[0].length && y >= 0) {
            if (this.bombs[x][y] && this.field[x][y] == 1) {
                alert("You lost!");
                window.location.reload();
            } else if (this.field[x][y] == 1) {
                this.field[x][y] = 0;
                if (this.getNearbyBombs(x, y) == 0) {
                    for (let newX = x - 1; newX <= x + 1; newX++) {
                        for (let newY = y - 1; newY <= y + 1; newY++) {
                            if (newX < this.field.length && newX >= 0 && newY < this.field[0].length && newY >= 0) {
                                this.field[newX][newY] == 1 ? this.uncoverSquare(newX, newY) : {};
                            }
                        }
                    }
                }
            };
            this.checkWin();
            this.drawField();
        }
    }

    drawSquare(x, y, type) {
        ctx.lineWidth = 3;
        x += 2, y += 2;
        type != 0 ? ctx.fillStyle = 'lightgrey' : ctx.fillStyle = 'darkgrey';
        ctx.fillRect(x * this.size, y * this.size, this.size, this.size);
        ctx.strokeStyle = 'black';
        ctx.strokeRect(x * this.size, y * this.size, this.size, this.size);
        if (type != 1) {
            const fontSize = this.size / 2;
            const number = this.getNearbyBombs(x - 2, y - 2)
            let finalPrint;
            ctx.font = `${fontSize}px monospace`;
            ctx.fillStyle = 'black';
            type == 0 ? finalPrint = number ? number : ' ' : {}
            type == 2 ? finalPrint = '🚩' : {}
            type == 3 ? finalPrint = '❓' : {}
            ctx.fillText(finalPrint, x * this.size + fontSize / (type == 0 ? 1.5 : 1.8), y * this.size + fontSize * 1.3);
        }
    }

    drawField() {
        canvas.width = window.innerWidth;
        canvas.height = window.innerHeight;
        const squareWidth = canvas.width / (this.field.length + 4);
        const squareHeight = canvas.height / (this.field[0].length + 4);
        squareHeight > squareWidth ? this.size = squareWidth : this.size = squareHeight;
        for (let x = 0; x < this.field.length; x++) {
            for (let y = 0; y < this.field[x].length; y++) {
                this.drawSquare(x, y, this.field[x][y]);
            }
        }
    }
}

let field = new Minesweeper(18, 18, 54);
window.addEventListener('resize', () => field.drawField());
canvas.addEventListener('click', (event) => {
    const rect = canvas.getBoundingClientRect();
    const x = Math.floor((event.clientX - rect.left - field.size * 2) / field.size);
    const y = Math.floor((event.clientY - rect.top - field.size * 2) / field.size);
    field.uncoverSquare(x, y)
});
canvas.addEventListener('contextmenu', (event) => {
    event.preventDefault();
    const rect = canvas.getBoundingClientRect();
    const x = Math.floor((event.clientX - rect.left - field.size * 2) / field.size);
    const y = Math.floor((event.clientY - rect.top - field.size * 2) / field.size);
    field.markSquare(x, y)
});