let totalMines = 15;
let gridWidth = 10;
let gridHeight = 10;
let grid, hasLost = false, hasWon = false;

function resetGame() {
	totalMines = parseInt(document.getElementById("tMines").value);
	gridWidth = parseInt(document.getElementById("gWidth").value);
	gridHeight = parseInt(document.getElementById("gHeight").value);
	
	hasWon = false;
	hasLost = false;
	grid = startGame();
}

function revealRest() {
	while (!hasWon) {
		let hasClickedOnce = false;
		for (let i = 0; i < gridHeight; i++) {
			for (let j = 0; j < gridWidth; j++) {
				if (!grid[i][j].isRevealed) {
					let current = grid[i][j].element;
					if (!grid[i][j].isFlagged && grid[i][j].isMine) {
						rightClickFunc(current);
						hasClickedOnce = true;
						break;
					} else if (!grid[i][j].isMine) {
						reveal(current);
						hasClickedOnce = true;
						break;
					}
				}
			}
			if (hasClickedOnce) {
				break;
			}
		}
		checkWin();
	}
}

function checkWin() {
	for (let i = 0; i < gridHeight; i++) {
		for (let j = 0; j < gridWidth; j++) {
			if (!grid[i][j].isRevealed && !grid[i][j].isFlagged) {
				return;
			}
		}
	}
	setTimeout(function(){
		alert("Du hast gewonnen!!!");
	}, 500);
	hasWon = true;
}

function endGame() {
	for (let i = 0; i < gridHeight; i++) {
		for (let j = 0; j < gridWidth; j++) {
			if (!grid[i][j].isFlagged) {
				grid[i][j].isRevealed = true;
				if (grid[i][j].isMine) {
					grid[i][j].element.src = "MINE.png";
				}
			}
		}
	}
	setTimeout(function(){
		alert("Du hast verloren!!!");
	}, 500);
	hasLost = true;
}

function reveal(eventTarget) {
	let et = eventTarget.parentElement;
	if (et && et.value) {
		let coords = et.value.split(' ');
		let clickY = parseInt(coords[0]);
		let clickX = parseInt(coords[1]);
		if (!grid[clickY][clickX].isFlagged) {
			let number, pDiv = document.createElement("div");
			let image = document.createElement("img");
			grid[clickY][clickX].isRevealed = true;
			if (grid[clickY][clickX].isMine) {
				image.src = "MINE.png";
				endGame();
			} else {
				image.src = "BLANK.png";
				let toBeRevealed = Array(), bombsNearby = 0;
				for (let i = -1; i < 2; i++) {
					for (let j = -1; j < 2; j++) {
						if (!(i == 0 && j == 0)) {
							const nY = clickY + i;
							const nX = clickX + j;
							if ((nX >= 0 && nX < gridWidth) && (nY >= 0 && nY < gridHeight)) {
								let nE = grid[nY][nX];
								if (!nE.isMine) {
									if (!nE.isRevealed) {
										toBeRevealed.push(nE.element);
									}
								} else {
									bombsNearby++;
									grid[clickY][clickX].isNumber = true;
								}
							}
						}
					}
				}
				if (bombsNearby == 0) {
					toBeRevealed.forEach(e=>{
						reveal(e);
					});
				} else {
					number = document.createElement("a");
					number.innerText = bombsNearby;
				}
				pDiv.appendChild(image);
				if (number) {
					pDiv.appendChild(number);
				}
				pDiv.ondblclick = doubleClickFunc;
				et.replaceChildren(pDiv);
				grid[clickY][clickX].element = image;
			}
			if (!hasLost) {
				checkWin();
			}
		}
	}
}

function doubleClickFunc(event) {
	if (!hasLost) {
		let et = event.target.parentElement.parentElement;
		if (et && et.value) {
			let coords = et.value.split(' ');
			let clickY = parseInt(coords[0]);
			let clickX = parseInt(coords[1]);
			if (grid[clickY][clickX].isNumber) {
				let toBeRevealed = Array();
				for (let i = -1; i < 2; i++) {
					for (let j = -1; j < 2; j++) {
						if (!(i == 0 && j == 0)) {
							const nY = clickY + i;
							const nX = clickX + j;
							if ((nX >= 0 && nX < gridWidth) && (nY >= 0 && nY < gridHeight)) {
								let nE = grid[nY][nX];
								if (nE.isMine && !nE.isFlagged) {
									endGame();
									break;
								} else {
									if (!nE.isRevealed) {
										toBeRevealed.push(nE.element);
									}
								}
							}
						}
					}
					if (hasLost) {
						break;
					}
				}
				if (!hasLost) {
					if (!checkWin()) {
						toBeRevealed.forEach(e=>{
							reveal(e);
						});
					}
				}
			}
		}
	}
}

function setFlag(eventTarget) {
	let et = eventTarget.parentElement;
	if (et && et.value) {
		let coords = et.value.split(' ');
		let clickY = parseInt(coords[0]);
		let clickX = parseInt(coords[1]);
		if (!grid[clickY][clickX].isRevealed) {
			let image = grid[clickY][clickX].element;
			if (!grid[clickY][clickX].isFlagged) {
				image.src = "FLAG.png";
				et.replaceChildren(image);
			} else {
				image.src = "PLATZHALTER.png";
				et.replaceChildren(image);
			}
			grid[clickY][clickX].isFlagged = !grid[clickY][clickX].isFlagged;
		}
	}
}

function rightClickFunc(event) {
	if (event.target) {
		event.preventDefault();
		if (!hasLost) {
			setFlag(event.target);
		}
	} else {
		setFlag(event);
	}
}

function onClickFunc(event) {
	if (!hasLost) {
		reveal(event.target);
	}
}

function startGame() {
	let g = Array();
	for (let i = 0; i < gridHeight; i++) {
		g.push(Array(gridWidth));
	}
	let t = document.getElementById("Game");
	t.innerHTML = "";
	for (let i = 0; i < gridHeight; i++) {
		let r = document.createElement("tr");
		for (let j = 0; j < gridWidth; j++) {
			let d = document.createElement("td");
			let image = document.createElement("img");
			image.src = "PLATZHALTER.png";
			image.onclick = onClickFunc;
			image.oncontextmenu = rightClickFunc;
			d.appendChild(image);
			d.value = i + " " + j;
			r.appendChild(d);
			g[i][j] = new Block(image);
		}
		t.appendChild(r);
	}
	let mC = 0;
	while (mC < totalMines) {
		let mX = Math.floor(Math.random()*gridWidth);
		let mY = Math.floor(Math.random()*gridHeight);
		if (!g[mY][mX].isMine) {
			g[mY][mX].isMine=true;
			mC++;
		}
	}
	return g;
}

function init() {
	grid = startGame();
	document.getElementById("gWidth").oninput = function() {
		let gHValue = document.getElementById("gHeight").value;
		let value = Math.floor(parseInt(this.value) * parseInt(gHValue) * 0.1);
		document.getElementById("tMines").max = value;
	};
	document.getElementById("gHeight").oninput = function() {
		let gWValue = document.getElementById("gWidth").value;
		let value = Math.floor(parseInt(this.value) * parseInt(gWValue) * 0.1) ;
		document.getElementById("tMines").max = value+"";
	};
}

class Block {
	constructor(e_) {
		this.element = e_;
		this.isMine = false;
		this.isRevealed = false;
		this.isFlagged = false;
		this.isNumber = false;
	}
}