const canvas = document.getElementById("mapCanvas");
const fogCanvas = document.createElement("canvas");
const ctx = canvas.getContext("2d");
const fogCtx = fogCanvas.getContext("2d");
const iframe = document.getElementById("worldmap-iframe");

let image = null;
let offsetX = 0, offsetY = 0;
let scale = 1;
let isDragging = false;
let startX, startY;
let fogEnabled = false;
let fogMode = "erase";
let brushSize = 50;
let mouseX = 0, mouseY = 0;

const channel = new BroadcastChannel("mapsync");
let MapX = 0;
let MapY = 0;
let MapZoom = 2;

function resizeCanvas() {
  canvas.width = window.innerWidth;
  canvas.height = window.innerHeight;
  draw();
  if (fogEnabled) drawBrushPreview(mouseX, mouseY);
}
window.addEventListener("resize", resizeCanvas);
resizeCanvas();

// === Fog Controls ===
document.getElementById("toggleFog").addEventListener("change", (e) => {
  fogEnabled = e.target.checked;
  channel.postMessage({ type: "fogEnabled", enabled: fogEnabled });
  draw();
  if (fogEnabled) drawBrushPreview(mouseX, mouseY);
});

document.getElementById("fogMode").addEventListener("click", () => {
  fogMode = fogMode === "erase" ? "paint" : "erase";
  document.getElementById("fogMode").innerText = fogMode === "erase" ? "Modus: Radierer" : "Modus: Nebel";
});

document.getElementById("fogClear").addEventListener("click", () => {
  const btn = document.getElementById("fogClear");
  btn.disabled = true;
  setTimeout(() => btn.disabled = false, 1000);
  fogCtx.clearRect(0, 0, fogCanvas.width, fogCanvas.height);
  syncFog(); draw();
  if (fogEnabled) drawBrushPreview(mouseX, mouseY);
});

document.getElementById("fogFull").addEventListener("click", () => {
  const btn = document.getElementById("fogFull");
  btn.disabled = true;
  setTimeout(() => btn.disabled = false, 1000);
  fogCtx.fillStyle = "rgba(50, 50, 50, 1)";
  fogCtx.fillRect(0, 0, fogCanvas.width, fogCanvas.height);
  syncFog(); draw();
  if (fogEnabled) drawBrushPreview(mouseX, mouseY);
});

document.getElementById("brushSize").addEventListener("input", (e) => {
  brushSize = 50 * parseInt(e.target.value);
});

// === Mouse Interaktion ===
canvas.addEventListener("dragover", e => e.preventDefault());
canvas.addEventListener("drop", e => {
  e.preventDefault();
  const file = e.dataTransfer.files[0];
  const reader = new FileReader();
  reader.onload = evt => {
    const img = new Image();
    img.onload = () => {
      image = img;
      //Fog auf Größe des Geladenen Bildes anpassen.
      fogCanvas.width = img.width;
      fogCanvas.height = img.height;
      fogCtx.clearRect(0, 0, fogCanvas.width, fogCanvas.height);
      draw();
      if (fogEnabled) drawBrushPreview(mouseX, mouseY);
      channel.postMessage({ type: "mapData", data: evt.target.result });
      channel.postMessage({ type: "fogEnabled", enabled: fogEnabled });
      syncFog();
    };
    img.src = evt.target.result;
  };
  reader.readAsDataURL(file);
});

function LoadImageMap(i) {
  const img = new Image();
  img.onload = () => {
    image = img;
    fogCanvas.width = img.width;
    fogCanvas.height = img.height;
    fogCtx.clearRect(0, 0, fogCanvas.width, fogCanvas.height);
    draw();
    if (fogEnabled) drawBrushPreview(mouseX, mouseY);
    channel.postMessage({ type: "mapData", data: i });
    channel.postMessage({ type: "fogEnabled", enabled: fogEnabled });
    syncFog();
  };
  img.src = i;
}

window.LoadImageMap = LoadImageMap;

canvas.addEventListener("mousedown", e => {
  if (e.button === 1) {
    isDragging = true;
    startX = e.clientX - offsetX;
    startY = e.clientY - offsetY;
  }
});
canvas.addEventListener("mouseup", () => { isDragging = false; });
canvas.addEventListener("mouseout", () => { isDragging = false; });
canvas.addEventListener("mousemove", e => {
  mouseX = e.clientX;
  mouseY = e.clientY;
  if (fogEnabled) draw();
  if (isDragging) {
    offsetX = e.clientX - startX;
    offsetY = e.clientY - startY;
    syncView();
    draw();
    if (fogEnabled) drawBrushPreview(mouseX, mouseY);
  } else if (fogEnabled && e.buttons === 1) {
    const x = (mouseX - offsetX) / scale;
    const y = (mouseY - offsetY) / scale;
    fogCtx.globalCompositeOperation = fogMode === "erase" ? "destination-out" : "source-over";
    fogCtx.fillStyle = "rgba(50, 50, 50, 0.9)";
    fogCtx.beginPath();
    fogCtx.arc(x, y, brushSize, 0, 2 * Math.PI);
    fogCtx.fill();
    syncFog(); draw();
    drawBrushPreview(mouseX, mouseY);
  }
});

canvas.addEventListener("wheel", e => {
  e.preventDefault();
  const worldX = (e.clientX - offsetX) / scale;
  const worldY = (e.clientY - offsetY) / scale;
  const zoomFactor = e.deltaY < 0 ? 1.1 : 0.9;
  scale *= zoomFactor;
  offsetX = e.clientX - worldX * scale;
  offsetY = e.clientY - worldY * scale;
  syncView(); draw();
  if (fogEnabled) drawBrushPreview(mouseX, mouseY);
});

function syncView() {
  channel.postMessage({ type: "viewData", offsetX, offsetY, scale });
}

function syncFog() {
  const fogURL = fogCanvas.toDataURL("image/png");
  channel.postMessage({ type: "fogData", data: fogURL });
}

function draw() {
  ctx.setTransform(scale, 0, 0, scale, offsetX, offsetY);
  ctx.clearRect(-offsetX / scale, -offsetY / scale, canvas.width / scale, canvas.height / scale);
  if (image) ctx.drawImage(image, 0, 0);
  if (fogEnabled && fogCanvas.width && fogCanvas.height) {
    ctx.globalAlpha = 0.4;
    ctx.drawImage(fogCanvas, 0, 0);
    ctx.globalAlpha = 1;
  }
  if (fogEnabled) drawBrushPreview(mouseX, mouseY);
}

function drawBrushPreview(mouseX, mouseY) {
  const worldX = (mouseX - offsetX) / scale;
  const worldY = (mouseY - offsetY) / scale;
  ctx.save();
  ctx.setTransform(scale, 0, 0, scale, offsetX, offsetY);
  ctx.strokeStyle = "rgba(255,255,255,0.8)";
  ctx.lineWidth = 2 / scale;
  ctx.beginPath();
  ctx.arc(worldX, worldY, brushSize, 0, 2 * Math.PI);
  ctx.stroke();
  ctx.restore();
}

window.addEventListener("keydown", (e) => {
  if (e.key.toLowerCase() === "f") {
    fogEnabled = !fogEnabled;
    document.getElementById("toggleFog").checked = fogEnabled;
    channel.postMessage({ type: "fogEnabled", enabled: fogEnabled });
    draw();
  }
});

document.getElementById("toggleHexgrid").addEventListener("change", (e) => {
  channel.postMessage({ type: "hexgrid", enabled: e.target.checked });
});

document.getElementById("gridScaleSlider").addEventListener("input", (e) => {
  const scale = parseFloat(e.target.value);
  channel.postMessage({ type: "hexgridScale", scale });
});



// === Weltkarte Funktionen ===
let worldMapMode = false;
let previousImageSrc = null;

// === Leaflet View Update Intervall ===
setInterval(() => {
  const iframe = document.getElementById("worldmap-iframe");
  if (iframe?.contentWindow && worldMapMode) {
    iframe.contentWindow.postMessage("getView", "*");
  }
}, 500);

window.addEventListener("message", (event) => {
  const data = event.data;
  if (data?.type === "viewData") {
    MapX = data.center.lng;
    MapY = data.center.lat;
    MapZoom = data.zoom;
    channel.postMessage({ type: "MapCoord", MapX, MapY, MapZoom}); //Dem Slave die Karten Werte schicken.
  }
});

const mapButton = document.getElementById("mapToggleButton");
if (mapButton) {
  mapButton.addEventListener("click", () => {
    if (!worldMapMode) {
      previousImageSrc = image?.src || "pause.png";
      loadMap();
      channel.postMessage({ type: "mapMode", enabled: true });
      mapButton.textContent = "↩️";
      worldMapMode = true;
      syncWorldMapView();
    } else {
      restoreImage(previousImageSrc);
      channel.postMessage({ type: "mapMode", enabled: false });
      mapButton.textContent = "🗺";
      worldMapMode = false;
    }
  });
}

//Laden der iframe WorldMap
function loadMap() {
  const iframe = document.getElementById("worldmap-iframe");
  if (!iframe) return;
  iframe.style.display = "block";
  if (iframe.contentWindow) {
    iframe.contentWindow.postMessage({ action: "syncRequest" }, "*");
  } else {
    iframe.onload = () => {
      iframe.contentWindow.postMessage({ action: "syncRequest" }, "*");
    };
  }
}
//Nach dem schließen der iframe WorldMap, wieder die letzte Map herstellen.
function restoreImage(src) {
  const iframe = document.getElementById("worldmap-iframe");
  const canvas = document.getElementById("mapCanvas");

  if (iframe) iframe.style.display = "none";
  if (canvas) canvas.style.display = "block";
  if (!src) return;

  const img = new Image();
  img.onload = () => {
    image = img;
    fogCanvas.width = img.width;
    fogCanvas.height = img.height;
    fogCtx.clearRect(0, 0, fogCanvas.width, fogCanvas.height);
    draw();
  };
  img.src = src;
}

function syncWorldMapView() {
  const iframe = document.getElementById("worldmap-iframe");
  if (worldMapMode && iframe?.contentWindow) {
    iframe.contentWindow.postMessage("getView", "*");
  }
}