const ROLE_ORDER = ["BackgroundFar", "BackgroundMid", "LevelVisual", "PropsBack", "PropsFront"];

const state = {
  map: createEmptyMap(),
  selected: null,
  view: { x: -80, y: -40, scale: 0.35 },
  gridSize: 10,
  dragging: null,
};

const elements = {};

document.addEventListener("DOMContentLoaded", () => {
  bindElements();
  bindEvents();
  resizeCanvas();
  loadSampleMap();
});

function bindElements() {
  for (const id of [
    "mapCanvas", "fileInput", "loadSampleButton", "downloadButton",
    "mapIdInput", "worldWidthInput", "worldHeightInput", "gridSizeInput",
    "objectList", "propertyPanel", "selectionSummary", "deleteButton",
    "tilesetList", "outputText", "statusText", "viewText",
    "addTilesetButton", "addLayerButton", "addCollisionButton",
    "addTileRectButton", "addBattleZoneButton", "addSpawnButton",
  ]) {
    elements[id] = document.getElementById(id);
  }
}

function bindEvents() {
  window.addEventListener("resize", resizeCanvas);
  elements.loadSampleButton.addEventListener("click", loadSampleMap);
  elements.fileInput.addEventListener("change", openFile);
  elements.downloadButton.addEventListener("click", downloadMap);
  elements.deleteButton.addEventListener("click", deleteSelected);

  elements.mapIdInput.addEventListener("change", () => {
    state.map.id = elements.mapIdInput.value.trim() || "stage";
    refresh();
  });
  elements.worldWidthInput.addEventListener("change", () => {
    state.map.world.width = numberValue(elements.worldWidthInput, state.map.world.width);
    refresh();
  });
  elements.worldHeightInput.addEventListener("change", () => {
    state.map.world.height = numberValue(elements.worldHeightInput, state.map.world.height);
    refresh();
  });
  elements.gridSizeInput.addEventListener("change", () => {
    state.gridSize = Math.max(1, numberValue(elements.gridSizeInput, state.gridSize));
    refresh();
  });

  elements.addCollisionButton.addEventListener("click", addCollision);
  elements.addTilesetButton.addEventListener("click", addTileset);
  elements.addLayerButton.addEventListener("click", addLayer);
  elements.addTileRectButton.addEventListener("click", addTileRect);
  elements.addBattleZoneButton.addEventListener("click", addBattleZone);
  elements.addSpawnButton.addEventListener("click", addSpawn);

  const canvas = elements.mapCanvas;
  canvas.addEventListener("mousedown", onCanvasMouseDown);
  canvas.addEventListener("mousemove", onCanvasMouseMove);
  canvas.addEventListener("mouseup", onCanvasMouseUp);
  canvas.addEventListener("mouseleave", onCanvasMouseUp);
  canvas.addEventListener("wheel", onCanvasWheel, { passive: false });
}

async function loadSampleMap() {
  try {
    const response = await fetch("../../game/assets/map/stage_01.map");
    if (!response.ok) {
      throw new Error(`HTTP ${response.status}`);
    }
    loadMapText(await response.text(), "Loaded stage_01.map");
  } catch (error) {
    setStatus(`Could not fetch stage_01.map. Use Open .map. ${error.message}`);
    loadMapText(defaultMapText(), "Loaded built-in starter map");
  }
}

function openFile(event) {
  const file = event.target.files[0];
  if (!file) return;
  const reader = new FileReader();
  reader.onload = () => loadMapText(String(reader.result || ""), `Opened ${file.name}`);
  reader.readAsText(file);
}

function loadMapText(text, status) {
  try {
    state.map = parseMap(text);
    state.selected = null;
    fitWorldToCanvas();
    setStatus(status);
    refresh();
  } catch (error) {
    setStatus(`Parse failed: ${error.message}`);
  }
}

function createEmptyMap() {
  return {
    id: "stage",
    world: { width: 1280, height: 720 },
    camera: { x: 0, y: 0, width: 1280, height: 720 },
    playerSpawn: { x: 120, y: 520 },
    collisions: [],
    tilesets: [],
    layers: [],
    battleZones: [],
  };
}

function parseMap(text) {
  const map = createEmptyMap();
  map.collisions = [];
  map.tilesets = [];
  map.layers = [];
  map.battleZones = [];

  let currentLayer = null;
  let currentBattleZone = null;
  const lines = text.split(/\r?\n/);
  for (let index = 0; index < lines.length; index += 1) {
    const tokens = tokenize(lines[index]);
    if (!tokens.length) continue;
    const command = tokens[0];
    const lineNumber = index + 1;

    if (command === "map") {
      map.id = requireToken(tokens, 1, lineNumber);
    } else if (command === "world") {
      map.world = { width: num(tokens, 1, lineNumber), height: num(tokens, 2, lineNumber) };
    } else if (command === "camera") {
      map.camera = rectFrom(tokens, 1, lineNumber);
    } else if (command === "player_spawn") {
      map.playerSpawn = { x: num(tokens, 1, lineNumber), y: num(tokens, 2, lineNumber) };
    } else if (command === "collision") {
      map.collisions.push(rectFrom(tokens, 1, lineNumber));
    } else if (command === "tileset") {
      map.tilesets.push({
        id: requireToken(tokens, 1, lineNumber),
        texture: requireToken(tokens, 2, lineNumber),
        tileWidth: num(tokens, 3, lineNumber),
        tileHeight: num(tokens, 4, lineNumber),
        color: colorFrom(tokens, 5, lineNumber, true),
      });
    } else if (command === "layer") {
      currentLayer = {
        id: requireToken(tokens, 1, lineNumber),
        role: requireToken(tokens, 2, lineNumber),
        parallax: num(tokens, 3, lineNumber),
        rects: [],
        tileRects: [],
      };
      map.layers.push(currentLayer);
    } else if (command === "endlayer") {
      currentLayer = null;
    } else if (command === "rect") {
      requireLayer(currentLayer, lineNumber);
      currentLayer.rects.push({ bounds: rectFrom(tokens, 1, lineNumber), color: colorFrom(tokens, 5, lineNumber, true) });
    } else if (command === "rect_sprite" || command === "rect_sprite_src") {
      requireLayer(currentLayer, lineNumber);
      const item = {
        bounds: rectFrom(tokens, 1, lineNumber),
        color: colorFrom(tokens, 5, lineNumber, true),
        texture: requireToken(tokens, 9, lineNumber),
        source: null,
      };
      if (command === "rect_sprite_src") {
        item.source = rectFrom(tokens, 10, lineNumber);
      }
      currentLayer.rects.push(item);
    } else if (command === "tile_rect") {
      requireLayer(currentLayer, lineNumber);
      currentLayer.tileRects.push({
        tileset: requireToken(tokens, 1, lineNumber),
        x: num(tokens, 2, lineNumber),
        y: num(tokens, 3, lineNumber),
        columns: intNum(tokens, 4, lineNumber),
        rows: intNum(tokens, 5, lineNumber),
        tileIndex: intNum(tokens, 6, lineNumber),
        color: colorFrom(tokens, 7, lineNumber, false),
      });
    } else if (command === "battle_zone") {
      currentBattleZone = {
        id: requireToken(tokens, 1, lineNumber),
        trigger: rectFrom(tokens, 2, lineNumber),
        camera: rectFrom(tokens, 6, lineNumber),
        spawns: [],
      };
      map.battleZones.push(currentBattleZone);
    } else if (command === "spawn") {
      if (!currentBattleZone) throw new Error(`Line ${lineNumber}: spawn outside battle_zone`);
      currentBattleZone.spawns.push({
        id: requireToken(tokens, 1, lineNumber),
        x: num(tokens, 2, lineNumber),
        y: num(tokens, 3, lineNumber),
      });
    } else if (command === "endbattle_zone") {
      currentBattleZone = null;
    } else {
      throw new Error(`Line ${lineNumber}: unknown command ${command}`);
    }
  }

  return map;
}

function serializeMap(map) {
  const lines = [];
  lines.push(`map ${map.id}`);
  lines.push(`world ${fmt(map.world.width)} ${fmt(map.world.height)}`);
  lines.push(`camera ${rectText(map.camera)}`);
  lines.push(`player_spawn ${fmt(map.playerSpawn.x)} ${fmt(map.playerSpawn.y)}`);
  lines.push("");

  for (const item of map.collisions) lines.push(`collision ${rectText(item)}`);
  lines.push("");

  for (const tileset of map.tilesets) {
    lines.push(`tileset ${tileset.id} ${tileset.texture} ${fmt(tileset.tileWidth)} ${fmt(tileset.tileHeight)} ${colorText(tileset.color, true)}`);
  }
  lines.push("");

  for (const layer of sortLayers(map.layers)) {
    lines.push(`layer ${layer.id} ${layer.role} ${fmt(layer.parallax)}`);
    for (const rect of layer.rects) {
      if (rect.texture && rect.source) {
        lines.push(`rect_sprite_src ${rectText(rect.bounds)} ${colorText(rect.color, true)} ${rect.texture} ${rectText(rect.source)}`);
      } else if (rect.texture) {
        lines.push(`rect_sprite ${rectText(rect.bounds)} ${colorText(rect.color, true)} ${rect.texture}`);
      } else {
        lines.push(`rect ${rectText(rect.bounds)} ${colorText(rect.color, true)}`);
      }
    }
    for (const tileRect of layer.tileRects) {
      lines.push(`tile_rect ${tileRect.tileset} ${fmt(tileRect.x)} ${fmt(tileRect.y)} ${fmt(tileRect.columns)} ${fmt(tileRect.rows)} ${fmt(tileRect.tileIndex)} ${colorText(tileRect.color, false)}`);
    }
    lines.push("endlayer");
    lines.push("");
  }

  for (const zone of map.battleZones) {
    lines.push(`battle_zone ${zone.id} ${rectText(zone.trigger)} ${rectText(zone.camera)}`);
    for (const spawn of zone.spawns) lines.push(`spawn ${spawn.id} ${fmt(spawn.x)} ${fmt(spawn.y)}`);
    lines.push("endbattle_zone");
    lines.push("");
  }

  return `${lines.join("\n").trim()}\n`;
}

function refresh() {
  elements.mapIdInput.value = state.map.id;
  elements.worldWidthInput.value = state.map.world.width;
  elements.worldHeightInput.value = state.map.world.height;
  elements.gridSizeInput.value = state.gridSize;
  elements.outputText.value = serializeMap(state.map);
  renderTilesets();
  renderObjectList();
  renderPropertyPanel();
  drawCanvas();
}

function renderTilesets() {
  elements.tilesetList.innerHTML = "";
  for (const tileset of state.map.tilesets) {
    const node = document.createElement("button");
    node.type = "button";
    node.className = "tileset-item";
    node.innerHTML = `<div class="object-title">${escapeHtml(tileset.id)}</div><div class="object-meta">${escapeHtml(tileset.texture)} | ${tileset.tileWidth}x${tileset.tileHeight}</div>`;
    node.addEventListener("click", () => {
      const index = state.map.tilesets.indexOf(tileset);
      state.selected = `tileset:${index}`;
      refresh();
    });
    elements.tilesetList.appendChild(node);
  }
}

function renderObjectList() {
  const objects = collectObjects();
  elements.objectList.innerHTML = "";
  for (const object of objects) {
    const node = document.createElement("button");
    node.type = "button";
    node.className = `object-item ${sameSelection(object.key, state.selected) ? "active" : ""}`;
    node.innerHTML = `<div class="object-title">${escapeHtml(object.title)}</div><div class="object-meta">${escapeHtml(object.meta)}</div>`;
    node.addEventListener("click", () => {
      state.selected = object.key;
      refresh();
    });
    elements.objectList.appendChild(node);
  }
}

function renderPropertyPanel() {
  const object = getSelectedObject();
  elements.propertyPanel.innerHTML = "";
  if (!object) {
    elements.selectionSummary.textContent = "Nothing selected.";
    elements.deleteButton.disabled = true;
    return;
  }

  elements.selectionSummary.textContent = `${object.title} | ${object.meta}`;
  elements.deleteButton.disabled = !object.deletable;
  const fields = object.fields();
  for (const field of fields) {
    const label = document.createElement("label");
    label.textContent = field.label;
    let input;
    if (field.options) {
      input = document.createElement("select");
      for (const option of field.options) {
        const node = document.createElement("option");
        node.value = option;
        node.textContent = option;
        input.appendChild(node);
      }
    } else {
      input = document.createElement("input");
      input.type = field.type || "number";
      if (input.type === "number") input.step = field.step || "1";
    }
    input.value = field.get();
    input.addEventListener("change", () => {
      field.set(input.type === "number" ? Number(input.value) : input.value);
      refresh();
    });
    label.appendChild(input);
    elements.propertyPanel.appendChild(label);
  }
}

function drawCanvas() {
  const canvas = elements.mapCanvas;
  const ctx = canvas.getContext("2d");
  ctx.clearRect(0, 0, canvas.width, canvas.height);
  ctx.save();
  ctx.translate(-state.view.x * state.view.scale, -state.view.y * state.view.scale);
  ctx.scale(state.view.scale, state.view.scale);

  drawWorld(ctx);
  drawGrid(ctx);
  drawLayers(ctx);
  drawCollisions(ctx);
  drawBattleZones(ctx);
  drawPlayerSpawn(ctx);
  drawSelection(ctx);

  ctx.restore();
  elements.viewText.textContent = `zoom ${state.view.scale.toFixed(2)} | grid ${state.gridSize}`;
}

function drawWorld(ctx) {
  ctx.fillStyle = "#151a20";
  ctx.fillRect(0, 0, state.map.world.width, state.map.world.height);
  ctx.strokeStyle = "#53606d";
  ctx.lineWidth = 2 / state.view.scale;
  ctx.strokeRect(0, 0, state.map.world.width, state.map.world.height);

  ctx.strokeStyle = "#4f7cff";
  ctx.setLineDash([12 / state.view.scale, 8 / state.view.scale]);
  ctx.strokeRect(state.map.camera.x, state.map.camera.y, state.map.camera.width, state.map.camera.height);
  ctx.setLineDash([]);
}

function drawGrid(ctx) {
  const step = Math.max(1, state.gridSize);
  ctx.strokeStyle = "rgba(255,255,255,0.05)";
  ctx.lineWidth = 1 / state.view.scale;
  for (let x = 0; x <= state.map.world.width; x += step) {
    ctx.beginPath();
    ctx.moveTo(x, 0);
    ctx.lineTo(x, state.map.world.height);
    ctx.stroke();
  }
  for (let y = 0; y <= state.map.world.height; y += step) {
    ctx.beginPath();
    ctx.moveTo(0, y);
    ctx.lineTo(state.map.world.width, y);
    ctx.stroke();
  }
}

function drawLayers(ctx) {
  for (const layer of sortLayers(state.map.layers)) {
    for (const rect of layer.rects) drawFilledRect(ctx, rect.bounds, rect.color, 0.55, "#7d8794");
    for (const tileRect of layer.tileRects) drawTileRect(ctx, tileRect);
  }
}

function drawTileRect(ctx, tileRect) {
  const tileset = state.map.tilesets.find((item) => item.id === tileRect.tileset);
  const tw = tileset ? tileset.tileWidth : 10;
  const th = tileset ? tileset.tileHeight : 10;
  const bounds = { x: tileRect.x, y: tileRect.y, width: tileRect.columns * tw, height: tileRect.rows * th };
  drawFilledRect(ctx, bounds, tileRect.color, 0.75, "#d7e1ea");
  ctx.strokeStyle = "rgba(255,255,255,0.22)";
  ctx.lineWidth = 1 / state.view.scale;
  for (let x = bounds.x; x <= bounds.x + bounds.width; x += tw) line(ctx, x, bounds.y, x, bounds.y + bounds.height);
  for (let y = bounds.y; y <= bounds.y + bounds.height; y += th) line(ctx, bounds.x, y, bounds.x + bounds.width, y);
}

function drawCollisions(ctx) {
  for (const rect of state.map.collisions) drawStrokeRect(ctx, rect, "rgba(255,104,104,0.95)", "rgba(255,104,104,0.10)");
}

function drawBattleZones(ctx) {
  for (const zone of state.map.battleZones) {
    drawStrokeRect(ctx, zone.trigger, "rgba(255,214,102,0.95)", "rgba(255,214,102,0.08)");
    drawStrokeRect(ctx, zone.camera, "rgba(84,168,255,0.75)", "rgba(84,168,255,0.05)");
    for (const spawn of zone.spawns) drawPoint(ctx, spawn.x, spawn.y, "#9ed06a");
  }
}

function drawPlayerSpawn(ctx) {
  drawPoint(ctx, state.map.playerSpawn.x, state.map.playerSpawn.y, "#ffffff");
}

function drawSelection(ctx) {
  const object = getSelectedObject();
  if (!object) return;
  const bounds = object.bounds && object.bounds();
  ctx.strokeStyle = "#54a8ff";
  ctx.lineWidth = 3 / state.view.scale;
  if (bounds) ctx.strokeRect(bounds.x, bounds.y, bounds.width, bounds.height);
}

function drawFilledRect(ctx, rect, color, alpha, stroke) {
  ctx.fillStyle = rgba(color, alpha);
  ctx.fillRect(rect.x, rect.y, rect.width, rect.height);
  ctx.strokeStyle = stroke;
  ctx.lineWidth = 1 / state.view.scale;
  ctx.strokeRect(rect.x, rect.y, rect.width, rect.height);
}

function drawStrokeRect(ctx, rect, stroke, fill) {
  ctx.fillStyle = fill;
  ctx.fillRect(rect.x, rect.y, rect.width, rect.height);
  ctx.strokeStyle = stroke;
  ctx.lineWidth = 2 / state.view.scale;
  ctx.strokeRect(rect.x, rect.y, rect.width, rect.height);
}

function drawPoint(ctx, x, y, color) {
  const r = 8 / state.view.scale;
  ctx.fillStyle = color;
  ctx.beginPath();
  ctx.arc(x, y, r, 0, Math.PI * 2);
  ctx.fill();
  ctx.strokeStyle = "#0b0d10";
  ctx.lineWidth = 2 / state.view.scale;
  ctx.stroke();
}

function line(ctx, x1, y1, x2, y2) {
  ctx.beginPath();
  ctx.moveTo(x1, y1);
  ctx.lineTo(x2, y2);
  ctx.stroke();
}

function collectObjects() {
  const objects = [
    objectForPoint("player", "Player Spawn", state.map.playerSpawn),
    objectForRect("camera", "Camera", state.map.camera),
  ];
  state.map.tilesets.forEach((tileset, index) => objects.push(objectForTileset(`tileset:${index}`, `Tileset ${tileset.id}`, tileset, true)));
  state.map.collisions.forEach((rect, index) => objects.push(objectForRect(`collision:${index}`, `Collision ${index + 1}`, rect, true)));
  state.map.layers.forEach((layer, layerIndex) => {
    objects.push(objectForLayer(`layer:${layerIndex}`, `Layer ${layer.id}`, layer, true));
    layer.rects.forEach((rect, rectIndex) => objects.push(objectForRect(`rect:${layerIndex}:${rectIndex}`, `${layer.id} Rect ${rectIndex + 1}`, rect.bounds, true)));
    layer.tileRects.forEach((tileRect, tileIndex) => objects.push(objectForTileRect(`tile:${layerIndex}:${tileIndex}`, `${layer.id} TileRect ${tileIndex + 1}`, tileRect, true)));
  });
  state.map.battleZones.forEach((zone, zoneIndex) => {
    objects.push(objectForRect(`zone:${zoneIndex}`, `Battle Zone ${zoneIndex + 1}`, zone.trigger, true, zone.id));
    objects.push(objectForRect(`zone_camera:${zoneIndex}`, `Zone Camera ${zoneIndex + 1}`, zone.camera, false, zone.id));
    zone.spawns.forEach((spawn, spawnIndex) => objects.push(objectForPoint(`spawn:${zoneIndex}:${spawnIndex}`, `Spawn ${spawn.id}`, spawn, true)));
  });
  return objects;
}

function objectForTileset(id, title, tileset, deletable) {
  return {
    key: id,
    title,
    meta: `${tileset.texture} | ${tileset.tileWidth}x${tileset.tileHeight}`,
    deletable,
    fields: () => [
      textField("ID", () => tileset.id, (v) => { renameTileset(tileset.id, v || tileset.id); }),
      textField("Texture", () => tileset.texture, (v) => { tileset.texture = v || tileset.texture; }),
      numberField("Tile W", () => tileset.tileWidth, (v) => { tileset.tileWidth = Math.max(1, v); }),
      numberField("Tile H", () => tileset.tileHeight, (v) => { tileset.tileHeight = Math.max(1, v); }),
      ...colorFields(tileset.color, true),
    ],
  };
}

function objectForLayer(id, title, layer, deletable) {
  return {
    key: id,
    title,
    meta: `${layer.role} | parallax ${layer.parallax}`,
    deletable,
    fields: () => [
      textField("ID", () => layer.id, (v) => { layer.id = v || layer.id; }),
      textField("Role", () => layer.role, (v) => { layer.role = v; }, ROLE_ORDER),
      numberField("Parallax", () => layer.parallax, (v) => { layer.parallax = v; }, "0.05"),
    ],
  };
}

function objectForRect(id, title, rect, deletable = false, meta = null) {
  return {
    key: id,
    title,
    meta: meta || `${fmt(rect.x)}, ${fmt(rect.y)}, ${fmt(rect.width)}x${fmt(rect.height)}`,
    deletable,
    bounds: () => rect,
    move(dx, dy) { rect.x += dx; rect.y += dy; },
    fields: () => rectFields(rect),
  };
}

function objectForPoint(id, title, point, deletable = false) {
  return {
    key: id,
    title,
    meta: `${fmt(point.x)}, ${fmt(point.y)}`,
    deletable,
    bounds: () => ({ x: point.x - 8, y: point.y - 8, width: 16, height: 16 }),
    move(dx, dy) { point.x += dx; point.y += dy; },
    fields: () => pointFields(point),
  };
}

function objectForTileRect(id, title, tileRect, deletable) {
  const tileset = state.map.tilesets.find((item) => item.id === tileRect.tileset);
  const tw = tileset ? tileset.tileWidth : 10;
  const th = tileset ? tileset.tileHeight : 10;
  return {
    key: id,
    title,
    meta: `${tileRect.tileset} ${tileRect.columns}x${tileRect.rows}`,
    deletable,
    bounds: () => ({ x: tileRect.x, y: tileRect.y, width: tileRect.columns * tw, height: tileRect.rows * th }),
    move(dx, dy) { tileRect.x += dx; tileRect.y += dy; },
    fields: () => [
      textField("Tileset", () => tileRect.tileset, (v) => { tileRect.tileset = v; }, state.map.tilesets.map((item) => item.id)),
      numberField("X", () => tileRect.x, (v) => { tileRect.x = v; }),
      numberField("Y", () => tileRect.y, (v) => { tileRect.y = v; }),
      numberField("Columns", () => tileRect.columns, (v) => { tileRect.columns = Math.max(1, Math.round(v)); }),
      numberField("Rows", () => tileRect.rows, (v) => { tileRect.rows = Math.max(1, Math.round(v)); }),
      numberField("Tile Index", () => tileRect.tileIndex, (v) => { tileRect.tileIndex = Math.max(0, Math.round(v)); }),
      ...colorFields(tileRect.color, false),
    ],
  };
}

function getSelectedObject() {
  if (!state.selected) return null;
  return collectObjects().find((object) => sameSelection(object.key, state.selected)) || null;
}

function onCanvasMouseDown(event) {
  const world = screenToWorld(event.offsetX, event.offsetY);
  const object = hitTest(world.x, world.y);
  if (object) {
    state.selected = object.key;
    state.dragging = { last: snapPoint(world) };
    refresh();
  } else {
    state.dragging = { pan: true, x: event.clientX, y: event.clientY, viewX: state.view.x, viewY: state.view.y };
  }
}

function onCanvasMouseMove(event) {
  if (!state.dragging) return;
  if (state.dragging.pan) {
    state.view.x = state.dragging.viewX - (event.clientX - state.dragging.x) / state.view.scale;
    state.view.y = state.dragging.viewY - (event.clientY - state.dragging.y) / state.view.scale;
    drawCanvas();
    return;
  }
  const object = getSelectedObject();
  if (!object || !object.move) return;
  const current = snapPoint(screenToWorld(event.offsetX, event.offsetY));
  const dx = current.x - state.dragging.last.x;
  const dy = current.y - state.dragging.last.y;
  if (dx || dy) {
    object.move(dx, dy);
    state.dragging.last = current;
    refresh();
  }
}

function onCanvasMouseUp() {
  state.dragging = null;
}

function onCanvasWheel(event) {
  event.preventDefault();
  const before = screenToWorld(event.offsetX, event.offsetY);
  const factor = event.deltaY < 0 ? 1.12 : 0.88;
  state.view.scale = clamp(state.view.scale * factor, 0.08, 4);
  const after = screenToWorld(event.offsetX, event.offsetY);
  state.view.x += before.x - after.x;
  state.view.y += before.y - after.y;
  drawCanvas();
}

function hitTest(x, y) {
  const objects = collectObjects().reverse();
  for (const object of objects) {
    const bounds = object.bounds && object.bounds();
    if (!bounds) continue;
    if (x >= bounds.x && x <= bounds.x + bounds.width && y >= bounds.y && y <= bounds.y + bounds.height) return object;
  }
  return null;
}

function addCollision() {
  const point = snapPoint(viewCenter());
  state.map.collisions.push({ x: point.x, y: point.y, width: 160, height: 40 });
  state.selected = `collision:${state.map.collisions.length - 1}`;
  refresh();
}

function addTileset() {
  const index = state.map.tilesets.length + 1;
  state.map.tilesets.push({
    id: `tileset_${index}`,
    texture: `assets/stage/stage_01/tiles/tileset_${index}.png`,
    tileWidth: 10,
    tileHeight: 10,
    color: { r: 0.62, g: 0.68, b: 0.73, a: 1 },
  });
  state.selected = `tileset:${state.map.tilesets.length - 1}`;
  refresh();
}

function addLayer() {
  const index = state.map.layers.length + 1;
  state.map.layers.push({
    id: `layer_${index}`,
    role: "PropsBack",
    parallax: 1,
    rects: [],
    tileRects: [],
  });
  state.selected = `layer:${state.map.layers.length - 1}`;
  refresh();
}

function addTileRect() {
  ensureLevelVisualLayer();
  if (!state.map.tilesets.length) {
    state.map.tilesets.push({ id: "graybox_tile", texture: "assets/stage/stage_01/tiles/graybox_tile.png", tileWidth: 10, tileHeight: 10, color: { r: 0.62, g: 0.68, b: 0.73, a: 1 } });
  }
  const layerIndex = state.map.layers.findIndex((layer) => layer.role === "LevelVisual");
  const layer = state.map.layers[layerIndex];
  const point = snapPoint(viewCenter());
  layer.tileRects.push({ tileset: state.map.tilesets[0].id, x: point.x, y: point.y, columns: 8, rows: 4, tileIndex: 0, color: { r: 0.62, g: 0.68, b: 0.73 } });
  state.selected = `tile:${layerIndex}:${layer.tileRects.length - 1}`;
  refresh();
}

function addBattleZone() {
  const point = snapPoint(viewCenter());
  state.map.battleZones.push({
    id: `zone_${String(state.map.battleZones.length + 1).padStart(2, "0")}`,
    trigger: { x: point.x, y: point.y, width: 520, height: 320 },
    camera: { x: Math.max(0, point.x - 520), y: 0, width: 1280, height: state.map.world.height },
    spawns: [],
  });
  state.selected = `zone:${state.map.battleZones.length - 1}`;
  refresh();
}

function addSpawn() {
  if (!state.map.battleZones.length) addBattleZone();
  const zoneIndex = Math.max(0, state.map.battleZones.length - 1);
  const zone = state.map.battleZones[zoneIndex];
  const point = snapPoint(viewCenter());
  zone.spawns.push({ id: `${zone.id}_enemy_${zone.spawns.length + 1}`, x: point.x, y: point.y });
  state.selected = `spawn:${zoneIndex}:${zone.spawns.length - 1}`;
  refresh();
}

function deleteSelected() {
  if (!state.selected) return;
  const parts = state.selected.split(":");
  if (parts[0] === "collision") state.map.collisions.splice(Number(parts[1]), 1);
  if (parts[0] === "tileset") {
    const tileset = state.map.tilesets[Number(parts[1])];
    if (tileset && isTilesetUsed(tileset.id)) {
      setStatus(`Cannot delete tileset ${tileset.id}: it is used by tile_rect.`);
      return;
    }
    state.map.tilesets.splice(Number(parts[1]), 1);
  }
  if (parts[0] === "layer") state.map.layers.splice(Number(parts[1]), 1);
  if (parts[0] === "rect") state.map.layers[Number(parts[1])].rects.splice(Number(parts[2]), 1);
  if (parts[0] === "tile") state.map.layers[Number(parts[1])].tileRects.splice(Number(parts[2]), 1);
  if (parts[0] === "zone") state.map.battleZones.splice(Number(parts[1]), 1);
  if (parts[0] === "spawn") state.map.battleZones[Number(parts[1])].spawns.splice(Number(parts[2]), 1);
  state.selected = null;
  refresh();
}

function downloadMap() {
  const blob = new Blob([serializeMap(state.map)], { type: "text/plain" });
  const url = URL.createObjectURL(blob);
  const link = document.createElement("a");
  link.href = url;
  link.download = `${state.map.id || "stage"}.map`;
  link.click();
  URL.revokeObjectURL(url);
}

function fitWorldToCanvas() {
  const canvas = elements.mapCanvas;
  const scaleX = canvas.width / Math.max(1, state.map.world.width);
  const scaleY = canvas.height / Math.max(1, state.map.world.height);
  state.view.scale = Math.max(0.08, Math.min(scaleX, scaleY) * 0.92);
  state.view.x = -((canvas.width / state.view.scale - state.map.world.width) / 2);
  state.view.y = -((canvas.height / state.view.scale - state.map.world.height) / 2);
}

function resizeCanvas() {
  const canvas = elements.mapCanvas;
  const rect = canvas.getBoundingClientRect();
  canvas.width = Math.max(1, Math.floor(rect.width * window.devicePixelRatio));
  canvas.height = Math.max(1, Math.floor(rect.height * window.devicePixelRatio));
  const ctx = canvas.getContext("2d");
  ctx.setTransform(window.devicePixelRatio, 0, 0, window.devicePixelRatio, 0, 0);
  canvas.width = Math.max(1, Math.floor(rect.width));
  canvas.height = Math.max(1, Math.floor(rect.height));
  drawCanvas();
}

function rectFields(rect) {
  return [
    numberField("X", () => rect.x, (v) => { rect.x = v; }),
    numberField("Y", () => rect.y, (v) => { rect.y = v; }),
    numberField("W", () => rect.width, (v) => { rect.width = Math.max(1, v); }),
    numberField("H", () => rect.height, (v) => { rect.height = Math.max(1, v); }),
  ];
}

function pointFields(point) {
  return [
    numberField("X", () => point.x, (v) => { point.x = v; }),
    numberField("Y", () => point.y, (v) => { point.y = v; }),
  ];
}

function colorFields(color, includeAlpha) {
  const fields = [
    numberField("R", () => color.r, (v) => { color.r = clamp(v, 0, 1); }, "0.01"),
    numberField("G", () => color.g, (v) => { color.g = clamp(v, 0, 1); }, "0.01"),
    numberField("B", () => color.b, (v) => { color.b = clamp(v, 0, 1); }, "0.01"),
  ];
  if (includeAlpha) fields.push(numberField("A", () => color.a, (v) => { color.a = clamp(v, 0, 1); }, "0.01"));
  return fields;
}

function numberField(label, get, set, step = "1") {
  return { label, type: "number", step, get, set };
}

function textField(label, get, set, options = null) {
  return { label, type: "text", options, get, set };
}

function ensureLevelVisualLayer() {
  if (!state.map.layers.some((layer) => layer.role === "LevelVisual")) {
    state.map.layers.push({ id: "level_visual", role: "LevelVisual", parallax: 1, rects: [], tileRects: [] });
  }
}

function sortLayers(layers) {
  return [...layers].sort((a, b) => ROLE_ORDER.indexOf(a.role) - ROLE_ORDER.indexOf(b.role));
}

function tokenize(line) {
  const tokens = [];
  for (const token of line.trim().split(/\s+/).filter(Boolean)) {
    if (token.startsWith("#")) break;
    tokens.push(token);
  }
  return tokens;
}

function requireLayer(layer, lineNumber) {
  if (!layer) throw new Error(`Line ${lineNumber}: command must be inside layer`);
}

function requireToken(tokens, index, lineNumber) {
  if (tokens.length <= index) throw new Error(`Line ${lineNumber}: missing token ${index}`);
  return tokens[index];
}

function num(tokens, index, lineNumber) {
  const value = Number(requireToken(tokens, index, lineNumber));
  if (!Number.isFinite(value)) throw new Error(`Line ${lineNumber}: invalid number ${tokens[index]}`);
  return value;
}

function intNum(tokens, index, lineNumber) {
  return Math.round(num(tokens, index, lineNumber));
}

function rectFrom(tokens, start, lineNumber) {
  return { x: num(tokens, start, lineNumber), y: num(tokens, start + 1, lineNumber), width: num(tokens, start + 2, lineNumber), height: num(tokens, start + 3, lineNumber) };
}

function colorFrom(tokens, start, lineNumber, includeAlpha) {
  return { r: num(tokens, start, lineNumber), g: num(tokens, start + 1, lineNumber), b: num(tokens, start + 2, lineNumber), a: includeAlpha ? num(tokens, start + 3, lineNumber) : 1 };
}

function rectText(rect) {
  return `${fmt(rect.x)} ${fmt(rect.y)} ${fmt(rect.width)} ${fmt(rect.height)}`;
}

function colorText(color, includeAlpha) {
  return includeAlpha ? `${fmt(color.r)} ${fmt(color.g)} ${fmt(color.b)} ${fmt(color.a)}` : `${fmt(color.r)} ${fmt(color.g)} ${fmt(color.b)}`;
}

function fmt(value) {
  return Number(value).toFixed(3).replace(/\.?0+$/, "");
}

function rgba(color, alphaMul) {
  const a = color.a === undefined ? 1 : color.a;
  return `rgba(${Math.round(color.r * 255)},${Math.round(color.g * 255)},${Math.round(color.b * 255)},${a * alphaMul})`;
}

function escapeHtml(value) {
  return String(value).replace(/[&<>"']/g, (char) => ({ "&": "&amp;", "<": "&lt;", ">": "&gt;", '"': "&quot;", "'": "&#39;" }[char]));
}

function sameSelection(a, b) {
  return a === b;
}

function numberValue(input, fallback) {
  const value = Number(input.value);
  return Number.isFinite(value) ? value : fallback;
}

function screenToWorld(x, y) {
  return { x: state.view.x + x / state.view.scale, y: state.view.y + y / state.view.scale };
}

function viewCenter() {
  const canvas = elements.mapCanvas;
  return screenToWorld(canvas.width / 2, canvas.height / 2);
}

function snapPoint(point) {
  return { x: Math.round(point.x / state.gridSize) * state.gridSize, y: Math.round(point.y / state.gridSize) * state.gridSize };
}

function clamp(value, min, max) {
  return Math.max(min, Math.min(max, value));
}

function setStatus(text) {
  elements.statusText.textContent = text;
}

function renameTileset(oldId, newId) {
  const cleanId = String(newId).trim();
  if (!cleanId) return;
  if (cleanId !== oldId && state.map.tilesets.some((item) => item.id === cleanId)) {
    setStatus(`Cannot rename tileset: ${cleanId} already exists.`);
    return;
  }
  const tileset = state.map.tilesets.find((item) => item.id === oldId);
  if (!tileset) return;
  tileset.id = cleanId;
  for (const layer of state.map.layers) {
    for (const tileRect of layer.tileRects) {
      if (tileRect.tileset === oldId) tileRect.tileset = cleanId;
    }
  }
}

function isTilesetUsed(id) {
  return state.map.layers.some((layer) => layer.tileRects.some((tileRect) => tileRect.tileset === id));
}

function defaultMapText() {
  return `map stage\nworld 1280 720\ncamera 0 0 1280 720\nplayer_spawn 120 520\n\ncollision 0 600 1280 80\n\ntileset graybox assets/stage/stage_01/tiles/graybox.png 10 10 0.62 0.68 0.73 1\n\nlayer level_visual LevelVisual 1\ntile_rect graybox 0 600 128 8 0 0.62 0.68 0.73\nendlayer\n`;
}