import { generateMapAsync } from "./mapGenerator.js";
import { drawMap } from "./renderer.js";
import { landuseLabel } from "./landuseCodes.js";
import { CELL_SIZE, MAP_H, MAP_W } from "./mapUtils.js";
import { clampCameraToWorld, createInitialCamera, createWorldMap, ensureWorldPaddingForCamera } from "./worldMap.js";
import { getViewportMap } from "./worldViewport.js";
import { PATCH_MIN_AREA, PATCH_MIN_HEIGHT, PATCH_MIN_WIDTH, buildPatchRects, generatePatch, validatePatchRect } from "./mapPatch.js";

const modes = [
  ["all", "All"],
  ["terrain", "Terrain"],
  ["history", "Premodern"],
  ["modern", "Modern"],
  ["development", "Development"],
  ["landuse", "Land Use"],
  ["admin", "Municipal Borders"],
  ["borders-debug", "Borders Debug"],
  ["transport-debug", "Transport Debug"],
];

const state = {
  seedText: "114514",
  generationType: "auto",
  mode: "all",
  showFeatures: true,
  showLabels: true,
  map: null,
  world: null,
  camera: { x: 0, y: 0 },
  viewportMap: null,
  viewWidth: MAP_W,
  viewHeight: MAP_H,
  hoverEntities: [],
  selectionRect: null,
  patchVariant: 0,
  zoom: 1,
  lastPatchResult: null,
};

const canvas = document.getElementById("mapCanvas");
const canvasShell = document.querySelector(".canvas-shell");
const seedInput = document.getElementById("seed");
const generationTypeInput = document.getElementById("generationType");
const patchTerrainTypeInput = document.getElementById("patchTerrainType");
const patchVariantInput = document.getElementById("patchVariant");
const generatePatchButton = document.getElementById("generatePatch");
const alternativePatchButton = document.getElementById("alternativePatch");
const patchStatusEl = document.getElementById("patchStatus");
const randomSeedButton = document.getElementById("randomSeed");
const showFeaturesInput = document.getElementById("showFeatures");
const showLabelsInput = document.getElementById("showLabels");
const modeGrid = document.getElementById("modeGrid");
const statsEl = document.getElementById("stats");
const tooltipEl = document.getElementById("mapTooltip");
const selectionSvgEl = document.getElementById("mapSelectionSvg");
const selectionEl = document.getElementById("mapSelection");
const progressEl = document.getElementById("generationProgress");
const progressStageEl = document.getElementById("generationProgressStage");
const progressTimingsEl = document.getElementById("generationProgressTimings");
let generationStartedAt = 0;
let generationCurrentStage = "";
let generationTimer = null;
let zoomRedrawRaf = null;
let zoomSettledTimer = null;

const dragState = {
  mode: null,
  pointerId: null,
  startClientX: 0,
  startClientY: 0,
  startCameraX: 0,
  startCameraY: 0,
  lastClientX: 0,
  lastClientY: 0,
  panRemainderX: 0,
  panRemainderY: 0,
  selectStart: null,
  selectEnd: null,
  selectPath: null,
  pendingCamera: null,
  panRaf: null,
};

function activeMap() {
  return state.viewportMap || state.map;
}

function clampZoom(value) {
  const parsed = Number(value);
  if (!Number.isFinite(parsed)) return 1;
  return Math.min(Math.max(parsed, 0.55), 2.8);
}

function viewportSizeForZoom(zoom = state.zoom) {
  const z = clampZoom(zoom || 1);
  return {
    width: Math.max(1, Math.ceil(MAP_W / z)),
    height: Math.max(1, Math.ceil(MAP_H / z)),
  };
}

function clampCameraForView(camera, size = viewportSizeForZoom(state.zoom)) {
  return clampCameraToWorld(camera, state.world, size?.width || MAP_W, size?.height || MAP_H);
}

function syncViewportSize() {
  const size = viewportSizeForZoom(state.zoom);
  state.viewWidth = size.width;
  state.viewHeight = size.height;
  return size;
}

function mapCellScreenSize(map = activeMap()) {
  const rect = canvas.getBoundingClientRect();
  const mapWidth = Math.max(1, map?.width || state.viewWidth || MAP_W);
  return rect.width ? rect.width / mapWidth : CELL_SIZE * clampZoom(state.zoom || 1);
}

function applyCanvasZoom() {
  if (!canvas) return;
  state.zoom = clampZoom(state.zoom || 1);
  // Keep the canvas element at a stable size.  Zoom is applied inside the
  // renderer transform, not by resizing the scrollable shell.
  canvas.style.width = `${MAP_W * CELL_SIZE}px`;
  canvas.style.height = `${MAP_H * CELL_SIZE}px`;
  updateSelectionOverlayFromWorldRect();
}

function displayedCellSize() {
  return mapCellScreenSize();
}

function screenPointToMapPixel(clientX, clientY, sizeOverride = null) {
  const rect = canvas.getBoundingClientRect();
  if (!rect.width || !rect.height) return null;
  const map = activeMap();
  const viewWidth = Math.max(1, sizeOverride?.width || map?.width || state.viewWidth || MAP_W);
  const viewHeight = Math.max(1, sizeOverride?.height || map?.height || state.viewHeight || MAP_H);
  const canvasX = (clientX - rect.left) * ((canvas.width || MAP_W * CELL_SIZE) / rect.width);
  const canvasY = (clientY - rect.top) * ((canvas.height || MAP_H * CELL_SIZE) / rect.height);
  const cellX = canvasX / Math.max(1e-6, (canvas.width || MAP_W * CELL_SIZE) / viewWidth);
  const cellY = canvasY / Math.max(1e-6, (canvas.height || MAP_H * CELL_SIZE) / viewHeight);
  return { x: cellX * CELL_SIZE, y: cellY * CELL_SIZE };
}

function mapPixelToScreenPoint(px, py) {
  const rect = canvas.getBoundingClientRect();
  const map = activeMap();
  const viewWidth = Math.max(1, map?.width || state.viewWidth || MAP_W);
  const viewHeight = Math.max(1, map?.height || state.viewHeight || MAP_H);
  const canvasX = (px / CELL_SIZE) * ((canvas.width || MAP_W * CELL_SIZE) / viewWidth);
  const canvasY = (py / CELL_SIZE) * ((canvas.height || MAP_H * CELL_SIZE) / viewHeight);
  return {
    x: canvas.offsetLeft + canvasX * (rect.width / Math.max(1, canvas.width || MAP_W * CELL_SIZE)),
    y: canvas.offsetTop + canvasY * (rect.height / Math.max(1, canvas.height || MAP_H * CELL_SIZE)),
  };
}

function mapClientToCell(event, sizeOverride = null) {
  const map = activeMap();
  if (!map && !sizeOverride) return null;
  const p = screenPointToMapPixel(event.clientX, event.clientY, sizeOverride);
  if (!p) return null;
  return {
    x: Math.floor(p.x / CELL_SIZE),
    y: Math.floor(p.y / CELL_SIZE),
  };
}

function viewportCellToWorldCell(cell) {
  if (!cell || !state.camera) return null;
  return {
    x: Math.round(state.camera.x || 0) + cell.x,
    y: Math.round(state.camera.y || 0) + cell.y,
  };
}

function clampCanvasPoint(event) {
  const rect = canvas.getBoundingClientRect();
  return {
    x: Math.min(Math.max(event.clientX - rect.left, 0), rect.width),
    y: Math.min(Math.max(event.clientY - rect.top, 0), rect.height),
  };
}

function screenPointToWorldCell(point) {
  const map = activeMap();
  if (!map || !point) return null;
  const rect = canvas.getBoundingClientRect();
  if (!rect.width || !rect.height) return null;
  const viewWidth = Math.max(1, map.width || state.viewWidth || MAP_W);
  const viewHeight = Math.max(1, map.height || state.viewHeight || MAP_H);
  const canvasX = point.x * ((canvas.width || MAP_W * CELL_SIZE) / rect.width);
  const canvasY = point.y * ((canvas.height || MAP_H * CELL_SIZE) / rect.height);
  const localX = Math.floor((canvasX / Math.max(1e-6, (canvas.width || MAP_W * CELL_SIZE) / viewWidth)));
  const localY = Math.floor((canvasY / Math.max(1e-6, (canvas.height || MAP_H * CELL_SIZE) / viewHeight)));
  const cameraX = Math.round(state.camera?.x || 0);
  const cameraY = Math.round(state.camera?.y || 0);
  return {
    x: cameraX + Math.min(Math.max(localX, 0), Math.max(0, map.width - 1)),
    y: cameraY + Math.min(Math.max(localY, 0), Math.max(0, map.height - 1)),
  };
}

function worldCellToOverlayPoint(point) {
  const cameraX = Math.round(state.camera?.x || 0);
  const cameraY = Math.round(state.camera?.y || 0);
  const screen = mapPixelToScreenPoint((point.x - cameraX + 0.5) * CELL_SIZE, (point.y - cameraY + 0.5) * CELL_SIZE);
  return { x: screen.x - canvas.offsetLeft, y: screen.y - canvas.offsetTop };
}

function simplifySelectionPath(points) {
  const out = [];
  for (const p of points || []) {
    if (!out.length || Math.hypot(out[out.length - 1].x - p.x, out[out.length - 1].y - p.y) >= 6) out.push(p);
  }
  return out;
}

function polygonArea(points) {
  let area = 0;
  for (let i = 0; i < points.length; i++) {
    const a = points[i];
    const b = points[(i + 1) % points.length];
    area += a.x * b.y - b.x * a.y;
  }
  return Math.abs(area) * 0.5;
}

function selectionPathToShape(points) {
  const simplified = simplifySelectionPath(points || []);
  if (simplified.length < 3) return null;
  const polygon = simplified.map(screenPointToWorldCell).filter(Boolean);
  if (polygon.length < 3) return null;
  const xs = polygon.map((p) => p.x);
  const ys = polygon.map((p) => p.y);
  return {
    kind: "lasso",
    polygon,
    x0: Math.min(...xs),
    y0: Math.min(...ys),
    x1: Math.max(...xs) + 1,
    y1: Math.max(...ys) + 1,
    areaCells: Math.max(1, Math.round(polygonArea(polygon))),
  };
}

function syncSelectionSvgToCanvas() {
  if (!selectionSvgEl || !canvas) return null;
  const rect = canvas.getBoundingClientRect();
  const width = Math.max(1, rect.width || canvas.clientWidth || canvas.width || 1);
  const height = Math.max(1, rect.height || canvas.clientHeight || canvas.height || 1);
  selectionSvgEl.style.left = `${canvas.offsetLeft}px`;
  selectionSvgEl.style.top = `${canvas.offsetTop}px`;
  selectionSvgEl.style.width = `${width}px`;
  selectionSvgEl.style.height = `${height}px`;
  selectionSvgEl.setAttribute("width", String(width));
  selectionSvgEl.setAttribute("height", String(height));
  selectionSvgEl.setAttribute("viewBox", `0 0 ${width} ${height}`);
  return { width, height };
}

function drawSelectionSvg(points, invalid = false) {
  if (!selectionSvgEl) return;
  const bounds = syncSelectionSvgToCanvas();
  if (!bounds || !points || points.length < 3) {
    selectionSvgEl.style.display = "none";
    selectionSvgEl.innerHTML = "";
    return;
  }
  const pts = points.map((p) => {
    const x = Math.min(Math.max(p.x, 0), bounds.width);
    const y = Math.min(Math.max(p.y, 0), bounds.height);
    return `${x},${y}`;
  }).join(" ");
  selectionSvgEl.innerHTML = `<polygon points="${pts}" />`;
  selectionSvgEl.style.display = "block";
  selectionSvgEl.classList.toggle("invalid", !!invalid);
}

function hideSelectionSvg() {
  if (!selectionSvgEl) return;
  selectionSvgEl.style.display = "none";
  selectionSvgEl.innerHTML = "";
  selectionSvgEl.classList.remove("invalid");
}

function updateSelectionOverlay() {
  if (!dragState.selectPath?.length) return;
  const liveShape = selectionPathToShape(dragState.selectPath);
  const validation = validatePatchRect(liveShape, state.world);
  drawSelectionSvg(dragState.selectPath, !validation.ok);
  if (selectionEl) selectionEl.style.display = "none";
  if (generatePatchButton) generatePatchButton.disabled = true;
  if (alternativePatchButton) alternativePatchButton.disabled = true;
  if (patchStatusEl) {
    const current = validation.rect || liveShape;
    patchStatusEl.textContent = validation.ok
      ? `Selected: ${formatRectSize(validation.rect)}. Release to confirm patch selection.`
      : `${validation.reason} Current: ${formatRectSize(current)}.`;
    patchStatusEl.classList.toggle("invalid", !validation.ok);
  }
}

function updateSelectionOverlayFromWorldRect() {
  if (!state.selectionRect || !state.camera || !activeMap()) return;
  const rect = canvas.getBoundingClientRect();
  if (!rect.width || !rect.height) return;
  if (Array.isArray(state.selectionRect.polygon) && state.selectionRect.polygon.length >= 3) {
    const points = state.selectionRect.polygon.map(worldCellToOverlayPoint)
      .map((p) => ({ x: Math.min(Math.max(p.x, 0), rect.width), y: Math.min(Math.max(p.y, 0), rect.height) }));
    drawSelectionSvg(points, !validatePatchRect(state.selectionRect, state.world).ok);
    if (selectionEl) selectionEl.style.display = "none";
    return;
  }
  const cameraX = Math.round(state.camera.x || 0);
  const cameraY = Math.round(state.camera.y || 0);
  const p0 = mapPixelToScreenPoint((state.selectionRect.x0 - cameraX) * CELL_SIZE, (state.selectionRect.y0 - cameraY) * CELL_SIZE);
  const p1 = mapPixelToScreenPoint((state.selectionRect.x1 - cameraX) * CELL_SIZE, (state.selectionRect.y1 - cameraY) * CELL_SIZE);
  const vx0 = p0.x - canvas.offsetLeft;
  const vy0 = p0.y - canvas.offsetTop;
  const vx1 = p1.x - canvas.offsetLeft;
  const vy1 = p1.y - canvas.offsetTop;
  const x0 = Math.min(Math.max(Math.min(vx0, vx1), 0), rect.width);
  const y0 = Math.min(Math.max(Math.min(vy0, vy1), 0), rect.height);
  const x1 = Math.min(Math.max(Math.max(vx0, vx1), 0), rect.width);
  const y1 = Math.min(Math.max(Math.max(vy0, vy1), 0), rect.height);
  if (x1 - x0 < 1 || y1 - y0 < 1) {
    selectionEl.style.display = "none";
    return;
  }
  hideSelectionSvg();
  selectionEl.style.display = "block";
  selectionEl.style.left = `${canvas.offsetLeft + x0}px`;
  selectionEl.style.top = `${canvas.offsetTop + y0}px`;
  selectionEl.style.width = `${Math.max(1, x1 - x0)}px`;
  selectionEl.style.height = `${Math.max(1, y1 - y0)}px`;
  const validation = validatePatchRect(state.selectionRect, state.world);
  selectionEl.classList.toggle("invalid", !validation.ok);
}

function formatRectSize(rect) {
  if (!rect) return "-";
  const w = Math.max(0, rect.x1 - rect.x0);
  const h = Math.max(0, rect.y1 - rect.y0);
  const area = Math.max(0, rect.areaCells || (w * h));
  return `${w} x ${h} cells / ${area.toLocaleString()} cells`;
}

function normalizePatchVariant(value) {
  const parsed = Number.parseInt(value, 10);
  return Number.isFinite(parsed) ? Math.max(0, parsed) >>> 0 : 0;
}

function setPatchVariant(value, { update = true } = {}) {
  state.patchVariant = normalizePatchVariant(value);
  if (patchVariantInput && patchVariantInput.value !== String(state.patchVariant)) {
    patchVariantInput.value = String(state.patchVariant);
  }
  if (update) updatePatchControls();
  return state.patchVariant;
}

function readPatchVariant() {
  return setPatchVariant(patchVariantInput?.value ?? state.patchVariant, { update: false });
}

function resetPatchVariant({ update = true } = {}) {
  return setPatchVariant(0, { update });
}

function updatePatchControls() {
  if (!patchStatusEl && !generatePatchButton) return;
  const validation = validatePatchRect(state.selectionRect, state.world);
  const variant = readPatchVariant();
  if (generatePatchButton) generatePatchButton.disabled = !validation.ok;
  if (alternativePatchButton) alternativePatchButton.disabled = !validation.ok;
  if (!patchStatusEl) return;
  if (!state.selectionRect) {
    patchStatusEl.textContent = `Right-drag a freeform area. Minimum: ${PATCH_MIN_WIDTH} x ${PATCH_MIN_HEIGHT} cells and ${PATCH_MIN_AREA.toLocaleString()} cells. Current variant: ${variant}.`;
    patchStatusEl.classList.toggle("invalid", false);
    return;
  }
  if (!validation.ok) {
    patchStatusEl.textContent = `${validation.reason} Current: ${formatRectSize(validation.rect || state.selectionRect)}.`;
    patchStatusEl.classList.toggle("invalid", true);
    return;
  }
  const rects = buildPatchRects(validation.rect, state.world);
  const patchText = state.lastPatchResult
    ? ` Last patch: ${state.lastPatchResult.label}, variant ${state.lastPatchResult.variant ?? "-"}, mode ${state.lastPatchResult.patchGenerationMode || "legacy-full-pipeline"}, terrain ${state.lastPatchResult.updatedCells.toLocaleString()} cells, coast ${state.lastPatchResult.coastCellsChanged || 0}, natural ${state.lastPatchResult.naturalRegionsUpdated || 0}${state.lastPatchResult.humanGeography?.ok ? `, connectors ${(state.lastPatchResult.humanGeography.roadConnectorsCreated || 0) + (state.lastPatchResult.humanGeography.railwayConnectorsCreated || 0)}, admin ${state.lastPatchResult.humanGeography.adminCellsReassigned || 0}, invalid ports ${state.lastPatchResult.humanGeography.invalidPortsRemoved || 0}` : ""}.`
    : "";
  patchStatusEl.textContent = `Variant: ${variant}. Core: ${formatRectSize(rects.coreRect)}. Write: ${formatRectSize(rects.writeRect)}. Context: ${formatRectSize(rects.contextRect)}. Repair: ${formatRectSize(rects.repairRect)}.${patchText}`;
  patchStatusEl.classList.toggle("invalid", false);
}

function clearDragMode() {
  dragState.mode = null;
  dragState.pointerId = null;
  dragState.pendingCamera = null;
  dragState.panRemainderX = 0;
  dragState.panRemainderY = 0;
  if (dragState.panRaf != null) {
    cancelAnimationFrame(dragState.panRaf);
    dragState.panRaf = null;
  }
  canvasShell?.classList.remove("panning", "selecting");
}

function schedulePanRedraw(camera) {
  dragState.pendingCamera = camera;
  if (dragState.panRaf != null) return;
  dragState.panRaf = requestAnimationFrame(() => {
    dragState.panRaf = null;
    if (!dragState.pendingCamera) return;
    const next = dragState.pendingCamera;
    dragState.pendingCamera = null;
    if (next.x === state.camera.x && next.y === state.camera.y) return;
    state.camera = next;
    // Do not auto-expand the backing world while a pointer drag is active.
    // Expansion shifts world coordinates; doing it mid-drag invalidates the
    // pointer-to-camera baseline and can make the viewport appear to jump.
    redraw({ fastTerrain: true, allowWorldExpand: false });
  });
}

function hideSelectionOverlay() {
  dragState.selectStart = null;
  dragState.selectEnd = null;
  dragState.selectPath = null;
  state.selectionRect = null;
  resetPatchVariant({ update: false });
  hideSelectionSvg();
  if (selectionEl) selectionEl.style.display = "none";
  updatePatchControls();
}

function selectionPixelsToCells(start, end) {
  const a = screenPointToWorldCell(start);
  const b = screenPointToWorldCell(end);
  if (!a || !b) return null;
  return {
    x0: Math.min(a.x, b.x),
    y0: Math.min(a.y, b.y),
    x1: Math.max(a.x, b.x) + 1,
    y1: Math.max(a.y, b.y) + 1,
  };
}

function selectionPixelsToShape(start, end, path = null) {
  if (Array.isArray(path) && path.length >= 3) return selectionPathToShape(path);
  return selectionPixelsToCells(start, end);
}

function handleMapPointerDown(event) {
  if (!state.world || !canvasShell) return;
  if (event.button !== 0 && event.button !== 2) return;
  dragState.pointerId = event.pointerId;
  dragState.startClientX = event.clientX;
  dragState.startClientY = event.clientY;
  dragState.startCameraX = state.camera.x;
  dragState.startCameraY = state.camera.y;
  dragState.lastClientX = event.clientX;
  dragState.lastClientY = event.clientY;
  dragState.panRemainderX = 0;
  dragState.panRemainderY = 0;
  tooltipEl?.classList.remove("visible");

  if (event.button === 0) {
    dragState.mode = "pan";
    canvasShell.classList.add("panning");
  } else {
    dragState.mode = "select";
    dragState.selectStart = clampCanvasPoint(event);
    dragState.selectEnd = dragState.selectStart;
    dragState.selectPath = [dragState.selectStart];
    canvasShell.classList.add("selecting");
    updateSelectionOverlay();
  }

  canvas.setPointerCapture?.(event.pointerId);
  event.preventDefault();
}

function handleMapPointerMove(event) {
  if (!dragState.mode || dragState.pointerId !== event.pointerId || !canvasShell) return;
  tooltipEl?.classList.remove("visible");

  if (dragState.mode === "pan") {
    const rect = canvas.getBoundingClientRect();
    const maxDeltaX = Math.max(320, rect.width * 0.72);
    const maxDeltaY = Math.max(240, rect.height * 0.72);
    const rawDx = event.clientX - dragState.lastClientX;
    const rawDy = event.clientY - dragState.lastClientY;
    dragState.lastClientX = event.clientX;
    dragState.lastClientY = event.clientY;

    // Pointer capture can occasionally deliver a stale/outlier coordinate after
    // a tab switch, resize, context-menu gesture, or OS-level event hiccup.  A
    // single implausibly large delta would otherwise become a large camera jump.
    if (Math.abs(rawDx) <= maxDeltaX && Math.abs(rawDy) <= maxDeltaY) {
      const cellSize = Math.max(1, displayedCellSize());
      const totalX = dragState.panRemainderX + rawDx / cellSize;
      const totalY = dragState.panRemainderY + rawDy / cellSize;
      const dxCells = totalX < 0 ? Math.ceil(totalX) : Math.floor(totalX);
      const dyCells = totalY < 0 ? Math.ceil(totalY) : Math.floor(totalY);
      dragState.panRemainderX = totalX - dxCells;
      dragState.panRemainderY = totalY - dyCells;
      if (dxCells || dyCells) {
        const base = dragState.pendingCamera || state.camera;
        const nextCamera = clampCameraForView({
          x: base.x - dxCells,
          y: base.y - dyCells,
        }, viewportSizeForZoom(state.zoom));
        schedulePanRedraw(nextCamera);
      }
    }
  } else if (dragState.mode === "select") {
    dragState.selectEnd = clampCanvasPoint(event);
    if (!dragState.selectPath || Math.hypot(dragState.selectEnd.x - dragState.selectPath[dragState.selectPath.length - 1].x, dragState.selectEnd.y - dragState.selectPath[dragState.selectPath.length - 1].y) >= 3) {
      dragState.selectPath = [...(dragState.selectPath || []), dragState.selectEnd];
    }
    updateSelectionOverlay();
  }

  event.preventDefault();
}

function handleMapPointerUp(event) {
  if (dragState.pointerId !== event.pointerId) return;
  const wasPanning = dragState.mode === "pan";
  if (dragState.mode === "select") {
    dragState.selectEnd = clampCanvasPoint(event);
    if (!dragState.selectPath || dragState.selectPath.length < 2) dragState.selectPath = [dragState.selectStart, dragState.selectEnd];
    else dragState.selectPath = [...dragState.selectPath, dragState.selectEnd];
    const shape = selectionPixelsToShape(dragState.selectStart, dragState.selectEnd, dragState.selectPath);
    const width = Math.abs(dragState.selectEnd.x - dragState.selectStart.x);
    const height = Math.abs(dragState.selectEnd.y - dragState.selectStart.y);
    if (shape && (dragState.selectPath.length >= 3 || (width >= 4 && height >= 4))) {
      state.selectionRect = shape;
      state.lastPatchResult = null;
      resetPatchVariant({ update: false });
      updateSelectionOverlayFromWorldRect();
      updatePatchControls();
    } else {
      hideSelectionOverlay();
    }
  }
  canvas.releasePointerCapture?.(event.pointerId);
  if (wasPanning && dragState.pendingCamera) {
    state.camera = dragState.pendingCamera;
    dragState.pendingCamera = null;
  }
  clearDragMode();
  if (wasPanning) redraw({ fastTerrain: false });
  event.preventDefault();
}

function parseSeed(seedText) {
  const numeric = Number.parseInt(seedText, 10);
  if (Number.isFinite(numeric)) return numeric >>> 0;

  let hash = 2166136261;
  for (const ch of seedText) hash = Math.imul(hash ^ ch.charCodeAt(0), 16777619);
  return hash >>> 0;
}

function insideCount(items) {
  return items.filter((item) => item.insidePrefecture).length;
}

function outsideCount(items) {
  return items.length - insideCount(items);
}

function countText(items) {
  return `${insideCount(items)} / outside ${outsideCount(items)}`;
}

function formatMs(ms) {
  if (!Number.isFinite(ms)) return "-";
  return ms >= 1000 ? `${(ms / 1000).toFixed(2)}s` : `${Math.round(ms)}ms`;
}

function renderTimingRows(timings = []) {
  if (!progressTimingsEl) return;
  progressTimingsEl.innerHTML = "";
  for (const row of timings) {
    const item = document.createElement("div");
    item.className = "progress-timing-row";
    const label = document.createElement("span");
    label.textContent = row.label;
    const value = document.createElement("strong");
    value.textContent = formatMs(row.ms);
    item.append(label, value);
    progressTimingsEl.append(item);
  }
}

function updateGenerationProgress(event) {
  if (!progressEl) return;
  progressEl.classList.remove("hidden");
  if (event?.status === "start") generationCurrentStage = event.label || "Preparing";
  if (progressStageEl) {
    const elapsed = generationStartedAt ? ` / elapsed ${formatMs(performance.now() - generationStartedAt)}` : "";
    progressStageEl.textContent = event?.status === "done"
      ? `Completed: ${event.label} / ${formatMs(event.ms)}${elapsed}`
      : `Running: ${event?.label || generationCurrentStage || "Preparing"}${elapsed}`;
  }
  renderTimingRows(event?.timings || []);
}

function setProgressVisible(visible, message = "Preparing") {
  if (!progressEl) return;
  progressEl.classList.toggle("hidden", !visible);
  if (visible) {
    generationStartedAt = performance.now();
    generationCurrentStage = message;
    if (generationTimer) window.clearInterval(generationTimer);
    generationTimer = window.setInterval(() => {
      if (progressStageEl && !progressEl.classList.contains("hidden")) {
        progressStageEl.textContent = `Running: ${generationCurrentStage || "Preparing"} / elapsed ${formatMs(performance.now() - generationStartedAt)}`;
      }
    }, 100);
  } else if (generationTimer) {
    window.clearInterval(generationTimer);
    generationTimer = null;
  }
  if (progressStageEl) progressStageEl.textContent = message;
  if (visible) renderTimingRows([]);
}

function nextFrame() {
  return new Promise((resolve) => requestAnimationFrame(() => resolve()));
}

function getStats(map) {
  return [
    ["Map Type", map.terrainTemplate?.terrainTypeLabel || map.terrainDebug?.terrainTypeLabel || "-"],
    ["Terrain ID", map.terrainTemplate?.terrainType || map.terrainDebug?.terrainType || "-"],
    ["Generation Total", map.generationTotalMs ? formatMs(map.generationTotalMs) : "-"],
    ["Geography Basis", map.geographyDebug?.version ? `${map.geographyDebug.version} / ${map.geographyDebug.stage || "-"}` : "-"],
    ...(map.generationTimings || []).map((row) => [`Time: ${row.label}`, formatMs(row.ms)]),
    ["Villages", countText(map.villages)],
    ["Market Towns", countText(map.markets)],
    ["Castles", countText(map.castles)],
    ["Premodern Roads", map.premodernRoads.length],
    ["Minor Roads", map.minorRoads.length],
    ["Prefecture", map.prefectureName || "-"],
    ["Neighbor Prefectures", (map.neighborPrefectures || []).map((p) => p.name).join(" / ") || "-"],
    ["Neighbor Features", map.neighborPrefectureDetails ? `${map.neighborPrefectureDetails.cities?.length || 0} cities / ${map.neighborPrefectureDetails.adminCenters?.length || 0} municipalities / ${map.neighborPrefectureDetails.roads?.length || 0} roads` : "-"],
    ["Prefectural Capital", map.prefecturalCapital?.name || "-"],
    ["Regional Capitals", (map.modernCities || []).filter((p) => p.isRegionalCapital).length],
    ["Modern Cities", countText(map.modernCities)],
    ["Ports", `${map.ports.filter((p) => p.portClass === "major").length} major / ${map.ports.filter((p) => p.portClass === "regional").length} regional / ${map.ports.filter((p) => p.portClass === "fishing").length} fishing / ${map.ports.filter((p) => p.portClass === "lake").length} lake`],
    ["Satellite Cities", countText(map.satelliteCities || [])],
    ["Population", (map.totalPopulation || 0).toLocaleString()],
    ["Rivers", `${map.mainRivers.length} main / ${(map.tributaryRivers || []).length} tributary / ${(map.smallStreams || []).length} hidden streams`],
    ["Neighbor Prefecture Borders", (map.regionalPrefectureBorders || []).length],
    ["Rail Lines", map.railways.length + map.branchRailways.length + (map.ringRailways || []).length + map.externalRailways.length],
    ["Industrial Zones", countText(map.industrialZones)],
    ["National Roads", `${map.nationalRoads.length} / pop cover ${Math.round((map.transportDebug?.nationalRoadPopulationCoverage || 0) * 100)}% / uncovered ${(map.transportDebug?.nationalRoadUncoveredPopulation || 0).toLocaleString()}`],
    ["General Ring Roads", (map.ringRoads || []).length],
    ["Expressways", map.expressways.length + map.externalExpressways.length],
    ["External Gateways", map.externalGateways.length],
    ["Interchanges", countText(map.interchanges)],
    ["Logistics Parks", countText(map.logisticsParks)],
    ["New Towns", countText(map.newTowns)],
    ["Municipalities", map.adminCenters.length],
    ["Prefecture source", map.regionalDebug?.prefectureSource ?? "-"],
  ];
}

function renderStats(map) {
  statsEl.innerHTML = "";
  for (const [labelText, valueText] of getStats(map)) {
    const row = document.createElement("div");
    row.className = "stat-row";

    const label = document.createElement("span");
    label.textContent = labelText;

    const value = document.createElement("strong");
    value.textContent = String(valueText);

    row.append(label, value);
    statsEl.append(row);
  }
}

function buildHoverEntities(map) {
  return [
    ...(map.modernCities || []),
    ...(map.ports || []),
    ...(map.stations || []),
    ...(map.interchanges || []),
    ...(map.industrialZones || []),
    ...(map.logisticsParks || []),
    ...(map.newTowns || []),
    ...(map.castles || []),
    ...(map.markets || []),
    ...(map.villages || []),
    ...(map.adminCenters || []),
  ];
}

function nearestEntity(items, x, y, maxDistance = 5) {
  let best = null;
  let bestD = maxDistance;
  for (const item of items || []) {
    if (!item || !Number.isFinite(item.x) || !Number.isFinite(item.y)) continue;
    const d = Math.hypot(item.x - x, item.y - y);
    if (d < bestD) { best = item; bestD = d; }
  }
  return best;
}

function landuseName(value) {
  return landuseLabel(value);
}

const ADMIN_ID_KEYS = ["adminId", "municipalityId", "adminNumericId", "id", "numericId"];
const PREFECTURE_ID_KEYS = ["prefectureRegionId", "prefectureId", "id", "numericId"];
const MUNICIPALITY_NAME_KEYS = ["municipalityName", "name", "canonicalSettlementName", "municipalityRootName", "generatedMunicipalityName", "label"];
const PREFECTURE_NAME_KEYS = ["prefectureName", "prefectureRegionName", "regionName", "name", "label"];
const POPULATION_KEYS = ["municipalityPopulation", "adminPopulation", "population", "estimatedPopulation"];

function numericIdOf(item, keys = ADMIN_ID_KEYS) {
  for (const key of keys) {
    const value = item?.[key];
    if (Number.isFinite(value)) return Math.floor(value);
  }
  return null;
}

function hasNumericId(item, id, keys = ADMIN_ID_KEYS) {
  if (!item || id == null || id < 0) return false;
  return keys.some((key) => Number.isFinite(item?.[key]) && Math.floor(item[key]) === Math.floor(id));
}

function firstUsableText(item, keys) {
  for (const key of keys) {
    const value = item?.[key];
    if (!looksNumericName(value)) return String(value).trim();
  }
  return "";
}

function firstPopulation(item) {
  for (const key of POPULATION_KEYS) {
    const value = item?.[key];
    if (Number.isFinite(value) && value > 0) return Math.round(value);
  }
  return null;
}

function adminCenterForId(map, adminId) {
  if (!map || adminId == null || adminId < 0) return null;
  const centers = (map.adminCenters || []).filter(Boolean);
  const exact = centers.find((center) => hasNumericId(center, adminId));
  if (exact) return exact;
  // Some legacy/admin debug arrays were once addressed by array index.  Keep this
  // only as a guarded fallback so numeric IDs are not mistaken for indexes.
  const direct = map.adminCenters?.[adminId];
  return hasNumericId(direct, adminId) ? direct : null;
}

function looksNumericName(name) {
  if (!name) return true;
  const text = String(name).trim();
  return !text || /^-?\d+(?:\s*[,，]\s*\d+)*$/u.test(text) || /^(Municipality|Prefecture|Admin|Region)\s*-?\d+/i.test(text);
}

function nearestNamedAdminCenter(map, cellIndex, maxDistance = 36, adminId = null) {
  if (!map || cellIndex < 0) return null;
  const x = cellIndex % map.width;
  const y = Math.floor(cellIndex / map.width);
  let best = null;
  let bestD = maxDistance;
  for (const center of map.adminCenters || []) {
    if (!center || !Number.isFinite(center.x) || !Number.isFinite(center.y)) continue;
    if (adminId != null && adminId >= 0 && !hasNumericId(center, adminId)) continue;
    if (!firstUsableText(center, MUNICIPALITY_NAME_KEYS)) continue;
    const d = Math.hypot(center.x - x, center.y - y);
    if (d < bestD) { best = center; bestD = d; }
  }
  return best;
}

function adminName(map, adminId, cellIndex = -1) {
  const center = adminCenterForId(map, adminId) || nearestNamedAdminCenter(map, cellIndex, 54, adminId);
  const name = firstUsableText(center, MUNICIPALITY_NAME_KEYS);
  if (name) return name;
  return adminId >= 0 ? "Unnamed municipality" : "-";
}

function adminPopulation(map, adminId, cellIndex = -1) {
  const center = adminCenterForId(map, adminId) || nearestNamedAdminCenter(map, cellIndex, 54, adminId);
  const centerPop = firstPopulation(center);
  if (centerPop !== null) return centerPop;
  let sum = 0;
  let found = false;
  for (const key of ["modernCities", "satelliteCities", "ports", "markets", "villages"]) {
    for (const p of map?.[key] || []) {
      if (!hasNumericId(p, adminId)) continue;
      const pop = firstPopulation(p);
      if (pop !== null) { sum += pop; found = true; }
    }
  }
  return found ? sum : null;
}

function prefectureNameForCell(map, i) {
  const id = map.prefectureRegionId?.[i] ?? -1;
  const region = (map.prefectureRegions || []).find((p) => hasNumericId(p, id, PREFECTURE_ID_KEYS));
  const regionName = firstUsableText(region, PREFECTURE_NAME_KEYS);
  if (regionName) return regionName;
  const adminId = map.adminId?.[i] ?? -1;
  const mappedPref = adminId >= 0 ? map.municipalityToPrefectureId?.[adminId] ?? -1 : -1;
  const center = mappedPref === id ? nearestNamedAdminCenter(map, i, 90, adminId) : null;
  const fromCenter = firstUsableText(center, ["prefectureName", "prefectureRegionName", "regionName"]);
  return fromCenter || (id >= 0 ? "Unnamed prefecture" : "-");
}

function updateTooltip(event) {
  const map = activeMap();
  if (!map || !tooltipEl || dragState.mode) return;
  const rect = canvas.getBoundingClientRect();
  const cell = mapClientToCell(event);
  if (!cell) return;
  const { x, y } = cell;
  if (x < 0 || y < 0 || x >= map.width || y >= map.height) {
    tooltipEl.classList.remove("visible");
    return;
  }
  const i = y * map.width + x;
  const worldCell = viewportCellToWorldCell({ x, y });
  const entity = nearestEntity(state.hoverEntities, x, y);
  const elevation = map.elevation?.[i] ?? 0;
  const density = map.populationDensity?.[i] ?? map.settlementScore?.[i] ?? 0;
  const hoveredAdminId = map.adminId?.[i] ?? -1;
  const hoveredAdminPopulation = adminPopulation(map, hoveredAdminId, i);
  const coordinateText = worldCell ? `World ${worldCell.x}, ${worldCell.y} / View ${x}, ${y}` : `${x}, ${y}`;
  const entityName = firstUsableText(entity, ["name", "facilityLabel", "municipalityName", "canonicalSettlementName", "kind"]);
  const entityTitle = entity
    ? `${entityName || adminName(map, hoveredAdminId, i) || entity.kind || "Feature"} / ${entity.kind || "Feature"}`
    : coordinateText;
  const lines = [
    `<strong>${entityTitle}</strong>`,
    `Prefecture: ${prefectureNameForCell(map, i)}`,
    `Admin: ${adminName(map, hoveredAdminId, i)}`,
    `Admin Pop: ${hoveredAdminPopulation === null ? "-" : hoveredAdminPopulation.toLocaleString()}`,
    `Land: ${map.sea?.[i] ? "Sea" : landuseName(map.landuse?.[i])}`,
    `Elevation: ${elevation.toFixed(3)} / Slope: ${(map.slope?.[i] ?? 0).toFixed(3)}`,
    `River: ${(map.river?.[i] ?? 0).toFixed(2)} / Density: ${density.toFixed(2)}`,
  ];
  if (entity?.population) lines.splice(1, 0, `Population: ${entity.population.toLocaleString()}`);
  tooltipEl.innerHTML = lines.join("<br>");
  const margin = 8;
  const offset = 14;
  const maxLeft = Math.max(margin, rect.width - tooltipEl.offsetWidth - margin);
  const maxTop = Math.max(margin, rect.height - tooltipEl.offsetHeight - margin);
  const desiredLeft = event.clientX - rect.left + offset;
  const desiredTop = event.clientY - rect.top + offset;
  tooltipEl.style.left = `${Math.min(Math.max(margin, desiredLeft), maxLeft)}px`;
  tooltipEl.style.top = `${Math.min(Math.max(margin, desiredTop), maxTop)}px`;
  tooltipEl.classList.add("visible");
}

function renderModeButtons() {
  modeGrid.innerHTML = "";
  for (const [key, label] of modes) {
    const button = document.createElement("button");
    button.type = "button";
    button.textContent = label;
    button.className = key === state.mode ? "mode-button active" : "mode-button";
    button.addEventListener("click", () => {
      state.mode = key;
      renderModeButtons();
      redraw();
    });
    modeGrid.append(button);
  }
}

async function regenerate() {
  state.seedText = seedInput.value;
  state.generationType = generationTypeInput?.value || "auto";
  setProgressVisible(true, "Preparing generation...");
  await nextFrame();
  try {
    state.map = await generateMapAsync(parseSeed(state.seedText), { onProgress: updateGenerationProgress, terrainType: state.generationType });
    state.world = createWorldMap(state.map);
    state.camera = createInitialCamera(state.world);
    state.lastPatchResult = null;
    resetPatchVariant({ update: false });
    hideSelectionOverlay();
    renderStats(state.map);
    redraw();
    if (progressStageEl) progressStageEl.textContent = `Done in ${formatMs(state.map.generationTotalMs || 0)}`;
    renderTimingRows(state.map.generationTimings || []);
    window.setTimeout(() => setProgressVisible(false), 900);
  } catch (error) {
    if (progressStageEl) progressStageEl.textContent = `Generation failed: ${error?.message || error}`;
    throw error;
  }
}


function derivePatchSeed(rect, terrainType, variant = 0) {
  let h = parseSeed(state.seedText) ^ 0x9e3779b9;
  h = Math.imul(h ^ (rect.x0 | 0), 1664525) >>> 0;
  h = Math.imul(h ^ (rect.y0 | 0), 1013904223) >>> 0;
  h = Math.imul(h ^ (rect.x1 | 0), 2246822519) >>> 0;
  h = Math.imul(h ^ (rect.y1 | 0), 3266489917) >>> 0;
  h = Math.imul(h ^ normalizePatchVariant(variant), 668265263) >>> 0;
  for (const ch of String(terrainType || "auto")) h = Math.imul(h ^ ch.charCodeAt(0), 16777619) >>> 0;
  return h >>> 0;
}


function handleCanvasWheel(event) {
  if (!state.world || !activeMap()) return;
  event.preventDefault();
  tooltipEl?.classList.remove("visible");
  const beforeSize = viewportSizeForZoom(state.zoom);
  const beforeCell = mapClientToCell(event, beforeSize);
  const beforeWorld = beforeCell ? viewportCellToWorldCell(beforeCell) : null;
  const oldZoom = clampZoom(state.zoom || 1);
  const delta = event.deltaY < 0 ? 1.10 : 1 / 1.10;
  const nextZoom = clampZoom(oldZoom * delta);
  if (Math.abs(nextZoom - oldZoom) < 0.001) return;
  state.zoom = nextZoom;
  const nextSize = syncViewportSize();
  if (beforeWorld) {
    const afterCell = mapClientToCell(event, nextSize);
    if (afterCell) {
      state.camera = clampCameraForView({
        x: beforeWorld.x - afterCell.x,
        y: beforeWorld.y - afterCell.y,
      }, nextSize);
    }
  }

  // Wheel events can fire dozens of times per second.  Do one lightweight redraw
  // per frame, then a full labeled/continuous redraw once zooming settles.
  if (zoomRedrawRaf == null) {
    zoomRedrawRaf = requestAnimationFrame(() => {
      zoomRedrawRaf = null;
      redraw({ fastTerrain: true, allowWorldExpand: false });
    });
  }
  if (zoomSettledTimer != null) clearTimeout(zoomSettledTimer);
  zoomSettledTimer = window.setTimeout(() => {
    zoomSettledTimer = null;
    redraw({ fastTerrain: false, allowWorldExpand: false });
  }, 140);
}

async function generateSelectedPatch() {
  const validation = validatePatchRect(state.selectionRect, state.world);
  if (!validation.ok) {
    updatePatchControls();
    return;
  }
  const terrainType = patchTerrainTypeInput?.value || generationTypeInput?.value || "auto";
  const variant = readPatchVariant();
  const seed = derivePatchSeed(validation.rect, terrainType, variant);
  setProgressVisible(true, "Generating selected patch...");
  await nextFrame();
  try {
    const result = generatePatch(state.world, validation.rect, { terrainType, seed, variant });
    if (!result.ok) {
      if (progressStageEl) progressStageEl.textContent = `Patch failed: ${result.reason || "invalid selection"}`;
      updatePatchControls();
      window.setTimeout(() => setProgressVisible(false), 1200);
      return;
    }
    state.lastPatchResult = result;
    redraw();
    renderStats(state.map);
    updatePatchControls();
    const human = result.humanGeography;
    const humanText = human?.ok ? ` / human: ${human.modernCities || 0} cities, ${human.ports || 0} ports, ${human.villages || 0} villages, ${(human.roadConnectorsCreated || 0) + (human.railwayConnectorsCreated || 0)} connectors, admin ${human.adminCellsReassigned || 0}, invalid ports ${human.invalidPortsRemoved || 0}` : "";
    if (progressStageEl) progressStageEl.textContent = `Patch generated: ${result.label} / variant ${result.variant ?? variant} / mode ${result.patchGenerationMode || "legacy-full-pipeline"} / core ${formatRectSize(result.rects.coreRect)} / write ${formatRectSize(result.rects.writeRect)} / terrain ${result.updatedCells.toLocaleString()} cells / coast ${result.coastCellsChanged || 0} / natural ${result.naturalRegionsUpdated || 0}${humanText}`;
    renderTimingRows(result.patchTimings || []);
    window.setTimeout(() => setProgressVisible(false), 900);
  } catch (error) {
    if (progressStageEl) progressStageEl.textContent = `Patch failed: ${error?.message || error}`;
    throw error;
  }
}

async function generateAlternativePatch() {
  const validation = validatePatchRect(state.selectionRect, state.world);
  if (!validation.ok) {
    updatePatchControls();
    return;
  }
  setPatchVariant(readPatchVariant() + 1, { update: false });
  await generateSelectedPatch();
}

function redraw(options = {}) {
  if (!state.world) return;
  const viewSize = syncViewportSize();
  const expansion = options.allowWorldExpand === false ? null : ensureWorldPaddingForCamera(state.world, state.camera, viewSize.width, viewSize.height);
  if (expansion?.expanded) {
    const ex = expansion.dx || 0;
    const ey = expansion.dy || 0;
    state.camera = { x: (state.camera?.x || 0) + ex, y: (state.camera?.y || 0) + ey };
    if (dragState.mode === "pan") {
      dragState.startCameraX += ex;
      dragState.startCameraY += ey;
      if (dragState.pendingCamera) dragState.pendingCamera = { x: dragState.pendingCamera.x + ex, y: dragState.pendingCamera.y + ey };
    }
    if (state.selectionRect) {
      state.selectionRect = {
        ...state.selectionRect,
        x0: state.selectionRect.x0 + ex,
        y0: state.selectionRect.y0 + ey,
        x1: state.selectionRect.x1 + ex,
        y1: state.selectionRect.y1 + ey,
        polygon: Array.isArray(state.selectionRect.polygon) ? state.selectionRect.polygon.map((p) => ({ x: p.x + ex, y: p.y + ey })) : state.selectionRect.polygon,
      };
    }
  }
  state.camera = clampCameraForView(state.camera, viewSize);
  state.viewportMap = getViewportMap(state.world, state.camera, viewSize.width, viewSize.height, { light: !!options.fastTerrain });
  state.hoverEntities = options.fastTerrain ? [] : buildHoverEntities(state.viewportMap);
  drawMap(canvas, state.viewportMap, {
    mode: state.mode,
    showFeatures: state.showFeatures && !options.fastTerrain,
    showLabels: state.showLabels && !options.fastTerrain,
    continuousTerrain: !options.fastTerrain,
    fastTerrain: !!options.fastTerrain,
    zoom: state.zoom || 1,
  });
  applyCanvasZoom();
  if (state.selectionRect && dragState.mode !== "select") updateSelectionOverlayFromWorldRect();
}

function init() {
  renderModeButtons();

  seedInput.addEventListener("change", regenerate);
  seedInput.addEventListener("keydown", (event) => {
    if (event.key === "Enter") regenerate();
  });

  generationTypeInput?.addEventListener("change", regenerate);
  patchTerrainTypeInput?.addEventListener("change", () => {
    state.lastPatchResult = null;
    resetPatchVariant({ update: false });
    updatePatchControls();
  });
  patchVariantInput?.addEventListener("change", () => setPatchVariant(patchVariantInput.value));
  patchVariantInput?.addEventListener("keydown", (event) => {
    if (event.key === "Enter") {
      setPatchVariant(patchVariantInput.value);
      generateSelectedPatch();
    }
  });
  generatePatchButton?.addEventListener("click", generateSelectedPatch);
  alternativePatchButton?.addEventListener("click", generateAlternativePatch);

  randomSeedButton.addEventListener("click", () => {
    seedInput.value = String(Math.floor(Math.random() * 9999999));
    regenerate();
  });

  showFeaturesInput.addEventListener("change", () => {
    state.showFeatures = showFeaturesInput.checked;
    redraw();
  });

  showLabelsInput.addEventListener("change", () => {
    state.showLabels = showLabelsInput.checked;
    redraw();
  });

  canvasShell?.setAttribute("tabindex", "0");
  canvas.addEventListener("contextmenu", (event) => event.preventDefault());
  canvas.addEventListener("wheel", handleCanvasWheel, { passive: false });
  canvas.addEventListener("pointerdown", handleMapPointerDown);
  canvas.addEventListener("pointermove", handleMapPointerMove);
  canvas.addEventListener("pointerup", handleMapPointerUp);
  canvas.addEventListener("pointercancel", handleMapPointerUp);
  canvas.addEventListener("mousemove", updateTooltip);
  canvas.addEventListener("mouseleave", () => {
    tooltipEl?.classList.remove("visible");
  });

  updatePatchControls();
  regenerate();
}

init();