import * as THREE from 'three';
import { TransformControls } from 'three/examples/jsm/controls/TransformControls.js';
import type {
  EditableMapDocument,
  EditableMapObject,
  MapEditorTransformMode,
} from '../map/editor/types';
import type { MapEditorDraftPreviewInstance } from '../map/mapSceneDraft';
import {
  DEFAULT_MAP_INSTANCE_TRANSFORM,
  type MapInstanceTransform,
  type SpawnPoint,
} from '../map/types';

export interface MapEditorLayerCallbacks {
  onSelect(id: string | null): void;
  onPreviewSelect(mapAssetId: string, objectId: string): void;
  onTransform(
    id: string,
    position: [number, number, number],
    quaternion: [number, number, number, number],
    scale: [number, number, number],
  ): void;
  onDragging(value: boolean): void;
}

function material(object: EditableMapObject): THREE.MeshStandardMaterial {
  const [r, g, b, a] = object.rgba;
  return new THREE.MeshStandardMaterial({
    color: new THREE.Color(r, g, b),
    emissive: new THREE.Color(0x000000),
    opacity: Math.min(a, 0.65),
    transparent: true,
    depthWrite: false,
  });
}
function mesh(geometry: THREE.BufferGeometry, object: EditableMapObject): THREE.Mesh {
  const result = new THREE.Mesh(geometry, material(object));
  result.castShadow = true;
  result.receiveShadow = true;
  result.renderOrder = 9;
  return result;
}
function spawnPreview(spawn: SpawnPoint): THREE.Group {
  const group = new THREE.Group();
  group.name = `__platform_map_editor_spawn_${spawn.id}`;
  group.position.set(spawn.position[0], spawn.position[1], spawn.position[2] + 0.03);
  group.rotation.z = (spawn.yawDeg * Math.PI) / 180;
  const markerMaterial = new THREE.MeshStandardMaterial({
    color: 0x22c55e,
    emissive: 0x14532d,
    transparent: true,
    opacity: 0.9,
  });
  const ring = new THREE.Mesh(new THREE.TorusGeometry(0.22, 0.025, 8, 24), markerMaterial);
  const arrow = new THREE.Mesh(new THREE.ConeGeometry(0.08, 0.32, 12), markerMaterial);
  ring.renderOrder = 9;
  arrow.renderOrder = 9;
  arrow.rotation.z = -Math.PI / 2;
  arrow.position.x = 0.25;
  group.add(ring, arrow);
  return group;
}
function objectPreview(object: EditableMapObject): THREE.Group {
  const group = new THREE.Group(),
    p = object.parameters;
  group.name = `__platform_map_editor_${object.id}`;
  group.userData.mapEditorObjectId = object.id;
  group.userData.mapEditorLocked = object.placementMode === 'locked';
  group.userData.mapEditorPlacementMode = object.placementMode;
  group.position.fromArray(object.pose.position);
  group.quaternion.set(
    object.pose.quaternion[1],
    object.pose.quaternion[2],
    object.pose.quaternion[3],
    object.pose.quaternion[0],
  );
  if (object.type === 'box')
    group.add(mesh(new THREE.BoxGeometry(p.sizeX, p.sizeY, p.sizeZ), object));
  else if (object.type === 'cylinder')
    group.add(
      mesh(
        new THREE.CylinderGeometry(p.radius, p.radius, p.height, 24).rotateX(Math.PI / 2),
        object,
      ),
    );
  else if (object.type === 'capsule')
    group.add(
      mesh(new THREE.CapsuleGeometry(p.radius, p.length, 8, 16).rotateX(Math.PI / 2), object),
    );
  else if (object.type === 'ramp') {
    const item = mesh(
      new THREE.BoxGeometry(Math.hypot(p.length, p.rise), p.width, p.thickness),
      object,
    );
    item.position.z = p.rise / 2;
    item.rotation.y = -Math.atan2(p.rise, p.length);
    group.add(item);
  } else
    for (let index = 0; index < p.count; index += 1) {
      const height = p.stepHeight * (index + 1);
      const item = mesh(new THREE.BoxGeometry(p.stepDepth, p.width, height), object);
      item.position.set(p.stepDepth * index, 0, height / 2);
      group.add(item);
    }
  group.traverse((child) => {
    child.userData.mapEditorObjectId = object.id;
  });
  return group;
}

function disposeGroupChildren(group: THREE.Group): void {
  const geometries = new Set<THREE.BufferGeometry>();
  const materials = new Set<THREE.Material>();
  for (const child of group.children)
    child.traverse((object) => {
      if (!(object instanceof THREE.Mesh)) return;
      geometries.add(object.geometry);
      for (const item of Array.isArray(object.material) ? object.material : [object.material])
        materials.add(item);
    });
  group.clear();
  for (const geometry of geometries) geometry.dispose();
  for (const item of materials) item.dispose();
}

export class MapEditorLayer {
  readonly group = new THREE.Group();
  readonly previewGroup = new THREE.Group();
  readonly transform: TransformControls;
  private readonly helper: THREE.Object3D;
  private readonly raycaster = new THREE.Raycaster();
  private readonly pointer = new THREE.Vector2();
  private readonly objects = new Map<string, THREE.Group>();
  private readonly previewInstances = new Map<string, THREE.Group>();
  private readonly surfaceIndicator = new THREE.Group();
  private readonly surfaceRingMaterial = new THREE.MeshBasicMaterial({
    color: 0x34d399,
    transparent: true,
    opacity: 0.42,
    depthTest: false,
    depthWrite: false,
    side: THREE.DoubleSide,
  });
  private readonly surfaceLineMaterial = new THREE.LineBasicMaterial({
    color: 0x6ee7b7,
    transparent: true,
    opacity: 0.7,
    depthTest: false,
  });
  private selectedId: string | null = null;
  private documentLoaded = false;
  private surfaceIndicatorScale = 0.25;
  private surfacePulseStarted = 0;

  constructor(
    private readonly scene: THREE.Scene,
    private readonly camera: THREE.Camera,
    domElement: HTMLElement,
    private readonly callbacks: MapEditorLayerCallbacks,
  ) {
    this.previewGroup.name = '__platform_map_editor_scene_previews__';
    this.group.name = '__platform_map_editor__';
    this.surfaceIndicator.name = '__platform_snap_surface_indicator__';
    const surfaceRing = new THREE.Mesh(
      new THREE.RingGeometry(0.72, 1, 48),
      this.surfaceRingMaterial,
    );
    surfaceRing.renderOrder = 110;
    const surfaceCross = new THREE.LineSegments(
      new THREE.BufferGeometry().setFromPoints([
        new THREE.Vector3(-1.18, 0, 0),
        new THREE.Vector3(1.18, 0, 0),
        new THREE.Vector3(0, -1.18, 0),
        new THREE.Vector3(0, 1.18, 0),
      ]),
      this.surfaceLineMaterial,
    );
    surfaceCross.renderOrder = 110;
    this.surfaceIndicator.add(surfaceRing, surfaceCross);
    this.surfaceIndicator.visible = false;
    scene.add(this.previewGroup, this.group, this.surfaceIndicator);
    this.transform = new TransformControls(camera, domElement);
    this.transform.setSpace('world');
    this.transform.setSize(0.8);
    this.transform.setTranslationSnap(0.1);
    this.transform.setRotationSnap(THREE.MathUtils.degToRad(5));
    this.helper = this.transform.getHelper();
    this.helper.name = '__platform_map_editor_transform__';
    this.helper.visible = false;
    scene.add(this.helper);
    this.transform.addEventListener('dragging-changed', (event) => {
      this.callbacks.onDragging(Boolean(event.value));
    });
    this.transform.addEventListener('mouseUp', () => this.commitTransform());
    this.setTransformMode('translate');
  }

  get enabled(): boolean {
    return this.documentLoaded || this.previewInstances.size > 0;
  }

  selectedBoundingSphere(): THREE.Sphere | null {
    const selected = this.selectedId ? this.objects.get(this.selectedId) : undefined;
    if (!selected) return null;
    selected.updateWorldMatrix(true, true);
    const bounds = new THREE.Box3().setFromObject(selected);
    if (bounds.isEmpty()) return null;
    return bounds.getBoundingSphere(new THREE.Sphere());
  }

  flashSurfaceAlignment(id?: string): void {
    if (id && id !== this.selectedId) return;
    const selected = this.selectedId ? this.objects.get(this.selectedId) : undefined;
    if (!selected || selected.userData.mapEditorLocked) return;
    this.positionSurfaceIndicator(selected);
    this.startSurfacePulse();
    this.surfaceIndicator.visible = true;
  }

  update(now: number): void {
    const selected = this.selectedId ? this.objects.get(this.selectedId) : undefined;
    if (!selected || selected.userData.mapEditorLocked) {
      this.surfaceIndicator.visible = false;
      return;
    }
    this.positionSurfaceIndicator(selected);
    const elapsed = now - this.surfacePulseStarted;
    const pulse = elapsed >= 0 && elapsed < 720 ? 1 - elapsed / 720 : 0;
    const wave = pulse * (0.16 + Math.sin((elapsed / 720) * Math.PI * 4) * 0.08);
    this.surfaceIndicator.scale.setScalar(this.surfaceIndicatorScale * (1 + wave));
    this.surfaceRingMaterial.opacity = 0.32 + pulse * 0.38;
    this.surfaceLineMaterial.opacity = 0.5 + pulse * 0.4;
  }

  setDocument(
    document: EditableMapDocument | null,
    instanceTransform: MapInstanceTransform = DEFAULT_MAP_INSTANCE_TRANSFORM,
  ): void {
    const selected = this.selectedId;
    this.clearObjects();
    this.group.position.set(instanceTransform.positionX, instanceTransform.positionY, 0);
    this.group.rotation.set(0, 0, THREE.MathUtils.degToRad(instanceTransform.yawDeg));
    this.group.updateMatrixWorld(true);
    this.documentLoaded = Boolean(document);
    this.transform.enabled = this.documentLoaded;
    if (!document) {
      this.selectObject(null, false);
      return;
    }
    for (const object of document.objects) {
      if (!object.enabled) continue;
      const preview = objectPreview(object);
      this.objects.set(object.id, preview);
      this.group.add(preview);
    }
    for (const spawn of document.spawnPoints) this.group.add(spawnPreview(spawn));
    this.selectObject(selected && this.objects.has(selected) ? selected : null, false);
  }

  /** 绘制非激活、但仍处于统一场景草稿中的认证资产实例。 */
  setPreviewInstances(instances: readonly MapEditorDraftPreviewInstance[]): void {
    this.clearPreviewInstances();
    for (const instance of instances) {
      const root = new THREE.Group();
      root.name = `__platform_map_editor_scene_preview_${instance.id}__`;
      root.userData.mapAssetId = instance.id;
      root.position.set(instance.transform.positionX, instance.transform.positionY, 0);
      root.rotation.z = THREE.MathUtils.degToRad(instance.transform.yawDeg);
      for (const object of instance.document.objects) {
        if (object.enabled) root.add(objectPreview(object));
      }
      for (const spawn of instance.document.spawnPoints) root.add(spawnPreview(spawn));
      root.traverse((object) => {
        object.userData.mapEditorMapAssetId = instance.id;
      });
      this.previewInstances.set(instance.id, root);
      this.previewGroup.add(root);
    }
  }

  setTransformMode(mode: MapEditorTransformMode): void {
    this.transform.setMode(mode);
    const translate = mode === 'translate';
    const scale = mode === 'scale';
    this.transform.showX = translate || scale;
    this.transform.showY = translate || scale;
    this.transform.showZ = translate || scale || mode === 'rotate';
    this.transform.showXY = translate;
    this.transform.showYZ = false;
    this.transform.showXZ = false;
    this.transform.showE = false;
  }

  setSnapping(translation: number | null, rotationDegrees: number | null): void {
    this.transform.setTranslationSnap(translation);
    this.transform.setRotationSnap(
      rotationDegrees === null ? null : THREE.MathUtils.degToRad(rotationDegrees),
    );
  }

  selectObject(id: string | null, notify = false): void {
    const previousId = this.selectedId;
    this.selectedId = id && this.objects.has(id) ? id : null;
    this.transform.detach();
    for (const [objectId, root] of this.objects)
      root.traverse((child) => {
        if (!(child instanceof THREE.Mesh)) return;
        const materials = Array.isArray(child.material) ? child.material : [child.material];
        for (const item of materials) {
          if (!(item instanceof THREE.MeshStandardMaterial)) continue;
          item.emissive.setHex(objectId === this.selectedId ? 0x1d4ed8 : 0x000000);
          item.emissiveIntensity = objectId === this.selectedId ? 0.45 : 1;
          item.opacity = objectId === this.selectedId ? 0.85 : 0.65;
        }
      });
    const selected = this.selectedId ? this.objects.get(this.selectedId) : undefined;
    const editable = Boolean(selected && !selected.userData.mapEditorLocked);
    if (selected && editable) {
      this.transform.attach(selected);
      this.positionSurfaceIndicator(selected);
      if (previousId !== this.selectedId) this.startSurfacePulse();
    } else this.surfaceIndicator.visible = false;
    this.helper.visible = editable;
    if (notify) this.callbacks.onSelect(this.selectedId);
  }

  /** 命中编辑对象或操纵器时消费左键；点击空白区域取消对象选中。 */
  handlePointerDown(
    event: PointerEvent,
    bounds: DOMRect,
    maximumDistance = Number.POSITIVE_INFINITY,
  ): boolean {
    if (!this.enabled || event.button !== 0) return false;
    if (this.transform.axis || this.transform.dragging) return true;
    this.pointer.x = ((event.clientX - bounds.left) / bounds.width) * 2 - 1;
    this.pointer.y = -((event.clientY - bounds.top) / bounds.height) * 2 + 1;
    this.raycaster.setFromCamera(this.pointer, this.camera);
    this.group.updateMatrixWorld(true);
    this.previewGroup.updateMatrixWorld(true);
    const hit = this.raycaster
      .intersectObjects([...this.objects.values(), ...this.previewInstances.values()], true)
      .find(
        (candidate) =>
          typeof candidate.object.userData.mapEditorObjectId === 'string' &&
          candidate.distance <= maximumDistance + 1e-3,
      );
    const objectId = hit?.object.userData.mapEditorObjectId;
    const mapAssetId = hit?.object.userData.mapEditorMapAssetId;
    if (typeof objectId === 'string' && typeof mapAssetId === 'string') {
      this.callbacks.onPreviewSelect(mapAssetId, objectId);
      return true;
    }
    if (typeof objectId === 'string') {
      this.selectObject(objectId, true);
      return true;
    }
    if (this.selectedId) this.selectObject(null, true);
    return false;
  }

  private startSurfacePulse(): void {
    const now = performance.now();
    this.surfacePulseStarted = window.matchMedia?.('(prefers-reduced-motion: reduce)').matches
      ? now - 720
      : now;
  }

  private positionSurfaceIndicator(selected: THREE.Group): void {
    selected.updateWorldMatrix(true, true);
    const bounds = new THREE.Box3().setFromObject(selected);
    if (bounds.isEmpty()) {
      this.surfaceIndicator.visible = false;
      return;
    }
    const center = bounds.getCenter(new THREE.Vector3());
    const size = bounds.getSize(new THREE.Vector3());
    const placementMode = selected.userData.mapEditorPlacementMode;
    const color = placementMode === 'gravity' ? 0x38bdf8 : 0x34d399;
    this.surfaceRingMaterial.color.setHex(color);
    this.surfaceLineMaterial.color.setHex(color);
    this.surfaceIndicatorScale = Math.min(1.5, Math.max(0.16, Math.max(size.x, size.y) * 0.62));
    this.surfaceIndicator.position.set(center.x, center.y, bounds.min.z + 0.004);
    this.surfaceIndicator.scale.setScalar(this.surfaceIndicatorScale);
    this.surfaceIndicator.visible = true;
  }

  private commitTransform(): void {
    if (!this.selectedId) return;
    const object = this.objects.get(this.selectedId);
    if (!object) return;
    const position: [number, number, number] = [
      object.position.x,
      object.position.y,
      object.position.z,
    ];
    const quaternion: [number, number, number, number] = [
      object.quaternion.w,
      object.quaternion.x,
      object.quaternion.y,
      object.quaternion.z,
    ];
    const scale: [number, number, number] = [object.scale.x, object.scale.y, object.scale.z];
    this.callbacks.onTransform(this.selectedId, position, quaternion, scale);
  }

  private clearObjects(): void {
    this.transform.detach();
    this.helper.visible = false;
    disposeGroupChildren(this.group);
    this.objects.clear();
  }

  private clearPreviewInstances(): void {
    disposeGroupChildren(this.previewGroup);
    this.previewInstances.clear();
  }

  clear(): void {
    this.documentLoaded = false;
    this.selectedId = null;
    this.clearObjects();
    this.clearPreviewInstances();
    this.group.position.set(0, 0, 0);
    this.group.rotation.set(0, 0, 0);
    this.surfaceIndicator.visible = false;
    this.surfacePulseStarted = 0;
    this.transform.enabled = false;
    this.callbacks.onDragging(false);
  }

  dispose(): void {
    this.clear();
    this.callbacks.onDragging(false);
    this.transform.dispose();
    this.helper.removeFromParent();
    for (const child of this.surfaceIndicator.children)
      if (child instanceof THREE.Mesh || child instanceof THREE.Line) child.geometry.dispose();
    this.surfaceRingMaterial.dispose();
    this.surfaceLineMaterial.dispose();
    this.surfaceIndicator.removeFromParent();
    this.previewGroup.removeFromParent();
    this.group.removeFromParent();
  }
}