import * as THREE from 'three'
import type { ItemTypeDefineOption } from '@/model/itemType/ItemTypeDefine.ts'
import { getAllItemTypes, getItemTypeByName } from '@/model/itemType/ItemTypeDefine.ts'
import type Viewport from '@/core/engine/Viewport'
import { Vector2 } from 'three/src/math/Vector2'
import EventBus from '@/runtime/EventBus.ts'
import Decimal from 'decimal.js'

/**
 * 确保所有实体之间的关系满足一致性：
 * - center 是双向的
 * - in/out 是相互对应的
 * - 不允许自己指向自己
 */
export function ensureEntityRelationsConsistency(items: ItemJson[]) {
  const itemMap = new Map<string, ItemJson>()

  // 构建 ID -> Item 映射，便于快速查找
  for (const item of items) {
    if (item.id) {
      itemMap.set(item.id, item)
    }
  }

  // 初始化关系集合
  const centerMap = new Map<string, Set<string>>() // A <-> B
  const inMap = new Map<string, Set<string>>()     // A <- B （B.in.push(A)）
  const outMap = new Map<string, Set<string>>()    // A -> B （B.out.push(A)）

  // 初始化所有节点的关系集
  for (const item of items) {
    const id = item.id
    if (!id) continue

    centerMap.set(id, new Set(item.dt?.center || []))
    inMap.set(id, new Set(item.dt?.in || []))
    outMap.set(id, new Set(item.dt?.out || []))
  }

  // Step 1: 补全 center 双向关系
  for (const [source, targets] of centerMap.entries()) {
    for (const target of targets) {
      if (!centerMap.get(target)?.has(source)) {
        centerMap.get(target)?.add(source)
      }
    }
  }

  // Step 2: 补全 in/out 对应关系
  for (const [source, targets] of outMap.entries()) {
    for (const target of targets) {
      if (!inMap.get(target)?.has(source)) {
        inMap.get(target)?.add(source)
      }
    }
  }

  for (const [source, targets] of inMap.entries()) {
    for (const target of targets) {
      if (!outMap.get(target)?.has(source)) {
        outMap.get(target)?.add(source)
      }
    }
  }

  // Step 3: 清理自环引用（center / in / out 都不能包含自己）
  for (const id of itemMap.keys()) {
    centerMap.get(id)?.delete(id)
    inMap.get(id)?.delete(id)
    outMap.get(id)?.delete(id)
  }

  // Step 4: 将补全后的关系写回原数据
  for (const item of items) {
    const id = item.id
    if (!id) continue

    item.dt = item.dt || {}

    item.dt.center = Array.from(centerMap.get(id) || [])
    item.dt.in = Array.from(inMap.get(id) || [])
    item.dt.out = Array.from(outMap.get(id) || [])
  }

  return items
}

/**
 * 获取线条的唯一 ID
 */
export function getLineId(startId: string, endId: string, type: LinkType): string {
  if (type === 'center' && startId > endId) {
    // 无序线, start / end 大的在前
    return `${type}$${endId}$${startId}`
  }
  // 其他的线是有序线
  // 线条必须加上 type, 因为 center 与 in/out 是可以并存的
  return `${type}$${startId}$${endId}`
}

/**
 * 获取某个 Object3D 先上查找最近的有效业务 Object3D
 * @param object
 */
export function getClosestObject(object: THREE.Object3D) {
  if (!object) {
    return undefined
  }
  while (object) {
    if (object.userData && object.userData.t && object.userData.entityId) {
      // 找到第一个有效的业务 Object3D
      return object
    }
    // 向上查找父级
    object = object.parent
  }
}

/**
 * 解析线条 ID, 返回 线条类型, 起点 ID 和终点 ID
 */
export function parseLineId(lineId): [LinkType, string, string] {
  const parts = lineId.split('$')
  if (parts.length !== 3) {
    throw new Error(`Invalid lineId format: ${lineId}`)
  }
  const type = parts[0] as LinkType
  const startId = parts[1]
  const endId = parts[2]
  return [type, startId, endId]
}

export function deletePointByKeyboard() {
  const viewport: Viewport = window['viewport']
  if (!viewport) {
    system.msg('没有找到当前视图')
    return
  }

  const entityId = viewport.state.selectedEntityId
  if (!entityId) {
    const multiSelectedEntityIds = viewport.state.multiSelectedEntityIds
    if (!multiSelectedEntityIds && multiSelectedEntityIds.length === 0) {
      system.msg('请选中要删除的实体', 'error')
      return
    }

    const stateManager = viewport.stateManager
    stateManager.beginStateUpdate()
    const deleteItems = _.remove(stateManager.vdata.items, (item) => multiSelectedEntityIds.includes(item.id))
    stateManager.endStateUpdate()
    if (deleteItems.length === 0) {
      system.msg('没有找到要删除的实体', 'error')
    } else {
      system.msg('删除了 ' + deleteItems.length + ' 个实体')
    }
    for (const deleteEntityId of multiSelectedEntityIds) {
      EventBus.dispatch('entityDeleted', {
        deleteEntityId: deleteEntityId
      })
      viewport.selectInspect.clearRedSelectionBoxes()
    }
    return
  }

  const stateManager = viewport.stateManager
  viewport.stateManager.beginStateUpdate()
  _.remove(stateManager.vdata.items, (item) => item.id === entityId)
  viewport.stateManager.endStateUpdate()

  if (viewport.state.selectedEntityId === entityId) {
    viewport.state.selectedObject = undefined
    viewport.state.selectedItem = undefined
    viewport.state.selectedEntityId = undefined
    viewport.state.selectedObjectSetter = undefined
  }

  EventBus.dispatch('entityDeleted', {
    deleteEntityId: entityId
  })

  system.msg('删除 [' + entityId + ']')
  viewport.selectInspect.clearSelectionBox()
}

export function escByKeyboard() {
  // 按下 ESC 键，取消当前操作
  const viewport: Viewport = window['viewport']
  if (!viewport) {
    system.msg('没有找到当前视图')
    return
  }

  viewport.interactionManager.exitInteraction()
  system.msg('操作已取消')
}

/**
 * 查找指定点附近指定距离内的所有 stateManager 下的 item 对象
 * 如果要修改数据做提交, 执行此方法之前必须执行 beginStateUpdate
 * @param viewport 视窗
 * @param point 点位 x,z 坐标
 * @param distance 距离
 */
export function findStateItemsByDistance(viewport: Viewport, point: Vector2, distance: number): ItemJson[] {
  const result: ItemJson[] = []

  for (const item of viewport.stateManager.vdata.items) {
    // 安全校验 tf 结构
    if (!item.tf || !Array.isArray(item.tf) || item.tf[0].length < 3) {
      continue
    }

    const [x, , z] = item.tf[0]
    const itemPoint = new Vector2(x, z)
    const dist = itemPoint.distanceTo(point)

    if (dist <= distance) {
      result.push(item)
    }
  }

  // 按距离升序排序（近距离优先）
  return result.sort((a, b) => {
    const aPos = new Vector2(a.tf[0][0], a.tf[0][2])
    const bPos = new Vector2(b.tf[0][0], b.tf[0][2])
    return aPos.distanceTo(point) - bPos.distanceTo(point)
  })
}

export function moveSelectedItem(direct: '↑' | '↓' | '←' | '→') {
  // 获取当前是否按住了 Shift
  const viewport: Viewport = window['viewport']
  if (!viewport) {
    system.msg('没有找到当前视图')
    return
  }

  let delta = 0.25
  if (CurrentMouseInfo.isShiftKey || CurrentMouseInfo.isMetaKey) {
    // 按住 Shift 键时，移动距离只有0.1
    delta = 0.1
  }

  const entityId = viewport.state.selectedEntityId
  if (!entityId) {
    const multiSelectedEntityIds = viewport.state.multiSelectedEntityIds
    if (!multiSelectedEntityIds && multiSelectedEntityIds.length === 0) {
      system.msg('请选中要调整坐标的实体', 'error')
      return
    }

    // 群体移动
    const stateManager = viewport.stateManager
    stateManager.beginStateUpdate()
    for (const item of stateManager.vdata.items) {
      if (multiSelectedEntityIds.includes(item.id)) {
        // 根据方向移动
        switch (direct) {
          case '↑':
            console.log('向上移动', item.tf[0][2],'-=', delta)
            item.tf[0][2] -= delta // 向上移动
            break
          case '↓':
            item.tf[0][2] += delta // 向下移动
            break
          case '←':
            item.tf[0][0] -= delta // 向左移动
            break
          case '→':
            item.tf[0][0] += delta // 向右移动
            break
        }
      }
    }
    stateManager.endStateUpdate()
    EventBus.dispatch('multiselectedObjectChanged', {
      multiSelectedObjects: viewport.state.multiSelectedObjects
    })
    EventBus.dispatch('selectedObjectPropertyChanged', {})
    return
  }

  const stateManager = viewport.stateManager
  viewport.stateManager.beginStateUpdate()
  for (const item of stateManager.vdata.items) {
    if (item.id === entityId) {
      // 根据方向移动
      switch (direct) {
        case '↑':
          item.tf[0][2] -= delta // 向上移动
          break
        case '↓':
          item.tf[0][2] += delta // 向下移动
          break
        case '←':
          item.tf[0][0] -= delta // 向左移动
          break
        case '→':
          item.tf[0][0] += delta // 向右移动
          break
      }
    }
  }
  viewport.stateManager.endStateUpdate()
  EventBus.dispatch('multiselectedObjectChanged', {
    multiSelectedObjects: viewport.state.multiSelectedObjects
  })
  EventBus.dispatch('selectedObjectPropertyChanged', {})
}

export function quickCopyByMouse() {
  // 获取鼠标位置，查看鼠标是否在某个 viewport 的画布上，并取得该 viewport
  if (!CurrentMouseInfo?.viewport ||
    isNaN(CurrentMouseInfo.x) || isNaN(CurrentMouseInfo.z) ||
    isNaN(CurrentMouseInfo.x) || isNaN(CurrentMouseInfo.z)) {
    system.msg('无法获取鼠标位置')
    return
  }

  const x = CurrentMouseInfo.x
  const z = CurrentMouseInfo.z
  const viewport: Viewport = CurrentMouseInfo.viewport
  // const point: THREE.Vector2 = currentMouseInfo.mouse
  //
  // const ray = new THREE.Raycaster()
  // ray.setFromCamera(point, viewport.camera)
  // const intersections = ray.intersectObjects(viewport.dragControl._dragObjects, true)
  //
  // if (intersections.length === 0) {
  //   system.msg('没有找到可复制的对象')
  //   return
  // }
  // console.log('intersections:', intersections)

  // 如果不在线上，查找1米内的有效点 Object3D, 如果有，则以这个点为起点, 延伸同类型的点，并让他们相连
  const items = findStateItemsByDistance(viewport, new Vector2(x, z), 1)
  if (items[0]) {
    // 找到一个有效点，执行复制操作
    viewport.interactionManager.startInteraction(items[0].t, { startPoint: items[0].id })
    return
  }

  // const r = findObject3DByCondition(viewport.scene, object => {
  //   // 判断 object 是否是有效的 Object3D, 并且是当前 viewport 的对象
  //   if (object instanceof THREE.Object3D && object.visible &&
  //     object.userData.type && viewport.toolbox[object.userData.type]) {
  //
  //     const toolbox: Toolbox = viewport.toolbox[object.userData.type]
  //
  //     // 检查是否在 0.2 米内
  //     const distance = object.position.distanceTo(new THREE.Vector3(x, 0, z))
  //     if (distance < 0.2) {
  //       // 找到一个有效点，执行复制操作
  //       viewport.toolStartObject = object
  //       viewport.state.cursorMode = object.userData.type
  //       // toolbox.start(object)
  //       system.msg('连线成功')
  //       return true
  //     }
  //   }
  //   return false
  // })

  if (!items || items.length === 0) {
    system.msg('鼠标所在位置，没有可复制的对象', 'error')
    return
  }
}

//
// /**
//  * 查找射线周围指定半径内的对象
//  */
// export function findObjectsInRadius(viewport: Viewport,
//                                     point: THREE.Vector2,
//                                     radius: number,
//                                     lines: { object: THREE.Object3D, distance: number }[],
//                                     points: { object: THREE.Object3D, distance: number }[]
// ): void {
//   const ray = new THREE.Raycaster()
//   ray.setFromCamera(point, viewport.camera)
//
//   viewport.dragControl._dragObjects.forEach(obj => {
//     if (obj instanceof THREE.Points) {
//       // 处理点云：遍历每个点
//       const distance = distanceToRay(ray, point)
//       if (distance <= radius) {
//         points.push({ object: obj, distance })
//       }
//
//     } else if (obj instanceof THREE.Line) {
//       // 处理线段：计算线段到射线的最近距离
//       const distance = getLineDistanceToRay(ray, obj)
//       if (distance <= radius) {
//         lines.push({ object: obj, distance })
//       }
//     }
//   })
// }
//
// /**
//  * 计算点到射线的最短距离
//  */
// function distanceToRay(ray: THREE.Raycaster, point: THREE.Vector2) {
//   const closestPoint = new THREE.Vector3()
//   ray.closestPointToPoint(point, closestPoint)
//   return point.distanceTo(closestPoint)
// }
//
// /**
//  * 计算线段到射线的最短距离
//  */
// function getLineDistanceToRay(ray: THREE.Raycaster, line: THREE.Line) {
//   const lineStart = new THREE.Vector3()
//   const lineEnd = new THREE.Vector3()
//   line.geometry.attributes.position.getXYZ(0, lineStart)
//   line.geometry.attributes.position.getXYZ(1, lineEnd)
//   line.localToWorld(lineStart)
//   line.localToWorld(lineEnd)
//
//   const lineSegment = new THREE.Line3(lineStart, lineEnd)
//   const closestOnRay = new THREE.Vector3()
//   const closestOnLine = new THREE.Vector3()
//   THREE.Line3.prototype.closestPointsRayLine ??= function(ray, line, closestOnRay, closestOnLine) {
//     // 实现射线与线段最近点计算（需自定义或使用数学库）
//   }
//
//   lineSegment.closestPointsRayLine(ray, true, closestOnRay, closestOnLine)
//   return closestOnRay.distanceTo(closestOnLine)
// }

/**
 * 考虑吸附的情况下计算鼠标事件位置
 */
export function calcPositionUseSnap(e: MouseEvent, point: THREE.Vector3) {
  // 按下 ctrl 键，不启用吸附，其他情况启用吸附
  const gridOption = worldModel.gridOption
  if (!e.ctrlKey && !e.metaKey) {
    if (gridOption.snapEnabled && gridOption.snapDistance > 0) {
      // 启用吸附, 针对 point 的 x 和 z 坐标进行吸附, 吸附距离为 gridOption.snapDistance
      const snapDistance = gridOption.snapDistance
      const newPoint = new THREE.Vector3(point.x, point.y, point.z)
      newPoint.x = Math.round(newPoint.x / snapDistance) * snapDistance
      newPoint.z = Math.round(newPoint.z / snapDistance) * snapDistance
      return newPoint
    }
  }

  return point
}

export function getAllControlPoints(): THREE.Object3D[] {
  const allPoints: THREE.Object3D[] = []

  getAllItemTypes().forEach((itemType: ItemTypeDefineOption) => {
    if (itemType.clazz && itemType.clazz.pointArray) {
      // 将每个 ItemType 的点添加到结果数组中
      allPoints.push(...itemType.clazz.pointArray)
    }
  })

  return allPoints
}

/**
 * 在给定的场景中查找具有指定 uuid 的 Object3D 对象
 */
export function findObject3DById(scene: THREE.Object3D, uuid: string): THREE.Object3D | undefined {
  const rets = findObject3DByCondition(scene, object => object.uuid === uuid)
  if (rets.length > 0) {
    return rets[0]
  }
  return undefined
}

/**
 * 在给定场景中查找满足特定条件的 Object3D 对象集合
 */
export function findObject3DByCondition(scene: THREE.Object3D, condition: (object: THREE.Object3D) => boolean): THREE.Object3D[] {
  const foundObjects: THREE.Object3D[] = []

  // 定义一个内部递归函数来遍历每个节点及其子节点
  function traverse(obj: THREE.Object3D) {
    if (condition(obj)) {
      foundObjects.push(obj)
    }

    // 遍历当前对象的所有子对象
    for (let i = 0; i < obj.children.length; i++) {
      traverse(obj.children[i])
    }
  }

  // 开始从场景根节点进行遍历
  traverse(scene)

  return foundObjects
}

export function loadSceneFromJson(viewport: Viewport, scene: THREE.Scene, items: ItemJson[]) {
  console.time('loadSceneFromJson')

  const object3ds: THREE.Object3D[] = []

  // beforeLoad 通知所有加载的对象, 模型加载开始
  getAllItemTypes().forEach((itemType: ItemTypeDefineOption) => {
    const ret = itemType.clazz.beforeLoad()
    Array.isArray(ret) && object3ds.push(...ret)
  })

  const loads = loadObject3DFromJson(items)
  Array.isArray(loads) && object3ds.push(...loads)

  // afterLoadComplete 通知所有加载的对象, 模型加载完成
  getAllItemTypes().forEach((itemType: ItemTypeDefineOption) => {
    const ret = itemType.clazz.afterLoadComplete(object3ds)
    Array.isArray(ret) && object3ds.push(...ret)
  })

  scene.add(...object3ds)

  // afterAddScene 通知所有加载的对象, 模型加载完成
  getAllItemTypes().forEach(itemType => {
    itemType.clazz.afterAddScene(viewport, scene, object3ds)
  })

  console.log('loadSceneFromJson:', items.length, 'items,', object3ds.length, 'objects')
  console.timeEnd('loadSceneFromJson')
}

function loadObject3DFromJson(items: ItemJson[]): THREE.Object3D[] {
  const result: THREE.Object3D[] = []

  for (const item of items) {
    if (!item || !item.t) {
      console.error('unkown item:', item)
      continue
    }

    const object3D: THREE.Object3D | undefined = getItemTypeByName(item.t)?.clazz.loadFromJson(item)
    if (object3D === undefined) {
      continue
    }

    if (_.isArray(item.items)) {
      // 如果有子元素，递归处理
      const children = loadObject3DFromJson(item.items)
      children.forEach(child => object3D.add(child))
    }

    result.push(object3D)
  }

  return result
}

/**
 * 十进制求和
 * @param collection
 * @param iteratee
 */
export function decimalSumBy<T>(collection: ArrayLike<T> | null | undefined, iteratee?: ((value: T) => number)): number {

  let sum = new Decimal(0)
  _.forEach(collection, (t) => {
    if (typeof iteratee === 'function') {
      sum = sum.add(new Decimal(iteratee(t)))
    } else {
      sum = sum.add(new Decimal(t))
    }
  })
  return sum.toNumber()
}