/**
 * CraneRail 3D Factory
 *
 * 스토커 내부 스태커 크레인의 주행 레일.
 * 바닥 레일 + 천장 가이드 레일로 크레인의 2축 이동(수평 주행 + 수직 승강)을 지원.
 *
 * 구조 (바닥 원점, y=0~depth):
 *   - 바닥 레일: 2개의 평행 트랙 (크레인 바퀴 주행)
 *   - 천장 가이드 레일: 2개의 평행 트랙 (마스트 상단 안내)
 *   - 수직 지지대: 양 끝단 기둥 (바닥~천장 연결)
 */

import * as THREE from 'three'
import * as BufferGeometryUtils from 'three/examples/jsm/utils/BufferGeometryUtils.js'
import { RealObjectGroup, registerRealObjectFactory } from '@hatiolab/things-scene'
import type { Component } from '@hatiolab/things-scene'
import { TRANSPORT_SURFACE_HEIGHT } from './machine-3d.js'
import { Z_FMSIM } from './z-priority'

const RAIL_COLOR = 0x666677
const SUPPORT_COLOR = 0x555566

/** 크레인 레일 기본 높이: 스토커와 동일 */
const DEFAULT_RAIL_DEPTH = 5 * TRANSPORT_SURFACE_HEIGHT

export class CraneRail3D extends RealObjectGroup {
  get zPriority(): number { return Z_FMSIM.CRANE_RAIL }

  get effectiveDepth(): number {
    const { depth } = this.component.state
    return depth || DEFAULT_RAIL_DEPTH
  }

  build() {
    super.build()

    const { width = 10, height = 10 } = this.component.state
    const w = Math.abs(width)
    const h = Math.abs(height)
    const d = this.effectiveDepth
    if (!w || !h) return

    const inner = this.components3D

    const railH = Math.max(d * 0.02, 2) // 레일 높이 (얇은 트랙)
    const railW = Math.max(h * 0.06, 2) // 레일 폭
    const supportThick = Math.max(Math.min(w, h) * 0.05, 2)

    const railMat = new THREE.MeshStandardMaterial({
      color: RAIL_COLOR,
      roughness: 0.3,
      metalness: 0.7,
    })

    const supportMat = new THREE.MeshStandardMaterial({
      color: SUPPORT_COLOR,
      roughness: 0.5,
      metalness: 0.5,
    })

    // ── 바닥 레일 (2개 평행 트랙) ──
    const bottomGeometries: THREE.BufferGeometry[] = []
    for (const zSign of [-1, 1]) {
      const rail = new THREE.BoxGeometry(w, railH, railW)
      rail.translate(0, railH / 2, zSign * (h / 2 - railW / 2))
      bottomGeometries.push(rail)
    }
    const bottomMesh = new THREE.Mesh(BufferGeometryUtils.mergeGeometries(bottomGeometries), railMat)
    bottomMesh.castShadow = true
    bottomMesh.receiveShadow = true
    inner.add(bottomMesh)

    // ── 천장 가이드 레일 (2개 평행 트랙) ──
    const topGeometries: THREE.BufferGeometry[] = []
    for (const zSign of [-1, 1]) {
      const rail = new THREE.BoxGeometry(w, railH, railW)
      rail.translate(0, d - railH / 2, zSign * (h / 2 - railW / 2))
      topGeometries.push(rail)
    }
    const topMesh = new THREE.Mesh(BufferGeometryUtils.mergeGeometries(topGeometries), railMat)
    topMesh.castShadow = true
    inner.add(topMesh)

    // ── 양 끝단 수직 지지대 (바닥~천장 연결) ──
    const supportH = d - railH * 2
    const supportGeometries: THREE.BufferGeometry[] = []
    for (const xSign of [-1, 1]) {
      for (const zSign of [-1, 1]) {
        const support = new THREE.BoxGeometry(supportThick, supportH, supportThick)
        support.translate(
          xSign * (w / 2 - supportThick / 2),
          railH + supportH / 2,
          zSign * (h / 2 - railW / 2)
        )
        supportGeometries.push(support)
      }
    }
    const supportMesh = new THREE.Mesh(BufferGeometryUtils.mergeGeometries(supportGeometries), supportMat)
    supportMesh.castShadow = true
    inner.add(supportMesh)
  }

  updateDimension() {}
  updateAlpha() {}

  onchange(after: Record<string, unknown>, before: Record<string, unknown>) {
    if ('width' in after || 'height' in after || 'depth' in after || 'fillStyle' in after || 'strokeStyle' in after) {
      this.update()
      return
    }
    super.onchange(after, before)
  }
}

registerRealObjectFactory('CraneRail', (component: Component) => new CraneRail3D(component))