import '../style.css'
import * as THREE from 'three'
import { OrbitControls } from 'three/addons/controls/OrbitControls.js'
import { STLLoader } from 'three/addons/loaders/STLLoader.js'
import type { GeometryFile, HierarchyNode } from '../../server/services/stepConverter'

// ---- Data injected by viewer.ejs -----------------------------------------

declare const __STEPVIEW__: {
  modelId:     number
  fileType:    'step' | 'stp' | 'stl'
  shareUrl:    string
  hasPdfs:     boolean
  hasGeometry: boolean   // pre-processed geometry JSON exists (STEP/STP only)
}

// ---- Scene state ---------------------------------------------------------

let renderer:    THREE.WebGLRenderer
let scene:       THREE.Scene
let camera:      THREE.PerspectiveCamera
let controls:    OrbitControls
let viewingDist: number = 200  // updated by fitCamera; used by fog toggle

// Map from geometry-JSON mesh index → Three.js Mesh, used by the tree panel
const meshObjects = new Map<number, THREE.Mesh>()

// ---- UI helpers ----------------------------------------------------------

function setLoading(msg: string) {
  const el = document.getElementById('loading-msg')
  if (el) el.textContent = msg
}

function hideLoading() {
  const overlay = document.getElementById('loading-overlay') as HTMLElement
  overlay.style.opacity = '0'
  setTimeout(() => { overlay.style.display = 'none' }, 300)
}

function showError(msg: string) {
  document.getElementById('loading-overlay')!.style.display = 'none'
  const overlay = document.getElementById('error-overlay')!
  overlay.classList.remove('hidden')
  overlay.classList.add('flex')
  const msgEl = document.getElementById('error-msg')
  if (msgEl) msgEl.textContent = msg
}

function showToast(msg: string, duration = 2200) {
  const toast    = document.getElementById('toast')!
  const toastMsg = document.getElementById('toast-msg')!
  toastMsg.textContent = msg
  toast.classList.remove('opacity-0', 'pointer-events-none')
  toast.classList.add('opacity-100')
  setTimeout(() => {
    toast.classList.add('opacity-0', 'pointer-events-none')
    toast.classList.remove('opacity-100')
  }, duration)
}

// ---- Scene setup ---------------------------------------------------------

function buildScene(canvas: HTMLCanvasElement) {
  renderer = new THREE.WebGLRenderer({ canvas, antialias: true, alpha: false })
  renderer.setPixelRatio(Math.min(window.devicePixelRatio, 2))
  renderer.setSize(window.innerWidth, window.innerHeight)
  renderer.setClearColor(0x0a0a0f, 1)
  renderer.shadowMap.enabled = true
  renderer.shadowMap.type    = THREE.PCFSoftShadowMap
  renderer.outputColorSpace   = THREE.SRGBColorSpace
  renderer.toneMapping        = THREE.ACESFilmicToneMapping
  renderer.toneMappingExposure = 1.1

  scene = new THREE.Scene()

  camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.001, 10000)
  camera.position.set(5, 3, 8)

  // Lighting — no fog: FogExp2 with a fixed density darkens large models
  // whose camera distance exceeds ~200 units, making them appear black.
  const ambient = new THREE.AmbientLight(0xffffff, 0.9)
  scene.add(ambient)

  const key = new THREE.DirectionalLight(0xffffff, 1.8)
  key.position.set(1, 2, 1.5)
  key.castShadow = true
  key.shadow.mapSize.set(2048, 2048)
  key.shadow.camera.near = 0.1
  key.shadow.camera.far  = 500
  scene.add(key)

  const fill = new THREE.DirectionalLight(0x8899cc, 0.4)
  fill.position.set(-2, 0.5, -1)
  scene.add(fill)

  const rim = new THREE.DirectionalLight(0xffffff, 0.25)
  rim.position.set(0, -1, -2)
  scene.add(rim)

  controls = new OrbitControls(camera, renderer.domElement)
  controls.enableDamping  = true
  controls.dampingFactor  = 0.06
  controls.minDistance    = 0.001
  controls.maxDistance    = 5000
  controls.panSpeed       = 0.8
  controls.rotateSpeed    = 0.6
  controls.zoomSpeed      = 1.2

  window.addEventListener('resize', () => {
    camera.aspect = window.innerWidth / window.innerHeight
    camera.updateProjectionMatrix()
    renderer.setSize(window.innerWidth, window.innerHeight)
  })
}

// ---- Render loop ---------------------------------------------------------

function startRenderLoop() {
  const clock = new THREE.Clock()
  function tick() {
    requestAnimationFrame(tick)
    controls.update()
    renderer.render(scene, camera)
    void clock
  }
  tick()
}

// ---- Camera fit ----------------------------------------------------------

function fitCamera(object: THREE.Object3D) {
  const box    = new THREE.Box3().setFromObject(object)
  const size   = box.getSize(new THREE.Vector3())
  const center = box.getCenter(new THREE.Vector3())
  const maxDim = Math.max(size.x, size.y, size.z)

  if (maxDim === 0) return

  const fovRad = camera.fov * (Math.PI / 180)
  const dist   = (maxDim / (2 * Math.tan(fovRad / 2))) * 1.6

  viewingDist = dist

  camera.near = maxDim * 0.0005
  camera.far  = maxDim * 200
  camera.updateProjectionMatrix()

  camera.position.set(
    center.x + dist * 0.55,
    center.y + dist * 0.35,
    center.z + dist,
  )
  camera.lookAt(center)
  controls.target.copy(center)
  controls.update()
}

// ---- Ground grid ---------------------------------------------------------

function addGrid(object: THREE.Object3D) {
  const box    = new THREE.Box3().setFromObject(object)
  const size   = box.getSize(new THREE.Vector3())
  const center = box.getCenter(new THREE.Vector3())
  const maxDim = Math.max(size.x, size.z) * 3

  const grid = new THREE.GridHelper(maxDim, 20, 0x1a1a2a, 0x1a1a2a)
  grid.position.set(center.x, box.min.y - 0.001, center.z)
  scene.add(grid)
}

// ---- Material factory ----------------------------------------------------

function makeMaterial(color: [number, number, number] | null): THREE.MeshStandardMaterial {
  const c = color
    ? new THREE.Color(color[0], color[1], color[2])
    : new THREE.Color(0x8fa3b8)
  return new THREE.MeshStandardMaterial({
    color:     c,
    roughness: 0.45,
    metalness: 0.25,
    side:      THREE.DoubleSide,
  })
}

// ---- Binary decode helpers (geometry v2) ---------------------------------

function b64ToFloat32(b64: string): Float32Array {
  const bin = atob(b64)
  const buf = new ArrayBuffer(bin.length)
  const u8  = new Uint8Array(buf)
  for (let i = 0; i < bin.length; i++) u8[i] = bin.charCodeAt(i)
  return new Float32Array(buf)
}

function b64ToUint32(b64: string): Uint32Array {
  const bin = atob(b64)
  const buf = new ArrayBuffer(bin.length)
  const u8  = new Uint8Array(buf)
  for (let i = 0; i < bin.length; i++) u8[i] = bin.charCodeAt(i)
  return new Uint32Array(buf)
}

// ---- STEP/STP loader (geometry JSON, pre-processed server-side) ----------

async function loadStepGeometry(): Promise<void> {
  setLoading('Fetching geometry…')
  const res = await fetch(`/files/geometry/${__STEPVIEW__.modelId}`)

  if (!res.ok) {
    const body = await res.json().catch(() => ({})) as { processing?: boolean }
    if (body.processing) {
      throw new Error('This model is still being processed. Please try again in a moment.')
    }
    throw new Error(`Could not load geometry (HTTP ${res.status})`)
  }

  // Stream the response body so there is visible activity during large downloads
  let text: string
  if (res.body) {
    const reader = res.body.getReader()
    const chunks: Uint8Array[] = []
    let loaded = 0
    while (true) {
      const { done, value } = await reader.read()
      if (done) break
      chunks.push(value)
      loaded += value.byteLength
      setLoading(`Downloading geometry… ${Math.round(loaded / 1024)} KB`)
    }
    setLoading('Parsing geometry…')
    text = new TextDecoder().decode(
      chunks.reduce((acc, c) => { const m = new Uint8Array(acc.length + c.length); m.set(acc); m.set(c, acc.length); return m }, new Uint8Array(0))
    )
  } else {
    text = await res.text()
  }

  // eslint-disable-next-line @typescript-eslint/no-explicit-any
  const data = JSON.parse(text) as GeometryFile & { version: number; meshes: any[] }

  if (!data.meshes || data.meshes.length === 0) {
    throw new Error('Geometry file contains no meshes.')
  }

  setLoading('Building 3D scene…')
  const group = new THREE.Group()
  const isV2  = data.version >= 2

  for (let i = 0; i < data.meshes.length; i++) {
    const mesh = data.meshes[i]
    const geo = new THREE.BufferGeometry()

    let positions: Float32Array
    let normals:   Float32Array | null
    let indices:   Uint32Array  | null

    if (isV2) {
      positions = b64ToFloat32(mesh.positions)
      normals   = mesh.normals ? b64ToFloat32(mesh.normals) : null
      indices   = mesh.indices ? b64ToUint32(mesh.indices)  : null
    } else {
      // Legacy v1: plain number arrays
      positions = new Float32Array(mesh.positions as number[])
      normals   = mesh.normals ? new Float32Array(mesh.normals as number[]) : null
      indices   = mesh.indices ? new Uint32Array(mesh.indices as number[])  : null
    }

    geo.setAttribute('position', new THREE.Float32BufferAttribute(positions, 3))
    if (normals && normals.length > 0) {
      geo.setAttribute('normal', new THREE.Float32BufferAttribute(normals, 3))
    }
    if (indices && indices.length > 0) {
      geo.setIndex(new THREE.Uint32BufferAttribute(indices, 1))
    }
    if (!normals || normals.length === 0) {
      geo.computeVertexNormals()
    }

    const threeMesh = new THREE.Mesh(geo, makeMaterial(mesh.color))
    meshObjects.set(i, threeMesh)
    group.add(threeMesh)
  }

  scene.add(group)
  fitCamera(group)
  addGrid(group)

  // Diagnostics — always log tree state so browser console can confirm what arrived
  console.log('[StepView] geometry version:', data.version)
  console.log('[StepView] mesh count:', data.meshes.length)
  console.log('[StepView] data.tree:', data.tree)

  const treeContent = document.getElementById('tree-content')
  if (!treeContent) return   // not a STEP model or panel removed

  if (!data.tree) {
    treeContent.innerHTML = '<p class="text-xs text-gray-500 px-4 py-3">No tree data — open the admin panel, edit this model, and click <strong class="text-gray-400">Retry Processing</strong> to rebuild geometry with tree support.</p>'
    return
  }

  const nodeCount = countNodes(data.tree)
  console.log('[StepView] tree node count:', nodeCount)

  if (nodeCount === 0) {
    treeContent.innerHTML = '<p class="text-xs text-gray-500 px-4 py-3">This file has no named components in its hierarchy.</p>'
    return
  }

  wireTreePanel(data.tree)
}

function countNodes(node: HierarchyNode): number {
  return 1 + node.children.reduce((acc, c) => acc + countNodes(c), 0)
}

// ---- STL loader (client-side, Three.js built-in) -------------------------

async function loadStl(): Promise<void> {
  setLoading('Fetching STL file…')
  const loader = new STLLoader()

  const geometry = await new Promise<THREE.BufferGeometry>((resolve, reject) => {
    loader.load(
      `/files/model/${__STEPVIEW__.modelId}`,
      resolve,
      (xhr) => {
        if (xhr.total) {
          const pct = Math.round((xhr.loaded / xhr.total) * 100)
          setLoading(`Downloading STL… ${pct}%`)
        }
      },
      reject,
    )
  })

  setLoading('Building 3D scene…')
  geometry.computeVertexNormals()

  // Center geometry at origin
  geometry.computeBoundingBox()
  const center = new THREE.Vector3()
  geometry.boundingBox!.getCenter(center)
  geometry.translate(-center.x, -center.y, -center.z)

  const mesh = new THREE.Mesh(geometry, makeMaterial(null))
  mesh.castShadow    = true
  mesh.receiveShadow = true
  scene.add(mesh)
  fitCamera(mesh)
  addGrid(mesh)
}

// ---- Model tree ----------------------------------------------------------

function setNodeVisible(node: HierarchyNode, visible: boolean) {
  for (const idx of node.meshes) {
    const m = meshObjects.get(idx)
    if (m) m.visible = visible
  }
  for (const child of node.children) setNodeVisible(child, visible)
}

function buildTreeNode(node: HierarchyNode, depth: number): HTMLElement {
  const label       = node.name.trim() || 'Solid'
  const hasChildren = node.children.length > 0

  const wrapper = document.createElement('div')

  const row = document.createElement('div')
  row.className = 'flex items-center gap-1 py-1 rounded-lg hover:bg-white/5 group select-none'
  row.style.paddingLeft = `${6 + depth * 14}px`
  row.style.paddingRight = '6px'

  // Chevron
  const chevron = document.createElement('span')
  chevron.className = `w-3.5 h-3.5 shrink-0 text-gray-600 transition-transform duration-150 ${hasChildren ? 'cursor-pointer' : 'invisible'}`
  chevron.innerHTML = `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2.5"><path stroke-linecap="round" stroke-linejoin="round" d="M9 5l7 7-7 7"/></svg>`

  // Eye toggle
  const EYE_ON  = `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.75"><path stroke-linecap="round" stroke-linejoin="round" d="M2.036 12.322a1.012 1.012 0 010-.639C3.423 7.51 7.36 4.5 12 4.5c4.638 0 8.573 3.007 9.963 7.178.07.207.07.431 0 .639C20.577 16.49 16.64 19.5 12 19.5c-4.638 0-8.573-3.007-9.963-7.178z"/><path stroke-linecap="round" stroke-linejoin="round" d="M15 12a3 3 0 11-6 0 3 3 0 016 0z"/></svg>`
  const EYE_OFF = `<svg viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="1.75"><path stroke-linecap="round" stroke-linejoin="round" d="M3.98 8.223A10.477 10.477 0 001.934 12C3.226 16.338 7.244 19.5 12 19.5c.993 0 1.953-.138 2.863-.395M6.228 6.228A10.45 10.45 0 0112 4.5c4.756 0 8.773 3.162 10.065 7.498a10.523 10.523 0 01-4.293 5.774M6.228 6.228L3 3m3.228 3.228l3.65 3.65m7.894 7.894L21 21m-3.228-3.228l-3.65-3.65m0 0a3 3 0 10-4.243-4.243m4.242 4.242L9.88 9.88"/></svg>`

  const eyeBtn = document.createElement('button')
  eyeBtn.className = 'w-3.5 h-3.5 shrink-0 text-gray-500 hover:text-white transition-colors opacity-0 group-hover:opacity-100'
  eyeBtn.title = 'Toggle visibility'
  eyeBtn.innerHTML = EYE_ON

  let visible = true
  eyeBtn.addEventListener('click', (e) => {
    e.stopPropagation()
    visible = !visible
    eyeBtn.innerHTML        = visible ? EYE_ON : EYE_OFF
    eyeBtn.style.opacity    = visible ? '' : '1'
    eyeBtn.style.color      = visible ? '' : 'rgb(248 113 113)'
    nameEl.style.opacity    = visible ? '' : '0.3'
    setNodeVisible(node, visible)
  })

  // Name
  const nameEl = document.createElement('span')
  nameEl.className = 'text-xs text-gray-300 truncate flex-1'
  nameEl.textContent = label

  row.append(chevron, eyeBtn, nameEl)
  wrapper.append(row)

  if (hasChildren) {
    const childrenEl = document.createElement('div')
    for (const child of node.children) {
      childrenEl.append(buildTreeNode(child, depth + 1))
    }

    let expanded = true
    chevron.style.transform = 'rotate(90deg)'

    const toggle = () => {
      expanded = !expanded
      chevron.style.transform      = expanded ? 'rotate(90deg)' : ''
      childrenEl.style.display     = expanded ? '' : 'none'
    }

    chevron.addEventListener('click', (e) => { e.stopPropagation(); toggle() })
    row.addEventListener('click', toggle)
    wrapper.append(childrenEl)
  }

  return wrapper
}

function wireTreePanel(root: HierarchyNode) {
  const content = document.getElementById('tree-content')
  if (!content) return

  // Skip an unnamed root wrapper — go straight to its children
  const topNodes = (!root.name && root.children.length > 0) ? root.children : [root]

  content.innerHTML = ''
  for (const node of topNodes) {
    content.append(buildTreeNode(node, 0))
  }
}

// ---- Viewer toolbar ------------------------------------------------------

function wireToolbar() {
  // Model tree panel toggle (always wired; content populated after geometry loads)
  const treePanel = document.getElementById('tree-panel')
  const treeBtn   = document.getElementById('tree-toggle-btn')
  const treeClose = document.getElementById('tree-close-btn')
  if (treePanel) {
    treeBtn?.addEventListener('click', () => {
      const closing = !treePanel.classList.contains('closed')
      treePanel.classList.toggle('closed')
      treeBtn.classList.toggle('text-accent', !closing)
    })
    treeClose?.addEventListener('click', () => {
      treePanel.classList.add('closed')
      treeBtn?.classList.remove('text-accent')
    })
  }

  // Copy-link
  const copyBtn = document.getElementById('copy-link-btn') as HTMLButtonElement | null
  if (copyBtn) {
    copyBtn.addEventListener('click', async () => {
      try {
        await navigator.clipboard.writeText(__STEPVIEW__.shareUrl)
      } catch {
        const ta = Object.assign(document.createElement('textarea'), {
          value: __STEPVIEW__.shareUrl,
          style: 'position:fixed;opacity:0',
        })
        document.body.appendChild(ta)
        ta.select()
        document.execCommand('copy')
        document.body.removeChild(ta)
      }
      const orig = copyBtn.innerHTML
      copyBtn.textContent = '✓ Copied!'
      setTimeout(() => { copyBtn.innerHTML = orig }, 2000)
    })
  }

  // Reset camera
  const resetBtn = document.getElementById('reset-camera-btn')
  if (resetBtn) {
    resetBtn.addEventListener('click', () => {
      // Re-fit camera to scene objects (exclude grid)
      const objects = scene.children.filter(c => !(c instanceof THREE.GridHelper))
      const group   = new THREE.Group()
      objects.forEach(o => group.add(o.clone()))
      if (group.children.length) fitCamera(group)
    })
  }

  // Fog toggle — off by default; density scaled to the loaded model's viewing distance
  let fogOn = false
  const fogBtn = document.getElementById('fog-btn')
  if (fogBtn) {
    fogBtn.addEventListener('click', () => {
      fogOn = !fogOn
      scene.fog = fogOn
        ? new THREE.FogExp2(0x0a0a0f, 0.5 / viewingDist)
        : null
      fogBtn.classList.toggle('text-accent', fogOn)
    })
  }

  // Wireframe toggle
  let wireframe = false
  const wireBtn = document.getElementById('wireframe-btn')
  if (wireBtn) {
    wireBtn.addEventListener('click', () => {
      wireframe = !wireframe
      scene.traverse(obj => {
        if (obj instanceof THREE.Mesh && obj.material instanceof THREE.MeshStandardMaterial) {
          obj.material.wireframe = wireframe
        }
      })
      wireBtn.classList.toggle('text-accent', wireframe)
    })
  }

  // PDF panel
  const pdfToggle = document.getElementById('pdf-toggle-btn')
  const pdfPanel  = document.getElementById('pdf-panel')
  const pdfClose  = document.getElementById('pdf-close-btn')

  if (pdfToggle && pdfPanel) {
    pdfToggle.addEventListener('click', () => pdfPanel.classList.toggle('closed'))
  }
  if (pdfClose && pdfPanel) {
    pdfClose.addEventListener('click', () => pdfPanel.classList.add('closed'))
  }

  // PDF tabs
  document.querySelectorAll<HTMLButtonElement>('.pdf-tab').forEach(tab => {
    tab.addEventListener('click', () => {
      const idx = tab.dataset.tab
      document.querySelectorAll('.pdf-tab').forEach(t => {
        t.classList.remove('border-accent', 'text-white')
        t.classList.add('border-transparent', 'text-gray-500')
      })
      tab.classList.add('border-accent', 'text-white')
      tab.classList.remove('border-transparent', 'text-gray-500')
      document.querySelectorAll<HTMLElement>('.pdf-frame').forEach(f => {
        f.classList.toggle('hidden', f.dataset.frame !== idx)
      })
    })
  })
}

// ---- Boot ----------------------------------------------------------------

async function boot() {
  const canvas = document.getElementById('viewer-canvas') as HTMLCanvasElement

  try {
    buildScene(canvas)
    startRenderLoop()
    wireToolbar()

    if (__STEPVIEW__.fileType === 'stl') {
      await loadStl()
    } else {
      // STEP / STP
      if (!__STEPVIEW__.hasGeometry) {
        throw new Error(
          'This model has not finished processing yet. ' +
          'Please check back shortly or contact your administrator.'
        )
      }
      await loadStepGeometry()
    }

    hideLoading()
  } catch (err) {
    console.error('[StepView]', err)
    showError(err instanceof Error ? err.message : String(err))
  }
}

boot()

export {}