import { NextRequest, NextResponse } from 'next/server'
import { Octokit } from '@octokit/rest'
import { extname, basename, join } from 'path'
import { mkdir, writeFile, readFile, unlink, rm } from 'fs/promises'
import { existsSync } from 'fs'
import { execFile } from 'child_process'
import { promisify } from 'util'

const execFileAsync = promisify(execFile)

export const runtime = 'nodejs'
export const dynamic = 'force-dynamic'

const MODEL_EXTENSIONS = new Set(['.glb', '.gltf'])
const TEXTURE_EXTENSIONS = new Set(['.png', '.jpg', '.jpeg', '.webp'])
const ALL_ALLOWED_EXTENSIONS = new Set([...MODEL_EXTENSIONS, ...TEXTURE_EXTENSIONS])

const TMP_DIR = join('/tmp', 'assets')

function sanitizeFilename(name: string): string {
  return basename(name)
    .replace(/[^a-zA-Z0-9._-]/g, '_')
    .replace(/_{2,}/g, '_')
    .toLowerCase()
}

function getOctokit(): Octokit {
  const token = process.env.GITHUB_TOKEN
  if (!token) throw new Error('GITHUB_TOKEN non configure')
  return new Octokit({ auth: token })
}

function parseRepoUrl(): { owner: string; repo: string } {
  const url = process.env.GIT_REPO_URL
  if (!url) throw new Error('GIT_REPO_URL non configure')

  const httpsMatch = url.match(/github\.com\/([^/]+)\/([^/.]+)/)
  const sshMatch = url.match(/github\.com:([^/]+)\/([^/.]+)/)
  const shortMatch = url.match(/^([^/]+)\/([^/]+)$/)

  const match = httpsMatch || sshMatch || shortMatch
  if (!match) throw new Error(`Format GIT_REPO_URL invalide: "${url}"`)

  return { owner: match[1], repo: match[2] }
}

// ---------------------------------------------------------------------------
// Blender Draco compression
// ---------------------------------------------------------------------------

async function compressWithBlender(
  inputPath: string,
  outputPath: string
): Promise<{ success: boolean; error?: string }> {
  const blenderPath = process.env.BLENDER_PATH || 'blender'
  const scriptPath = join(process.cwd(), 'scripts', 'compress.py')

  if (!existsSync(scriptPath)) {
    return { success: false, error: 'scripts/compress.py introuvable' }
  }

  try {
    await execFileAsync(blenderPath, [
      '--background',
      '--python', scriptPath,
      '--',
      '-i', inputPath,
      '-o', outputPath,
      '--draco-level', '7',
      '--texture-size', '512',
      '-q',
    ], { timeout: 120_000 })

    if (!existsSync(outputPath)) {
      return { success: false, error: 'Blender n\'a pas produit de fichier compresse' }
    }

    return { success: true }
  } catch (err) {
    const message = err instanceof Error ? err.message : String(err)
    return { success: false, error: `Compression Blender echouee: ${message}` }
  }
}

// ---------------------------------------------------------------------------
// Parse uploaded file from FormData
// ---------------------------------------------------------------------------

async function parseUpload(req: NextRequest) {
  const formData = await req.formData()
  const file = formData.get('file') as File | null
  const folderName = (formData.get('folderName') as string | null)?.trim() || 'assets'
  const fileType = formData.get('fileType') as string | null
  const textureName = formData.get('textureName') as string | null

  if (!file || file.size === 0) {
    throw new Error('Aucun fichier recu')
  }

  const originalSafe = sanitizeFilename(file.name)
  const ext = extname(originalSafe).toLowerCase()

  if (!ALL_ALLOWED_EXTENSIONS.has(ext)) {
    throw new Error(`Extension non autorisee: "${ext}"`)
  }

  const safeFolderName = sanitizeFilename(folderName).replace(/[^a-zA-Z0-9-_]/g, '-')

  let filename: string
  if (fileType === 'texture' && textureName) {
    filename = sanitizeFilename(textureName)
  } else {
    filename = originalSafe
  }

  const isModel = MODEL_EXTENSIONS.has(ext)
  const buffer = Buffer.from(await file.arrayBuffer())

  return { filename, buffer, safeFolderName, isModel }
}

// ---------------------------------------------------------------------------
// Push a single file to GitHub via the API
// ---------------------------------------------------------------------------

async function pushFileToGitHub(
  filePath: string,
  contentBase64: string,
  folderName: string
): Promise<{ commitUrl: string }> {
  const octokit = getOctokit()
  const { owner, repo } = parseRepoUrl()
  const branch = process.env.GIT_BRANCH ?? 'main'

  // 1. Get latest commit on branch
  const { data: ref } = await octokit.git.getRef({
    owner,
    repo,
    ref: `heads/${branch}`,
  })
  const latestCommitSha = ref.object.sha

  // 2. Get that commit's tree
  const { data: commit } = await octokit.git.getCommit({
    owner,
    repo,
    commit_sha: latestCommitSha,
  })

  // 3. Create blob
  const { data: blob } = await octokit.git.createBlob({
    owner,
    repo,
    content: contentBase64,
    encoding: 'base64',
  })

  // 4. Create tree
  const { data: newTree } = await octokit.git.createTree({
    owner,
    repo,
    base_tree: commit.tree.sha,
    tree: [
      {
        path: filePath,
        mode: '100644',
        type: 'blob',
        sha: blob.sha,
      },
    ],
  })

  // 5. Create commit
  const timestamp = new Date().toISOString()
  const { data: newCommit } = await octokit.git.createCommit({
    owner,
    repo,
    message: `Design Update: ${folderName} [${timestamp}]`,
    tree: newTree.sha,
    parents: [latestCommitSha],
  })

  // 6. Update branch ref
  await octokit.git.updateRef({
    owner,
    repo,
    ref: `heads/${branch}`,
    sha: newCommit.sha,
  })

  return { commitUrl: newCommit.html_url }
}

// ---------------------------------------------------------------------------
// POST handler
// ---------------------------------------------------------------------------

export async function POST(req: NextRequest) {
  // --- Auth ---
  const secret = req.headers.get('x-upload-secret')
  const expectedSecret = process.env.UPLOAD_SECRET_KEY

  if (!expectedSecret) {
    return NextResponse.json(
      { success: false, error: 'Configuration serveur incomplete (UPLOAD_SECRET_KEY manquant)' },
      { status: 500 }
    )
  }

  if (!secret || secret !== expectedSecret) {
    return NextResponse.json(
      { success: false, error: "Cle d'authentification invalide" },
      { status: 401 }
    )
  }

  // --- Parse upload ---
  let filename: string
  let buffer: Buffer
  let safeFolderName: string
  let isModel: boolean

  try {
    ;({ filename, buffer, safeFolderName, isModel } = await parseUpload(req))
  } catch (err) {
    const message = err instanceof Error ? err.message : 'Erreur inconnue'
    return NextResponse.json({ success: false, error: message }, { status: 400 })
  }

  // --- Write to /tmp ---
  const tmpFolder = join(TMP_DIR, safeFolderName)
  await mkdir(tmpFolder, { recursive: true })
  const tmpFilePath = join(tmpFolder, filename)
  await writeFile(tmpFilePath, buffer)

  let contentToUpload: Buffer = buffer
  let compressed = false
  let compressionError: string | undefined

  // --- Compress model with Blender (if available) ---
  if (isModel) {
    const stem = filename.replace(/\.[^.]+$/, '')
    const compressedPath = join(tmpFolder, `${stem}_compressed.glb`)

    const result = await compressWithBlender(tmpFilePath, compressedPath)

    if (result.success && existsSync(compressedPath)) {
      contentToUpload = await readFile(compressedPath)
      compressed = true
      // Clean up compressed temp file
      await unlink(compressedPath).catch(() => {})
    } else {
      // Blender not available or failed — push original
      compressionError = result.error
    }
  }

  // Clean up original temp file
  await unlink(tmpFilePath).catch(() => {})
  // Clean up folder if empty
  await rm(tmpFolder, { recursive: true, force: true }).catch(() => {})

  // --- Push to GitHub ---
  const gitPath = `public/assets/${safeFolderName}/${filename}`
  const contentBase64 = contentToUpload.toString('base64')

  try {
    const { commitUrl } = await pushFileToGitHub(gitPath, contentBase64, safeFolderName)

    return NextResponse.json({
      success: true,
      filename,
      compressed,
      compressionError: compressionError || undefined,
      message: compressed
        ? `"${filename}" compresse avec Draco et pousse sur GitHub.`
        : `"${filename}" pousse sur GitHub${compressionError ? ' (sans compression: ' + compressionError + ')' : ''}.`,
      commitUrl,
    })
  } catch (err) {
    const message = err instanceof Error ? err.message : 'Erreur GitHub inconnue'
    return NextResponse.json(
      { success: false, error: `Push GitHub echoue: ${message}` },
      { status: 500 }
    )
  }
}