import { join } from 'path'
import { existsSync } from 'fs'
import { mkdir, writeFile, readFile, unlink, rm } from 'fs/promises'
import { TMP_DIR } from '@/lib/constants'
import { compressWithBlender } from '@/lib/blender'
import { compressTextureBuffer } from '@/lib/texture-compression'
import { classifyAssetCategory } from '@/lib/asset-classification'
import type { ParsedFile, PreparedAssetSummary } from '@/lib/types'

interface PushFile {
  path: string
  contentBase64: string
}

interface PrepareGitAssetsParams {
  folderName: string
  parsedFiles: ParsedFile[]
}

interface PrepareGitAssetsResult {
  filesToPush: PushFile[]
  modelFilename: string
  assetSummaries: PreparedAssetSummary[]
  compressed: boolean
  compressionError?: string
}

export async function prepareGitAssets({
  folderName,
  parsedFiles,
}: PrepareGitAssetsParams): Promise<PrepareGitAssetsResult> {
  const filesToPush: PushFile[] = []
  const assetSummaries: PreparedAssetSummary[] = []
  let modelFilename = ''
  let compressed = false
  let compressionError: string | undefined

  for (const pf of parsedFiles) {
    let content = pf.buffer

    if (pf.isModel) {
      modelFilename = pf.filename
      let modelCompressed = false

      const tmpFolder = join(TMP_DIR, folderName)
      await mkdir(tmpFolder, { recursive: true })
      const tmpFilePath = join(tmpFolder, pf.filename)
      await writeFile(tmpFilePath, pf.buffer)

      const stem = pf.filename.replace(/\.[^.]+$/, '')
      const compressedPath = join(tmpFolder, `${stem}_compressed.glb`)

      try {
        const result = await compressWithBlender(tmpFilePath, compressedPath)

        if (result.success && existsSync(compressedPath)) {
          content = await readFile(compressedPath)
          compressed = true
          modelCompressed = true
          await unlink(compressedPath).catch(() => {})
        } else {
          compressionError = result.error
        }
      } finally {
        await unlink(tmpFilePath).catch(() => {})
        await rm(tmpFolder, { recursive: true, force: true }).catch(() => {})
      }

      assetSummaries.push({
        filename: pf.filename,
        kind: 'model',
        compressed: modelCompressed,
      })
    } else {
      const category = classifyAssetCategory(pf.filename)

      const textureResult = await compressTextureBuffer(pf.filename, pf.buffer)
      content = textureResult.buffer

      if (textureResult.error && !compressionError) {
        compressionError = textureResult.error
      }

      assetSummaries.push({
        filename: pf.filename,
        kind: category === 'assets' ? 'asset' : 'texture',
        category,
        compressed: textureResult.compressed,
      })
    }

    filesToPush.push({
      path: `public/models/${folderName}/${pf.filename}`,
      contentBase64: content.toString('base64'),
    })
  }

  return {
    filesToPush,
    modelFilename,
    assetSummaries,
    compressed,
    compressionError,
  }
}