import { mkdir, readdir, stat } from 'node:fs/promises'
import { extname, join } from 'node:path'
import sharp from 'sharp'
import {
  POST_THUMBNAIL_HEIGHT,
  POST_THUMBNAIL_QUALITY,
  POST_THUMBNAIL_WIDTH,
  getPostThumbnailDirectoryPath,
  getPostThumbnailPathForFile,
  isPostThumbnailSource
} from '../server/utils/post-thumbnail-image.js'

const uploadRoot = join(process.cwd(), 'public', 'uploads', 'posts')

/**
 * 게시물 업로드 이미지 파일 목록을 수집한다.
 * @param {string} directoryPath - 탐색 디렉터리
 * @returns {Promise<string[]>} 이미지 파일 경로 목록
 */
const collectPostImages = async (directoryPath) => {
  let entries = []

  try {
    entries = await readdir(directoryPath, { withFileTypes: true })
  } catch {
    return []
  }

  const files = []

  for (const entry of entries) {
    const entryPath = join(directoryPath, entry.name)

    if (entry.isDirectory()) {
      if (entry.name === 'thumbs') {
        continue
      }

      files.push(...await collectPostImages(entryPath))
      continue
    }

    if (entry.isFile() && isPostThumbnailSource('', entry.name)) {
      files.push(entryPath)
    }
  }

  return files
}

/**
 * 게시물 이미지 카드 썸네일을 생성한다.
 * @param {string} imagePath - 원본 이미지 경로
 * @returns {Promise<boolean>} 새로 생성했는지 여부
 */
const createPostThumbnail = async (imagePath) => {
  const thumbnailPath = getPostThumbnailPathForFile(imagePath)

  try {
    await stat(thumbnailPath)
    return false
  } catch {
    await mkdir(getPostThumbnailDirectoryPath(imagePath), { recursive: true })
  }

  await sharp(imagePath)
    .rotate()
    .resize({
      width: POST_THUMBNAIL_WIDTH,
      height: POST_THUMBNAIL_HEIGHT,
      fit: 'cover',
      position: 'centre',
      withoutEnlargement: true
    })
    .webp({ quality: POST_THUMBNAIL_QUALITY })
    .toFile(thumbnailPath)

  return true
}

const images = await collectPostImages(uploadRoot)
let createdCount = 0
let skippedCount = 0

for (const imagePath of images) {
  if (!isPostThumbnailSource('', imagePath) || extname(imagePath).toLowerCase() === '.gif') {
    skippedCount += 1
    continue
  }

  if (await createPostThumbnail(imagePath)) {
    createdCount += 1
  } else {
    skippedCount += 1
  }
}

process.stdout.write(`게시물 카드 썸네일 생성 완료: 생성 ${createdCount}개, 건너뜀 ${skippedCount}개\n`)