import { existsSync, readFileSync } from 'node:fs'
import postgres from 'postgres'
import {
  createPostBodyThumbnailForImageUrl,
  extractPostImageUrlsFromContent,
  getExistingPostBodyPreviewThumbnailUrl,
  getExistingPostBodyThumbnailUrl,
  getExistingPostLightboxThumbnailUrl,
  getPostBodyThumbnailUrl
} from '../server/utils/post-thumbnail-image.js'

/**
 * 로컬 실행용 환경 파일을 process.env에 반영한다.
 * @returns {void}
 */
const loadEnvironmentFile = () => {
  const candidates = [
    process.env.ENV_FILE,
    '.env.development',
    '.env'
  ].filter(Boolean)
  const envFile = candidates.find((filePath) => existsSync(filePath))

  if (!envFile) {
    return
  }

  const lines = readFileSync(envFile, 'utf8').split(/\r?\n/)

  for (const line of lines) {
    const trimmedLine = line.trim()

    if (!trimmedLine || trimmedLine.startsWith('#')) {
      continue
    }

    const separatorIndex = trimmedLine.indexOf('=')

    if (separatorIndex === -1) {
      continue
    }

    const key = trimmedLine.slice(0, separatorIndex).trim()
    const rawValue = trimmedLine.slice(separatorIndex + 1).trim()

    if (!key || process.env[key] !== undefined) {
      continue
    }

    process.env[key] = rawValue.replace(/^['"]|['"]$/g, '')
  }
}

/**
 * 게시물 본문 목록을 조회한다.
 * @returns {Promise<Array<{ content: string }>>} 게시물 본문 목록
 */
const listPostContents = async () => {
  loadEnvironmentFile()

  if (!process.env.DATABASE_URL) {
    throw new Error('DATABASE_URL 환경 변수가 필요합니다.')
  }

  const sql = postgres(process.env.DATABASE_URL, {
    max: 1,
    idle_timeout: 5,
    connect_timeout: 10
  })

  try {
    return await sql`
      SELECT content
      FROM posts
      WHERE content IS NOT NULL
      ORDER BY COALESCE(published_at, updated_at) DESC
    `
  } finally {
    await sql.end({ timeout: 5 })
  }
}

const postContents = await listPostContents()
const imageUrls = [...new Set(postContents
  .flatMap((post) => extractPostImageUrlsFromContent(post.content))
  .filter((url) => getPostBodyThumbnailUrl(url)))]
let createdCount = 0
let skippedCount = 0
let failedCount = 0

for (const imageUrl of imageUrls) {
  if (
    getExistingPostBodyThumbnailUrl(imageUrl)
    && getExistingPostBodyPreviewThumbnailUrl(imageUrl)
    && getExistingPostLightboxThumbnailUrl(imageUrl)
  ) {
    skippedCount += 1
    continue
  }

  const thumbnailUrl = await createPostBodyThumbnailForImageUrl(imageUrl)

  if (thumbnailUrl) {
    createdCount += 1
  } else {
    failedCount += 1
  }
}

process.stdout.write([
  '게시물 본문 표시용 이미지 생성 완료:',
  `게시물 ${postContents.length}개`,
  `대상 ${imageUrls.length}개`,
  `생성 ${createdCount}개`,
  `기존 ${skippedCount}개`,
  `실패 ${failedCount}개`
].join(' ') + '\n')