/**
 * OA PDF 预览页 query 解析（短 fileUrl / 兼容旧 url）
 * 微信 onLoad 可能已 decode 一次；须安全二次解码，并兼容大小写 key。
 */

const LOG_TAG = '[oa-pdf-preview]'

export function pdfPreviewLog(...args) {
  try {
    console.log(LOG_TAG, ...args)
  } catch (_) {
    /* ignore */
  }
}

export function safeDecodeURIComponent(value) {
  const raw = String(value == null ? '' : value).trim()
  if (!raw) return ''
  try {
    return decodeURIComponent(raw)
  } catch (_) {
    return raw
  }
}

/** 按候选 key 取值；忽略大小写；兼容微信偶发改写 */
export function pickQueryValue(query, keys) {
  const q = query && typeof query === 'object' ? query : {}
  const list = Array.isArray(keys) ? keys : [keys]
  for (let i = 0; i < list.length; i++) {
    const k = list[i]
    if (k == null) continue
    if (Object.prototype.hasOwnProperty.call(q, k) && q[k] != null) {
      const v = String(q[k]).trim()
      if (v) return v
    }
  }
  const lowerMap = {}
  Object.keys(q).forEach((k) => {
    lowerMap[String(k).toLowerCase()] = q[k]
  })
  for (let i = 0; i < list.length; i++) {
    const k = String(list[i] || '').toLowerCase()
    if (!k) continue
    if (lowerMap[k] != null) {
      const v = String(lowerMap[k]).trim()
      if (v) return v
    }
  }
  return ''
}

/**
 * @returns {{ fileUrl: string, legacyUrl: string, name: string, rawKeys: string[] }}
 */
export function parsePdfPreviewQuery(query) {
  const rawKeys = Object.keys(query && typeof query === 'object' ? query : {})
  const fileUrl = safeDecodeURIComponent(
    pickQueryValue(query, ['fileUrl', 'fileurl', 'file_url', 'f'])
  )
  const legacyUrl = safeDecodeURIComponent(
    pickQueryValue(query, ['url', 'downloadUrl', 'download_url'])
  )
  const name =
    safeDecodeURIComponent(pickQueryValue(query, ['name', 'fileName', 'file_name', 'n'])) ||
    'approval.pdf'
  return { fileUrl, legacyUrl, name, rawKeys }
}

/**
 * 后端 MINIO_BASE_URL 常配成同域相对路径（如 /minio/zkxw），预签名改写后也是
 * `/minio/zkxw/...?X-Amz-...`。微信 downloadFile 必须绝对 http(s)。
 *
 * @param {string} url
 * @param {{ apiBaseUrl?: string, minioBaseUrl?: string }} [bases]
 */
export function toAbsoluteDownloadUrl(url, bases = {}) {
  const s = String(url || '').trim()
  if (!s) return ''
  if (/^https?:\/\//i.test(s)) return s
  if (s.startsWith('//')) return 'https:' + s

  const apiBase = String(bases.apiBaseUrl || '').trim()
  const minioBase = String(bases.minioBaseUrl || '').trim()
  const originFrom = (base) => {
    const m = String(base || '').match(/^(https?:\/\/[^/]+)/i)
    return m ? m[1] : ''
  }
  const origin = originFrom(apiBase) || originFrom(minioBase)

  if (s.startsWith('/')) {
    return origin ? origin + s : ''
  }

  // 相对 object key
  const minio = minioBase.replace(/\/$/, '')
  if (/^https?:\/\//i.test(minio)) {
    return minio + '/' + s.replace(/^\//, '')
  }
  if (minio.startsWith('/') && origin) {
    return origin + minio + '/' + s.replace(/^\//, '')
  }
  return ''
}

/**
 * 拼 MinIO 公网直链（无预签名）。
 * 预签名经相对路径改写后微信 downloadFile 常 403；公网直链对本环境可 200。
 */
export function buildDirectMinioUrl(fileUrl, bases = {}) {
  const raw = String(fileUrl || '').trim()
  if (!raw) return ''

  const minioBase = String(bases.minioBaseUrl || '').replace(/\/$/, '')
  const apiBase = String(bases.apiBaseUrl || '').trim()
  const originMatch = (apiBase || minioBase).match(/^(https?:\/\/[^/]+)/i)
  const origin = originMatch ? originMatch[1] : ''

  // 已是绝对 http(s)：去掉 query（签名）后若可识别为同域 MinIO 则规范化，否则原样去 query
  if (/^https?:\/\//i.test(raw)) {
    const noQuery = raw.split('?')[0]
    try {
      const u = new URL(noQuery)
      const minioPath = minioBase.replace(/^https?:\/\/[^/]+/i, '') || ''
      if (minioPath && u.pathname.indexOf(minioPath) === 0) {
        return origin && minioPath.startsWith('/')
          ? origin + u.pathname
          : noQuery
      }
    } catch (_) {
      /* ignore */
    }
    return noQuery
  }

  // 根相对：/minio/zkxw/key.pdf?... → 拼 origin
  if (raw.startsWith('/')) {
    const pathOnly = raw.split('?')[0]
    return origin ? origin + pathOnly : toAbsoluteDownloadUrl(pathOnly, bases)
  }

  // object key：去掉可能误带的 minio 路径前缀
  let key = raw.replace(/^\//, '').split('?')[0]
  const minioPath = minioBase.replace(/^https?:\/\/[^/]+/i, '').replace(/^\//, '')
  if (minioPath && key.indexOf(minioPath + '/') === 0) {
    key = key.slice(minioPath.length + 1)
  }
  return toAbsoluteDownloadUrl(key, bases)
}