const ERP_LOGIN_PAGE = '/pages/erpLoginConfirm/erpLoginConfirm'
const ERP_LOGIN_PAGE_PATH = 'pages/erpLoginConfirm/erpLoginConfirm'

const decodeRepeated = value => {
  let text = String(value || '').trim()
  for (let index = 0; index < 3; index += 1) {
    try {
      const decoded = decodeURIComponent(text)
      if (decoded === text) {
        break
      }
      text = decoded
    } catch (error) {
      break
    }
  }
  return text
}

const extractParam = (value, names) => {
  const raw = decodeRepeated(value)
  for (let index = 0; index < names.length; index += 1) {
    const name = names[index]
    const matched = raw.match(new RegExp(`(?:^|[?&])${name}=([^&]+)`))
    if (matched && matched[1]) {
      return decodeRepeated(matched[1])
    }
  }
  return ''
}

const extractRawParam = (value, names) => {
  const raw = String(value || '').trim()
  for (let index = 0; index < names.length; index += 1) {
    const name = names[index]
    const matched = raw.match(new RegExp(`(?:^|[?&])${name}=([^&]+)`))
    if (matched && matched[1]) {
      return matched[1]
    }
  }
  return ''
}

const erpSceneFromText = value => {
  const rawText = String(value || '').trim()
  const rawScene = extractRawParam(rawText, ['scene'])
  if (rawScene) {
    const decodedScene = decodeRepeated(rawScene)
    const nested = erpSceneFromText(decodedScene)
    if (nested) {
      return nested
    }
    const sceneTicket = extractParam(decodedScene, ['ticket', 't'])
    const sessionId = extractParam(rawText, ['session_id', 'sessionId', 's'])
    if (sceneTicket && sessionId) {
      return `t=${sceneTicket}&s=${sessionId}`
    }
  }
  const raw = decodeRepeated(value)
  if (!raw) {
    return ''
  }
  const nestedScene = extractParam(raw, ['scene'])
  if (nestedScene) {
    const nested = erpSceneFromText(nestedScene)
    if (nested) {
      return nested
    }
  }
  const ticket = extractParam(raw, ['ticket', 't'])
  const sessionId = extractParam(raw, ['session_id', 'sessionId', 's'])
  if (!ticket || !sessionId) {
    return ''
  }
  return `t=${ticket}&s=${sessionId}`
}

const isErpLoginPath = value => decodeRepeated(value).replace(/^\/+/, '').includes(ERP_LOGIN_PAGE_PATH)

const buildErpLoginConfirmUrlFromScanResult = scanResult => {
  const candidates = [
    scanResult && scanResult.path,
    scanResult && scanResult.result,
    scanResult && scanResult.rawData,
  ]
  for (let index = 0; index < candidates.length; index += 1) {
    const candidate = decodeRepeated(candidates[index])
    if (!candidate) {
      continue
    }
    const scene = erpSceneFromText(candidate)
    if (scene && (isErpLoginPath(candidate) || !extractParam(scene, ['mold']))) {
      return `${ERP_LOGIN_PAGE}?scene=${encodeURIComponent(scene)}`
    }
  }
  return ''
}

module.exports = {
  buildErpLoginConfirmUrlFromScanResult,
  decodeRepeated,
}