import {
  decodeBase64OrOriginal,
  getCipher,
  getIfNotBlank,
  normalizeHost,
  parseQueryString,
  parseRequiredPort,
  stripUriScheme,
} from './helpers'

export function URI_SSR(uri: string): IProxyshadowsocksRConfig {
  const afterScheme = stripUriScheme(uri, 'ssr', 'Invalid ssr uri')
  if (!afterScheme) {
    throw new Error('Invalid ssr uri')
  }
  const line = decodeBase64OrOriginal(afterScheme)

  // handle IPV6 & IPV4 format
  let splitIdx = line.indexOf(':origin')
  if (splitIdx === -1) {
    splitIdx = line.indexOf(':auth_')
  }
  if (splitIdx === -1) {
    throw new Error('Invalid ssr uri')
  }
  const serverAndPort = line.substring(0, splitIdx)
  const portIdx = serverAndPort.lastIndexOf(':')
  if (portIdx === -1) {
    throw new Error('Invalid ssr uri: missing port')
  }
  const server = normalizeHost(serverAndPort.substring(0, portIdx))
  const port = parseRequiredPort(
    serverAndPort.substring(portIdx + 1),
    'Invalid ssr uri: invalid port',
  )

  const params = line
    .substring(splitIdx + 1)
    .split('/?')[0]
    .split(':')
  let proxy: IProxyshadowsocksRConfig = {
    name: 'SSR',
    type: 'ssr',
    server,
    port,
    protocol: params[0],
    cipher: getCipher(params[1]),
    obfs: params[2],
    password: decodeBase64OrOriginal(params[3]),
  }

  // get other params
  const otherParams: Record<string, string> = {}
  const rawOtherParams = parseQueryString(line.split('/?')[1])
  for (const [key, value] of Object.entries(rawOtherParams)) {
    const trimmed = value?.trim()
    if (trimmed) {
      otherParams[key] = trimmed
    }
  }

  proxy = {
    ...proxy,
    name: otherParams.remarks
      ? decodeBase64OrOriginal(otherParams.remarks).trim()
      : (proxy.server ?? ''),
    'protocol-param': getIfNotBlank(
      decodeBase64OrOriginal(otherParams.protoparam || '').replace(/\s/g, ''),
    ),
    'obfs-param': getIfNotBlank(
      decodeBase64OrOriginal(otherParams.obfsparam || '').replace(/\s/g, ''),
    ),
  }
  return proxy
}