import jwt from 'jsonwebtoken'
import { Role } from '../roles'

class AuthError extends Error {
  constructor(message?) {
    super(message ? `Not authorized: ${message}` : 'Not authorized')
  }
}

export function signInToken({ userId, role }): string {
  return jwt.sign({ userId, role }, process.env.APP_SECRET)
}

function userTokenIsValid(token) {
  try {
    jwt.verify(token, process.env.APP_SECRET)
    return true
  } catch (error) {
    return false
  }
}

export function userIsSignin(ctx) {
  return userTokenIsValid(ctx.request.get('authorization'))
}

// Since we use default options (HS256), we receive an object as a response. We assume a valid token is passed.
function getTokenData(token) {
  return jwt.verify(token, process.env.APP_SECRET)
}

function getFieldFromToken(authorization, fieldName) {
  const token = authorization.replace('Bearer ', '')
  try {
    const tokenData = getTokenData(token)
    return tokenData[fieldName]
  } catch (error) {
    throw new AuthError(error)
  }
}

export function getUserId(ctx) {
  return getFieldFromToken(ctx.request.get('Authorization'), 'userId')
}

export function getRole(ctx) {
  return getFieldFromToken(ctx.request.get('Authorization'), 'role')
}

export function getUserIdRest(req) {
  const {
    headers: { authorization },
  } = req
  if (!authorization) throw new AuthError()
  return getFieldFromToken(authorization, 'userId')
}

/**
 * ADMIN
 */
export function getAdminToken() {
  return jwt.sign({ role: Role[Role.Admin] }, process.env.ADMIN_SECRET)
}

export function adminTokenIsValid(token) {
  try {
    jwt.verify(token, process.env.ADMIN_SECRET)
    return true
  } catch (error) {
    return false
  }
}

export function adminIsSignin(ctx) {
  return adminTokenIsValid(ctx.request.get('authorization'))
}

export const testables = {
  getFieldFromToken: getFieldFromToken,
  getTokenData: getTokenData,
  adminTokenIsValid: adminTokenIsValid,
  userTokenIsValid: userTokenIsValid,
}