import { ClientOptions, Logger } from './types'

// TODO - remove this if/when we decide to abandon this idea.
// There's some WIP/research commented out here that could be used for building adapters for auth0/okta/cognito/etc
// using a common interface (similar to redwoodjs's auth solution). Could be cool, but not sure it's worth the effort at
// this point.
//
// Not using any of this for now in favor of simple getCredentials option. Better not to maintain auth state
// internally until we're sure we can provide a nice abstraction for it.

export interface AuthStateChangeEvent {
  type: 'LOGGED_IN' | 'LOGGED_OUT' | 'SET_TOKEN' | 'ERROR'
  token?: string | null
}

// Just sketching out idea for now.
export interface AuthAdapter {
  login: ({ username, password }: { username: string; password: string }) => Promise<{ accessToken: string }>
  logout: () => Promise<void>
  getUser: () => Promise<any>
  isAuthenticated: () => Promise<boolean>
}

export const createAuth = (options: ClientOptions, { _logger }: { _logger: Logger }) => {
  const _onAuthStateChangeCallbacks = [] as ((event: AuthStateChangeEvent) => void)[]
  function _fireAuthStateChangedCallbacks(event: AuthStateChangeEvent) {
    _onAuthStateChangeCallbacks.forEach((callback) => callback(event))
  }
  function _onAuthStateChange(callback: (event: AuthStateChangeEvent) => void) {
    _onAuthStateChangeCallbacks.push(callback)
  }

  //  Update type when there is more than one provider and we know what the interface should be
  // @eslint-disable-next-line
  let authAdapter: AuthAdapter | null
  // if (options?.auth?.provider === 'VENDIA_USER') {
  //   authAdapter = getVendiaUserAuth({ _logger })
  // }

  const auth = {
    login: async ({ username, password }: { username: string; password: string }) => {
      if (authAdapter === null) {
        throw new Error('auth.provider must be set via options to use this method.')
      }

      _logger('Logging in...')
      const tokens = await authAdapter.login({ username, password })

      _fireAuthStateChangedCallbacks({ type: 'SET_TOKEN', token: tokens.accessToken })
      _fireAuthStateChangedCallbacks({ type: 'LOGGED_IN' })
    },
    logout: () => {
      if (authAdapter === null) {
        throw new Error('auth.provider must be set via options to use this method.')
      }

      _logger('Logging out...')
      authAdapter.logout()

      _fireAuthStateChangedCallbacks({ type: 'SET_TOKEN', token: null })
      _fireAuthStateChangedCallbacks({ type: 'LOGGED_OUT' })
    },
    getUser: () => {
      if (authAdapter === null) {
        throw new Error('auth.provider must be set via options to use this method.')
      }

      _logger('Getting user...')

      return authAdapter.getUser()
    },
    isAuthenticated: () => {
      if (authAdapter === null) {
        throw new Error('auth.provider must be set via options to use this method.')
      }

      _logger('Checking if authenticated...')

      return authAdapter.isAuthenticated()
    },
    onAuthStateChange: _onAuthStateChange,

    /**
     * Set a JWT token to use with Vendia's Custom JWT auth option
     * @param token - the JWT access token created by your auth provider. Do not add the "Bearer" prefix to the token.
     */
    setToken: (token: string | null) => {
      _fireAuthStateChangedCallbacks({ type: 'SET_TOKEN', token })
    },
  }

  return {
    // Internal
    _onAuthStateChange: _onAuthStateChange,

    // Public
    auth,
  }
}