class AuthService 
  attr_accessor :token, :user

  def initialize(options)
    @username = options[:username]
    @password = options[:password]
    @token = options[:token]
    @auth_header = options[:auth_header]

    setup
  end

  def setup
    @token = @auth_header.split[1] if auth_header_valid?

    set_token if @token.nil?
    set_user if @token
  end

  def auth_header_valid?
    return false unless @auth_header
    auth_header_arr = @auth_header.split
    return false if auth_header_arr.count != 2 
    return false if auth_header_arr[0] != "Bearer"
    true
  end

  private
  def set_token 
    @token = TokenService.generate(user_id: @user.id) if allow?
  end

  def set_user 
    @user = User.find_by(id: TokenService.new(token: @token).user_id)
  end

  def allow?
    @user = User.find_by(username: @username)
    if @user and @user.authenticate(@password)
      true
    else 
      false
    end
  end
end

class TokenService
  attr_accessor :token
  
  def initialize(options)
    @token = options[:token]
  end

  def self.generate(payload)
    JWT.encode(payload, nil, 'none')
  end

  def decode
    begin
      JWT.decode(@token, nil, false)
    rescue
      nil 
    end
  end

  def payload 
    decode[0] if decode
  end

  def user_id
    payload["user_id"]
  end
end

class AuthController < ApplicationController
  before_action :set_auth, only: [:create]

  def create
    if @auth.token
      render json: { jwt: @auth.token }
    else
      render json: { error: {message: "Sorry, the credential is invalid"} }
    end
  end

  private 
  def auth_params 
    params.require(:auth).permit(:username, :password)
  end

  def set_auth
    @auth = AuthService.new(auth_params)
  end
end

class DashboardController < ApplicationController
  before_action :set_auth, only: [:index]

  def index
    if @auth.auth_header_valid?
      render json: { success: { message: "Welcome to dashboard, #{@auth.user.username}" } } 
    else 
      render json: { error: { message: "Sorry, you're not authenticated" } }
    end
  end

  private 
  def set_auth
    @auth = AuthService.new(auth_header: request.authorization)
  end
end