require 'oauth2'
require 'blabla_client/version'
require 'blabla_client/trip'

module BlablaClient

  # Note : token expiration is ignored for now (current token expires on 15/04/2015)
  # PREVIOUS_TOKEN = 'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHAiOjE0MjY0MjY5NTUsImNsaWVudCI6ImE3NzM3ODdhNmI2YjM0NzlhMjk5NTg0MDUwMmUwNDZkNGE0NDNjYmE2MDFjMDk2Y2U1NGI4OTcyYjRkZTdjNzkiLCJzY29wZSI6IiIsInVzZXIiOm51bGx9.dOZF0wbZtW6_Vfa5dU6_X831yGCJlsSZE7gkdp2lldg'
  CURRENT_TOKEN = 'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHAiOjE0MjkxMzIwMDUsImNsaWVudCI6ImE3NzM3ODdhNmI2YjM0NzlhMjk5NTg0MDUwMmUwNDZkNGE0NDNjYmE2MDFjMDk2Y2U1NGI4OTcyYjRkZTdjNzkiLCJzY29wZSI6IiIsInVzZXIiOm51bGx9.HKdhHE8XilgrK9cfK6GYUWFbaaQDg_fOWdc0Ze06qIA'

  # token "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHAiOjE0MjY0MjY5NTUsImNsaWVudCI6ImE3NzM3ODdhNmI2YjM0NzlhMjk5NTg0MDUwMmUwNDZkNGE0NDNjYmE2MDFjMDk2Y2U1NGI4OTcyYjRkZTdjNzkiLCJzY29wZSI6IiIsInVzZXIiOm51bGx9.dOZF0wbZtW6_Vfa5dU6_X831yGCJlsSZE7gkdp2lldg"
  # expires_at : 1426426958
  # expires_in : 2419200

  # Configuration defaults (as of API v3)
  @config = {
      :auth_site => 'https://www.blablacar.fr',
      :token_path => '/oauth/v2/access_token',
      :client_id => '',
      :client_secret => '',
      :api_url => 'https://api.blablacar.fr/api/v2/trips'
  }

  @valid_config_keys = @config.keys
  @logger = Logger.new(STDOUT)

  # Configure through hash
  def self.configure(opts = {})
    opts.each {|k,v| @config[k.to_sym] = v if @valid_config_keys.include? k.to_sym}
  end

  def self.config
    @config
  end

  def self.available_trips(departure, arrival, date_range_start, date_range_end, page = 1)
    trips = []
    range_start = normalize_date(date_range_start)
    range_end = normalize_date(date_range_end)
    begin
      response = get_response(departure, arrival, range_start, range_end, page)
      trips = Trip.parse_response(response.body)
      @logger.info("Retrieved #{trips[:trips].length} trips for page #{page} of request #{departure}-#{arrival} from #{range_start} to #{range_end}")
    rescue OAuth2::Error => e
      http_code = e.response.status
      @logger.error("An error occurred while calling the API on #{@config[:api_url]}")
      @logger.error("Response : #{e.response}")
      @logger.error("Code : #{e.code}")
      @logger.error("HTTP status code : #{http_code}")
      @logger.error("Description : #{e.description}")
      if http_code == 403
        @logger.info('Token seems to have expired - Retrying with a new one')
        trips = renew_and_get_trips(departure, arrival, range_start, range_end, page)
      end
    end
    trips
  end

  def self.normalize_date(date)
    if date.is_a?(Date) || date.is_a?(DateTime) || date.is_a?(Time)
      date_as_object = date
    else
      date_as_object = Date.parse(date)
    end
    date_as_object.strftime('%d-%m-%Y')
  end

  private

  def self.renew_and_get_trips(departure, arrival, date_range_start, date_range_end, page)
    trips = []
    begin
      response = get_response(departure, arrival, date_range_start, date_range_end, page, true)
      trips = Trip.parse_response(response.body)
      @logger.info("Retrieved #{trips[:trips].length} trips for page #{page} of request #{departure}-#{arrival} from #{date_range_start} to #{date_range_start}")
    rescue OAuth2::Error => e
      http_code = e.response.status
      @logger.error("An error occurred while calling the API on #{@config[:api_url]} after attempting to renew the token")
      @logger.error("Response : #{e.response}")
      @logger.error("Code : #{e.code}")
      @logger.error("HTTP status code : #{http_code}")
      @logger.error("Description : #{e.description}")
    end
    trips
  end

  def self.get_response(departure, arrival, date_range_start, date_range_end, page, renew_token = false)
    client = OAuth2::Client.new(@config[:client_id], @config[:client_secret], :site => @config[:auth_site], :token_url => @config[:token_path])
    token = renew_token ? client.client_credentials.get_token : OAuth2::AccessToken.new(client, CURRENT_TOKEN, :mode => :query)
    token.get(@config[:api_url],
              :params => {
                             :_format => 'json',
                             :fn => departure,
                             :tn => arrival,
                             :db => date_range_start,
                             :de => date_range_end,
                             :seats => '1',
                             :page => page
                         }
    )
  end
end