require 'fitbit_api/base'
require 'fitbit_api/activities'
require 'fitbit_api/heart_rate'
require 'fitbit_api/goals'
require 'fitbit_api/alarms'
require 'fitbit_api/body'
require 'fitbit_api/devices'
require 'fitbit_api/food'
require 'fitbit_api/friends'
require 'fitbit_api/sleep'
require 'fitbit_api/user'
require 'fitbit_api/water'

module FitbitAPI
  class Client
    attr_accessor :api_version, :unit_system, :locale, :scope, :snake_case_keys, :symbolize_keys
    attr_reader   :user_id

    def initialize(opts)
      missing_args = [:client_id, :client_secret] - opts.keys
      raise FitbitAPI::InvalidArgumentError, "Required arguments: #{missing_args.join(', ')}" if missing_args.size > 0

      %w(client_id client_secret redirect_uri site_url authorize_url token_url
      unit_system locale scope api_version snake_case_keys symbolize_keys).each do |attr|
        instance_variable_set("@#{attr}", (opts[attr.to_sym] || FitbitAPI.send(attr)))
      end

      @client = OAuth2::Client.new(@client_id, @client_secret, site: @site_url,
                                   authorize_url: @authorize_url, token_url: @token_url)

      restore_token(opts[:refresh_token]) if opts[:refresh_token]
    end

    def auth_url
      @client.auth_code.authorize_url(redirect_uri: @redirect_uri, scope: @scope)
    end

    def get_token(auth_code)
      @token = @client.auth_code.get_token(auth_code, redirect_uri: @redirect_uri, headers: auth_header)
      @user_id = @token.params['user_id']
      return @token
    end

    def restore_token(refresh_token)
      @token = OAuth2::AccessToken.from_hash(@client, refresh_token: refresh_token).refresh!(headers: auth_header)
      @user_id = @token.params['user_id']
      return @token
    end

    def token
      @token.expired? ? refresh_token : @token
    end

    def refresh_token
      @token = @token.refresh!(headers: auth_header)
    end

    def auth_header
      { 'Authorization' => ('Basic ' + Base64.encode64(@client_id + ':' + @client_secret)) }
    end

    def request_headers
      {
        'User-Agent' => "fitbit_api-#{FitbitAPI::VERSION} gem (#{FitbitAPI::REPO_URL})",
        'Accept-Language' => @unit_system,
        'Accept-Locale' => @locale
      }
    end

    def get(path, opts={})
      params = opts.delete(:params) || {}
      response = token.get(("#{@api_version}/" + path), params: deep_keys_to_camel_case!(params), headers: request_headers).response
      object = MultiJson.load(response.body) unless response.status == 204
      process_keys!(object, opts)
    end

    def post(path, opts={})
      response = token.post(("#{@api_version}/" + path), body: deep_keys_to_camel_case!(opts), headers: request_headers).response
      object = MultiJson.load(response.body) unless response.status == 204
      process_keys!(object, opts)
    end

    def delete(path, opts={})
      response = token.delete(("#{@api_version}/" + path), headers: request_headers).response
      object = MultiJson.load(response.body) unless response.status == 204
      process_keys!(object, opts)
    end

    def process_keys!(object, opts={})
      deep_keys_to_snake_case!(object) if (opts[:snake_case_keys] || snake_case_keys)
      deep_symbolize_keys!(object) if (opts[:symbolize_keys] || symbolize_keys)
      return object
    end
  end
end