module SynapsePay
  class APIMethod

    attr_accessor :path
    attr_accessor :method
    attr_accessor :params
    attr_accessor :headers

    attr_accessor :response_body
    attr_accessor :response_code
    attr_accessor :error

    attr_accessor :api_base

    def initialize(method, path, params, headers, object)
      @api_base = api_base || SynapsePay.api_base

      @method = method.to_sym
      @path = PathBuilder.build(path, object, params)
      @params = ParamsBuilder.build(params)
      @headers = HeadersBuilder.build(headers)
    end

    def execute
      begin
        response = Requester.request(method, url, params, headers)
        @response_body = response.body
        @response_code = response.code
      rescue Exception => e
        @response_body = e.http_body if e.respond_to?(:http_body)
        @response_code = e.http_code if e.respond_to?(:http_code)
        @error = compose_error(e)
        raise @error
      end

      response_json
    end

    def url
      "#{api_base}#{@path}"
    end

    def response_json
      begin
        json = Util.symbolize_keys(JSON.parse(@response_body))
      rescue JSON::ParserError
        @error = APIError.new("Unable to parse the server response as JSON.", self)
        raise @error
      end
      if(!json[:success])
        @error = APIError.new(json, self)
        raise @error
      end
      json
    end

    def compose_error(error)
      msg = "An error occured while making the API call."

      case error
      when RestClient::ExceptionWithResponse
        return error_with_response(error)

      when RestClient::RequestTimeout
        msg = "The request timed out while making the API call."

      when RestClient::ServerBrokeConnection
        msg = "The connection to the server broke before the request completed."

      when SocketError
        msg = "An unexpected error occured while trying to connect to " \
          "the API. You may be seeing this message because your DNS is " \
          "not working. To check, try running 'host #{SynapsePay.api_base}' "\
          "from the command line."

      else
        msg = "An unexpected error occured. If this problem persists let us " \
          "know at #{SynapsePay.support_email}."
      end

      return APIConnectionError.new(msg, self)
    end

    # Handle a few common cases.
    def error_with_response(error)
      case @response_code
      when 400, 404
        return APIError.new("Invalid request. Please check the URL and parameters.", self)
      when 401
        return AuthenticationError.new("Authentication failed. Please check your API key and verify that it is correct.", self)
      else
        return APIError.new("An error occured while making the API call.", self)
      end
    end

  end
end