module Faraday
  module Adapter
    # test = Faraday::Connection.new do
    #   use Faraday::Adapter::Test do |stub|
    #     stub.get '/nigiri/sake.json' do
    #       [200, {}, 'hi world']
    #     end
    #   end
    # end
    # 
    # resp = test.get '/nigiri/sake.json'
    # resp.body # => 'hi world'
    #
    class Test < Middleware
      attr_accessor :stubs

      def self.loaded?() false end

      class Stubs
        def initialize
          # {:get => [Stub, Stub]}
          @stack = {}
          yield self if block_given?
        end

        def empty?
          @stack.empty?
        end

        def match(request_method, path, body)
          return false if !@stack.key?(request_method)
          stub = @stack[request_method].detect { |stub| stub.matches?(path, body) }
          @stack[request_method].delete stub
        end

        def get(path, &block)
          new_stub(:get, path, &block)
        end

        def head(path, &block)
          new_stub(:head, path, &block)
        end

        def post(path, body=nil, &block)
          new_stub(:post, path, body, &block)
        end

        def put(path, body=nil, &block)
          new_stub(:put, path, body, &block)
        end

        def delete(path, &block)
          new_stub(:delete, path, &block)
        end

        def new_stub(request_method, path, body=nil, &block)
          (@stack[request_method] ||= []) << Stub.new(path, body, block)
        end

        # Raises an error if any of the stubbed calls have not been made.
        def verify_stubbed_calls
          failed_stubs = []
          @stack.each do |method, stubs|
            unless stubs.size == 0
              failed_stubs.concat(stubs.map {|stub|
                "Expected #{method} #{stub}."
              })
            end
          end
          raise failed_stubs.join(" ") unless failed_stubs.size == 0
        end
      end

      class Stub < Struct.new(:path, :body, :block)
        def matches?(request_path, request_body)
          request_path == path && (body.to_s.size.zero? || request_body == body)
        end

        def to_s
          "#{path} #{body}"
        end
      end

      def initialize app, stubs=nil, &block
        super(app)
        @stubs = stubs || Stubs.new
        configure(&block) if block
      end

      def configure
        yield stubs
      end

      def request_uri url
        (url.path != "" ? url.path : "/") +
        (url.query ? "?#{url.query}" : "")
      end

      def call(env)
        if stub = stubs.match(env[:method], request_uri(env[:url]), env[:body])
          status, headers, body = stub.block.call(env)
          env.update \
            :status           => status,
            :response_headers => headers,
            :body             => body
        else
          raise "no stubbed request for #{env[:method]} #{request_uri(env[:url])} #{env[:body]}"
        end
        @app.call(env)
      end
    end
  end
end