# frozen_string_literal: true

module Faraday
  class Adapter
    # @example
    #   test = Faraday::Connection.new do
    #     use Faraday::Adapter::Test do |stub|
    #       # Define matcher to match the request
    #       stub.get '/resource.json' do
    #         # return static content
    #         [200, {'Content-Type' => 'application/json'}, 'hi world']
    #       end
    #
    #       # response with content generated based on request
    #       stub.get '/showget' do |env|
    #         [200, {'Content-Type' => 'text/plain'}, env[:method].to_s]
    #       end
    #
    #       # A regular expression can be used as matching filter
    #       stub.get /\A\/items\/(\d+)\z/ do |env, meta|
    #         # in case regular expression is used, an instance of MatchData
    #         # can be received
    #         [200,
    #          {'Content-Type' => 'text/plain'},
    #          "showing item: #{meta[:match_data][1]}"
    #         ]
    #       end
    #
    #       # You can set strict_mode to exactly match the stubbed requests.
    #       stub.strict_mode = true
    #     end
    #   end
    #
    #   resp = test.get '/resource.json'
    #   resp.body # => 'hi world'
    #
    #   resp = test.get '/showget'
    #   resp.body # => 'get'
    #
    #   resp = test.get '/items/1'
    #   resp.body # => 'showing item: 1'
    #
    #   resp = test.get '/items/2'
    #   resp.body # => 'showing item: 2'
    class Test < Faraday::Adapter
      attr_accessor :stubs

      # A stack of Stubs
      class Stubs
        class NotFound < StandardError
        end

        def initialize(strict_mode: false)
          # { get: [Stub, Stub] }
          @stack = {}
          @consumed = {}
          @strict_mode = strict_mode
          yield(self) if block_given?
        end

        def empty?
          @stack.empty?
        end

        # @param env [Faraday::Env]
        def match(env)
          request_method = env[:method]
          return false unless @stack.key?(request_method)

          stack = @stack[request_method]
          consumed = (@consumed[request_method] ||= [])

          stub, meta = matches?(stack, env)
          if stub
            consumed << stack.delete(stub)
            return stub, meta
          end
          matches?(consumed, env)
        end

        def get(path, headers = {}, &block)
          new_stub(:get, path, headers, &block)
        end

        def head(path, headers = {}, &block)
          new_stub(:head, path, headers, &block)
        end

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

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

        def patch(path, body = nil, headers = {}, &block)
          new_stub(:patch, path, headers, body, &block)
        end

        def delete(path, headers = {}, &block)
          new_stub(:delete, path, headers, &block)
        end

        def options(path, headers = {}, &block)
          new_stub(:options, path, headers, &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|
            next if stubs.empty?

            failed_stubs.concat(
              stubs.map do |stub|
                "Expected #{method} #{stub}."
              end
            )
          end
          raise failed_stubs.join(' ') unless failed_stubs.empty?
        end

        # Set strict_mode. If the value is true, this adapter tries to find matched requests strictly,
        # which means that all of a path, parameters, and headers must be the same as an actual request.
        def strict_mode=(value)
          @strict_mode = value
          @stack.each do |_method, stubs|
            stubs.each do |stub|
              stub.strict_mode = value
            end
          end
        end

        protected

        def new_stub(request_method, path, headers = {}, body = nil, &block)
          normalized_path, host =
            if path.is_a?(Regexp)
              path
            else
              [
                Faraday::Utils.normalize_path(path),
                Faraday::Utils.URI(path).host
              ]
            end
          path, query = normalized_path.respond_to?(:split) ? normalized_path.split('?') : normalized_path
          headers = Utils::Headers.new(headers)

          stub = Stub.new(host, path, query, headers, body, @strict_mode, block)
          (@stack[request_method] ||= []) << stub
        end

        # @param stack [Hash]
        # @param env [Faraday::Env]
        def matches?(stack, env)
          stack.each do |stub|
            match_result, meta = stub.matches?(env)
            return stub, meta if match_result
          end
          nil
        end
      end

      # Stub request
      class Stub < Struct.new(:host, :path, :query, :headers, :body, :strict_mode, :block) # rubocop:disable Style/StructInheritance
        # @param env [Faraday::Env]
        def matches?(env)
          request_host = env[:url].host
          request_path = Faraday::Utils.normalize_path(env[:url].path)
          request_headers = env.request_headers
          request_body = env[:body]

          # meta is a hash used as carrier
          # that will be yielded to consumer block
          meta = {}
          [(host.nil? || host == request_host) &&
            path_match?(request_path, meta) &&
            params_match?(env) &&
            (body.to_s.size.zero? || request_body == body) &&
            headers_match?(request_headers), meta]
        end

        def path_match?(request_path, meta)
          if path.is_a?(Regexp)
            !!(meta[:match_data] = path.match(request_path))
          else
            path == request_path
          end
        end

        # @param env [Faraday::Env]
        def params_match?(env)
          request_params = env[:params]
          params = env.params_encoder.decode(query) || {}

          if strict_mode
            return Set.new(params) == Set.new(request_params)
          end

          params.keys.all? do |key|
            request_params[key] == params[key]
          end
        end

        def headers_match?(request_headers)
          if strict_mode
            headers_with_user_agent = headers.dup.tap do |hs|
              # NOTE: Set User-Agent in case it's not set when creating Stubs.
              #       Users would not want to set Faraday's User-Agent explicitly.
              hs[:user_agent] ||= Connection::USER_AGENT
            end
            return Set.new(headers_with_user_agent) == Set.new(request_headers)
          end

          headers.keys.all? do |key|
            request_headers[key] == headers[key]
          end
        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

      # @param env [Faraday::Env]
      def call(env)
        super

        env.request.params_encoder ||= Faraday::Utils.default_params_encoder
        env[:params] = env.params_encoder.decode(env[:url].query) || {}
        stub, meta = stubs.match(env)

        unless stub
          raise Stubs::NotFound, "no stubbed request for #{env[:method]} "\
                                 "#{env[:url]} #{env[:body]}"
        end

        block_arity = stub.block.arity
        status, headers, body =
          if block_arity >= 0
            stub.block.call(*[env, meta].take(block_arity))
          else
            stub.block.call(env, meta)
          end
        save_response(env, status, body, headers)

        @app.call(env)
      end
    end
  end
end