# frozen_string_literal: true

require 'rspec/rails/api/metadata'

module RSpec
  module Rails
    module Api
      module DSL
        # All these methods will be available in example groups
        # (anything but 'it', 'example', 'for_code')
        module ExampleGroup
          ##
          # First method to be called in a spec file # as it will initialize the
          # metadata.
          #
          # @param name        [String] Resource name
          # @param description [String] Resource description
          def resource(name, description = '')
            metadata[:rra] ||= Metadata.new
            metadata[:rra].add_resource name, description
          end

          ##
          # Describes an entity
          #
          # @param type   [Symbol] Name of the entity for reference
          # @param fields [Hash]   Fields declarations
          #
          # @return [void]
          def entity(type, fields)
            metadata[:rra].add_entity type, fields
          end

          ##
          # Describes request or path parameters
          #
          # @param type   [Symbol] Name of the parameters set for reference
          # @param fields [Hash]   Fields declarations
          #
          # @return [void]
          def parameters(type, fields)
            metadata[:rra].add_parameter type, fields
          end

          ##
          # Declares parameters used in URLS (_path_)
          # Use `fields` or `defined` but not both.
          #
          # @param [Hash, nil]   fields  An attributes declaration
          # @param [Symbol, nil] defined An entity reference
          #
          # @return [void]
          def path_params(fields: nil, defined: nil)
            if defined && !metadata[:rra].parameters[defined]
              raise "Parameter #{defined} was not defined with the 'parameters' method"
            end

            fields ||= metadata[:rra].parameters[defined]

            metadata[:rra].add_path_params fields
          end

          ##
          # Declares parameters for a request body
          # Use `attributes` or `defined` but not both.
          #
          # @param [Hash, nil]   attributes An attributes declaration
          # @param [Symbol, nil] defined    An entity reference.
          #
          # @return [void]
          def request_params(attributes: nil, defined: nil)
            if defined && !metadata[:rra].parameters[defined]
              raise "Parameter #{defined} was not defined with the 'parameters' method"
            end

            attributes ||= metadata[:rra].parameters[defined]

            metadata[:rra].add_request_params attributes
          end

          ##
          # Defines a GET action
          #
          # @param [String] url         URL to test
          # @param [String] summary     What the action does
          # @param [String] description Longer description
          #
          # @return [void]
          def on_get(url, summary = nil, description = nil, &block)
            on_action(:get, url, summary, description, &block)
          end

          ##
          # Defines a POST action
          #
          # @param [String] url         URL to test
          # @param [String] summary     What the action does
          # @param [String] description Longer description
          #
          # @return [void]
          def on_post(url, summary = nil, description = nil, &block)
            on_action(:post, url, summary, description, &block)
          end

          ##
          # Defines a PUT action
          #
          # @param [String] url         URL to test
          # @param [String] summary     What the action does
          # @param [String] description Longer description
          #
          # @return [void]
          def on_put(url, summary = nil, description = nil, &block)
            on_action(:put, url, summary, description, &block)
          end

          ##
          # Defines a PATCH action
          #
          # @param [String] url         URL to test
          # @param [String] summary     What the action does
          # @param [String] description Longer description
          #
          # @return [void]
          def on_patch(url, summary = nil, description = nil, &block)
            on_action(:patch, url, summary, description, &block)
          end

          ##
          # Defines a DELETE action
          #
          # @param [String] url         URL to test
          # @param [String] summary     What the action does
          # @param [String] description Longer description
          #
          # @return [void]
          def on_delete(url, summary = nil, description = nil, &block)
            on_action(:delete, url, summary, description, &block)
          end

          ##
          # Adds an HTTP code declaration to metadata, with expected result
          # If no expectation is provided, the response will be expected to be empty
          #
          # @param status_code [Number]  Status code to test for
          # @param description [String]  Description of the route/status pair
          # @param expect_many [Symbol]  Check the response for a list of given entity
          # @param expect_one  [Symbol]  Check the response for a given entity
          # @param test_only   [Boolean] When true, test the response without filling the documentation
          #
          # @return [void]
          #
          def for_code(status_code, description = nil, expect_many: nil, expect_one: false, test_only: false, &block)
            description ||= Rack::Utils::HTTP_STATUS_CODES[status_code]

            metadata[:rra].add_status_code(status_code, description) unless test_only
            metadata[:rra].add_expectations(expect_one, expect_many)
            metadata[:rra_current_example] = metadata[:rra].current_example

            describe "->#{test_only ? ' test' : ''} #{status_code} - #{description}" do
              execute_for_code_block(block)
            end
          end

          private

          ##
          # Currently fill metadata with the action
          #
          # @param [Symbol]      action      HTTP verb
          # @param [String]      url         URL to test
          # @param [String, nil] summary     What the action does
          # @param [String, nil] description Longer description
          #
          # @return [void]
          def on_action(action, url, summary, description, &block)
            metadata[:rra].add_action(action, url, summary, description)

            describe("#{action.upcase} #{url}", &block)
          end

          ##
          # Visit the URL and test response
          #
          # @param callback_block [block]   Block to execute for testing the response
          #
          # @return [void]
          def execute_for_code_block(callback_block)
            example 'Test response and create documentation', caller: callback_block.send(:caller) do
              instance_eval(&callback_block) if callback_block
            end
          end
        end
      end
    end
  end
end

RSpec::Core::ExampleGroup.extend(RSpec::Rails::Api::DSL::ExampleGroup)