Class: MCP::Rails::ServerGenerator::ServerWriter

Inherits:
Object
  • Object
show all
Defined in:
lib/mcp/rails/server_generator/server_writer.rb

Class Method Summary collapse

Class Method Details

.generate_parameter(param, indent_level = 1) ⇒ Object 



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# File 'lib/mcp/rails/server_generator/server_writer.rb', line 54

def self.generate_parameter(param, indent_level = 1)
  indent = "  " * indent_level
  name = param[:name].to_sym
  required = param[:required] ? ", required: true" : ""
  description = param[:description] ? ", description: \"#{param[:description]}\"" : ""

  if param[:type] == :array
    if param[:item_type]
      # Scalar array: argument :name, Array, items: Type
      type_str = "Array, items: #{type_to_class(param[:item_type])}"
      "#{indent}argument :#{name}, #{type_str}#{required}#{description}"
    elsif param[:nested]
      # Array of objects: argument :name, Array do ... end
      nested_params = param[:nested].map { |np| generate_parameter(np, indent_level + 1) }.join("\n")
      "#{indent}argument :#{name}, Array#{required}#{description} do\n#{nested_params}\n#{indent}end"
    else
      raise "Array parameter must have either item_type or nested parameters"
    end
  elsif param[:type] == :object && param[:nested]
    # Object: argument :name do ... end
    nested_params = param[:nested].map { |np| generate_parameter(np, indent_level + 1) }.join("\n")
    "#{indent}argument :#{name}#{required}#{description} do\n#{nested_params}\n#{indent}end"
  else
    # Scalar type: argument :name, Type
    type_str = type_to_class(param[:type])
    "#{indent}argument :#{name}, #{type_str}#{required}#{description}"
  end
end

.helper_methods(base_uri, bypass_csrf_key) ⇒ Object 



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# File 'lib/mcp/rails/server_generator/server_writer.rb', line 113

def self.helper_methods(base_uri, bypass_csrf_key)
  return test_helper_methods(base_uri, bypass_csrf_key) if ::Rails.env.test?
  "    def transform_args(args)\n      if args.is_a?(Hash)\n        args.transform_keys { |key| key.to_s.gsub(/([a-z])([A-Z])/, '\\\\1_\\\\2').gsub(/([A-Z])([A-Z][a-z])/, '\\\\1_\\\\2').downcase }\n          .transform_values { |value| transform_args(value) }\n      else\n        args # Return non-hash values (e.g., strings, integers) unchanged\n      end\n    end\n\n    def parse_response(response)\n      response_body = JSON.parse(response.body)\n      case response_body\n      when Hash\n        if response_body[\"status\"] == \"error\"\n          raise \"From Rails Server: \\\#{response_body[\"message\"]}\"\n        else\n          response_body.dig(\"data\").to_json\n        end\n      else\n        raise \"None MCP response from Rails Server\"\n      end\n    rescue => e\n      raise \"Parsing JSON failed: \\\#{e.message}\"\n    end\n\n    def get_resource(uri, arguments = {})\n      response = HTTParty.get(\"\#{base_uri}\\\#{uri}\", query: transform_args(arguments), headers: { \"Accept\" => \"application/vnd.mcp+json, application/json\" })\n      parse_response(response)\n    end\n\n    def post_resource(uri, payload = {})\n      headers = { \"Accept\" => \"application/vnd.mcp+json, application/json\" }\n      headers[\"X-Bypass-CSRF\"] = \"\#{bypass_csrf_key}\"\n      response = HTTParty.post(\"\#{base_uri}\\\#{uri}\", body: transform_args(payload), headers: headers)\n      parse_response(response)\n    end\n\n    def patch_resource(uri, payload = {})\n      headers = { \"Accept\" => \"application/vnd.mcp+json, application/json\" }\n      headers[\"X-Bypass-CSRF\"] = \"\#{bypass_csrf_key}\"\n      response = HTTParty.patch(\"\#{base_uri}\\\#{uri}\", body: transform_args(payload), headers: headers)\n      parse_response(response)\n    end\n\n    def delete_resource(uri, payload = {})\n      headers = { \"Accept\" => \"application/vnd.mcp+json, application/json\" }\n      headers[\"X-Bypass-CSRF\"] = \"\#{bypass_csrf_key}\"\n      response = HTTParty.delete(\"\#{base_uri}\\\#{uri}\", body: transform_args(payload), headers: headers)\n      parse_response(response)\n    end\n  RUBY\nend\n"

.route_block(route, config) ⇒ Object 



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# File 'lib/mcp/rails/server_generator/server_writer.rb', line 169

def self.route_block(route, config)
  uri = route[:path]
  route[:url_parameters].each do |url_parameter|
    uri = uri.gsub(":#{url_parameter[:name]}", "\#{args[:#{url_parameter[:name]}]}")
  end

  env_vars = config.env_vars.map do |var|
    "args[:#{var.downcase}] = ENV['#{var}']"
  end.join("\n")

  method = route[:method].to_s.downcase
  helper_method = "#{method}_resource"

  "    call do |args|\n      \#{env_vars}\n      \#{helper_method}(\"\#{uri}\", args)\n    end\n  RUBY\nend\n"

.ruby_invocation ⇒ Object 



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# File 'lib/mcp/rails/server_generator/server_writer.rb', line 83

def self.ruby_invocation
  "    #!/usr/bin/env ruby\n\n    # Find the nearest Gemfile by walking up the directory tree\n    def find_nearest_gemfile(start_dir)\n      current_dir = File.expand_path(start_dir)\n      loop do\n        gemfile = File.join(current_dir, \"Gemfile\")\n        return gemfile if File.exist?(gemfile)\n        parent_dir = File.dirname(current_dir)\n        break if parent_dir == current_dir # Reached root (e.g., \"/\")\n        current_dir = parent_dir\n      end\n      nil # No Gemfile found\n    end\n\n    # If not already running under bundle exec, re-execute with the nearest Gemfile\n    unless ENV[\"BUNDLE_GEMFILE\"] # Check if already running under Bundler\n      gemfile = find_nearest_gemfile(__dir__) # __dir__ is the script's directory\n      if gemfile\n        ENV[\"BUNDLE_GEMFILE\"] = gemfile\n        exec(\"bundle\", \"exec\", \"ruby\", __FILE__, *ARGV) # Re-run with bundle exec\n      else\n        warn \"Warning: No Gemfile found in any parent directory.\"\n      end\n    end\n  RUBY\nend\n"

.test_helper_methods(base_uri, bypass_csrf_key) ⇒ Object 



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# File 'lib/mcp/rails/server_generator/server_writer.rb', line 190

def self.test_helper_methods(base_uri, bypass_csrf_key)
  "    def parse_response(test_context)\n      # Would be url: \#{base_uri}\n      parsed_body = JSON.parse(test_context.response.body)\n      case parsed_body\n      when Hash\n        if parsed_body[\"status\"] == \"error\"\n          raise \"From Rails Server: \\\#{parsed_body[\"message\"]}\"\n        else\n          parsed_body.dig(\"data\")\n        end\n      else\n        raise \"None MCP response from Rails Server\"\n      end\n    rescue => e\n      raise \"Parsing JSON failed: \\\#{e.message}\"\n    end\n\n    def get_resource(uri, arguments = {})\n      test_context = arguments.delete(:test_context)\n      test_context.get uri, params: arguments, headers: { \"Accept\" => \"application/vnd.mcp+json, application/json\" }, as: :mcp\n      parse_response(test_context)\n    end\n\n    def post_resource(uri, payload = {}, headers = {})\n      test_context = payload.delete(:test_context)\n      headers = { \"Accept\" => \"application/vnd.mcp+json, application/json\" }\n      headers[\"X-Bypass-CSRF\"] = \"\#{bypass_csrf_key}\"\n      test_context.post uri, params: payload, headers: headers, as: :mcp\n      parse_response(test_context)\n    end\n\n    def patch_resource(uri, payload = {})\n      test_context = payload.delete(:test_context)\n      headers = { \"Accept\" => \"application/vnd.mcp+json, application/json\" }\n      headers[\"X-Bypass-CSRF\"] = \"\#{bypass_csrf_key}\"\n      test_context.patch uri, params: payload.merge(headers: headers), as: :mcp\n      parse_response(test_context)\n    end\n\n    def delete_resource(uri, payload = {})\n      test_context = payload.delete(:test_context)\n      headers = { \"Accept\" => \"application/vnd.mcp+json, application/json\" }\n      headers[\"X-Bypass-CSRF\"] = \"\#{bypass_csrf_key}\"\n      test_context.delete uri, params: payload.merge(headers: headers), as: :mcp\n      parse_response(test_context)\n    end\n  RUBY\nend\n"

.type_to_class(type) ⇒ Object 



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# File 'lib/mcp/rails/server_generator/server_writer.rb', line 43

def self.type_to_class(type)
  case type
  when :string then "String"
  when :integer then "Integer"
  when :number then "Float"
  when :boolean then "TrueClass"
  when :array then "Array"
  else "String"  # Default to String
  end
end

.write_server(routes_data, config, base_url, bypass_csrf_key, engine = nil) ⇒ Object 



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# File 'lib/mcp/rails/server_generator/server_writer.rb', line 4

def self.write_server(routes_data, config, base_url, bypass_csrf_key, engine = nil)
  # Get engine-specific configuration if available
  config = config.for_engine(engine)

  file_name = engine ? "#{config.server_name}_server.rb" : "server.rb"
  file_path = File.join(config.output_directory.to_s, file_name)
  FileUtils.mkdir_p(File.dirname(file_path))

  File.open(file_path, "w") do |file|
    file.puts ruby_invocation
    file.puts
    file.puts %(require "mcp")
    file.puts %(require "httparty")
    file.puts
    file.puts helper_methods(base_url, bypass_csrf_key)
    file.puts

    file.puts %(name "#{config.server_name}")
    file.puts %(version "#{config.server_version}")

    routes_data.each do |route|
      file.puts %(tool "#{route[:tool_name].underscore}" do)
      file.puts "  description \"#{route[:description].sub(/\//, ' ')}\""
      route[:accepted_parameters].each do |param|
        file.puts generate_parameter(param)
      end
      file.puts route_block(route, config).lines.map { |line| "  #{line}" }.join
      file.puts "end"
      file.puts
    end
  end

  current_mode = File.stat(file_path).mode
  new_mode = current_mode | 0111  # Add execute (u+x, g+x, o+x)
  File.chmod(new_mode, file_path)

  file_path
end