module PowerStencil
  module Project

    module Plugins

      def plugins
        @plugins ||= {}
      end

      def create_new_local_plugin_tree(plugin_name, new_plugin_path, overwrite_files: false)
        raise PowerStencil::Error, "Plugin '#{plugin_name}' already exists !" if plugins.keys.include? plugin_name
        raise PowerStencil::Error, "Invalid plugin name '#{plugin_name}'" if (plugin_name.underscore =~ /^[_[:lower:]][_[:alnum:]]*$/).nil?
        entity_engine.dsl = PowerStencil::Dsl::PluginGeneration
        entity_engine.render_source entity_type_templates_templates[:plugin_definition],
                                    new_plugin_path,
                                    overwrite_files: overwrite_files,
                                    main_entry_point: plugin_name

      end

      def plugins_sorted_by_dependency
        solver = PowerStencil::Utils::DependencySolver.new
        plugin_names = plugins.keys

        plugins.each do |_, plugin|
          unless plugin.dependencies.nil?
            plugin.dependencies.each do |dependency_name|
              raise PowerStencil::Error, "Invalid dependency '#{dependency_name}'declared for plugin '#{plugin.name}' !" unless plugin_names.include? dependency_name
            end
          end
          solver[plugin.name] = plugin.dependencies.nil? ? [] : plugin.dependencies
        end
        solver.tsort.map { |plugin_name| plugins[plugin_name] }
      rescue TSort::Cyclic => e
        PowerStencil::Error.report_error e
        raise PowerStencil::Error, 'Plugins cyclical dependency error !'
      end


      private

      def bootstrap_plugins
        @plugins = {}
        initialize_gem_plugins
        initialize_local_plugins
        require_plugins_entry_points
        command_line_manager.definition_hash_to_commands
        register_plugins_processors
      end

      def register_plugins_processors
        plugins.each do |_, plugin|
          if plugin.capabilities[:processors]
            plugin.register_processors
          end
        end
      end

      def require_plugins_entry_points
        plugins_sorted_by_dependency.each do |plugin|
          plugin.require_entry_point
        end
      end

      def initialize_gem_plugins
        if config[:project_plugins].empty?
          PowerStencil.logger.info 'No gem plugin found in project'
          return
        end
        config[:project_plugins].each do |plugin_definition|

          (gem_name, gem_req) = PowerStencil::Plugins::Base.plugin_definition_to_name_and_req plugin_definition
          raise PowerStencil::Error, "Plugin '#{gem_name}' already exists !" unless plugins[gem_name].nil?

          plugin = PowerStencil::Plugins::Base.new(gem_name, self, type: :gem, gem_req: gem_req)
          plugins[plugin.name] = plugin
        end
      end

      def initialize_local_plugins
        unless File.directory? project_local_plugins_path
          PowerStencil.logger.info "No local plugin found in '#{project_local_plugins_path}'"
          return
        end

        Dir.entries(project_local_plugins_path)
            .select { |e| File.directory? File.join(project_local_plugins_path, e) }
            .reject { |d| %w(. ..).include? d }
            .sort
            .each do |candidate|
          begin
            raise PowerStencil::Error, "Plugin '#{candidate}' already exists !" unless plugins[candidate].nil?
            plugin = PowerStencil::Plugins::Base.new(candidate, self)
            plugins[plugin.name] = plugin
          rescue PowerStencil::Error => pse
            logger.puts_and_logs pse.message, logs_as: :error
            logger.puts_and_logs "Discarding invalid plugin '#{candidate}'.", logs_as: :error
          end
        end

      end

    end

  end
end