# frozen_string_literal: true

require_relative 'route_builder'
require_relative 'meta_builder'

module Meta
  module RouteDSL
    class ApplicationBuilder
      include MetaBuilder::Delegator

      def initialize(prefix = nil, &block)
        @mod_prefix = prefix
        @before_callbacks = []
        @after_callbacks = []
        @error_guards = []
        @meta_builder = MetaBuilder.new
        @mod_builders = []
        @shared_mods = []

        instance_exec &block if block_given?
      end

      def build(parent_path: '', meta: {}, before_callbacks: [], after_callbacks: [])
        # 合并 meta 时不仅仅是覆盖，比如 parameters 参数需要合并
        meta2 = (meta || {}).merge(@meta_builder.build)
        if meta[:parameters] && meta2[:parameters]
          meta2[:parameters] = meta[:parameters].merge(meta2[:parameters])
        end

        # 构建子模块
        before_callbacks += @before_callbacks
        after_callbacks = @after_callbacks + after_callbacks
        mods = @mod_builders.map { |builder| builder.build(parent_path: Utils::Path.join(parent_path, @mod_prefix), meta: meta2, before_callbacks: before_callbacks, after_callbacks: after_callbacks) }

        Application.new(
          prefix: @mod_prefix,
          mods: mods,
          shared_mods: @shared_mods,
          error_guards: @error_guards
        )
      end

      def shared(*mods, &block)
        @shared_mods += mods
        @shared_mods << Module.new(&block) if block_given?
      end

      # 定义路由块
      def route(path, method = nil, &block)
        route_builder = RouteDSL::RouteBuilder.new(path, method, &block)
        @mod_builders << route_builder
        route_builder
      end

      # 定义子模块
      def namespace(path, &block)
        @mod_builders << ApplicationBuilder.new(path, &block)
      end

      # 应用另一个模块
      def apply(builder, tags: nil)
        @mod_builders << BindingMeta.new(builder, tags ? { tags: tags } : {})
      end

      # 定义模块内的公共逻辑
      def before(&block)
        @before_callbacks << block
      end

      def after(&block)
        @after_callbacks << block
      end

      def rescue_error(error_class, &block)
        @error_guards << { error_class: error_class, caller: block }
      end

      # 定义应用到子模块的公共逻辑
      def meta(&block)
        @meta_builder.instance_exec &block
      end

      # 添加 get、post、put、patch、delete 路由方法
      [:get, :post, :put, :patch, :delete].each do |method|
        define_method(method) do |path = '', &block|
          route(path, method, &block)
        end
      end

      # 绑定 Meta，绑定的 Meta 会覆盖父级的 Meta，用于 Application.apply 方法
      class BindingMeta
        def initialize(builder, meta)
          @builder = builder
          @meta = meta
        end

        def build(parent_path: '', meta: {}, before_callbacks: [], after_callbacks: [])
          # 合并 meta 时不仅仅是覆盖，比如 parameters 参数需要合并
          meta2 = (meta || {}).merge(@meta)
          if meta[:parameters] && meta2[:parameters]
            meta2[:parameters] = meta[:parameters].merge(meta2[:parameters])
          end
          @builder.build(parent_path: parent_path, meta: meta2, before_callbacks: before_callbacks, after_callbacks: after_callbacks)
        end
      end
    end
  end
end