package router

import (
	"net/http"
	"os"
	"path/filepath"
	"server/internal/config"
	"server/internal/middleware"
	"server/internal/pkg/httputil"

	"github.com/go-chi/chi/v5"
	"go.uber.org/fx"
)

type Group string

const (
	AdminPublicRoutes Group = "admin_public_routes"
	AdminRoutes       Group = "admin_routes"
	SiteRoutes        Group = "site_routes"
)

type Registrar interface {
	Register(r chi.Router)
}

type Params struct {
	fx.In

	JWT            *middleware.JWTMiddleware
	Auth           *middleware.AuthMiddleware
	Logger         *middleware.LoggerMiddleware
	AccessLog      *middleware.AccessLogMiddleware
	RequestContext *middleware.RequestContextMiddleware
	Config         *config.Config

	AdminPublicRoutes []Registrar `group:"admin_public_routes"`
	AdminRoutes       []Registrar `group:"admin_routes"`
	SiteRoutes        []Registrar `group:"site_routes"`
}

func NewRouter(p Params, cfg *config.Config) *chi.Mux {
	mux := chi.NewRouter()

	// 中间件顺序很重要 洋葱模型 越靠前的中间件 包裹范围越大
	// 请求进入：
	//
	//A 前置代码
	//    |
	//    B 前置代码
	//        |
	//        C 前置代码
	//            |
	//            Handler
	//        C 后置代码
	//    B 后置代码
	//A 后置代码
	//
	//响应返回：
	mux.Use(
		p.RequestContext.Middleware,
		p.Logger.Middleware,
		p.AccessLog.Middleware,
	)

	if config.IsDev() {
		// 开放静态目录
		registerStaticFiles(mux, cfg.File.UploadDir)

		// 开发阶段：遍历所有已注册路由的清单接口（无鉴权）
		mux.Get("/api/admin/routes", ListRoutes(mux))
	}

	mux.Route("/api/admin", func(r chi.Router) {
		// 免鉴权接口
		for _, route := range p.AdminPublicRoutes {
			route.Register(r)
		}

		r.Group(func(r chi.Router) {
			// jwt 和 auth中间件
			r.Use(p.JWT.Middleware)
			r.Use(p.Auth.Middleware(mux))

			// 循环挂载所有后台业务模块
			for _, route := range p.AdminRoutes {
				route.Register(r)
			}
		})
	})

	mux.Route("/api", func(r chi.Router) {
		for _, route := range p.SiteRoutes {
			route.Register(r)
		}
	})

	return mux
}

func registerStaticFiles(r chi.Router, uploadDir string) {
	rootDir, _ := os.Getwd()

	uploadsDir := filepath.Join(rootDir, uploadDir)

	r.Handle("/static/*", http.StripPrefix("/static/", http.FileServer(http.Dir(uploadsDir))))
}

// RouteInfo 路由信息
type RouteInfo struct {
	Method string `json:"method"`
	Path   string `json:"path"`
}

// ListRoutes 遍历所有已注册的路由
func ListRoutes(mux *chi.Mux) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		var routes []RouteInfo

		err := chi.Walk(mux, func(method string, route string, _ http.Handler, _ ...func(http.Handler) http.Handler) error {
			routes = append(routes, RouteInfo{Method: method, Path: route})
			return nil
		})
		if err != nil {
			httputil.Fail(w, err)
			return
		}

		httputil.Ok(w, routes)
	}
}

func AsRegistrar(group Group, f any) any {
	return fx.Annotate(
		f,
		fx.As(new(Registrar)),
		fx.ResultTags(`group:"`+string(group)+`"`),
	)
}