package router

import (
	"io/fs"
	"net/http"
	"path/filepath"
	"strings"
	"time"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"vision-tool/internal/config"
	"vision-tool/internal/handler"
	"vision-tool/internal/middleware"
	"vision-tool/internal/model"
	"vision-tool/internal/repository"
	"vision-tool/internal/service"
)

// Setup 构建路由，并完成分层依赖注入：
// db → repository → service → handler → router。
// webFS 为 //go:embed web 的嵌入文件系统，用于内嵌前端。
func Setup(cfg *config.Config, db *gorm.DB, webFS fs.FS) *gin.Engine {
	r := gin.New()
	r.Use(gin.Logger(), gin.Recovery(), middleware.CORS())

	// ---------- 分层依赖注入 ----------
	userRepo := repository.NewUserRepository(db)
	authSvc := service.NewAuthService(userRepo, cfg.JWT.Secret, time.Duration(cfg.JWT.ExpireHours)*time.Hour)
	visionSvc := service.NewVisionService(&cfg.AI)
	authH := handler.NewAuthHandler(authSvc)
	visionH := handler.NewVisionHandler(visionSvc, cfg.Upload)

	// 识别接口免鉴权，用令牌桶限流防刷
	analyzeLimiter := middleware.NewRateLimiter(10, 20)

	// ---------- API 路由 ----------
	api := r.Group("/api")
	api.GET("/health", func(c *gin.Context) {
		c.JSON(http.StatusOK, model.OK(gin.H{"status": "ok"}))
	})

	v1 := api.Group("/v1")
	{
		// 管理员初始化（方式 A：check + init）
		v1.GET("/admin/check", authH.Check)
		v1.POST("/admin/init", authH.Init)

		// 认证
		v1.POST("/auth/login", authH.Login)
		v1.GET("/user/profile", middleware.JWTAuth(cfg.JWT.Secret), authH.Profile)

		// 在线图片识别（免鉴权 + 限流）
		v1.POST("/vision/analyze", analyzeLimiter.Middleware(), visionH.Analyze)
	}

	// ---------- 静态资源 ----------
	// 上传图片
	r.StaticFS("/uploads", http.Dir(cfg.Upload.Path))

	// 内嵌前端：未匹配路由统一走 NoRoute
	//  /api/*  /uploads/* → 404；embed 内文件 → 直接返回；其余 → index.html（SPA 回退）
	assets, err := fs.Sub(webFS, "web")
	if err != nil {
		panic("web 目录嵌入失败: " + err.Error())
	}
	r.NoRoute(func(c *gin.Context) {
		path := c.Request.URL.Path
		if strings.HasPrefix(path, "/api/") || strings.HasPrefix(path, "/uploads/") {
			c.JSON(http.StatusNotFound, model.Err(model.CodeNotFound, "接口不存在"))
			return
		}
		if data, err := fs.ReadFile(assets, strings.TrimPrefix(path, "/")); err == nil {
			c.Data(http.StatusOK, mimeByExt(path), data)
			return
		}
		index, _ := fs.ReadFile(assets, "index.html")
		c.Data(http.StatusOK, "text/html; charset=utf-8", index)
	})

	return r
}

// mimeByExt 按扩展名返回静态资源 Content-Type。
func mimeByExt(path string) string {
	switch filepath.Ext(path) {
	case ".css":
		return "text/css; charset=utf-8"
	case ".js":
		return "application/javascript; charset=utf-8"
	case ".svg":
		return "image/svg+xml"
	case ".png":
		return "image/png"
	case ".jpg", ".jpeg":
		return "image/jpeg"
	default:
		return "text/html; charset=utf-8"
	}
}