package middleware

import (
	"fmt"
	"net/http"

	"gofaster/internal/auth/model"
	"gofaster/internal/auth/repository"

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

// PermissionMiddleware 权限中间件
func PermissionMiddleware(db *gorm.DB, jwtSecret string) gin.HandlerFunc {
	return func(c *gin.Context) {
		// 获取用户信息
		userID := GetUserID(c)
		if userID == 0 {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "用户未认证"})
			c.Abort()
			return
		}

		// 获取当前请求的路由信息
		path := c.Request.URL.Path
		method := c.Request.Method

		// 检查路由映射
		routeMappingRepo := repository.NewRouteMappingRepository(db)
		routeMapping, err := routeMappingRepo.FindByBackendRoute(path, method)
		if err != nil {
			// 如果找不到路由映射，允许通过（可能是公开接口）
			c.Next()
			return
		}

		// 检查用户是否有权限访问该路由
		if err := checkUserPermission(db, userID, routeMapping); err != nil {
			c.JSON(http.StatusForbidden, gin.H{"error": fmt.Sprintf("权限不足: %s", err.Error())})
			c.Abort()
			return
		}

		c.Next()
	}
}

// checkUserPermission 检查用户权限
func checkUserPermission(db *gorm.DB, userID uint, routeMapping *model.RouteMapping) error {
	// 这里实现三级权限检查逻辑
	// 1. 菜单级别权限
	// 2. 权限组级别权限
	// 3. 路由级别权限

	// 暂时返回nil，允许所有已认证用户访问
	// TODO: 实现完整的权限检查逻辑
	return nil
}

// OptionalPermissionMiddleware 可选的权限中间件（不强制要求权限）
func OptionalPermissionMiddleware(db *gorm.DB, jwtSecret string) gin.HandlerFunc {
	return func(c *gin.Context) {
		// 获取用户信息
		userID := GetUserID(c)
		if userID == 0 {
			// 没有用户信息，继续处理请求
			c.Next()
			return
		}

		// 获取当前请求的路由信息
		path := c.Request.URL.Path
		method := c.Request.Method

		// 检查路由映射
		routeMappingRepo := repository.NewRouteMappingRepository(db)
		routeMapping, err := routeMappingRepo.FindByBackendRoute(path, method)
		if err != nil {
			// 如果找不到路由映射，继续处理请求
			c.Next()
			return
		}

		// 检查用户是否有权限访问该路由
		if err := checkUserPermission(db, userID, routeMapping); err != nil {
			// 权限不足，但因为是可选权限，所以继续处理请求
			c.Set("permission_warning", fmt.Sprintf("权限不足: %s", err.Error()))
		}

		c.Next()
	}
}

// GetRouteAuthGroup 获取路由的权限分组
func GetRouteAuthGroup(c *gin.Context, db *gorm.DB) string {
	path := c.Request.URL.Path
	method := c.Request.Method

	routeMappingRepo := repository.NewRouteMappingRepository(db)
	routeMapping, err := routeMappingRepo.FindByBackendRoute(path, method)
	if err != nil {
		return "Unknown"
	}

	return routeMapping.AuthGroup
}

// HasPermission 检查用户是否有指定权限
func HasPermission(c *gin.Context, db *gorm.DB, requiredAuthGroup string) bool {
	userID := GetUserID(c)
	if userID == 0 {
		return false
	}

	// 获取当前路由的权限分组
	currentAuthGroup := GetRouteAuthGroup(c, db)

	// 简单的权限检查逻辑
	// Read权限可以访问Read和Edit
	// Edit权限只能访问Edit
	if requiredAuthGroup == "Read" {
		return currentAuthGroup == "Read" || currentAuthGroup == "Edit"
	} else if requiredAuthGroup == "Edit" {
		return currentAuthGroup == "Edit"
	}

	return false
}