package handlers

import (
	"log/slog"
	"net/http"
	"time"

	"goblog/database"
	"goblog/models"

	"github.com/gin-gonic/gin"
	"github.com/golang-jwt/jwt/v5"
)

var jwtSecret = []byte("your-secret-key-change-in-production")

func JWTSecret() []byte {
	return jwtSecret
}

// AdminMenuItem 后台菜单项
type AdminMenuItem struct {
	Key  string `json:"key"`  // 页面标识，与页面 div 的 data-page 对应
	Name string `json:"name"` // 菜单显示名称
}

// AdminMenuGroup 后台菜单分组（Group 为空表示顶级菜单）
type AdminMenuGroup struct {
	Group string          `json:"group"`
	Items []AdminMenuItem `json:"items"`
}

// GetMenusByRole 根据角色返回后台菜单
func GetMenusByRole(role string) []AdminMenuGroup {
	if role == "admin" {
		return []AdminMenuGroup{
			{Group: "", Items: []AdminMenuItem{
				{Key: "dashboard", Name: "仪表盘"},
			}},
			{Group: "内容管理", Items: []AdminMenuItem{
				{Key: "posts", Name: "文章管理"},
				{Key: "categories", Name: "分类管理"},
				{Key: "tags", Name: "标签管理"},
				{Key: "pages", Name: "页面管理"},
				{Key: "comments", Name: "评论管理"},
			}},
			{Group: "系统管理", Items: []AdminMenuItem{
				{Key: "users", Name: "用户管理"},
				{Key: "files", Name: "文件管理"},
				{Key: "themes", Name: "主题管理"},
				{Key: "settings", Name: "基础设置"},
			}},
		}
	}
	// 普通用户：仪表盘 + 文章管理 + 评论管理
	return []AdminMenuGroup{
		{Group: "", Items: []AdminMenuItem{
			{Key: "dashboard", Name: "仪表盘"},
			{Key: "posts", Name: "文章管理"},
			{Key: "comments", Name: "评论管理"},
		}},
	}
}

// 登录请求
type LoginRequest struct {
	Username string `json:"username" binding:"required"`
	Password string `json:"password" binding:"required"`
}

// 注册请求
type RegisterRequest struct {
	Username string `json:"username" binding:"required,min=3,max=50"`
	Password string `json:"password" binding:"required,min=6"`
	Nickname string `json:"nickname"`
	Email    string `json:"email" binding:"required,email"`
}

// JWT Claims
type Claims struct {
	UserID   uint   `json:"user_id"`
	Username string `json:"username"`
	Role     string `json:"role"`
	jwt.RegisteredClaims
}

// 登录
func Login(c *gin.Context) {
	var req LoginRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var user models.User
	if err := database.DB.Where("username = ?", req.Username).First(&user).Error; err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "用户名或密码错误"})
		return
	}

	if user.Status == 0 || !user.IsActive {
		c.JSON(http.StatusForbidden, gin.H{"error": "账号已被禁用"})
		return
	}

	// 使用 User 模型的 CheckPassword 方法
	if !user.CheckPassword(req.Password) {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "用户名或密码错误"})
		return
	}

	// 记录登录信息
	if err := user.RecordLogin(database.DB); err != nil {
		slog.Warn("记录登录信息失败", "user_id", user.ID, "error", err)
	}

	// 生成 JWT
	claims := Claims{
		UserID:   user.ID,
		Username: user.Username,
		Role:     user.Role,
		RegisteredClaims: jwt.RegisteredClaims{
			ExpiresAt: jwt.NewNumericDate(time.Now().Add(7 * 24 * time.Hour)),
			IssuedAt:  jwt.NewNumericDate(time.Now()),
		},
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	tokenString, err := token.SignedString(jwtSecret)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "生成令牌失败"})
		return
	}

	// 同时写入 Cookie，供服务端渲染后台页面时识别登录态
	c.SetCookie("token", tokenString, 7*24*3600, "/", "", false, true)

	c.JSON(http.StatusOK, gin.H{
		"token": tokenString,
		"user": gin.H{
			"id":            user.ID,
			"username":      user.Username,
			"nickname":      user.Nickname,
			"email":         user.Email,
			"role":          user.Role,
			"avatar":        user.Avatar,
			"last_login_at": user.LastLoginAt,
			"login_count":   user.LoginCount,
		},
		// 菜单由登录接口根据角色返回
		"menus": GetMenusByRole(user.Role),
	})
}

// 退出登录（清除服务端 Cookie）
func Logout(c *gin.Context) {
	c.SetCookie("token", "", -1, "/", "", false, true)
	c.JSON(http.StatusOK, gin.H{"message": "已退出登录"})
}

// WebLogout 前台页面退出登录（清除 Cookie 后回首页）
func WebLogout(c *gin.Context) {
	c.SetCookie("token", "", -1, "/", "", false, true)
	c.Redirect(http.StatusFound, "/")
}

// 获取当前用户信息
func GetCurrentUser(c *gin.Context) {
	userID, _ := c.Get("userID")

	var user models.User
	if err := database.DB.First(&user, userID).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "用户不存在"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"data": user})
}

// 更新用户信息
func UpdateUser(c *gin.Context) {
	userID, _ := c.Get("userID")

	var user models.User
	if err := database.DB.First(&user, userID).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "用户不存在"})
		return
	}

	var req struct {
		Nickname string `json:"nickname"`
		Email    string `json:"email"`
		Avatar   string `json:"avatar"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	updates := map[string]interface{}{}
	if req.Nickname != "" {
		updates["nickname"] = req.Nickname
	}
	if req.Email != "" {
		updates["email"] = req.Email
	}
	if req.Avatar != "" {
		updates["avatar"] = req.Avatar
	}

	if err := database.DB.Model(&user).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "更新失败"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"data": user})
}

// 修改密码
func ChangePassword(c *gin.Context) {
	userID, _ := c.Get("userID")

	var user models.User
	if err := database.DB.First(&user, userID).Error; err != nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "用户不存在"})
		return
	}

	var req struct {
		OldPassword string `json:"old_password" binding:"required"`
		NewPassword string `json:"new_password" binding:"required,min=6"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	// 使用 User 模型的 CheckPassword 方法
	if !user.CheckPassword(req.OldPassword) {
		c.JSON(http.StatusBadRequest, gin.H{"error": "原密码错误"})
		return
	}

	// 使用 User 模型的 SetPassword 方法
	if err := user.SetPassword(req.NewPassword); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "密码加密失败"})
		return
	}

	if err := database.DB.Save(&user).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "修改密码失败"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "密码修改成功"})
}