package handler

import (
	"net/http"

	"github.com/gin-gonic/gin"
	"note-manager/middleware"
	"note-manager/service"
)

// AuthHandler 认证处理器（多租户账号：注册/登录/登出/当前用户）
type AuthHandler struct {
	userSvc *service.UserService
}

// NewAuthHandler 创建认证处理器
func NewAuthHandler(userSvc *service.UserService) *AuthHandler {
	return &AuthHandler{userSvc: userSvc}
}

// REGISTER 注册请求
type registerReq struct {
	Username    string `json:"username"`
	Password    string `json:"password"`
	DisplayName string `json:"display_name"`
}

// Register 注册新用户
// 首个注册用户自动成为 admin，并接管历史遗留笔记。
func (h *AuthHandler) Register(c *gin.Context) {
	var req registerReq
	if err := c.ShouldBindJSON(&req); err != nil {
		fail(c, http.StatusBadRequest, "请求参数错误")
		return
	}
	u, err := h.userSvc.Register(req.Username, req.Password, req.DisplayName)
	if err != nil {
		fail(c, http.StatusBadRequest, err.Error())
		return
	}
	// 注册成功即自动登录
	token, _ := middleware.NewSession(u.ID)
	secure := c.Request.TLS != nil
	middleware.SetAuthCookie(c, token, secure)
	success(c, gin.H{"id": u.ID, "username": u.Username, "display_name": u.DisplayName, "role": u.Role})
}

// Login 登录（用户名 + 密码）
func (h *AuthHandler) Login(c *gin.Context) {
	var req struct {
		Username string `json:"username"`
		Password string `json:"password"`
	}
	// 兼容 form 提交（后台登录页）
	if err := c.ShouldBindJSON(&req); err != nil {
		req.Username = c.PostForm("username")
		req.Password = c.PostForm("password")
	}
	if req.Password == "" || req.Username == "" {
		fail(c, http.StatusBadRequest, "请输入用户名和密码")
		return
	}
	u, err := h.userSvc.Login(req.Username, req.Password)
	if err != nil {
		fail(c, http.StatusUnauthorized, err.Error())
		return
	}
	token, _ := middleware.NewSession(u.ID)
	secure := c.Request.TLS != nil
	middleware.SetAuthCookie(c, token, secure)
	success(c, gin.H{"id": u.ID, "username": u.Username, "display_name": u.DisplayName, "role": u.Role})
}

// Logout 登出
func (h *AuthHandler) Logout(c *gin.Context) {
	middleware.RevokeSession(middleware.GetAuthToken(c))
	middleware.ClearAuthCookie(c)
	success(c, nil)
}

// Me 返回当前登录用户信息（未登录返回 null）
func (h *AuthHandler) Me(c *gin.Context) {
	uid := middleware.GetUserID(c)
	if uid == 0 {
		success(c, gin.H{
			"registration_enabled": h.userSvc.RegistrationEnabled(),
		})
		return
	}
	u, err := h.userSvc.GetByID(uid)
	if err != nil {
		success(c, nil)
		return
	}
	success(c, gin.H{
		"id":                  u.ID,
		"username":            u.Username,
		"display_name":        u.DisplayName,
		"role":                u.Role,
		"registration_enabled": h.userSvc.RegistrationEnabled(),
	})
}

// GetRegistrationStatus 获取注册开关状态（管理员）
func (h *AuthHandler) GetRegistrationStatus(c *gin.Context) {
	if !h.userSvc.IsAdmin(middleware.GetUserID(c)) {
		fail(c, http.StatusForbidden, "仅管理员可操作")
		return
	}
	success(c, gin.H{"registration_enabled": h.userSvc.RegistrationEnabled()})
}

// SetRegistration 切换注册开关（管理员）
func (h *AuthHandler) SetRegistration(c *gin.Context) {
	if !h.userSvc.IsAdmin(middleware.GetUserID(c)) {
		fail(c, http.StatusForbidden, "仅管理员可操作")
		return
	}
	var req struct {
		Enabled bool `json:"enabled"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		fail(c, http.StatusBadRequest, "请求参数错误")
		return
	}
	if err := h.userSvc.SetRegistrationEnabled(req.Enabled); err != nil {
		fail(c, http.StatusInternalServerError, err.Error())
		return
	}
	success(c, gin.H{"registration_enabled": req.Enabled})
}