package auth

import (
	"errors"
	"net/http"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
	"senlinai-agent/backend/internal/models"
)

type Handler struct {
	service *Service
}

func NewHandler(service *Service) *Handler {
	return &Handler{service: service}
}

func (h *Handler) Register(router gin.IRouter) {
	router.POST("/auth/login", h.login)
	router.GET("/auth/me", h.me)
	router.PATCH("/auth/me", h.updateMe)
}

func (h *Handler) login(c *gin.Context) {
	var input struct {
		Email    string `json:"email"`
		Password string `json:"password"`
	}
	if err := c.ShouldBindJSON(&input); err != nil {
		abortWithError(c, http.StatusBadRequest, "invalid_request", "请求参数无效")
		return
	}
	token, err := h.service.Login(input.Email, input.Password)
	if err != nil {
		abortWithError(c, http.StatusUnauthorized, "invalid_credentials", "邮箱或密码错误")
		return
	}
	userID, err := h.service.VerifySession(token)
	if err != nil {
		abortWithError(c, http.StatusInternalServerError, "internal_error", "登录状态创建失败")
		return
	}
	user, err := h.service.CurrentUser(userID)
	if err != nil {
		abortWithError(c, http.StatusInternalServerError, "internal_error", "用户资料加载失败")
		return
	}
	c.JSON(http.StatusOK, gin.H{"token": token, "user": currentUserDTO(*user)})
}

type CurrentUserDTO struct {
	Email       string `json:"email"`
	DisplayName string `json:"displayName"`
}

func (h *Handler) me(c *gin.Context) {
	userID, ok := CurrentUserID(c)
	if !ok {
		abortWithError(c, http.StatusUnauthorized, "unauthorized", "请先登录后再操作")
		return
	}
	user, err := h.service.CurrentUser(userID)
	if err != nil {
		writeProfileError(c, err)
		return
	}
	c.JSON(http.StatusOK, currentUserDTO(*user))
}

func (h *Handler) updateMe(c *gin.Context) {
	userID, ok := CurrentUserID(c)
	if !ok {
		abortWithError(c, http.StatusUnauthorized, "unauthorized", "请先登录后再操作")
		return
	}
	var input struct {
		DisplayName     string `json:"displayName"`
		CurrentPassword string `json:"currentPassword"`
		NewPassword     string `json:"newPassword"`
	}
	if err := c.ShouldBindJSON(&input); err != nil {
		abortWithError(c, http.StatusBadRequest, "invalid_request", "个人资料参数无效")
		return
	}
	user, err := h.service.UpdateCurrentUser(userID, input.DisplayName, input.CurrentPassword, input.NewPassword)
	if err != nil {
		writeProfileError(c, err)
		return
	}
	c.JSON(http.StatusOK, currentUserDTO(*user))
}

func currentUserDTO(user models.SaUser) CurrentUserDTO {
	return CurrentUserDTO{Email: user.Email, DisplayName: user.DisplayName}
}

func writeProfileError(c *gin.Context, err error) {
	switch {
	case errors.Is(err, gorm.ErrRecordNotFound):
		abortWithError(c, http.StatusNotFound, "not_found", "用户不存在")
	case errors.Is(err, ErrProfileNameRequired), errors.Is(err, ErrPasswordTooShort), errors.Is(err, ErrCurrentPassword):
		abortWithError(c, http.StatusBadRequest, "invalid_request", err.Error())
	default:
		abortWithError(c, http.StatusInternalServerError, "internal_error", "个人资料更新失败")
	}
}