package handler

import (
	"errors"
	"net/http"

	"github.com/gin-gonic/gin"

	"vision-tool/internal/model"
	"vision-tool/internal/service"
)

// AuthHandler HTTP 处理器：管理员初始化 / 登录 / 用户信息。
type AuthHandler struct {
	svc *service.AuthService
}

func NewAuthHandler(svc *service.AuthService) *AuthHandler {
	return &AuthHandler{svc: svc}
}

type initRequest struct {
	Username string `json:"username" binding:"required,min=2,max=32"`
	Password string `json:"password" binding:"required,min=6,max=64"`
}

type loginRequest struct {
	Username string `json:"username" binding:"required"`
	Password string `json:"password" binding:"required"`
}

// Check  GET /api/v1/admin/check — 管理员是否已初始化
func (h *AuthHandler) Check(c *gin.Context) {
	initialized, err := h.svc.CheckAdmin()
	if err != nil {
		c.JSON(http.StatusInternalServerError, model.Err(model.CodeServerErr, err.Error()))
		return
	}
	c.JSON(http.StatusOK, model.OK(gin.H{"initialized": initialized}))
}

// Init  POST /api/v1/admin/init — 初始化管理员（仅首次）
func (h *AuthHandler) Init(c *gin.Context) {
	var req initRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Err(model.CodeBadParam, "用户名 2-32 位，密码至少 6 位"))
		return
	}
	if err := h.svc.InitAdmin(req.Username, req.Password); err != nil {
		if errors.Is(err, service.ErrAdminExists) {
			c.JSON(http.StatusConflict, model.Err(model.CodeConflict, err.Error()))
			return
		}
		c.JSON(http.StatusInternalServerError, model.Err(model.CodeServerErr, err.Error()))
		return
	}
	c.JSON(http.StatusOK, model.OK(gin.H{"message": "管理员初始化成功"}))
}

// Login  POST /api/v1/auth/login — 登录获取 JWT token
func (h *AuthHandler) Login(c *gin.Context) {
	var req loginRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, model.Err(model.CodeBadParam, "请输入用户名和密码"))
		return
	}
	token, err := h.svc.Login(req.Username, req.Password)
	if err != nil {
		if errors.Is(err, service.ErrInvalidCredentials) {
			c.JSON(http.StatusUnauthorized, model.Err(model.CodeUnauthorized, err.Error()))
			return
		}
		c.JSON(http.StatusInternalServerError, model.Err(model.CodeServerErr, err.Error()))
		return
	}
	c.JSON(http.StatusOK, model.OK(gin.H{"token": token}))
}

// Profile  GET /api/v1/user/profile — 当前用户信息（JWT 保护）
func (h *AuthHandler) Profile(c *gin.Context) {
	userID := c.GetUint("user_id")
	user, err := h.svc.Profile(userID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, model.Err(model.CodeServerErr, err.Error()))
		return
	}
	c.JSON(http.StatusOK, model.OK(user))
}