package auth

import (
	"net/http"

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

type Handler struct {
	authService *Service
}

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

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

type RegisterRequest struct {
	Username string `json:"username" binding:"required,min=3,max=50"`
	Password string `json:"password" binding:"required,min=6"`
}

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

	token, err := h.authService.Login(c.Request.Context(), req.Username, req.Password)
	if err != nil {
		switch err {
		case ErrUserNotFound, ErrInvalidCredentials:
			c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid credentials"})
		default:
			c.JSON(http.StatusInternalServerError, gin.H{"error": "login failed"})
		}
		return
	}

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

func (h *Handler) Register(c *gin.Context) {
	var req RegisterRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request", "details": err.Error()})
		return
	}

	user, token, err := h.authService.Register(c.Request.Context(), req.Username, req.Password)
	if err != nil {
		switch err {
		case ErrUserExists:
			c.JSON(http.StatusConflict, gin.H{"error": "user already exists"})
		case ErrPasswordTooShort:
			c.JSON(http.StatusBadRequest, gin.H{"error": "password too short"})
		default:
			c.JSON(http.StatusInternalServerError, gin.H{"error": "registration failed"})
		}
		return
	}

	c.JSON(http.StatusCreated, gin.H{
		"user": gin.H{
			"id":       user.ID,
			"username": user.Username,
		},
		"token": token,
	})
}