package handler

import (
	"net/http"
	"strings"
	"time"

	"github.com/gin-gonic/gin"

	"github.com/yourname/cyrene-ai/gateway/internal/config"
)

// AuthHandler 认证处理器
type AuthHandler struct {
	cfg *config.Config
}

// NewAuthHandler 创建认证处理器
func NewAuthHandler(cfg *config.Config) *AuthHandler {
	return &AuthHandler{cfg: cfg}
}

// Register 用户注册 (需要邮箱验证码)
func (h *AuthHandler) Register(c *gin.Context) {
	// 检查注册开关
	if !h.cfg.RegistrationEnabled {
		c.JSON(http.StatusForbidden, gin.H{"error": "当前不开放公开注册，请使用管理员账户登录"})
		return
	}

	var req struct {
		Username string `json:"username" binding:"required,min=2,max=32"`
		Password string `json:"password" binding:"required,min=6,max=64"`
		Email    string `json:"email" binding:"required,email"`
		// MVP阶段：验证码仅做格式校验，后续接入邮件服务
		VerifyCode string `json:"verify_code" binding:"required,len=6"`
	}

	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效: " + err.Error()})
		return
	}

	// MVP阶段：验证码简单校验 (开发环境接受 "000000")
	if req.VerifyCode != "000000" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "验证码错误 (开发阶段请使用 000000)"})
		return
	}

	// 邮箱域名简单校验
	if !strings.Contains(req.Email, "@") || !strings.Contains(req.Email, ".") {
		c.JSON(http.StatusBadRequest, gin.H{"error": "邮箱格式无效"})
		return
	}

	// MVP阶段：使用username直接作为userID
	// 后续需要接入用户服务进行真实注册
	userID := "user_" + req.Username

	// 生成JWT
	token, err := h.cfg.GenerateToken(userID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "生成令牌失败"})
		return
	}

	c.JSON(http.StatusCreated, gin.H{
		"user_id": userID,
		"token":   token,
		"expires": time.Now().Add(h.cfg.JWTExpiryHours).Unix(),
	})
}

// Login 用户登录 (支持管理员账户)
func (h *AuthHandler) Login(c *gin.Context) {
	var req struct {
		Username string `json:"username" binding:"required"`
		Password string `json:"password" binding:"required"`
	}

	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效"})
		return
	}

	var userID string

	// 管理员账户验证
	if req.Username == h.cfg.AdminUsername {
		// 管理员必须提供正确的密码
		if req.Password != h.cfg.AdminPassword {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "管理员密码错误"})
			return
		}
		userID = "admin_" + req.Username
	} else {
		// MVP阶段：普通用户登录 (简化逻辑，后续需要验证密码哈希)
		userID = "user_" + req.Username
	}

	token, err := h.cfg.GenerateToken(userID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "生成令牌失败"})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"user_id": userID,
		"token":   token,
		"expires": time.Now().Add(h.cfg.JWTExpiryHours).Unix(),
	})
}

// RefreshToken 刷新令牌
func (h *AuthHandler) RefreshToken(c *gin.Context) {
	authHeader := c.GetHeader("Authorization")
	if authHeader == "" || len(authHeader) < 8 {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "未提供认证令牌"})
		return
	}

	tokenString := authHeader[7:] // 去掉 "Bearer "
	userID, err := h.cfg.ValidateToken(tokenString)
	if err != nil {
		c.JSON(http.StatusUnauthorized, gin.H{"error": "令牌无效或已过期"})
		return
	}

	newToken, err := h.cfg.GenerateToken(userID)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "刷新令牌失败"})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"token":   newToken,
		"expires": time.Now().Add(h.cfg.JWTExpiryHours).Unix(),
	})
}