package system

import (
	"errors"
	"time"

	"git.echol.cn/loser/ai_proxy/server/global"
	"git.echol.cn/loser/ai_proxy/server/model/system"
	"git.echol.cn/loser/ai_proxy/server/model/system/request"
	"git.echol.cn/loser/ai_proxy/server/model/system/response"
	"git.echol.cn/loser/ai_proxy/server/utils"
	"github.com/golang-jwt/jwt/v5"
	"golang.org/x/crypto/bcrypt"
)

type UserService struct{}

// Login 用户登录
func (s *UserService) Login(req *request.LoginRequest) (resp response.LoginResponse, err error) {
	var user system.SysUser
	err = global.GVA_DB.Where("username = ?", req.Username).First(&user).Error
	if err != nil {
		return resp, errors.New("用户名或密码错误")
	}

	// 验证密码
	err = bcrypt.CompareHashAndPassword([]byte(user.Password), []byte(req.Password))
	if err != nil {
		return resp, errors.New("用户名或密码错误")
	}

	// 检查用户状态
	if user.Status != "active" {
		return resp, errors.New("用户已被禁用")
	}

	// 生成 JWT Token
	token, err := s.generateToken(user.ID, user.Username, user.Role)
	if err != nil {
		return resp, errors.New("生成Token失败")
	}

	resp.Token = token
	resp.User = response.UserInfo{
		ID:       user.ID,
		Username: user.Username,
		Nickname: user.Nickname,
		Email:    user.Email,
		Phone:    user.Phone,
		Avatar:   user.Avatar,
		Role:     user.Role,
		Status:   user.Status,
	}

	return resp, nil
}

// Register 用户注册
func (s *UserService) Register(req *request.RegisterRequest) (user system.SysUser, err error) {
	// 检查用户名是否存在
	var count int64
	global.GVA_DB.Model(&system.SysUser{}).Where("username = ?", req.Username).Count(&count)
	if count > 0 {
		return user, errors.New("用户名已存在")
	}

	// 加密密码
	hashedPassword, err := bcrypt.GenerateFromPassword([]byte(req.Password), bcrypt.DefaultCost)
	if err != nil {
		return user, errors.New("密码加密失败")
	}

	// 生成 API Key
	apiKey, err := utils.GenerateRandomString(32)
	if err != nil {
		return user, errors.New("生成API Key失败")
	}
	apiKey = "ak-" + apiKey

	user = system.SysUser{
		Username: req.Username,
		Password: string(hashedPassword),
		Email:    req.Email,
		Role:     "user",
		Status:   "active",
		APIKey:   apiKey,
	}

	err = global.GVA_DB.Create(&user).Error
	return user, err
}

// GetUserInfo 获取用户信息
func (s *UserService) GetUserInfo(userID uint) (info response.UserInfo, err error) {
	var user system.SysUser
	err = global.GVA_DB.First(&user, userID).Error
	if err != nil {
		return info, errors.New("用户不存在")
	}

	info = response.UserInfo{
		ID:       user.ID,
		Username: user.Username,
		Nickname: user.Nickname,
		Email:    user.Email,
		Phone:    user.Phone,
		Avatar:   user.Avatar,
		Role:     user.Role,
		Status:   user.Status,
	}

	return info, nil
}

// GetUserList 获取用户列表
func (s *UserService) GetUserList(page, pageSize int) (list []response.UserInfo, total int64, err error) {
	var users []system.SysUser
	offset := (page - 1) * pageSize

	db := global.GVA_DB.Model(&system.SysUser{})
	err = db.Count(&total).Error
	if err != nil {
		return
	}

	err = db.Limit(pageSize).Offset(offset).Order("created_at DESC").Find(&users).Error
	if err != nil {
		return
	}

	for _, user := range users {
		list = append(list, response.UserInfo{
			ID:       user.ID,
			Username: user.Username,
			Nickname: user.Nickname,
			Email:    user.Email,
			Phone:    user.Phone,
			Avatar:   user.Avatar,
			Role:     user.Role,
			Status:   user.Status,
		})
	}

	return list, total, nil
}

// UpdateUser 更新用户
func (s *UserService) UpdateUser(req *request.UpdateUserRequest) error {
	updates := map[string]interface{}{}

	if req.Nickname != "" {
		updates["nickname"] = req.Nickname
	}
	if req.Email != "" {
		updates["email"] = req.Email
	}
	if req.Phone != "" {
		updates["phone"] = req.Phone
	}
	if req.Avatar != "" {
		updates["avatar"] = req.Avatar
	}
	if req.Role != "" {
		updates["role"] = req.Role
	}
	if req.Status != "" {
		updates["status"] = req.Status
	}

	return global.GVA_DB.Model(&system.SysUser{}).Where("id = ?", req.ID).Updates(updates).Error
}

// DeleteUser 删除用户
func (s *UserService) DeleteUser(userID uint) error {
	return global.GVA_DB.Delete(&system.SysUser{}, userID).Error
}

// GetAPIKey 获取用户的 API Key
func (s *UserService) GetAPIKey(userID uint) (string, error) {
	var user system.SysUser
	err := global.GVA_DB.Select("api_key").First(&user, userID).Error
	return user.APIKey, err
}

// RegenerateAPIKey 重新生成 API Key
func (s *UserService) RegenerateAPIKey(userID uint) (string, error) {
	randomStr, err := utils.GenerateRandomString(32)
	if err != nil {
		return "", errors.New("生成API Key失败")
	}
	apiKey := "ak-" + randomStr
	err = global.GVA_DB.Model(&system.SysUser{}).Where("id = ?", userID).Update("api_key", apiKey).Error
	return apiKey, err
}

// generateToken 生成 JWT Token
func (s *UserService) generateToken(userID uint, username, role string) (string, error) {
	claims := jwt.MapClaims{
		"user_id":  userID,
		"username": username,
		"role":     role,
		"exp":      time.Now().Add(24 * time.Hour).Unix(),
	}

	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
	return token.SignedString([]byte(global.GVA_CONFIG.JWT.SigningKey))
}