package services

import (
	"errors"
	"fmt"
	"math/rand"
	"strings"
	"sync"
	"time"

	"server/models"
	"server/pkg/passwordutil"
)

// resetCodeItem 存储找回密码的验证码
type resetCodeItem struct {
	Code      string
	Channel   string
	ExpiredAt time.Time
}

var resetCodeStore sync.Map

// resetCodeKey 生成密码重置验证码的存储key
func resetCodeKey(tenantName, account, phone, channel string) string {
	key := strings.ToLower(strings.TrimSpace(tenantName)) + "|" +
		strings.ToLower(strings.TrimSpace(account)) + "|" +
		strings.ToLower(strings.TrimSpace(phone)) + "|" +
		strings.TrimSpace(channel)
	return key
}

// VerifyTenantAccount 第一步：验证租户和账号是否存在
// 返回该账号关联的手机号和邮箱（用于第二步选择验证方式）
func VerifyTenantAccount(tenantName, account string) (phone, email string, err error) {
	tenantName = strings.TrimSpace(tenantName)
	account = strings.TrimSpace(account)

	if tenantName == "" || account == "" {
		return "", "", errors.New("租户名称和账号不能为空")
	}

	// 验证租户是否存在
	var tenant models.SystemTenant
	if err := models.Orm.QueryTable(new(models.SystemTenant)).
		Filter("tenant_name", tenantName).
		One(&tenant); err != nil {
		return "", "", errors.New("租户不存在")
	}
	if tenant.Status != 1 {
		return "", "", errors.New("租户已停用")
	}

	// 验证该租户下的账号是否存在
	var tenantUser models.SystemTenantUser
	if err := models.Orm.QueryTable(new(models.SystemTenantUser)).
		Filter("tid", tenant.ID).
		Filter("account", account).
		One(&tenantUser); err != nil {
		return "", "", errors.New("账号不存在")
	}
	if tenantUser.Status == 0 {
		return "", "", errors.New("账号已禁用")
	}

	// 返回该账号的手机号和邮箱
	phoneStr := ""
	if tenantUser.Phone != nil {
		phoneStr = strings.TrimSpace(*tenantUser.Phone)
	}
	emailStr := ""
	if tenantUser.Email != nil {
		emailStr = strings.TrimSpace(*tenantUser.Email)
	}

	if phoneStr == "" && emailStr == "" {
		return "", "", errors.New("账号未绑定手机号或邮箱，无法重置密码")
	}

	return phoneStr, emailStr, nil
}

// SendResetCode 第二步：验证手机号并发送验证码
func SendResetCode(tenantName, account, phone, channel string) error {
	tenantName = strings.TrimSpace(tenantName)
	account = strings.TrimSpace(account)
	phone = strings.TrimSpace(phone)
	channel = strings.TrimSpace(channel)

	if tenantName == "" || account == "" || phone == "" {
		return errors.New("租户名称、账号和手机号不能为空")
	}
	if channel != "sms" && channel != "email" {
		return errors.New("仅支持短信或邮箱验证码")
	}

	// 验证租户是否存在
	var tenant models.SystemTenant
	if err := models.Orm.QueryTable(new(models.SystemTenant)).
		Filter("tenant_name", tenantName).
		One(&tenant); err != nil {
		return errors.New("租户不存在")
	}

	// 验证该租户下的账号和手机号是否匹配
	var tenantUser models.SystemTenantUser
	if err := models.Orm.QueryTable(new(models.SystemTenantUser)).
		Filter("tid", tenant.ID).
		Filter("account", account).
		One(&tenantUser); err != nil {
		return errors.New("账号不存在")
	}
	if tenantUser.Status == 0 {
		return errors.New("账号已禁用")
	}

	// 根据验证渠道验证用户信息
	if channel == "sms" {
		if tenantUser.Phone == nil || strings.TrimSpace(*tenantUser.Phone) != phone {
			return errors.New("手机号不匹配，请确认您输入的手机号正确")
		}
	} else if channel == "email" {
		if tenantUser.Email == nil || strings.TrimSpace(*tenantUser.Email) != phone {
			return errors.New("邮箱不匹配，请确认您输入的邮箱正确")
		}
	}

	// 生成验证码
	rand.Seed(time.Now().UnixNano())
	code := fmt.Sprintf("%06d", rand.Intn(1000000))

	// 发送验证码
	if channel == "sms" {
		content := "密码重置验证码：" + code
		if err := enqueueSMSTaskForPasswordReset(tenant.ID, phone, content, code); err != nil {
			return errors.New("短信发送失败，请重试")
		}
	}
	// TODO: 实现邮箱验证码发送逻辑

	// 存储验证码（5分钟有效期）
	resetCodeStore.Store(resetCodeKey(tenantName, account, phone, channel), resetCodeItem{
		Code:      code,
		Channel:   channel,
		ExpiredAt: time.Now().Add(5 * time.Minute),
	})

	return nil
}

// VerifyResetCode 验证重置密码的验证码
func VerifyResetCode(tenantName, account, phone, channel, code string) error {
	tenantName = strings.TrimSpace(tenantName)
	account = strings.TrimSpace(account)
	phone = strings.TrimSpace(phone)
	channel = strings.TrimSpace(channel)
	code = strings.TrimSpace(code)

	if code == "" {
		return errors.New("验证码不能为空")
	}

	key := resetCodeKey(tenantName, account, phone, channel)
	val, ok := resetCodeStore.Load(key)
	if !ok {
		return errors.New("验证码不存在或已失效")
	}

	item, ok := val.(resetCodeItem)
	if !ok {
		return errors.New("验证码状态异常")
	}

	if time.Now().After(item.ExpiredAt) {
		resetCodeStore.Delete(key)
		return errors.New("验证码已过期")
	}

	if item.Code != code {
		return errors.New("验证码错误")
	}

	// 验证通过后删除验证码
	resetCodeStore.Delete(key)
	return nil
}

// ResetPassword 第三步：重置密码
func ResetPassword(tenantName, account, phone, smsCode, newPassword, confirmPassword string) error {
	tenantName = strings.TrimSpace(tenantName)
	account = strings.TrimSpace(account)
	phone = strings.TrimSpace(phone)
	smsCode = strings.TrimSpace(smsCode)
	newPassword = strings.TrimSpace(newPassword)
	confirmPassword = strings.TrimSpace(confirmPassword)

	if tenantName == "" || account == "" || phone == "" {
		return errors.New("租户名称、账号和手机号不能为空")
	}
	if newPassword == "" {
		return errors.New("新密码不能为空")
	}
	if newPassword != confirmPassword {
		return errors.New("两次密码不一致")
	}
	if len(newPassword) < 6 {
		return errors.New("密码长度不能少于6个字符")
	}

	// 验证验证码（验证码验证后会被删除）
	if err := VerifyResetCode(tenantName, account, phone, "sms", smsCode); err != nil {
		return err
	}

	// 验证租户
	var tenant models.SystemTenant
	if err := models.Orm.QueryTable(new(models.SystemTenant)).
		Filter("tenant_name", tenantName).
		One(&tenant); err != nil {
		return errors.New("租户不存在")
	}

	// 查询用户
	var tenantUser models.SystemTenantUser
	if err := models.Orm.QueryTable(new(models.SystemTenantUser)).
		Filter("tid", tenant.ID).
		Filter("account", account).
		One(&tenantUser); err != nil {
		return errors.New("账号不存在")
	}

	// 验证手机号
	if tenantUser.Phone == nil || strings.TrimSpace(*tenantUser.Phone) != phone {
		return errors.New("手机号不匹配")
	}

	// 哈希新密码
	hashedPassword, err := passwordutil.Hash(newPassword)
	if err != nil {
		return errors.New("密码处理失败")
	}

	// 更新密码
	_, err = models.Orm.QueryTable(new(models.SystemTenantUser)).
		Filter("id", tenantUser.ID).
		Update(map[string]interface{}{
			"password": hashedPassword,
		})
	if err != nil {
		return errors.New("密码更新失败")
	}

	return nil
}

// enqueueSMSTaskForPasswordReset 发送密码重置短信任务
func enqueueSMSTaskForPasswordReset(tid uint64, phone, content, code string) error {
	// 重用已有的短信发送逻辑
	return enqueueSMSTaskForLogin(tid, phone, content, code)
}