package models

import (
	"time"
)

// CardKey 卡密表
type CardKey struct {
	ID           int       `json:"id"`
	Key          string    `json:"key"` // 格式: XXXX-XXXX-XXXX-XXXX
	MaxUses      int       `json:"max_uses"`
	UsedCount    int       `json:"used_count"`
	ValidityType string    `json:"validity_type"` // month/quarter/year/custom
	ExpiresAt    time.Time `json:"expires_at"`
	IsActive     bool      `json:"is_active"`
	CreatedByID  int       `json:"created_by_id"`
	CreatedAt    time.Time `json:"created_at"`
}

// TableName 返回表名
func (CardKey) TableName() string {
	return "card_keys"
}

// IsExpired 检查卡密是否过期
func (c *CardKey) IsExpired() bool {
	return time.Now().After(c.ExpiresAt)
}

// IsUsable 检查卡密是否可用
func (c *CardKey) IsUsable() bool {
	return c.IsActive && !c.IsExpired() && c.UsedCount < c.MaxUses
}

// RemainingUses 返回剩余使用次数
func (c *CardKey) RemainingUses() int {
	remaining := c.MaxUses - c.UsedCount
	if remaining < 0 {
		return 0
	}
	return remaining
}