package models

import (
	"time"

	"gorm.io/gorm"
)

// Friendship 好友关系表模型
// 存储已确认的好友关系（双向存储：A→B 和 B→A 各存一条记录）
type Friendship struct {
	ID        int64   `gorm:"primaryKey;autoIncrement;column:id"`
	UserID    int64   `gorm:"not null;uniqueIndex:uk_friendships_user_friend_star;index:idx_friendships_user_star_status;index:idx_friendships_user_star_created;index:idx_friendships_list_query;column:user_id"`
	FriendID  int64   `gorm:"not null;uniqueIndex:uk_friendships_user_friend_star;index:idx_friendships_friend_star;index:idx_friendships_list_query;column:friend_id"`
	StarID    int64   `gorm:"not null;uniqueIndex:uk_friendships_user_friend_star;index:idx_friendships_user_star_status;index:idx_friendships_user_star_created;index:idx_friendships_list_query;column:star_id"`
	Status    string  `gorm:"type:varchar(20);not null;default:'accepted';index:idx_friendships_user_star_status;index:idx_friendships_list_query;column:status"` // accepted, blocked
	Remark    *string `gorm:"type:varchar(50);index:idx_friendships_list_query;column:remark"`                                                                    // 备注名（好友昵称）
	Intimacy  int32   `gorm:"default:0;not null;column:intimacy"`                                                                                                 // 亲密度（预留字段）
	CreatedAt int64   `gorm:"not null;index:idx_friendships_user_star_created,sort:desc;index:idx_friendships_list_query;column:created_at"`
	UpdatedAt int64   `gorm:"not null;column:updated_at"`

	// 关联关系
	User   User `gorm:"foreignKey:UserID;references:ID;constraint:OnDelete:CASCADE"`
	Friend User `gorm:"foreignKey:FriendID;references:ID;constraint:OnDelete:CASCADE"`
	Star   Star `gorm:"foreignKey:StarID;references:StarID;constraint:OnDelete:CASCADE"`
}

// TableName 指定表名
func (Friendship) TableName() string {
	return "friendships"
}

// BeforeCreate 创建前钩子
func (f *Friendship) BeforeCreate(tx *gorm.DB) error {
	now := time.Now().UnixMilli()
	f.CreatedAt = now
	f.UpdatedAt = now

	// 验证不能添加自己为好友
	if f.UserID == f.FriendID {
		return gorm.ErrCheckConstraintViolated
	}

	return nil
}

// BeforeUpdate 更新前钩子
func (f *Friendship) BeforeUpdate(tx *gorm.DB) error {
	f.UpdatedAt = time.Now().UnixMilli()
	return nil
}

// FriendRequest 好友请求表模型
// 存储好友请求的历史记录（保留所有状态的记录）
type FriendRequest struct {
	ID          int64   `gorm:"primaryKey;autoIncrement;column:id"`
	FromUserID  int64   `gorm:"not null;index:idx_friend_requests_from_status;index:idx_friend_requests_users_star;column:from_user_id"`
	ToUserID    int64   `gorm:"not null;index:idx_friend_requests_to_status;index:idx_friend_requests_users_star;column:to_user_id"`
	StarID      int64   `gorm:"not null;index:idx_friend_requests_star;index:idx_friend_requests_users_star;column:star_id"`
	Message     *string `gorm:"type:varchar(200);column:message"`                                                                                                    // 请求附带消息
	Status      string  `gorm:"type:varchar(20);not null;default:'pending';index:idx_friend_requests_to_status;index:idx_friend_requests_from_status;column:status"` // pending, accepted, rejected, expired
	CreatedAt   int64   `gorm:"not null;index:idx_friend_requests_to_status,sort:desc;index:idx_friend_requests_from_status,sort:desc;index:idx_friend_requests_users_star,sort:desc;column:created_at"`
	UpdatedAt   int64   `gorm:"not null;column:updated_at"`
	ExpiresAt   *int64  `gorm:"index:idx_friend_requests_expires;column:expires_at"` // 过期时间（毫秒时间戳）
	ProcessedAt *int64  `gorm:"column:processed_at"`                                 // 处理时间（毫秒时间戳）

	// 关联关系
	FromUser User `gorm:"foreignKey:FromUserID;references:ID;constraint:OnDelete:CASCADE"`
	ToUser   User `gorm:"foreignKey:ToUserID;references:ID;constraint:OnDelete:CASCADE"`
	Star     Star `gorm:"foreignKey:StarID;references:StarID;constraint:OnDelete:CASCADE"`
}

// TableName 指定表名
func (FriendRequest) TableName() string {
	return "friend_requests"
}

// BeforeCreate 创建前钩子
func (fr *FriendRequest) BeforeCreate(tx *gorm.DB) error {
	now := time.Now().UnixMilli()
	fr.CreatedAt = now
	fr.UpdatedAt = now

	// 验证不能请求自己为好友
	if fr.FromUserID == fr.ToUserID {
		return gorm.ErrCheckConstraintViolated
	}

	// 设置默认状态
	if fr.Status == "" {
		fr.Status = FriendRequestStatusPending
	}

	// 注意：过期时间应该在 Service 层创建 FriendRequest 之前设置
	// Service 层会根据 friend_config.go 中的配置计算过期时间
	// 这里不再设置过期时间，避免硬编码和配置不一致

	return nil
}

// BeforeUpdate 更新前钩子
func (fr *FriendRequest) BeforeUpdate(tx *gorm.DB) error {
	fr.UpdatedAt = time.Now().UnixMilli()
	return nil
}

// IsExpired 检查请求是否已过期
func (fr *FriendRequest) IsExpired() bool {
	if fr.ExpiresAt == nil {
		return false
	}
	return time.Now().UnixMilli() > *fr.ExpiresAt
}

// IsPending 检查请求是否为待处理状态
func (fr *FriendRequest) IsPending() bool {
	return fr.Status == FriendRequestStatusPending
}

// IsAccepted 检查请求是否已接受
func (fr *FriendRequest) IsAccepted() bool {
	return fr.Status == FriendRequestStatusAccepted
}

// IsRejected 检查请求是否已拒绝
func (fr *FriendRequest) IsRejected() bool {
	return fr.Status == FriendRequestStatusRejected
}

// 常量定义

// 好友关系状态
const (
	FriendshipStatusAccepted = "accepted" // 已接受
	FriendshipStatusBlocked  = "blocked"  // 已屏蔽（预留）
)

// 好友请求状态
const (
	FriendRequestStatusPending  = "pending"  // 待处理
	FriendRequestStatusAccepted = "accepted" // 已接受
	FriendRequestStatusRejected = "rejected" // 已拒绝
	FriendRequestStatusExpired  = "expired"  // 已过期
)

// 好友请求类型（用于查询）
const (
	FriendRequestTypeReceived = "received" // 收到的请求
	FriendRequestTypeSent     = "sent"     // 发出的请求
)