package model

import (
	"context"
	"time"

	"spark-server/internal/module/friend/entity"
)

// FriendRelation maps table friend_relations.
type FriendRelation struct {
	UserSmall int64     `gorm:"column:user_small;primaryKey;comment:两人中较小的 user_id，保证同一对用户只有一行"`
	UserBig   int64     `gorm:"column:user_big;primaryKey;comment:两人中较大的 user_id"`
	CreatedAt time.Time `gorm:"column:created_at;comment:成为好友时间"`
}

func (FriendRelation) TableName() string { return "friend_relations" }

func (r *FriendRelation) entity() *entity.Relation {
	if r == nil {
		return nil
	}
	return &entity.Relation{UserSmall: r.UserSmall, UserBig: r.UserBig, CreatedAt: r.CreatedAt}
}

func (m *Repo) GetRelation(ctx context.Context, a, b int64) (*entity.Relation, error) {
	db, err := m.session(ctx)
	if err != nil {
		return nil, err
	}
	small, big := entity.OrderUsers(a, b)
	var row FriendRelation
	if err := db.Where("user_small = ? AND user_big = ?", small, big).Take(&row).Error; err != nil {
		return nil, mapDBErr(err)
	}
	return row.entity(), nil
}

func (m *Repo) ListFriends(ctx context.Context, userID int64, limit int) ([]*entity.Relation, error) {
	db, err := m.session(ctx)
	if err != nil {
		return nil, err
	}
	limit = entity.ClampLimit(limit)
	var rows []FriendRelation
	err = db.Where("user_small = ? OR user_big = ?", userID, userID).
		Order("created_at DESC").Limit(limit).Find(&rows).Error
	if err != nil {
		return nil, mapDBErr(err)
	}
	out := make([]*entity.Relation, 0, len(rows))
	for i := range rows {
		out = append(out, rows[i].entity())
	}
	return out, nil
}