package model

import (
	"context"

	"gorm.io/gorm"
)

type UserFollow struct {
	*Model
	UserId   int64 `gorm:"column:user_id;default:0;NOT NULL"`    // 用户id
	ToUserId int64 `gorm:"column:to_user_id;default:0;NOT NULL"` // 被关注的用户id
}

func (m *UserFollow) TableName() string {
	return "p_user_follow"
}

type UserFollowModel struct {
	conn *gorm.DB
}

func NewUserFollowModel(conn *gorm.DB) UserFollowModel {
	return UserFollowModel{
		conn: conn,
	}
}

// GetFansList 获取用户的粉丝列表
func (m *UserFollowModel) GetFansList(ctx context.Context, userId int64, page, pageSize int) ([]*UserFollow, error) {
	var follows []*UserFollow
	offset := (page - 1) * pageSize

	err := m.conn.WithContext(ctx).
		Where("to_user_id = ? AND is_del = 0", userId).
		Offset(offset).
		Limit(pageSize).
		Order("created_on desc").
		Find(&follows).Error

	if err != nil {
		return nil, err
	}
	return follows, nil
}

// GetFollowsList 获取用户的关注列表
func (m *UserFollowModel) GetFollowsList(ctx context.Context, userId int64, page, pageSize int) ([]*UserFollow, error) {
	var follows []*UserFollow
	offset := (page - 1) * pageSize

	err := m.conn.WithContext(ctx).
		Where("user_id = ? AND is_del = 0", userId).
		Offset(offset).
		Limit(pageSize).
		Order("created_on desc").
		Find(&follows).Error

	if err != nil {
		return nil, err
	}
	return follows, nil
}

// CheckMutualFollows 批量检查用户之间的关注关系
func (m *UserFollowModel) CheckMutualFollows(ctx context.Context, userId int64, targetUserIds []int64) (map[int64]bool, error) {
	var follows []*UserFollow
	result := make(map[int64]bool)

	// 初始化结果map
	for _, targetId := range targetUserIds {
		result[targetId] = false
	}

	// 查询当前用户是否关注了目标用户们
	err := m.conn.WithContext(ctx).
		Where("user_id = ? AND to_user_id IN ? AND is_del = 0", userId, targetUserIds).
		Find(&follows).Error

	if err != nil {
		return nil, err
	}

	// 标记已关注的用户
	for _, follow := range follows {
		result[follow.ToUserId] = true
	}

	return result, nil
}

// UnFollow 取消关注
func (m *UserFollowModel) UnFollow(ctx context.Context, userId, toUserId int64) error {
	return m.conn.WithContext(ctx).
		Model(&UserFollow{}).
		Where("user_id = ? AND to_user_id = ? AND is_del = 0", userId, toUserId).
		Update("is_del", 1).Error
}

// Follow 关注用户
func (m *UserFollowModel) Follow(ctx context.Context, userId, toUserId int64) error {
	return m.conn.WithContext(ctx).Create(&UserFollow{
		UserId:   userId,
		ToUserId: toUserId,
	}).Error
}