package mysqldao

import (
	"context"

	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/global"
	"git.lzcwy.cn/zhengchiliu/zt-closet-backend/internal/mysqlmodel"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

// CollectDao 收藏数据访问
type CollectDao struct {
	db *gorm.DB
}

// NewCollectDao 创建收藏 DAO
func NewCollectDao() *CollectDao {
	return &CollectDao{db: global.MysqlEngine}
}

// CollectCreate 创建收藏记录
func (d *CollectDao) CollectCreate(ctx context.Context, collect *mysqlmodel.Collect) error {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.CollectCreate")
	defer span.End()

	if err := d.db.WithContext(ctx).Create(collect).Error; err != nil {
		span.RecordError(err)
		return err
	}
	return nil
}

// CollectUpsertOn 收藏幂等写入：唯一索引冲突时仅置 status=1，防并发重复插入。
func (d *CollectDao) CollectUpsertOn(ctx context.Context, collect *mysqlmodel.Collect) error {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.CollectUpsertOn")
	defer span.End()

	if err := d.db.WithContext(ctx).Clauses(clause.OnConflict{
		Columns:   []clause.Column{{Name: "collect_type"}, {Name: "target_id"}, {Name: "user_id"}},
		DoUpdates: clause.AssignmentColumns([]string{"status"}),
	}).Create(collect).Error; err != nil {
		span.RecordError(err)
		return err
	}
	return nil
}

// CollectUpdateStatus 更新收藏状态（1=已收藏 0=已取消）
func (d *CollectDao) CollectUpdateStatus(ctx context.Context, id int64, status int8) error {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.CollectUpdateStatus")
	defer span.End()

	if err := d.db.WithContext(ctx).Model(&mysqlmodel.Collect{}).Where("id = ?", id).UpdateColumn("status", status).Error; err != nil {
		span.RecordError(err)
		return err
	}
	return nil
}

// CollectGetByTargetAndUser 查询用户在目标上的收藏记录
func (d *CollectDao) CollectGetByTargetAndUser(ctx context.Context, collectType int8, targetID, userID int64) (*mysqlmodel.Collect, error) {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.CollectGetByTargetAndUser")
	defer span.End()

	var collect mysqlmodel.Collect
	if err := d.db.WithContext(ctx).Where("collect_type = ? AND target_id = ? AND user_id = ?", collectType, targetID, userID).First(&collect).Error; err != nil {
		span.RecordError(err)
		return nil, err
	}
	return &collect, nil
}

// CollectCountByTarget 统计目标收藏数（仅 status=1）
func (d *CollectDao) CollectCountByTarget(ctx context.Context, collectType int8, targetID int64) (int64, error) {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.CollectCountByTarget")
	defer span.End()

	var count int64
	if err := d.db.WithContext(ctx).Model(&mysqlmodel.Collect{}).
		Where("collect_type = ? AND target_id = ? AND status = ?", collectType, targetID, int8(1)).
		Count(&count).Error; err != nil {
		span.RecordError(err)
		return 0, err
	}
	return count, nil
}

// CollectCountByTargets 批量统计多个目标的收藏数（仅 status=1），返回 targetID -> count；空入参短路。
func (d *CollectDao) CollectCountByTargets(ctx context.Context, collectType int8, targetIDs []int64) (map[int64]int64, error) {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.CollectCountByTargets")
	defer span.End()

	counts := make(map[int64]int64, len(targetIDs))
	if len(targetIDs) == 0 {
		return counts, nil
	}

	var rows []struct {
		TargetID int64 `gorm:"column:target_id"`
		Cnt      int64 `gorm:"column:cnt"`
	}
	if err := d.db.WithContext(ctx).Model(&mysqlmodel.Collect{}).
		Select("target_id, COUNT(*) AS cnt").
		Where("collect_type = ? AND target_id IN ? AND status = ?", collectType, targetIDs, int8(1)).
		Group("target_id").
		Scan(&rows).Error; err != nil {
		span.RecordError(err)
		return nil, err
	}
	for _, r := range rows {
		counts[r.TargetID] = r.Cnt
	}
	return counts, nil
}

// CollectListTargetIDsByUserPage 分页查询用户收藏的目标ID列表（仅 status=1，且目标穿搭对本人可见），返回 ids 与总数。
//
// 可见性口径与 service.isOutfitPublicVisible 保持一致：本人收藏自己的穿搭始终可见；
// 收藏他人穿搭要求「公开(2) + 审核通过(2) + 状态正常(1)」。
// 联表过滤而非服务层过滤，是为了让 total 与实际返回条数口径一致
//（此前只按 collects 计数，穿搭转私/删除后会返回 total 虚高、页内条数偏少的空洞页）。
func (d *CollectDao) CollectListTargetIDsByUserPage(ctx context.Context, collectType int8, userID int64, page, pageSize int) ([]int64, int64, error) {
	ctx, span := global.Tracer.Start(ctx, "mysqldao.CollectListTargetIDsByUserPage")
	defer span.End()

	q := d.db.WithContext(ctx).Model(&mysqlmodel.Collect{}).
		Joins("JOIN outfits o ON o.id = collects.target_id AND o.deleted_at = 0").
		Where("collects.collect_type = ? AND collects.user_id = ? AND collects.status = ?", collectType, userID, int8(1)).
		Where("o.user_id = ? OR (o.is_public = ? AND o.audit_status = ? AND o.status = ?)", userID, 2, 2, 1)

	var total int64
	if err := q.Count(&total).Error; err != nil {
		span.RecordError(err)
		return nil, 0, err
	}

	var ids []int64
	if err := q.Order("collects.id DESC").Offset((page-1)*pageSize).Limit(pageSize).
		Pluck("collects.target_id", &ids).Error; err != nil {
		span.RecordError(err)
		return nil, 0, err
	}
	return ids, total, nil
}