package activity

import (
    "context"
    "encoding/hex"
    "encoding/json"

    "bindbox-game/internal/repository/mysql/dao"
    "bindbox-game/internal/repository/mysql/model"
)

// BatchDrawForUsers 批量为用户执行抽奖并写入日志与收据
// 参数: issueID 期ID, userIDs 用户ID数组
// 返回: 抽奖结果集合与错误
func (s *service) BatchDrawForUsers(ctx context.Context, issueID int64, userIDs []int64) ([]BatchDrawItem, error) {
    rewards, err := s.readDB.ActivityRewardSettings.WithContext(ctx).
        Where(s.readDB.ActivityRewardSettings.IssueID.Eq(issueID)).
        Order(s.readDB.ActivityRewardSettings.Sort).
        Find()
    if err != nil {
        return nil, err
    }
    rewardMap := make(map[int64]string, len(rewards))
    for _, r := range rewards { rewardMap[r.ID] = r.Name }

    draws := make([]BatchDrawItem, 0, len(userIDs))
    err = s.writeDB.Transaction(func(tx *dao.Query) error {
        for _, uid := range userIDs {
            rec, err := s.ExecuteDrawWithEffects(ctx, issueID, uid)
            if err != nil { return err }

            isWinner := int32(0)
            if rec.SelectedItemId > 0 { isWinner = 1 }

            drawLog := &model.ActivityDrawLogs{
                UserID:   uid,
                IssueID:  issueID,
                RewardID: rec.SelectedItemId,
                IsWinner: isWinner,
                Level:    1,
            }
            if err := tx.ActivityDrawLogs.WithContext(ctx).Create(drawLog); err != nil { return err }

            itemsSnapshot, _ := json.Marshal(rec.Items)
            receipt := &model.ActivityDrawReceipts{
                DrawLogID:      drawLog.ID,
                AlgoVersion:    rec.AlgoVersion,
                RoundID:        rec.RoundId,
                DrawID:         rec.DrawId,
                ClientID:       rec.ClientId,
                Timestamp:      rec.Timestamp,
                ServerSeedHash: hex.EncodeToString(rec.ServerSeedHash),
                ServerSubSeed:  hex.EncodeToString(rec.ServerSubSeed),
                ClientSeed:     hex.EncodeToString(rec.ClientSeed),
                Nonce:          int64(rec.Nonce),
                ItemsRoot:      hex.EncodeToString(rec.ItemsRoot),
                WeightsTotal:   int64(rec.WeightsTotal),
                SelectedIndex:  int32(rec.SelectedIndex),
                RandProof:      hex.EncodeToString(rec.RandProof),
                Signature:      "",
                ItemsSnapshot:  string(itemsSnapshot),
            }
            if err := tx.ActivityDrawReceipts.WithContext(ctx).Create(receipt); err != nil { return err }

            name := ""
            if rec.SelectedItemId > 0 { name = rewardMap[rec.SelectedItemId] }
            draws = append(draws, BatchDrawItem{
                UserID:     uid,
                DrawID:     rec.DrawId,
                RewardID:   rec.SelectedItemId,
                RewardName: name,
                IsWinner:   rec.SelectedItemId > 0,
                Receipt:    rec,
            })
        }
        return nil
    })
    if err != nil { return nil, err }
    return draws, nil
}