package codes

import (
	"context"
	"database/sql"
	"encoding/json"
	"fmt"
	"time"
)

// GrantPaidSubscriptionTx 在调用方事务里执行支付驱动的订阅开通/续期。
// 与兑换码走同一段叠加语义(applySubscription):同 plan 有活跃订阅则原地
// 延长 max(expires,now)+days,否则新建 source='pay' 的一行。ref 为审计
// 追踪串(如 "pay:<out_trade_no>"),审计写失败不影响事务(与兑换一致)。
func (svc *Service) GrantPaidSubscriptionTx(
	ctx context.Context, tx *sql.Tx, userID int64, plan PlanCode, days int, ref string,
) (subID int64, expiresAt time.Time, err error) {
	planID, err := svc.store.GetPlanIDTx(ctx, tx, plan)
	if err != nil {
		return 0, time.Time{}, err
	}
	subID, expiresAt, err = svc.applySubscription(ctx, tx, userID, planID, days, "pay")
	if err != nil {
		return 0, time.Time{}, err
	}
	meta, _ := json.Marshal(map[string]any{
		"plan": string(plan), "duration_days": days, "sub_id": subID,
	})
	_ = svc.store.WriteAuditLog(ctx, tx, fmt.Sprintf("user:%d", userID), "pay_grant", ref, string(meta))
	return subID, expiresAt, nil
}

// GrantRewardTx 发放奖励会员天数(Pro,source∈{invite,task}),与付费/兑换码同一条
// applySubscription 延时逻辑(max(到期,now)+days;已有活跃 pro 则原地顺延)。审计走 audit_log。
func (svc *Service) GrantRewardTx(
	ctx context.Context, tx *sql.Tx, userID int64, days int, source, auditAction, ref string,
) (int64, time.Time, error) {
	planID, err := svc.store.GetPlanIDTx(ctx, tx, PlanPro)
	if err != nil {
		return 0, time.Time{}, err
	}
	subID, expiresAt, err := svc.applySubscription(ctx, tx, userID, planID, days, source)
	if err != nil {
		return 0, time.Time{}, err
	}
	meta, _ := json.Marshal(map[string]any{"days": days, "source": source, "sub_id": subID})
	_ = svc.store.WriteAuditLog(ctx, tx, fmt.Sprintf("user:%d", userID), auditAction, ref, string(meta))
	return subID, expiresAt, nil
}