"""一次性回填:给历史账户补开户赠送的 genesis 流水(只补凭证,不改任何余额)。
对每个 account,若"首条流水之前的隐含余额">0 且尚无 trial_grant 流水,补一条 RECHARGE,
created_at 设为开户时间(早于所有流水),balance_after=该隐含开户额度。幂等可重跑。
跑法:cd backend && DJANGO_SETTINGS_MODULE=airshelf.settings.development .venv/bin/python ../qa/backfill_genesis_ledger.py
"""
import os, sys
from decimal import Decimal

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "backend"))
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "airshelf.settings.development")
import django  # noqa: E402

django.setup()

from django.db import transaction  # noqa: E402
from apps.billing.models import CreditAccount, CreditLedger  # noqa: E402

Z = Decimal("0")
fixed = 0
for acct in CreditAccount.objects.select_related("team").all():
    led = CreditLedger.objects.filter(team=acct.team)
    if led.filter(metadata__kind="trial_grant").exists():
        continue  # 已有 genesis
    first = led.order_by("created_at", "id").first()
    if first is None:
        # 纯开户无任何流水:开户额度即 balance
        opening = acct.balance
        genesis_time = acct.created_at
    else:
        delta = first.amount if first.ledger_type in ("recharge", "refund", "adjustment") else (-first.amount if first.ledger_type == "charge" else Z)
        opening = first.balance_after - delta
        genesis_time = acct.created_at if acct.created_at < first.created_at else first.created_at
    if opening <= Z:
        continue
    with transaction.atomic():
        g = CreditLedger.objects.create(
            team=acct.team,
            user=acct.team.owner,
            ledger_type=CreditLedger.Type.RECHARGE,
            amount=opening,
            balance_after=opening,
            reason="新用户试用额度赠送(历史回填)",
            metadata={"kind": "trial_grant", "backfilled": True},
        )
        # created 字段由 auto_now_add 控制,需手动回拨到开户时刻,保证它排在所有流水之前
        CreditLedger.objects.filter(id=g.id).update(created_at=genesis_time)
    fixed += 1
    print(f"  + {acct.team} 补 genesis ¥{opening} @ {genesis_time:%Y-%m-%d %H:%M}")

print(f"\n回填完成:{fixed} 个账户补齐 genesis 流水(余额未变动)")