"""pipeline_llm.accounting — 异步出账循环（owner 模型三方账）。

扫 llm_usage 中 accounting_status='pending' 的用量流水（owner 模型、调用方≠平台），
逐条映射模型→产品，调产品层 product_accounting_generic 出三方账
（客户付/商户营收/供应商成本，客户折扣精确到产品），成功置 'accounted'。

与账号/存储的同步记账分工明确（2026-09 用户定夺）：
  - 账号/存储：purchase_realtime 同步记账
  - 模型（本模块）：调用时只记成本侧 + pending 流水，出账走本循环（异步）

单循环守卫（多进程部署时防重复出账）：Redis SETNX llm_acc:lock（db4，与限流同库）。
"""

import asyncio
import logging
import time

from ahserver.serverenv import ServerEnv

from .gateway import _get_db, _redis

logger = logging.getLogger("pipeline_llm.accounting")

_SCAN_INTERVAL = 60      # 扫描间隔（秒）
_BATCH = 200             # 每批处理条数
_LOCK_KEY = 'llm_acc:lock'
_LOCK_TTL = 90           # 锁 TTL（略大于单批预算耗时）


async def _get_pending(sor):
    recs = await sor.sqlExe(
        "SELECT id, org_id, user_id, model_id, req_tokens, resp_tokens, cost, ppid "
        "FROM llm_usage WHERE accounting_status='pending' AND status='ok' "
        "ORDER BY created_at LIMIT %d" % _BATCH, {})
    await sor.sqlExe("COMMIT", {})
    return recs or []


async def _find_product_id(sor, model_id):
    """llm_model.id → product.id（产品层导入时按 resource_ref_id 建立）。"""
    recs = await sor.sqlExe(
        "SELECT id FROM product WHERE resource_ref_id=${r}$ AND status='1' LIMIT 1",
        {"r": model_id})
    await sor.sqlExe("COMMIT", {})
    return (getattr(recs[0], 'id', '') or '') if recs else ''


async def _settle_one(sor, row):
    """单条出账。成功置 accounted；失败置 failed 并记录原因（不静默重试死循环）。"""
    env = ServerEnv()
    model_id = getattr(row, 'model_id', '') or ''
    product_id = await _find_product_id(sor, model_id)
    if not product_id:
        await sor.U('llm_usage', {
            'id': row.id, 'accounting_status': 'failed',
            'note': '出账失败：模型(%s)未映射到产品，请先在产品管理导入产线模型' % model_id,
        })
        await sor.sqlExe("COMMIT", {})
        logger.warning("pipeline_llm.accounting: model %s 无产品映射，流水 %s 置 failed",
                       model_id, row.id)
        return False
    usage_data = {
        'prompt_tokens': int(getattr(row, 'req_tokens', 0) or 0),
        'completion_tokens': int(getattr(row, 'resp_tokens', 0) or 0),
    }
    fn = getattr(env, 'product_accounting_generic', None)
    if fn is None:
        # 产品模块未加载 → 保留 pending 下轮再试
        return False
    result = await fn(
        product_id=product_id,
        usage_data=usage_data,
        userorgid=getattr(row, 'org_id', '') or '',
        userid=getattr(row, 'user_id', '') or '',
    )
    if not result or not result.get('success', result.get('orderid')):
        msg = str((result or {}).get('message', result))[:180]
        await sor.U('llm_usage', {
            'id': row.id, 'accounting_status': 'failed',
            'note': '出账失败：%s' % msg,
        })
        await sor.sqlExe("COMMIT", {})
        logger.error("pipeline_llm.accounting: 流水 %s 出账失败: %s", row.id, msg)
        return False
    # 回填客户应付 + 置已出账
    await sor.sqlExe(
        "UPDATE llm_usage SET charge=${c}$, accounting_status='accounted', "
        "note=CONCAT(COALESCE(note,''),'|accounted:',${o}$) WHERE id=${i}$",
        {"c": float((result or {}).get('customer_amount', 0) or 0),
         "o": str((result or {}).get('orderid', ''))[:40],
         "i": row.id})
    await sor.sqlExe("COMMIT", {})
    return True


async def _run_one_pass():
    """一轮扫描-出账。返回处理条数。"""
    db, dbname = _get_db()
    async with db.sqlorContext(dbname) as sor:
        rows = await _get_pending(sor)
    if not rows:
        return 0
    ok_n = 0
    for row in rows:
        try:
            db, dbname = _get_db()
            async with db.sqlorContext(dbname) as sor:
                if await _settle_one(sor, row):
                    ok_n += 1
        except Exception as e:
            logger.error("pipeline_llm.accounting: 流水 %s 出账异常: %s",
                         getattr(row, 'id', ''), e)
            try:
                db, dbname = _get_db()
                async with db.sqlorContext(dbname) as sor:
                    await sor.U('llm_usage', {
                        'id': row.id, 'accounting_status': 'failed',
                        'note': '出账异常：%s' % str(e)[:180],
                    })
                    await sor.sqlExe("COMMIT", {})
            except Exception:
                pass
    return ok_n


async def llm_usage_accounting_loop():
    """后台循环：抢分布式锁 → 出账一批 → 睡。永不抛出。

    只由独立记账进程（app/pipeline_accounting_worker.py）运行，
    不挂进 web 服务器的事件循环（同步记账在 web，异步记账在独立进程）。
    """
    logger.info("[pipeline_llm] 异步出账循环已启动（间隔 %ds）", _SCAN_INTERVAL)
    while True:
        try:
            r = _redis()
            if r is not None:
                # 抢锁（多进程只跑一个）；Redis 故障则直接跑（与限流 fail-open 一致）
                got = False
                try:
                    got = bool(r.set(_LOCK_KEY, str(time.time()), nx=True, ex=_LOCK_TTL))
                except Exception:
                    got = True
                if not got:
                    await asyncio.sleep(_SCAN_INTERVAL)
                    continue
            await _run_one_pass()
        except Exception as e:
            logger.error("pipeline_llm.accounting: 循环异常（继续）: %s", e)
        await asyncio.sleep(_SCAN_INTERVAL)