"""保留成功读取实际观察到的当前版本，不把历史最大ID当成当前值。"""

from sqlalchemy import inspect, select, tuple_

from app.models import TPlusSourceHead, TPlusSyncRecord
from app.services.tplus.staging import prepare_row


def observe_rows(session, batch, mapping, rows):
    """每页提交前记录所有读到的源版本，包括去重跳过的 A→B→A。"""
    # V15 运行中的升级窗口继续允许原读取功能；工作区本身要求 V16。
    if not inspect(session.connection()).has_table(TPlusSourceHead.__tablename__):
        return
    prepared = [
        prepare_row(batch.batch_no, mapping.entity_type, mapping.source_table, r)
        for r in rows
        if r.get("id") is not None
    ]
    wanted = [(r["source_id"], r["row_hash"]) for r in prepared]
    if not wanted:
        return
    records = {
        (r.source_id, r.row_hash): r.id
        for r in session.scalars(
            select(TPlusSyncRecord).where(
                TPlusSyncRecord.entity_type == mapping.entity_type,
                tuple_(TPlusSyncRecord.source_id, TPlusSyncRecord.row_hash).in_(wanted),
            )
        )
    }
    source = batch.source_database
    if not source:
        raise ValueError("源账套身份缺失，不能发布当前快照")
    current = {
        h.source_id: h
        for h in session.scalars(
            select(TPlusSourceHead).where(
                TPlusSourceHead.source_database == source,
                TPlusSourceHead.entity_type == mapping.entity_type,
                TPlusSourceHead.source_id.in_([v[0] for v in wanted]),
            )
        )
    }
    for row in prepared:
        record_id = records.get((row["source_id"], row["row_hash"]))
        if record_id is None:
            continue
        head = current.get(row["source_id"])
        if head is None:
            head = TPlusSourceHead(
                source_database=source,
                entity_type=mapping.entity_type,
                source_id=row["source_id"],
                record_id=record_id,
                batch_no=batch.batch_no,
            )
            session.add(head)
            current[row["source_id"]] = head
        head.record_id, head.batch_no = record_id, batch.batch_no
        raw = row["payload_json"]
        head.source_parent_id = str(raw["source_parent_id"]) if raw.get("source_parent_id") is not None else None
        customer = raw.get("idcustomer", raw.get("idpartner"))
        head.source_customer_id = str(customer) if customer is not None else None
        day = raw.get("voucherdate", raw.get("voucherDate"))
        head.source_date = str(day)[:10] if day is not None else None