"""F4b 断言测试：到期未收款「展示口径」与「落库口径」同源（任务 dama-cashplan-zombie-alert-cleanup-20260913 B 段）

背景：check_cash_alerts() 写库路径已按 get_balance_snapshot_mode() 过滤余额快照批次，
但 forecast_cash_flow_with_plans() 的 summary / suggestions 仍按未过滤集合统计 ⇒
同一次响应里「写入 0 条」与「展示 216 笔 / 200.72 万」并存（DAMA 复核 fullstack-20260913-0703 §3.3）。

本用例锁定：
  1) 默认 skip：summary.overdue_receive_count/amount 不含快照批次行；excluded 字段可见
  2) per_customer（旧行为）：逐户全额计入
  3) aggregate（写库侧 1 条/批次）：展示按批次数计
  4) suggestions 文案与 summary 同口径，且对未计入批次显式标注
  5) summarize_overdue_receives() 纯函数口径矩阵（含 upcoming_7d 同源）
"""
from datetime import datetime, timedelta

import pytest
from sqlalchemy.orm import Session

from app.models import CashPlan
from app.utils.cash_forecast_engine import (
    BALANCE_SNAPSHOT_SOURCES,
    forecast_cash_flow_with_plans,
    get_balance_snapshot_mode,
    summarize_overdue_receives,
)

SNAP_SRC = "bohai_ar_20260630"  # ∈ BALANCE_SNAPSHOT_SOURCES
EID = 1
TODAY = datetime.now().replace(hour=0, minute=0, second=0, microsecond=0)


def _seed(db: Session):
    """业务逾期 2 笔（20 + 30 万）+ 快照批次逾期 3 笔（10 + 20 + 30 万）"""
    rows = [
        # 业务行（source 非快照名单）
        CashPlan(entity_id=EID, plan_type="receive", status="pending", source="manual",
                 amount=20.0, counterparty="业务A", plan_date=TODAY - timedelta(days=9)),
        CashPlan(entity_id=EID, plan_type="receive", status="pending", source=None,
                 amount=30.0, counterparty="业务B", plan_date=TODAY - timedelta(days=3)),
        # 快照批次行
        CashPlan(entity_id=EID, plan_type="receive", status="pending", source=SNAP_SRC,
                 amount=10.0, counterparty="快照A", plan_date=TODAY - timedelta(days=75)),
        CashPlan(entity_id=EID, plan_type="receive", status="pending", source=SNAP_SRC,
                 amount=20.0, counterparty="快照B", plan_date=TODAY - timedelta(days=75)),
        CashPlan(entity_id=EID, plan_type="receive", status="pending", source=SNAP_SRC,
                 amount=30.0, counterparty="快照C", plan_date=TODAY - timedelta(days=75)),
    ]
    for r in rows:
        db.add(r)
    db.commit()
    return rows


def _overdue_rows(db: Session):
    return db.query(CashPlan).filter(
        CashPlan.entity_id == EID,
        CashPlan.plan_type == "receive",
        CashPlan.status == "pending",
        CashPlan.plan_date < TODAY,
    ).all()


# ── 1. 纯函数口径矩阵 ────────────────────────────────────────────────
class TestSummarizeOverdueReceives:

    def test_default_is_skip_and_excludes_snapshot(self, db: Session):
        assert get_balance_snapshot_mode() == "skip"
        rows = _seed(db)
        meta = summarize_overdue_receives(_overdue_rows(db))
        assert meta["mode"] == "skip"
        assert meta["count"] == 2, "skip 下只计业务行"
        assert meta["amount"] == 50.0
        assert meta["raw_count"] == 5
        assert meta["raw_amount"] == 110.0
        assert meta["snapshot_rows_excluded"] == 3
        assert meta["snapshot_rows_excluded_amount"] == 60.0
        assert meta["snapshot_rows_total"] == 3
        assert meta["snapshot_batches"] == [{"source": SNAP_SRC, "count": 3, "amount": 60.0}]

    def test_per_customer_counts_everything(self, db: Session):
        _seed(db)
        meta = summarize_overdue_receives(_overdue_rows(db), mode="per_customer")
        assert meta["count"] == 5
        assert meta["amount"] == 110.0
        assert meta["snapshot_rows_excluded"] == 0

    def test_aggregate_counts_batches(self, db: Session):
        _seed(db)
        meta = summarize_overdue_receives(_overdue_rows(db), mode="aggregate")
        # 写库侧 aggregate = 1 条/批次 ⇒ 展示 = 2 业务行 + 1 批次 = 3 条，金额全量 110 万
        assert meta["count"] == 3
        assert meta["amount"] == 110.0
        assert meta["snapshot_rows_excluded"] == 2  # 3 行里 2 行被折叠进批次条目
        assert len(meta["snapshot_batches"]) == 1

    def test_batch_list_is_internal_whitelist(self):
        assert SNAP_SRC in BALANCE_SNAPSHOT_SOURCES


# ── 2. 端到端：forecast_cash_flow_with_plans 的 summary/suggestions ──
class TestForecastSummaryAlignment:

    def test_skip_mode_summary_excludes_snapshot(self, db: Session):
        """默认 skip：summary 口径 = 落库口径（断言「写入 0 条 / 展示 3 笔」不再发生）"""
        _seed(db)
        result = forecast_cash_flow_with_plans(EID, db, days=30)
        s = result["summary"]
        assert s["snapshot_mode"] == "skip"
        assert s["overdue_receive_count"] == 2
        assert s["overdue_receive_amount"] == 50.0
        assert s["snapshot_rows_excluded"] == 3
        assert s["overdue_receive_count_raw"] == 5
        assert s["overdue_receive_amount_raw"] == 110.0

    def test_skip_mode_suggestion_discloses_excluded_batch(self, db: Session):
        _seed(db)
        result = forecast_cash_flow_with_plans(EID, db, days=30)
        msgs = [x["message"] for x in result["suggestions"] if "应收款到期未收" in x["message"]]
        assert msgs, "应保留业务行催收建议"
        msg = msgs[0]
        assert msg.startswith("有2笔应收款到期未收，合计50.0万")
        assert "余额快照批次3行/60.0万未计入" in msg

    def test_no_business_overdue_means_no_overdue_suggestion(self, db: Session):
        """只有快照批次（博海今日实况）：skip 下不产生「到期未收」建议 —— 与 new_alerts=0 一致"""
        db.add(CashPlan(entity_id=EID, plan_type="receive", status="pending", source=SNAP_SRC,
                        amount=198.27, counterparty="快照户", plan_date=TODAY - timedelta(days=75)))
        db.commit()
        result = forecast_cash_flow_with_plans(EID, db, days=30)
        assert result["summary"]["overdue_receive_count"] == 0
        assert result["summary"]["snapshot_rows_excluded"] == 1
        assert not [x for x in result["suggestions"] if "应收款到期未收" in x["message"]]

    def test_per_customer_env_restores_old_display(self, db: Session, monkeypatch):
        monkeypatch.setenv("CMA_CASH_SNAPSHOT_MODE", "per_customer")
        _seed(db)
        result = forecast_cash_flow_with_plans(EID, db, days=30)
        s = result["summary"]
        assert s["snapshot_mode"] == "per_customer"
        assert s["overdue_receive_count"] == 5
        assert s["overdue_receive_amount"] == 110.0
        assert s["snapshot_rows_excluded"] == 0

    def test_aggregate_env_display_matches_write_side(self, db: Session, monkeypatch):
        monkeypatch.setenv("CMA_CASH_SNAPSHOT_MODE", "aggregate")
        _seed(db)
        result = forecast_cash_flow_with_plans(EID, db, days=30)
        s = result["summary"]
        assert s["snapshot_mode"] == "aggregate"
        assert s["overdue_receive_count"] == 3
        assert s["overdue_receive_amount"] == 110.0

    def test_upcoming_7d_excludes_snapshot_rows(self, db: Session):
        """upcoming_7d 同源：快照行的 plan_date 非真实到期日，skip 下不计入"""
        db.add(CashPlan(entity_id=EID, plan_type="receive", status="pending", source="manual",
                        amount=5.0, counterparty="近7天", plan_date=TODAY + timedelta(days=3)))
        db.add(CashPlan(entity_id=EID, plan_type="receive", status="pending", source=SNAP_SRC,
                        amount=7.0, counterparty="快照7天", plan_date=TODAY + timedelta(days=3)))
        db.commit()
        result = forecast_cash_flow_with_plans(EID, db, days=30)
        assert result["summary"]["upcoming_7d_count"] == 1

    def test_entity_isolation_and_status_filter(self, db: Session):
        """口径修正不影响实体隔离/状态过滤（只算本实体 pending 逾期应收）"""
        _seed(db)
        db.add(CashPlan(entity_id=2, plan_type="receive", status="pending", source="manual",
                        amount=999.0, counterparty="博海", plan_date=TODAY - timedelta(days=9)))
        db.add(CashPlan(entity_id=EID, plan_type="receive", status="completed", source="manual",
                        amount=888.0, counterparty="已完成", plan_date=TODAY - timedelta(days=9)))
        db.commit()
        result = forecast_cash_flow_with_plans(EID, db, days=30)
        assert result["summary"]["overdue_receive_count"] == 2
        assert result["summary"]["overdue_receive_amount"] == 50.0