"""NAV history backfill (0.2.43): old eNAV files add past quarters to valuation history
WITHOUT touching current holdings — no cost-basis regression, no resurrected positions."""

import io
from datetime import date, datetime

import openpyxl
from sqlmodel import select

from ten31portal.models import (
    Entity, EntityType, Holding, Position, RoundStatus, Valuation, ValuationRound,
)


def _enav_file(report: datetime, hld_rows: list[tuple], alloc_rows: list[dict] | None = None) -> bytes:
    """Minimal eNAV workbook: an HLD sheet (and optionally an ALLOC SI roster).

    hld_rows: (security_name, quantity, cost, value) tuples.
    """
    wb = openpyxl.Workbook()
    ws = wb.active
    ws.title = "HLD"
    ws["A1"] = report  # _enav_as_of scans the top-left cells for the report date
    ws.append([None])
    ws.append(["SECURITY NAME", "QUANTITY", "COST BASIS - BOOK", "MARKET VALUE (BOOK)"])
    for name, qty, cost, value in hld_rows:
        ws.append([name, qty, cost, value])
    if alloc_rows is not None:
        alloc = wb.create_sheet("ALLOC SI")
        alloc.append(["INVESTOR ID", "INVESTOR TYPE", "INVESTOR NAME",
                      "COMMITTED CAPITAL", "CONTRIBUTIONS", "(DISTRIBUTIONS)", "ENDING BALANCE"])
        for r in alloc_rows:
            alloc.append([r.get("id"), "LP", r["name"],
                          r.get("commit", 0), r.get("contrib", 0), r.get("distrib", 0), r["ending"]])
    out = io.BytesIO()
    wb.save(out)
    return out.getvalue()


def _fund_with_current_book(session):
    """A fund holding one position (cost $100) with its NAV already signed for Q1 2026."""
    fund = Entity(name="LTPF I", type=EntityType.fund)
    session.add(fund)
    session.commit()
    session.refresh(fund)
    holding = Holding(entity_id=fund.id, company_name="Acme")
    session.add(holding)
    session.commit()
    pos = Position(holding_id=holding.id, security_name="Acme - Series A",
                   investment_date=date(2023, 1, 1), cost_cents=100_00)
    session.add(pos)
    session.commit()
    session.refresh(pos)
    rnd = ValuationRound(entity_id=fund.id, quarter_end=date(2026, 3, 31),
                         status=RoundStatus.approved, is_seed=True)
    session.add(rnd)
    session.commit()
    session.refresh(rnd)
    session.add(Valuation(round_id=rnd.id, position_id=pos.id, value_cents=900_00))
    session.commit()
    return fund, pos


def test_old_file_becomes_history_round_without_touching_book(auth_client, session):
    fund, pos = _fund_with_current_book(session)
    old = _enav_file(datetime(2025, 9, 30), [
        ("Acme - Series A", 10, 123.0, 555.0),   # matches today's book
        ("Ghost - SAFE", 5, 999.0, 999.0),       # sold since; must NOT be created
    ])

    resp = auth_client.post(
        f"/api/import/schedule?entity_id={fund.id}&commit=true",
        files={"file": ("old.xlsx", io.BytesIO(old), "application/octet-stream")},
    )
    assert resp.status_code == 200, resp.text
    body = resp.json()
    assert body["history_only"] is True
    assert body["status"] == "added"
    assert body["matched"] == 1 and body["unmatched"] == 1

    session.expire_all()
    # The quarter landed in valuation history with the matched row's value only.
    hist_round = session.exec(select(ValuationRound).where(
        ValuationRound.entity_id == fund.id, ValuationRound.quarter_end == date(2025, 9, 30)
    )).first()
    assert hist_round is not None
    vals = session.exec(select(Valuation).where(Valuation.round_id == hist_round.id)).all()
    assert [(v.position_id, v.value_cents) for v in vals] == [(pos.id, 555_00)]
    # Today's book is untouched: cost basis kept, no ghost position resurrected.
    assert session.get(Position, pos.id).cost_cents == 100_00
    assert session.exec(select(Holding).where(Holding.company_name == "Ghost")).first() is None


def test_signed_round_is_kept(auth_client, session):
    fund, pos = _fund_with_current_book(session)
    signed = ValuationRound(entity_id=fund.id, quarter_end=date(2025, 9, 30),
                            status=RoundStatus.approved, is_seed=False)
    session.add(signed)
    session.commit()
    old = _enav_file(datetime(2025, 9, 30), [("Acme - Series A", 10, 123.0, 555.0)])

    resp = auth_client.post(
        f"/api/import/schedule?entity_id={fund.id}&commit=true",
        files={"file": ("old.xlsx", io.BytesIO(old), "application/octet-stream")},
    )
    assert resp.status_code == 200, resp.text
    assert resp.json()["status"] == "kept-signed"
    session.expire_all()
    assert session.exec(select(Valuation).join(
        ValuationRound, Valuation.round_id == ValuationRound.id
    ).where(ValuationRound.quarter_end == date(2025, 9, 30))).all() == []


def test_batch_backfill_also_records_nav(auth_client, session):
    from tests.conftest import make_user
    from ten31portal.models import CapitalAccountStatement, EntityAccess, UserRole

    fund, pos = _fund_with_current_book(session)
    lp = make_user(session, username="lp", name="Alice Trust", role=UserRole.investor)
    session.add(EntityAccess(user_id=lp.id, entity_id=fund.id))
    session.commit()

    old = _enav_file(
        datetime(2025, 9, 30),
        [("Acme - Series A", 10, 123.0, 555.0), ("Ghost - SAFE", 5, 999.0, 999.0)],
        alloc_rows=[{"id": "INV-1", "name": "Alice Trust", "commit": 1000, "contrib": 400, "ending": 420}],
    )

    for expected_status in ("added", "updated"):  # second pass proves idempotency
        resp = auth_client.post(
            "/api/import/capital-accounts/batch",
            data={"entity_id": str(fund.id)},
            files=[("files", ("old.xlsx", io.BytesIO(old), "application/octet-stream"))],
        )
        assert resp.status_code == 200, resp.text
        f = resp.json()["files"][0]
        assert f["error"] is None and f["skipped"] == []
        assert f["statements_written"] == 1
        assert f["nav_status"] == expected_status
        assert f["nav_matched"] == 1 and f["nav_unmatched"] == 1
        assert f["nav_cents"] == 555_00

    session.expire_all()
    stmts = session.exec(select(CapitalAccountStatement).where(
        CapitalAccountStatement.entity_id == fund.id
    )).all()
    assert len(stmts) == 1  # upserted, not duplicated
    rounds = session.exec(select(ValuationRound).where(
        ValuationRound.entity_id == fund.id, ValuationRound.quarter_end == date(2025, 9, 30)
    )).all()
    assert len(rounds) == 1
    assert session.get(Position, pos.id).cost_cents == 100_00