"""Postgres-only-Prüfung der Grafana-Views (Ausbaustufe 11).

Läuft nur mit FB_TEST_PG_URL (Wegwerf-Postgres, DB-Name muss auf '_test'
enden - Schutz gegen versehentliche Ausführung gegen die Produktiv-DB).
Beispiel:
  podman run -d --rm --name a11-pg -e POSTGRES_PASSWORD=wegwerf \
    -e POSTGRES_DB=fb_test -p 127.0.0.1:55432:5432 docker.io/library/postgres:17.10
  FB_TEST_PG_URL=postgresql+psycopg://postgres:wegwerf@127.0.0.1:55432/fb_test \
    .venv/bin/python -m pytest -q tests/test_views_pg.py
"""
import os
from datetime import timedelta
from decimal import Decimal

import pytest
from sqlalchemy import create_engine, text
from sqlalchemy.engine import make_url
from sqlalchemy.orm import Session

from app.db import Base
import app.models  # noqa: F401
from app.models.tables import (Account, ProjectionPoint, ProjectionResult,
                               Scenario, Transaction)
from app.models.views import RESERVED_SCENARIO_NAME, VIEWS, create_views

PG_URL = os.environ.get("FB_TEST_PG_URL")
pytestmark = pytest.mark.skipif(not PG_URL, reason="FB_TEST_PG_URL nicht gesetzt")


def _reset(engine):
    with engine.begin() as conn:
        for name in VIEWS:
            conn.execute(text(f"DROP VIEW IF EXISTS {name} CASCADE"))
    Base.metadata.drop_all(engine)


@pytest.fixture
def pg():
    assert make_url(PG_URL).database.endswith("_test"), "nur Wegwerf-DB *_test!"
    engine = create_engine(PG_URL)
    _reset(engine)
    Base.metadata.create_all(engine)
    create_views(engine)
    with Session(engine) as session:
        yield session
    _reset(engine)
    engine.dispose()


def test_v_projection_ist_serie_und_szenario_ab_heute(pg):
    today = pg.execute(text("SELECT CURRENT_DATE")).scalar()
    acc = Account(bank="t", iban="DE-PG-1", name="Testkonto", type="giro",
                  anchor_date=today - timedelta(days=10),
                  anchor_balance=Decimal("1000.00"))
    pg.add(acc)
    pg.flush()
    pg.add(Transaction(account_id=acc.id, booking_date=today - timedelta(days=2),
                       amount=Decimal("-100.00"), purpose="t", counterparty="t",
                       status="confirmed", dedup_hash="pg-1"))
    stale = Scenario(name="Veraltet", description="")
    empty = Scenario(name="Ohne Punkte", description="")
    pg.add_all([stale, empty])
    pg.flush()
    # Veraltete Momentaufnahme: Punkte von heute-5 bis heute+5.
    for off in range(-5, 6):
        pg.add(ProjectionPoint(scenario_id=stale.id, day=today + timedelta(days=off),
                               balance=Decimal("5000.00")))
    pg.add(ProjectionResult(scenario_id=stale.id, computed_at=today,
                            low_point_date=today, low_point_balance=Decimal("0")))
    pg.commit()

    rows = pg.execute(text(
        "SELECT scenario, day, balance FROM v_projection ORDER BY scenario, day")).all()
    ist = [r for r in rows if r.scenario == RESERVED_SCENARIO_NAME]
    sc = [r for r in rows if r.scenario == "Veraltet"]
    assert max(r.day for r in ist) == today
    assert [r.balance for r in ist if r.day == today] == [Decimal("900.00")]
    # Szenario startet heute am Ist-Saldo, keine alten Punkte davor.
    assert sc[0].day == today and sc[0].balance == Decimal("900.00")
    assert all(r.day >= today for r in sc)
    assert [r.balance for r in sc[1:]] == [Decimal("5000.00")] * 5
    assert not any(r.scenario == "Ohne Punkte" for r in rows)