from datetime import date, timedelta
from decimal import Decimal


def _seed_recent_rates(rate: str = "0.95") -> None:
    from app.database import SessionLocal
    from app.models import ExchangeRate

    db = SessionLocal()
    try:
        today = date.today()
        for delta in range(0, 7):
            day = today - timedelta(days=delta)
            if db.get(ExchangeRate, (day, "CHF")) is None:
                db.add(ExchangeRate(date=day, currency="CHF", rate_per_eur=Decimal(rate)))
        db.commit()
    finally:
        db.close()


def _mk_account(admin, **kw):
    body = {"name": "A", "type": "girokonto", "currency": "EUR", "opening_balance_cents": 0}
    body.update(kw)
    r = admin.post("/api/accounts", json=body)
    assert r.status_code == 201, r.text
    return r.json()


def test_starter_categories_present(admin):
    groups = admin.get("/api/categories").json()
    assert len(groups) >= 6
    names = {c["name"] for g in groups for c in g["categories"]}
    assert {"Gehalt", "Lebensmittel", "Sparen & Investments"} <= names


def test_currency_validation(admin):
    r = admin.post("/api/accounts", json={"name": "X", "currency": "USD"})
    assert r.status_code == 422


def test_identifiers_stored_and_deduped(admin):
    acc = _mk_account(
        admin,
        name="Mit IBAN",
        identifiers=[
            {"kind": "iban", "value": "DE12 3456"},
            {"kind": "iban", "value": "de123456"},  # normiert identisch -> dedupliziert
            {"kind": "card_no", "value": "1234"},
        ],
    )
    kinds = sorted((i["kind"], i["value"]) for i in acc["identifiers"])
    assert len(acc["identifiers"]) == 2
    assert ("card_no", "1234") in kinds


def test_balance_and_cross_currency_transfer(admin):
    _seed_recent_rates("0.95")
    d = date.today()
    eur = _mk_account(admin, name="Giro", currency="EUR", opening_balance_cents=100000)
    chf = _mk_account(admin, name="Spar", type="sparkonto", currency="CHF", opening_balance_cents=0)

    admin.post("/api/transactions", json={"type": "income", "date": str(d), "account_id": eur["id"], "amount_cents": 50000})
    admin.post("/api/transactions", json={"type": "expense", "date": str(d), "account_id": eur["id"], "amount_cents": 20000})
    assert admin.get(f"/api/accounts/{eur['id']}").json()["balance_cents"] == 130000

    # Transfer 100 EUR -> CHF (0.95) = 95 CHF gutgeschrieben.
    r = admin.post("/api/transactions", json={
        "type": "transfer", "date": str(d), "account_id": eur["id"],
        "to_account_id": chf["id"], "amount_cents": 10000,
    })
    assert r.status_code == 201, r.text
    assert r.json()["to_amount_cents"] == 9500
    assert admin.get(f"/api/accounts/{eur['id']}").json()["balance_cents"] == 120000
    assert admin.get(f"/api/accounts/{chf['id']}").json()["balance_cents"] == 9500


def test_transfer_requires_other_account(admin):
    eur = _mk_account(admin, name="Solo", currency="EUR")
    d = date.today()
    r = admin.post("/api/transactions", json={
        "type": "transfer", "date": str(d), "account_id": eur["id"],
        "to_account_id": eur["id"], "amount_cents": 100,
    })
    assert r.status_code == 400