"""Sync-status derivation (UX-17) and CSV export (ARCH-18)."""

import csv
import io
from datetime import datetime, timedelta
from decimal import Decimal

from app.models.models import (
    Bank,
    Category,
    Currency,
    ExchangeRate,
    Transaction,
    TransactionSource,
    TransactionType,
)
from app.services.csv_export import build_transactions_csv
from app.services.sync_status import compute_sync_status
from app.timeutil import utcnow


def by_key(statuses: list[dict]) -> dict[str, dict]:
    return {s["key"]: s for s in statuses}


class TestSyncStatus:
    def test_empty_db_reports_never(self, session):
        statuses = by_key(compute_sync_status(session))
        assert len(statuses) == 5
        assert all(s["status"] == "never" for s in statuses.values())
        assert all(s["last_received"] is None for s in statuses.values())

    def test_fresh_data_is_ok_and_stale_warns(self, session):
        fresh = Transaction(
            amount=Decimal("1"),
            merchant="X",
            date=utcnow(),
            source=TransactionSource.CREDIT_CARD,
            bank=Bank.BAC,
        )
        fresh.created_at = utcnow() - timedelta(days=1)
        stale_salary = Transaction(
            amount=Decimal("1"),
            merchant="EMPLOYER",
            date=utcnow(),
            transaction_type=TransactionType.SALARY,
            source=TransactionSource.TRANSFER,
        )
        stale_salary.created_at = utcnow() - timedelta(days=60)
        session.add(fresh)
        session.add(stale_salary)
        session.add(
            ExchangeRate(
                date=utcnow(),
                buy_rate=Decimal("500"),
                sell_rate=Decimal("510"),
            )
        )
        session.commit()

        statuses = by_key(compute_sync_status(session))
        assert statuses["bac_credit_card"]["status"] == "ok"
        assert statuses["bac_credit_card"]["age_days"] == 1.0
        assert statuses["salary"]["status"] == "warning"
        assert statuses["exchange_rate"]["status"] == "ok"
        assert statuses["municipal"]["status"] == "never"


class TestCsvExport:
    def _seed(self, session):
        cat = Category(name="Food")
        session.add(cat)
        session.commit()
        session.refresh(cat)
        session.add(
            Transaction(
                amount=Decimal("1500.50"),
                merchant="SODA, LA \"BUENA\"",  # exercises CSV quoting
                date=datetime(2026, 4, 2),
                category_id=cat.id,
                currency=Currency.CRC,
            )
        )
        session.add(
            Transaction(
                amount=Decimal("10"),
                merchant="CASHTHING",
                date=datetime(2026, 4, 3),
                source=TransactionSource.CASH,
            )
        )
        session.commit()

    def test_full_export_with_quoting_and_category(self, session):
        self._seed(session)
        text = build_transactions_csv(session)
        rows = list(csv.reader(io.StringIO(text)))
        assert rows[0][:3] == ["id", "date", "merchant"]
        assert len(rows) == 3  # header + 2
        newest_first = rows[1]
        assert newest_first[2] == "CASHTHING"
        soda = rows[2]
        assert soda[2] == 'SODA, LA "BUENA"'  # round-trips through quoting
        assert soda[4] == "1500.50"
        assert soda[9] == "Food"

    def test_source_filter(self, session):
        self._seed(session)
        text = build_transactions_csv(session, source=TransactionSource.CASH)
        rows = list(csv.reader(io.StringIO(text)))
        assert len(rows) == 2
        assert rows[1][2] == "CASHTHING"