from pathlib import Path

import pytest

from fin_hub.services.ledger import (
    import_csv,
    list_current_plan_entitlements,
    plan_month_report,
    record_plan_entitlement,
)

FIXTURES = Path(__file__).parent / "fixtures"


def test_unknown_token_entitlement_requires_plan_label(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    with pytest.raises(ValueError, match="plan_label"):
        record_plan_entitlement(
            provider="anthropic",
            plan="claude-max",
            period_month="2026-08",
            unit="token",
            quantity="unknown",
            source="vendor-plan",
            ledger_path=ledger,
        )
    record = record_plan_entitlement(
        provider="anthropic",
        plan="claude-max",
        period_month="2026-08",
        unit="plan",
        plan_label="Max 20x",
        source="vendor-plan",
        ledger_path=ledger,
    )
    assert record.quantity is None
    assert record.quantity_unknown is True
    assert record.unit == "plan"
    assert record.plan_label == "Max 20x"


def test_plan_entitlement_revision_is_append_only(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    original = record_plan_entitlement(
        provider="openai",
        provider_account="org-demo",
        plan="api-prepaid",
        period_month="2026-08",
        unit="token",
        quantity=1_000_000,
        currency="EUR",
        source="dashboard-v1",
        ledger_path=ledger,
    )
    with pytest.raises(ValueError, match=original.id):
        record_plan_entitlement(
            provider="openai",
            provider_account="org-demo",
            plan="api-prepaid",
            period_month="2026-08",
            unit="token",
            quantity=2_000_000,
            currency="EUR",
            source="dashboard-v2",
            ledger_path=ledger,
        )
    revised = record_plan_entitlement(
        provider="openai",
        provider_account="org-demo",
        plan="api-prepaid",
        period_month="2026-08",
        unit="token",
        quantity=2_000_000,
        currency="EUR",
        source="dashboard-v2",
        revision_of=original.id,
        ledger_path=ledger,
    )
    current = list_current_plan_entitlements(ledger_path=ledger)
    assert [row.id for row in current] == [revised.id]
    assert current[0].quantity == 2_000_000
    assert current[0].revision_of == original.id
    assert current[0].quantity_unknown is False


def test_plan_month_report_joins_booked_cost_to_unknown_capacity(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    import_csv(FIXTURES / "ai-plans.csv", "ai-plan", ledger_path=ledger)
    record_plan_entitlement(
        provider="anthropic",
        plan="claude-max",
        period_month="2026-08",
        unit="plan",
        plan_label="Max 20x",
        currency="EUR",
        source="vendor-plan",
        ledger_path=ledger,
    )
    record_plan_entitlement(
        provider="openai",
        provider_account="org-demo",
        plan="api-prepaid",
        period_month="2026-08",
        unit="token",
        quantity=500_000,
        currency="EUR",
        source="usage-dashboard",
        ledger_path=ledger,
    )

    rows = {f"{row.provider}:{row.plan}": row for row in plan_month_report(ledger_path=ledger)}
    claude = rows["anthropic:claude-max"]
    assert claude.booked_amount == 200
    assert claude.booked_currency == "EUR"
    assert claude.entitled_quantity is None
    assert claude.quantity_unknown is True
    assert claude.plan_label == "Max 20x"
    assert claude.join_status == "matched"
    openai = rows["openai:api-prepaid"]
    assert openai.booked_amount == 40
    assert openai.entitled_quantity == 500_000
    assert openai.join_status == "matched"


def test_plan_month_does_not_silently_join_currency_mismatch(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    import_csv(FIXTURES / "ai-plans.csv", "ai-plan", ledger_path=ledger)
    record_plan_entitlement(
        provider="anthropic",
        plan="claude-max",
        period_month="2026-08",
        unit="token",
        quantity=100,
        currency="USD",
        source="vendor-plan",
        ledger_path=ledger,
    )
    row = plan_month_report(ledger_path=ledger, period_month="2026-08")[0]
    assert row.provider == "anthropic"
    assert row.booked_currency == "EUR"
    assert row.entitled_quantity == 100
    assert row.join_status == "currency_mismatch"


def test_multiplier_does_not_invent_a_token_ceiling(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    record = record_plan_entitlement(
        provider="anthropic",
        plan="claude-max",
        period_month="2026-08",
        unit="multiplier",
        quantity=20,
        plan_label="Max 20x",
        source="vendor-plan",
        ledger_path=ledger,
    )
    assert record.unit == "multiplier"
    assert record.quantity == 20
    assert record.quantity_unknown is False
    report = plan_month_report(ledger_path=ledger)
    assert report[0].join_status == "entitlement_only"
    assert report[0].booked_amount is None
    assert report[0].entitled_quantity == 20