import sqlite3
from pathlib import Path

import pytest

from fin_hub.services.evaluate import evaluate_runway
from fin_hub.services.evidence import build_runway_report, seed_fixture_ledger, write_runway_evidence
from fin_hub.services.ledger import import_csv, monthly_burn_series, monthly_summary, set_opening_balance

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


def test_ledger_import_and_monthly_summary(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    set_opening_balance(ledger, 12000.0)

    cloud = import_csv(FIXTURES / "cloud-costs.csv", "cloud", ledger_path=ledger)
    host = import_csv(FIXTURES / "hosteurope.csv", "hosteurope", ledger_path=ledger)

    assert cloud.rows_imported == 3
    assert host.rows_imported == 2

    rollups = monthly_summary(ledger_path=ledger)
    eur_totals = {rollup.period_month: rollup.total for rollup in rollups if rollup.currency == "EUR"}
    assert eur_totals["2026-06"] == pytest.approx(85.5 + 99.8)

    burns = monthly_burn_series(ledger_path=ledger, currency="EUR")
    assert burns == [pytest.approx(185.3)]


def test_ledger_import_skips_unchanged_file(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    first = import_csv(FIXTURES / "cloud-costs.csv", "cloud", ledger_path=ledger)
    second = import_csv(FIXTURES / "cloud-costs.csv", "cloud", ledger_path=ledger)
    assert first.rows_imported == 3
    assert second.skipped is True
    assert second.rows_imported == 0


def test_ledger_import_preserves_client_attribution(tmp_path: Path):
    source = tmp_path / "attributed.csv"
    source.write_text(
        "product,amount,currency,invoice_date,client_id,application_id,app_instance_id\n"
        "Managed cluster,42.00,EUR,2026-07-01,acme,portal,prod-01\n",
        encoding="utf-8",
    )
    ledger = tmp_path / "ledger.db"

    import_csv(source, "hosteurope", ledger_path=ledger)

    with sqlite3.connect(ledger) as conn:
        row = conn.execute(
            "SELECT client_id, application_id, app_instance_id, cost_attribution_key "
            "FROM ledger_entries"
        ).fetchone()
    assert row == (
        "acme",
        "portal",
        "prod-01",
        "client:acme|app:portal|instance:prod-01",
    )


def test_existing_ledger_schema_is_migrated_additively(tmp_path: Path):
    ledger = tmp_path / "legacy.db"
    with sqlite3.connect(ledger) as conn:
        conn.execute(
            "CREATE TABLE ledger_entries ("
            "id INTEGER PRIMARY KEY, source_type TEXT NOT NULL, category TEXT NOT NULL, "
            "label TEXT NOT NULL, amount REAL NOT NULL, currency TEXT NOT NULL, "
            "period_month TEXT NOT NULL, incurred_on TEXT, source_path TEXT NOT NULL, "
            "imported_at TEXT NOT NULL)"
        )

    monthly_summary(ledger_path=ledger)

    with sqlite3.connect(ledger) as conn:
        columns = {row[1] for row in conn.execute("PRAGMA table_info(ledger_entries)")}
    assert {
        "client_id",
        "application_id",
        "app_instance_id",
        "cost_attribution_key",
    }.issubset(columns)


def test_evaluate_runway_from_ledger(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    seed_fixture_ledger(ledger_path=ledger, opening_balance=12000.0)
    report = evaluate_runway(ledger_path=ledger, alert_threshold_months=3.0)
    assert report["runway"]["current_balance"] == 12000.0
    assert report["runway"]["monthly_burn"] > 0


def test_build_runway_report_and_write_evidence(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    seed_fixture_ledger(ledger_path=ledger, opening_balance=12000.0)
    text = build_runway_report(ledger_path=ledger)
    assert "Runway Dogfood Evidence" in text
    assert "2026-06" in text

    output = write_runway_evidence(
        ledger_path=ledger,
        output_dir=tmp_path / "evidence",
        opening_balance=12000.0,
    )
    assert output.exists()
    assert "runway-dogfood-" in output.name