import json
from pathlib import Path

import pytest

from fin_hub.services.exchange import ingest_planning_evidence
from fin_hub.services.ledger import import_csv, monthly_summary
from fin_hub.services.session_tokens import (
    ingest_session_token_evidence,
    ingest_session_token_file,
    list_current_session_token_evidence,
    summarize_session_token_evidence,
)

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


def test_ingest_mixed_aggregates_and_summarize(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    record = ingest_session_token_file(
        FIXTURES / "session-tokens-2026-08.json", ledger_path=ledger
    )
    again = ingest_session_token_file(
        FIXTURES / "session-tokens-2026-08.json", ledger_path=ledger
    )
    assert again.record_id == record.record_id
    summary = summarize_session_token_evidence(record)
    assert summary.unknown_residual is False
    assert summary.tokens_measured == 150
    assert summary.tokens_derived == 30
    assert summary.tokens_estimated == 1500
    assert "excluded" not in summary.by_basis
    assert set(summary.by_basis) == {"measured", "derived", "estimated"}
    assert summary.by_basis["derived"].method == "state-hub-task-share"
    stored = list_current_session_token_evidence(ledger_path=ledger)
    assert [item.record_id for item in stored] == [record.record_id]
    assert monthly_summary(ledger_path=ledger) == []


def test_empty_month_is_unknown_residual_not_zero(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    record = ingest_session_token_evidence(
        {
            "record_id": "session-tokens:state-hub:2026-07",
            "period_start": "2026-07-01",
            "period_end": "2026-07-31",
            "captured_at": "2026-08-15T12:00:00Z",
            "source_evidence": ["state-hub:/token-events/aggregate/?month=2026-07"],
            "totals": {
                "superseded": {
                    "tokens_in": 9,
                    "tokens_out": 1,
                    "event_count": 1,
                    "confidence": "0",
                }
            },
        },
        ledger_path=ledger,
    )
    summary = summarize_session_token_evidence(record)
    assert summary.unknown_residual is True
    assert summary.tokens_measured is None
    assert summary.tokens_derived is None
    assert summary.tokens_estimated is None
    assert summary.coverage is None


def test_allocated_events_require_a_method():
    with pytest.raises(ValueError, match="method"):
        ingest_session_token_evidence(
            {
                "record_id": "session-tokens:bad",
                "period_start": "2026-08-01",
                "period_end": "2026-08-31",
                "captured_at": "2026-08-15T12:00:00Z",
                "source_evidence": ["state-hub"],
                "totals": {
                    "allocated": {
                        "tokens_in": 1,
                        "tokens_out": 1,
                        "event_count": 1,
                    }
                },
            },
            ledger_path=Path("/tmp/unused"),
        )


def test_session_tokens_cannot_be_posted_as_planning_usage(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    payload = json.loads((FIXTURES / "session-tokens-2026-08.json").read_text())
    with pytest.raises(ValueError, match="not resource-control"):
        ingest_planning_evidence(payload, ledger_path=ledger)
    with pytest.raises(ValueError, match="usage_observation"):
        ingest_session_token_evidence(
            {
                "record_type": "usage_observation",
                "record_id": "usage:1",
                "period_start": "2026-08-01",
                "period_end": "2026-08-31",
                "resource_id": "resource:invented",
                "source_evidence": ["nope"],
                "created_at": "2026-08-15T12:00:00Z",
                "measures": [{"name": "tokens", "value": "1", "unit": "token"}],
            },
            ledger_path=ledger,
        )


def test_session_tokens_cannot_be_imported_as_booked_spend(tmp_path: Path):
    ledger = tmp_path / "ledger.db"
    with pytest.raises(ValueError, match="Unknown source type"):
        import_csv(FIXTURES / "session-tokens-2026-08.json", "session-tokens", ledger_path=ledger)
    with pytest.raises(ValueError, match="booked spend"):
        ingest_session_token_evidence(
            {
                "record_type": "booked_cost",
                "financial_fact_id": "fact:1",
            },
            ledger_path=ledger,
        )