# =============================================================================
# Projet : AIR — Accounting Intermediate Representation
# Auteur : Simon-Pierre Boucher
# Contact : contact@spboucher.ai
# Fichier : test_golden.py
# Description : Golden tests — AIR documents compiled against expected journal entries.
# =============================================================================
"""Golden tests.

Each case in tests/golden/cases/*.yaml holds an AIR document and the exact
journal entries the compiler must produce under the ca-qc-2026 policy set.
Expected figures are derived from cited official sources
(docs/research/canada-gst-qst.md, fx-handling.md) — never from memory.
"""
from __future__ import annotations

from decimal import Decimal
from pathlib import Path

import pytest
import yaml

from aic.compiler import compile_document
from alsl.loader import load_policy_set
from core.events import AirDocument

ROOT = Path(__file__).resolve().parents[2]
CASES_DIR = Path(__file__).parent / "cases"
POLICY_FILE = ROOT / "alsl" / "policies" / "ca-qc-2026.yaml"


def _load_cases() -> list[dict]:
    cases: list[dict] = []
    for path in sorted(CASES_DIR.glob("*.yaml")):
        data = yaml.safe_load(path.read_text(encoding="utf-8"))
        cases.extend(data["cases"])
    return cases

CASES = _load_cases()


@pytest.fixture(scope="module")
def policies():
    return load_policy_set(POLICY_FILE)


def _lines_as_tuples(lines) -> list[tuple[str, str, Decimal, str]]:
    return sorted(
        (l.account.code, l.side.value, l.amount.amount, l.amount.currency)
        for l in lines
    )


def _expected_as_tuples(raw) -> list[tuple[str, str, Decimal, str]]:
    return sorted(
        (str(acct), str(side), Decimal(str(amount)), str(ccy))
        for acct, side, amount, ccy in raw
    )


@pytest.mark.parametrize("case", CASES, ids=[c["name"] for c in CASES])
def test_golden(case: dict, policies) -> None:
    document = AirDocument.model_validate(case["air"])
    journal, _diags = compile_document(document, policies)

    entries = {e.id: e for e in journal.entries}
    expected = {e["id"]: e for e in case["expected_entries"]}

    assert sorted(entries) == sorted(expected), (
        f"{case['name']}: produced entries {sorted(entries)} "
        f"!= expected {sorted(expected)}"
    )
    for entry_id, exp in expected.items():
        got = _lines_as_tuples(entries[entry_id].lines)
        want = _expected_as_tuples(exp["lines"])
        assert got == want, (
            f"{case['name']} / {entry_id}:\n  got:  {got}\n  want: {want}"
        )


def test_all_golden_lines_have_provenance(policies) -> None:
    """Traceability: every posted line points into the provenance graph and
    traces back to a subtotal rooted in the source event."""
    for case in CASES:
        document = AirDocument.model_validate(case["air"])
        journal, _ = compile_document(document, policies)
        for entry in journal.entries:
            for line in entry.lines:
                assert line.provenance_id is not None
                chain = journal.provenance.trace(line.provenance_id)
                roots = [n for n in chain if n.kind == "event_subtotal"]
                assert roots, f"{case['name']}: line has no event_subtotal root"
                assert roots[-1].source_ref == entry.source_event_id