"""PRD §5.4 FRFM046 / FRFM049 — daily GL re-validation + recovery."""
from __future__ import annotations

from datetime import timedelta
from decimal import Decimal
from unittest.mock import patch

import pytest
from django.utils import timezone

from apps.core.audit.models import AuditLog
from apps.core.audit.tasks import persist_audit_log
from apps.rims.finance.models import (
    Budget,
    BudgetLine,
    DisbursementExecution,
    DisbursementRequest,
    GLEntry,
)
from apps.rims.finance.services_gl import post_gl_entries, revalidate_gl_entry
from apps.rims.finance.tasks import revalidate_gl_entries
from apps.rims.grants.models import Application, Award, GrantCall


@pytest.fixture(autouse=True)
def _sync_audit():
    with patch("apps.core.audit.tasks.write_audit_log.delay", side_effect=lambda **kw: persist_audit_log(**kw)):
        with patch(
            "apps.core.audit.mixins.transaction.on_commit",
            side_effect=lambda fn: fn(),
        ):
            yield


def _executed(applicant_user, institution, finance_user) -> DisbursementExecution:
    call = GrantCall.objects.create(
        title=f"6F-rev call {timezone.now().timestamp()}",
        slug=f"6f-rev-{int(timezone.now().timestamp() * 1000) % 10_000_000}",
        call_type="grant",
        opens_at=timezone.now() - timedelta(days=200),
        closes_at=timezone.now() + timedelta(days=10),
        status=GrantCall.Status.PUBLISHED,
    )
    app = Application.objects.create(call=call, applicant=applicant_user, institution=institution)
    award = Award.objects.create(
        application=app,
        amount=Decimal("4000"),
        currency="USD",
        awarded_at=timezone.now(),
        project_end_date=timezone.now().date() + timedelta(days=365),
    )
    budget = Budget.objects.create(award=award, name="Rev budget", currency="USD")
    BudgetLine.objects.create(budget=budget, label="L", amount=Decimal("4000"))
    request = DisbursementRequest.objects.create(
        budget=budget,
        amount=Decimal("500.00"),
        requested_by=finance_user,
        status=DisbursementRequest.Status.APPROVED,
    )
    exe = DisbursementExecution.objects.create(
        request=request,
        status=DisbursementExecution.Status.EXECUTED,
        executed_at=timezone.now(),
    )
    return exe


@pytest.mark.django_db
def test_revalidate_flags_unbalanced_pair(applicant_user, institution, finance_user):
    """PRD §5.4 FRFM049 — re-validation flips broken pair to flagged."""
    execution = _executed(applicant_user, institution, finance_user)
    # Manually mutate one half of the pair to break balance.
    entries = list(GLEntry.objects.filter(execution=execution))
    assert len(entries) == 2
    debit = next(e for e in entries if e.debit)
    debit.debit = Decimal("999.99")
    debit.save(update_fields=["debit"])
    revalidate_gl_entry(debit)
    debit.refresh_from_db()
    assert debit.validation_status == GLEntry.ValidationStatus.FLAGGED
    assert AuditLog.objects.filter(action="GL_FLAGGED").exists()


@pytest.mark.django_db
def test_celery_beat_recovers_pending_executions(applicant_user, institution, finance_user):
    """PRD §5.4 FRFM046 — the daily beat posts GL rows for executions stuck
    in gl_posting_status='pending' from a signal failure."""
    execution = _executed(applicant_user, institution, finance_user)
    # Wipe GLEntries and reset gl_posting_status to simulate signal failure.
    GLEntry.objects.filter(execution=execution).delete()
    DisbursementExecution.objects.filter(pk=execution.pk).update(gl_posting_status="pending")
    count = revalidate_gl_entries()
    assert count >= 1
    execution.refresh_from_db()
    assert execution.gl_posting_status == "posted"
    assert GLEntry.objects.filter(execution=execution).count() == 2