"""FC-5: backup + rollback service tests.

Uses tmp_path to avoid touching real /images/_backups/. Subprocess
calls (pg_dump, tar) are monkeypatched — the real shell-out is exercised
in operator-side smoke testing on the homelab, not in unit tests.
"""
import pytest

from backend.app.services.migrators import backup as backup_mod

pytestmark = pytest.mark.integration


@pytest.mark.asyncio
async def test_create_backup_writes_sql_and_tar(monkeypatch, tmp_path):
    calls = []

    def fake_run(cmd, **kwargs):
        calls.append(cmd)
        # Touch the expected output file so existence checks pass downstream.
        if "pg_dump" in cmd[0]:
            outpath = tmp_path / "_backups" / f"fc_{kwargs['_test_ts']}.sql"
            outpath.write_text("-- fake pg_dump output")
        else:
            outpath = tmp_path / "_backups" / f"fc_{kwargs['_test_ts']}.tar.zst"
            outpath.write_bytes(b"\x28\xb5\x2f\xfd")  # zstd magic
        from types import SimpleNamespace
        return SimpleNamespace(returncode=0, stdout=b"", stderr=b"")

    monkeypatch.setattr(backup_mod, "_run_subprocess", fake_run)

    result = backup_mod.create_backup(
        db_url="postgresql://x", images_root=tmp_path, tag="pre_migration",
    )
    assert "sql_path" in result
    assert "tar_path" in result
    assert result["tag"] == "pre_migration"
    assert any("pg_dump" in c[0] for c in calls)
    assert any(c[0] == "tar" for c in calls)


@pytest.mark.asyncio
async def test_find_latest_backup_by_tag(monkeypatch, tmp_path):
    # Create two manifests with different tags.
    backups_dir = tmp_path / "_backups"
    backups_dir.mkdir()
    import json
    (backups_dir / "fc_20260101T000000Z.json").write_text(json.dumps({
        "backup_id": "20260101T000000Z", "tag": "manual",
        "created_at": "2026-01-01T00:00:00+00:00",
        "sql_path": "/x/a.sql", "tar_path": "/x/a.tar.zst",
    }))
    (backups_dir / "fc_20260202T000000Z.json").write_text(json.dumps({
        "backup_id": "20260202T000000Z", "tag": "pre_migration",
        "created_at": "2026-02-02T00:00:00+00:00",
        "sql_path": "/x/b.sql", "tar_path": "/x/b.tar.zst",
    }))

    found = backup_mod.find_latest_backup(tmp_path, tag="pre_migration")
    assert found is not None
    assert found["backup_id"] == "20260202T000000Z"

    missing = backup_mod.find_latest_backup(tmp_path, tag="nonexistent")
    assert missing is None