from tht.teardown import teardown_to_phase


def test_teardown_to_phase_4_deletes_phase5plus_artifacts(tmp_path):
    s = tmp_path / "sess"
    s.mkdir()
    (s / "schema_linking.json").write_text("{}")    # F4 artifact
    (s / "cte_plan.json").write_text("[]")          # F6 artifact
    (s / "ctes").mkdir()
    (s / "ctes" / "x.sql").write_text("SELECT 1")   # F6 artifact
    (s / "sql_final.sql").write_text("SELECT 1")    # F7 artifact
    report = teardown_to_phase(s, target_phase=4)
    assert (s / "schema_linking.json").exists()     # F4 preserved (target is 4)
    assert not (s / "cte_plan.json").exists()       # F6 deleted (>4)
    assert not (s / "ctes").exists()                # F6 dir deleted
    assert not (s / "sql_final.sql").exists()       # F7 deleted
    assert "cte_plan.json" in report.deleted_files
    assert "sql_final.sql" in report.deleted_files


def test_teardown_to_phase_1_deletes_everything(tmp_path):
    """Rollback a F1 cancella tutti gli artefatti (tutte le fasi > 1)."""
    s = tmp_path / "sess"
    s.mkdir()
    (s / "question.md").write_text("q")             # F3 artifact
    (s / "schema_linking.json").write_text("{}")    # F4 artifact
    (s / "cte_plan.json").write_text("[]")          # F6 artifact
    (s / "ctes").mkdir()
    (s / "ctes" / "a.sql").write_text("SELECT 1")
    (s / "sql_final.sql").write_text("SELECT 1")    # F7 artifact
    report = teardown_to_phase(s, target_phase=1)
    assert not (s / "question.md").exists()
    assert not (s / "schema_linking.json").exists()
    assert not (s / "cte_plan.json").exists()
    assert not (s / "ctes").exists()
    assert not (s / "sql_final.sql").exists()
    assert len(report.deleted_files) >= 4


def test_teardown_to_phase_7_preserves_phase6_artifacts(tmp_path):
    """Rollback a F7 preserva gli artefatti delle fasi <= 7."""
    s = tmp_path / "sess"
    s.mkdir()
    (s / "schema_linking.json").write_text("{}")    # F4 artifact
    (s / "cte_plan.json").write_text("[]")          # F6 artifact
    (s / "ctes").mkdir()
    (s / "ctes" / "a.sql").write_text("SELECT 1")   # F6 artifact
    (s / "sql_final.sql").write_text("SELECT 1")    # F7 artifact
    report = teardown_to_phase(s, target_phase=7)
    assert (s / "schema_linking.json").exists()
    assert (s / "cte_plan.json").exists()
    assert (s / "ctes").exists()
    assert (s / "sql_final.sql").exists()           # F7 preserved (target is 7)
    assert report.deleted_files == []               # nothing > 7 has artifacts


def test_teardown_to_phase_on_empty_session_is_noop(tmp_path):
    s = tmp_path / "sess"
    s.mkdir()
    report = teardown_to_phase(s, target_phase=4)
    assert report.deleted_files == []


def test_teardown_to_phase_nonexistent_artifacts_no_error(tmp_path):
    """Se gli artefatti non esistono (sessione nuova), teardown non fallisce."""
    s = tmp_path / "sess"
    s.mkdir()
    report = teardown_to_phase(s, target_phase=1)
    assert report.deleted_files == []


def test_teardown_deletes_orphaned_cte_files_not_in_current_plan(tmp_path):
    """Il bug degli orfani CTE: dopo un re-derive con piano diverso, i vecchi .sql
    non piu' nel piano restano su disco e bloccano finalize. teardown li pulisce."""
    s = tmp_path / "sess"
    s.mkdir()
    (s / "ctes").mkdir()
    (s / "ctes" / "old_cte.sql").write_text("SELECT 1")   # orphan
    (s / "ctes" / "another.sql").write_text("SELECT 2")   # orphan
    report = teardown_to_phase(s, target_phase=5)  # F6 has ctes/ as artifact
    assert not (s / "ctes").exists()
    # i nomi dei file orfani sono registrati
    assert "old_cte.sql" in report.deleted_files
    assert "another.sql" in report.deleted_files