"""Minimal tests for git_helper standalone execution and get_backup_branch_name.

git_helper.py runs as a subprocess on Windows and must NOT import comfyui_manager.
Tests validate: (1) no forbidden imports via AST, (2) subprocess-level standalone
execution, (3) get_backup_branch_name behavioural correctness.
"""

import ast
import pathlib
import subprocess
import sys
import textwrap

import pytest

_GIT_HELPER_PATH = pathlib.Path(__file__).resolve().parents[2] / "comfyui_manager" / "common" / "git_helper.py"


# ---------------------------------------------------------------------------
# 1. No comfyui_manager imports (AST check — no execution)
# ---------------------------------------------------------------------------

def test_no_comfyui_manager_import():
    """git_helper.py must be free of comfyui_manager imports (Windows subprocess safety)."""
    tree = ast.parse(_GIT_HELPER_PATH.read_text(encoding="utf-8"))
    for node in ast.walk(tree):
        if isinstance(node, ast.ImportFrom) and node.module and "comfyui_manager" in node.module:
            pytest.fail(f"Forbidden import at line {node.lineno}: from {node.module}")


# ---------------------------------------------------------------------------
# 2. Standalone subprocess execution (mirrors the actual Windows bug scenario)
# ---------------------------------------------------------------------------

def test_standalone_subprocess_can_load(tmp_path):
    """git_helper.py must load in a subprocess without comfyui_manager on sys.path."""
    (tmp_path / "folder_paths.py").touch()

    # Run git_helper.py in a clean subprocess with stripped sys.path.
    # git_helper.py has a module-level sys.argv dispatcher that calls sys.exit,
    # so we set argv to --check with a dummy path to avoid IndexError, then
    # catch the SystemExit to verify the function loaded successfully.
    script = textwrap.dedent(f"""\
        import sys, os
        sys.path = [p for p in sys.path
                    if "comfyui_manager" not in p and "comfyui-manager" not in p]
        os.environ["COMFYUI_PATH"] = {str(tmp_path)!r}

        import importlib.util
        spec = importlib.util.spec_from_file_location("git_helper", {str(_GIT_HELPER_PATH)!r})
        mod = importlib.util.module_from_spec(spec)

        # Intercept sys.exit from module-level argv dispatcher
        real_exit = sys.exit
        exit_code = [None]
        def fake_exit(code=0):
            exit_code[0] = code
            raise SystemExit(code)
        sys.exit = fake_exit

        try:
            spec.loader.exec_module(mod)
        except SystemExit:
            pass
        finally:
            sys.exit = real_exit

        # The function must be defined regardless of argv dispatcher outcome
        assert hasattr(mod, "get_backup_branch_name"), "Function not defined"
        name = mod.get_backup_branch_name()
        assert name.startswith("backup_"), f"Bad name: {{name}}"
        print(f"OK: {{name}}")
    """)

    result = subprocess.run(
        [sys.executable, "-c", script],
        capture_output=True, text=True, timeout=30,
    )
    assert result.returncode == 0, f"stderr: {result.stderr}"
    assert "OK: backup_" in result.stdout


# ---------------------------------------------------------------------------
# 3. get_backup_branch_name behavioural tests (function extracted via AST)
# ---------------------------------------------------------------------------

@pytest.fixture(scope="module")
def _get_backup_branch_name():
    """Extract and compile get_backup_branch_name from git_helper.py source."""
    source = _GIT_HELPER_PATH.read_text(encoding="utf-8")
    tree = ast.parse(source)

    for node in ast.walk(tree):
        if isinstance(node, ast.FunctionDef) and node.name == "get_backup_branch_name":
            func_source = ast.get_source_segment(source, node)
            assert func_source is not None
            ns = {}
            exec(compile(ast.parse(func_source), "<test>", "exec"), ns)  # noqa: S102
            return ns["get_backup_branch_name"]

    pytest.fail("get_backup_branch_name not found in git_helper.py")


class _FakeHead:
    def __init__(self, name):
        self.name = name


class _FakeRepo:
    def __init__(self, branch_names):
        self.heads = [_FakeHead(n) for n in branch_names]


def test_basic_name_format(_get_backup_branch_name):
    import time
    name = _get_backup_branch_name()
    assert name.startswith("backup_")
    expected = f"backup_{time.strftime('%Y%m%d_%H%M%S')}"
    assert name == expected


def test_no_collision(_get_backup_branch_name):
    repo = _FakeRepo(["main", "dev"])
    name = _get_backup_branch_name(repo)
    assert name.startswith("backup_")


def test_single_collision(_get_backup_branch_name):
    import time
    ts = time.strftime("%Y%m%d_%H%M%S")
    repo = _FakeRepo(["main", f"backup_{ts}"])
    name = _get_backup_branch_name(repo)
    assert name == f"backup_{ts}_1"


def test_multi_collision(_get_backup_branch_name):
    import time
    ts = time.strftime("%Y%m%d_%H%M%S")
    repo = _FakeRepo([f"backup_{ts}", f"backup_{ts}_1", f"backup_{ts}_2"])
    name = _get_backup_branch_name(repo)
    assert name == f"backup_{ts}_3"


def test_repo_none_returns_base(_get_backup_branch_name):
    name = _get_backup_branch_name(None)
    assert name.startswith("backup_")


def test_repo_heads_exception_returns_base(_get_backup_branch_name):
    """When repo.heads raises, fall back to base name without suffix."""

    class _BrokenRepo:
        @property
        def heads(self):
            raise RuntimeError("simulated git error")

    name = _get_backup_branch_name(_BrokenRepo())
    assert name.startswith("backup_")
    assert "_1" not in name  # no suffix — exception path returns base


def test_uuid_fallback_on_full_collision(_get_backup_branch_name):
    """When all 99 suffixes are taken, fall back to UUID."""
    import time
    ts = time.strftime("%Y%m%d_%H%M%S")
    # All names from backup_TS through backup_TS_99 are taken
    taken = [f"backup_{ts}"] + [f"backup_{ts}_{i}" for i in range(1, 100)]
    repo = _FakeRepo(taken)
    name = _get_backup_branch_name(repo)
    assert name.startswith(f"backup_{ts}_")
    # UUID suffix is 6 hex chars
    suffix = name[len(f"backup_{ts}_"):]
    assert len(suffix) == 6, f"Expected 6-char UUID suffix, got: {suffix}"