import importlib.util
from pathlib import Path
import subprocess

import pytest


SCRIPT = Path(__file__).parents[1] / "scripts/install_shared_generated_guard.py"
spec = importlib.util.spec_from_file_location("shared_guard", SCRIPT)
guard = importlib.util.module_from_spec(spec)
spec.loader.exec_module(guard)


def repository(tmp_path):
    repo = tmp_path / "repo"
    repo.mkdir()
    subprocess.run(["git", "init", str(repo)], check=True, capture_output=True)
    hooks = tmp_path / "shared-hooks"
    hooks.mkdir()
    subprocess.run(["git", "-C", str(repo), "config", "core.hooksPath", str(hooks)], check=True)
    return repo, hooks


def test_real_shared_hook_rejects_generated_only_and_retains_other_hooks(tmp_path):
    repo, hooks = repository(tmp_path)
    other = hooks / "prepare-commit-msg"
    other.write_text("# existing owner hook\n")
    before = other.read_bytes()
    assert guard.install(repo)["status"] == "missing"
    assert not (hooks / "pre-commit").exists()
    assert guard.install(repo, True)["changed"]
    assert not guard.install(repo, True)["changed"]
    (repo / "WORK-RECORDS.md").write_text("derived\n")
    subprocess.run(["git", "-C", str(repo), "add", "WORK-RECORDS.md"], check=True)
    assert subprocess.run([str(hooks / "pre-commit")], cwd=repo, capture_output=True).returncode == 1
    (repo / "implementation.py").write_text("print('source')\n")
    subprocess.run(["git", "-C", str(repo), "add", "implementation.py"], check=True)
    assert subprocess.run([str(hooks / "pre-commit")], cwd=repo, capture_output=True).returncode == 0
    assert other.read_bytes() == before


def test_foreign_or_redirected_guard_is_never_replaced(tmp_path):
    repo, hooks = repository(tmp_path)
    hook = hooks / "pre-commit"
    hook.write_text("owner implementation\n")
    with pytest.raises(ValueError):
        guard.install(repo, True)
    assert hook.read_text() == "owner implementation\n"
    hook.unlink()
    private = tmp_path / "unrelated"
    private.write_text("retained\n")
    hook.symlink_to(private)
    with pytest.raises(ValueError):
        guard.install(repo, True)
    assert private.read_text() == "retained\n"


def test_reviewed_scanner_composition_is_preserved(tmp_path):
    repo, hooks = repository(tmp_path)
    content = (SCRIPT.parents[1] / 'docs/changes/CUST-WP-0080/secret-hooks-pre-commit').read_bytes()
    hook = hooks / 'pre-commit'
    hook.write_bytes(content)
    hook.chmod(0o755)
    assert not guard.install(repo, True)['changed']
    assert hook.read_bytes() == content
    hook.write_bytes(content + b'\n# unreviewed revision\n')
    with pytest.raises(ValueError):
        guard.install(repo, True)


@pytest.mark.parametrize("existing_local", [False, True])
def test_make_install_recognizes_existing_shared_guard(tmp_path, existing_local):
    import shutil

    repo, hooks = repository(tmp_path)
    source = SCRIPT.parents[1]
    shutil.copyfile(source / "Makefile", repo / "Makefile")
    (repo / "scripts").mkdir()
    for name in ("install_shared_generated_guard.py", "check_generated_only_commit.py",
                 "generated-pre-commit.sh"):
        shutil.copyfile(source / "scripts" / name, repo / "scripts" / name)
    if existing_local:
        hooks = repo / ".git" / "hooks"
        subprocess.run(["git", "-C", str(repo), "config", "core.hooksPath", str(hooks)], check=True)
        shutil.copyfile(source / "scripts/generated-pre-commit.sh", hooks / "pre-commit")
        (hooks / "pre-commit").chmod(0o755)
    other = hooks / "prepare-commit-msg"
    other.write_text("owner hook\n")
    for _ in range(2):
        result = subprocess.run(["make", "generated-commit-hook"], cwd=repo,
                                capture_output=True, text=True)
        assert result.returncode == 0, result.stderr
    assert other.read_text() == "owner hook\n"
    (repo / "WORK-RECORDS.md").write_text("generated\n")
    subprocess.run(["git", "-C", str(repo), "add", "WORK-RECORDS.md"], check=True)
    assert subprocess.run([str(hooks / "pre-commit")], cwd=repo,
                          capture_output=True).returncode == 1


def test_reviewed_hook_generation_upgrade_preserves_scanner(tmp_path):
    repo, hooks = repository(tmp_path)
    original = (SCRIPT.parents[1] / 'docs/changes/CUST-WP-0080/secret-hooks-pre-commit').read_bytes()
    hook = hooks / 'pre-commit'
    hook.write_bytes(original)
    hook.chmod(0o755)
    assert guard.install(repo, True, enable_generation=True)['changed']
    marker = b'python3 /home/worsch/the-custodian/scripts/run_generated_work_records_hook.py\n'
    assert hook.read_bytes().replace(marker, b'') == original
    assert not guard.install(repo, True, enable_generation=True)['changed']
    (repo / 'WORK-RECORDS.md').write_text('generated only')
    subprocess.run(['git', '-C', str(repo), 'add', 'WORK-RECORDS.md'], check=True)
    assert subprocess.run([str(hook)], cwd=repo, capture_output=True).returncode == 1