import os
import subprocess
from pathlib import Path

WORK = Path(os.environ["TB_WORK"])

EXPECTED_APP = '''VERSION = 2

DEFAULTS = {"retries": 3, "timeout": 30}


def main():
    return "v2"


def load(path):
    with open(path, "r", encoding="utf-8") as handle:
        return handle.read()
'''

ORIGINAL_SUBJECTS = [
    "Initial import",
    "Add plan notes",
    "Add config loader",
    "Drop legacy module",
    "Document build",
]


def git(*args):
    return subprocess.run(
        ["git"] + list(args),
        cwd=str(WORK),
        capture_output=True,
        text=True,
        encoding="utf-8",
    )


def subjects():
    result = git("log", "--format=%s", "main")
    assert result.returncode == 0, result.stderr
    return [line for line in result.stdout.splitlines() if line]


def test_app_py_restored_from_config_loader_commit():
    path = WORK / "src" / "app.py"
    assert path.is_file(), "src/app.py was not restored"
    assert path.read_text(encoding="utf-8") == EXPECTED_APP


def test_restore_commit_message():
    assert "restore app.py" in subjects()


def test_app_py_is_committed_not_just_written():
    result = git("ls-files", "--error-unmatch", "src/app.py")
    assert result.returncode == 0, "src/app.py is not tracked"


def test_recovered_branch_points_at_the_wip_commit():
    ref = git("rev-parse", "--verify", "refs/heads/recovered")
    assert ref.returncode == 0, "branch 'recovered' does not exist"
    message = git("log", "-1", "--format=%s", "recovered")
    assert message.stdout.strip() == "wip: plan"


def test_recovered_is_not_an_ancestor_of_main():
    ref = git("rev-parse", "--verify", "refs/heads/recovered")
    assert ref.returncode == 0, "branch 'recovered' does not exist"
    result = git("merge-base", "--is-ancestor", "recovered", "main")
    assert result.returncode == 1, "the rescued commit must stay off main"


def test_recovered_commit_keeps_the_work_in_progress_plan():
    blob = git("show", "recovered:notes/plan.md")
    assert blob.returncode == 0, "recovered commit has no notes/plan.md"
    assert "step two" in blob.stdout


def test_tag_v1_points_at_the_config_loader_commit():
    tag = git("rev-list", "-n", "1", "v1.0")
    assert tag.returncode == 0, "tag v1.0 does not exist"
    subject = git("log", "-1", "--format=%s", tag.stdout.strip())
    assert subject.stdout.strip() == "Add config loader"


def test_junk_is_ignored_but_still_present():
    for rel in ("debug.log", "build/tmp.o"):
        assert (WORK / rel).is_file(), "%s was deleted" % rel
        result = git("check-ignore", "-q", rel)
        assert result.returncode == 0, "%s is not ignored" % rel


def test_worktree_is_clean():
    status = git("status", "--porcelain")
    assert status.stdout.strip() == "", "dirty tree:\n%s" % status.stdout


def test_original_history_is_preserved():
    current = subjects()
    for subject in ORIGINAL_SUBJECTS:
        assert subject in current, "commit %r disappeared from main" % subject