"""Unit tests for porcelain parsing and ChangeType mapping (Section 6)."""

from __future__ import annotations

import pytest

from git_auto_tracker.changes.models import ChangeType
from git_auto_tracker.errors import GitError
from git_auto_tracker.git.status import RawStatusEntry, parse_porcelain_z


def _build(entries: list[tuple[str, str, str | None]]) -> bytes:
    """Serialize porcelain -z records: 'XY path' + optional origin path."""
    parts: list[bytes] = []
    for xy, path, previous in entries:
        parts.append(f"{xy} {path}".encode())
        if previous:
            parts.append(previous.encode())
    return b"\x00".join(parts) + b"\x00"


class TestParsePorcelainZ:
    def test_modified(self) -> None:
        raw = _build([(" M", "config.xml", None)])
        (entry,) = parse_porcelain_z(raw)
        assert entry.path == "config.xml"
        assert entry.change_type is ChangeType.MODIFIED

    def test_untracked_is_added(self) -> None:
        raw = _build([("??", "new.xml", None)])
        (entry,) = parse_porcelain_z(raw)
        assert entry.change_type is ChangeType.ADDED

    def test_deleted(self) -> None:
        raw = _build([(" D", "gone.xml", None)])
        (entry,) = parse_porcelain_z(raw)
        assert entry.change_type is ChangeType.DELETED

    def test_staged_deletion(self) -> None:
        raw = _build([("D ", "gone.xml", None)])
        (entry,) = parse_porcelain_z(raw)
        assert entry.change_type is ChangeType.DELETED

    def test_rename_with_previous(self) -> None:
        raw = _build([("R ", "new.xml", "old.xml")])
        (entry,) = parse_porcelain_z(raw)
        assert entry.change_type is ChangeType.RENAMED
        assert entry.previous_path == "old.xml"

    def test_filenames_with_spaces_and_unicode(self) -> None:
        raw = _build([(" M", "Station PS101/räumliche Datei.xml", None)])
        (entry,) = parse_porcelain_z(raw)
        assert entry.path == "Station PS101/räumliche Datei.xml"

    def test_trailing_empty_chunks_ignored(self) -> None:
        raw = b"\x00\x00 M a.xml\x00\x00"
        entries = parse_porcelain_z(raw)
        assert len(entries) == 1

    def test_invalid_xy_rejected(self) -> None:
        with pytest.raises(GitError):
            parse_porcelain_z(b"XX path.xml\x00")


class TestChangeTypeMapping:
    def test_staged_addition(self) -> None:
        entry = RawStatusEntry.from_zy_pair("A ", "a.xml", None)
        assert entry.change_type is ChangeType.ADDED

    def test_staged_rename(self) -> None:
        entry = RawStatusEntry.from_zy_pair("R ", "a.xml", "b.xml")
        assert entry.change_type is ChangeType.RENAMED