"""Tests for the m2pack binary discovery helper."""

from __future__ import annotations

import os
import stat
from pathlib import Path

import pytest

from metin_release.errors import ValidationError
from metin_release.m2pack_binary import ENV_VAR, resolve_m2pack_binary


def _make_stub(tmp_path: Path, name: str = "m2pack") -> Path:
    stub = tmp_path / name
    stub.write_text("#!/bin/sh\necho '{}'\n")
    stub.chmod(stub.stat().st_mode | stat.S_IEXEC | stat.S_IXGRP | stat.S_IXOTH)
    return stub


def test_env_var_override_wins(tmp_path: Path, monkeypatch):
    stub = _make_stub(tmp_path)
    # Scrub PATH so shutil.which can't resolve m2pack
    monkeypatch.setenv("PATH", "/nonexistent")
    monkeypatch.setenv(ENV_VAR, str(stub))
    resolved = resolve_m2pack_binary()
    assert resolved == stub.resolve()


def test_env_var_empty_falls_through_to_path(tmp_path: Path, monkeypatch):
    stub = _make_stub(tmp_path)
    monkeypatch.setenv(ENV_VAR, "   ")  # blank-ish
    monkeypatch.setenv("PATH", str(tmp_path))
    resolved = resolve_m2pack_binary()
    assert resolved == stub.resolve()


def test_env_var_pointing_nowhere_raises(tmp_path: Path, monkeypatch):
    monkeypatch.setenv(ENV_VAR, str(tmp_path / "does-not-exist"))
    monkeypatch.setenv("PATH", "/nonexistent")
    with pytest.raises(ValidationError) as exc:
        resolve_m2pack_binary()
    assert exc.value.error_code == "m2pack_not_found"


def test_path_fallback_used_when_env_unset(tmp_path: Path, monkeypatch):
    stub = _make_stub(tmp_path)
    monkeypatch.delenv(ENV_VAR, raising=False)
    monkeypatch.setenv("PATH", str(tmp_path))
    resolved = resolve_m2pack_binary()
    assert resolved == stub.resolve()


def test_missing_binary_raises_validation_error(monkeypatch):
    monkeypatch.delenv(ENV_VAR, raising=False)
    monkeypatch.setenv("PATH", "/nonexistent")
    with pytest.raises(ValidationError) as exc:
        resolve_m2pack_binary()
    assert exc.value.error_code == "m2pack_not_found"
    assert "M2PACK_BINARY" in str(exc.value)


def test_custom_env_mapping_parameter(tmp_path: Path):
    stub = _make_stub(tmp_path)
    fake_env = {ENV_VAR: str(stub)}
    resolved = resolve_m2pack_binary(env=fake_env)
    assert resolved == stub.resolve()