"""Tests for Atlasbot's per-file coverage contract script."""

from __future__ import annotations

import json
import subprocess
import sys
from pathlib import Path


SCRIPT = Path(__file__).resolve().parents[1] / "scripts" / "check_coverage.py"


def _run_check(tmp_path: Path, coverage_payload: dict) -> subprocess.CompletedProcess[str]:
    """Run the coverage script against a temporary Atlasbot source tree."""

    coverage_path = tmp_path / "coverage.json"
    coverage_path.write_text(json.dumps(coverage_payload), encoding="utf-8")
    return subprocess.run(
        [sys.executable, str(SCRIPT), str(coverage_path), "--root", "atlasbot", "--threshold", "95"],
        cwd=tmp_path,
        text=True,
        capture_output=True,
        check=False,
    )


def test_missing_source_file_fails_coverage_contract(tmp_path: Path) -> None:
    """Every non-init production source file must appear in the coverage report."""

    source_root = tmp_path / "atlasbot"
    source_root.mkdir()
    (source_root / "__init__.py").write_text("", encoding="utf-8")
    (source_root / "covered.py").write_text("value = 1\n", encoding="utf-8")
    (source_root / "missing.py").write_text("value = 2\n", encoding="utf-8")

    result = _run_check(
        tmp_path,
        {"files": {"atlasbot/covered.py": {"summary": {"percent_covered": 100.0}}}},
    )

    assert result.returncode == 1
    assert "atlasbot/missing.py: missing from coverage report" in result.stdout
    assert "atlasbot/__init__.py" not in result.stdout


def test_low_or_malformed_file_coverage_fails_contract(tmp_path: Path) -> None:
    """Covered files still fail if their per-file percentage is bad or missing."""

    source_root = tmp_path / "atlasbot"
    source_root.mkdir()
    (source_root / "low.py").write_text("value = 1\n", encoding="utf-8")
    (source_root / "malformed.py").write_text("value = 2\n", encoding="utf-8")

    result = _run_check(
        tmp_path,
        {
            "files": {
                "atlasbot/low.py": {"summary": {"percent_covered": 94.9}},
                "atlasbot/malformed.py": {"summary": {}},
            }
        },
    )

    assert result.returncode == 1
    assert "atlasbot/low.py: 94.90% < 95.00%" in result.stdout
    assert "atlasbot/malformed.py: coverage percent missing" in result.stdout


def test_complete_per_file_coverage_passes_contract(tmp_path: Path) -> None:
    """The contract passes when every production file is present above threshold."""

    source_root = tmp_path / "atlasbot"
    source_root.mkdir()
    (source_root / "covered.py").write_text("value = 1\n", encoding="utf-8")

    result = _run_check(
        tmp_path,
        {"files": {"atlasbot/covered.py": {"summary": {"percent_covered": 95.0}}}},
    )

    assert result.returncode == 0
    assert result.stdout == ""