"""Tests for config and image error conditions, and exception attribute contracts."""

from pathlib import Path

import pytest

from errors import (
    ConfigFileError,
    ConfigNotLoadedError,
    ConfigValidationError,
    ImageFileNotFoundError,
    ImageReadError,
)
from logic.images import crop_save, prep_img_b64, serve_crop

# ── Helpers ───────────────────────────────────────────────────────────────────


def _make_png(tmp_path: Path, filename: str = "img.png") -> Path:
    """Write a minimal 4x4 red PNG to tmp_path and return its path."""
    from PIL import Image

    path = tmp_path / filename
    img = Image.new("RGB", (4, 4), color=(255, 0, 0))
    img.save(path, format="PNG")
    return path


def _make_corrupt(tmp_path: Path, filename: str = "bad.jpg") -> Path:
    """Write a file with invalid image bytes and return its path."""
    path = tmp_path / filename
    path.write_bytes(b"this is not an image\xff\xfe")
    return path


# ── ImageFileNotFoundError ────────────────────────────────────────────────────


def test_prep_img_b64_file_not_found(tmp_path: Path) -> None:
    missing = tmp_path / "missing.png"
    with pytest.raises(ImageFileNotFoundError) as exc_info:
        prep_img_b64(missing)
    assert exc_info.value.path == missing
    assert str(missing) in str(exc_info.value)


def test_crop_save_file_not_found(tmp_path: Path) -> None:
    missing = tmp_path / "missing.png"
    with pytest.raises(ImageFileNotFoundError) as exc_info:
        crop_save(missing, 0, 0, 2, 2)
    assert exc_info.value.path == missing


def test_serve_crop_file_not_found(tmp_path: Path) -> None:
    missing = tmp_path / "missing.png"
    with pytest.raises(ImageFileNotFoundError) as exc_info:
        serve_crop(missing, None)
    assert exc_info.value.path == missing


# ── ImageReadError ────────────────────────────────────────────────────────────


def test_prep_img_b64_corrupt_file(tmp_path: Path) -> None:
    bad = _make_corrupt(tmp_path)
    with pytest.raises(ImageReadError) as exc_info:
        prep_img_b64(bad)
    assert exc_info.value.path == bad
    assert str(bad) in str(exc_info.value)
    assert exc_info.value.reason  # non-empty reason


def test_crop_save_corrupt_file(tmp_path: Path) -> None:
    bad = _make_corrupt(tmp_path)
    with pytest.raises(ImageReadError) as exc_info:
        crop_save(bad, 0, 0, 2, 2)
    assert exc_info.value.path == bad


def test_serve_crop_corrupt_file(tmp_path: Path) -> None:
    bad = _make_corrupt(tmp_path)
    with pytest.raises(ImageReadError) as exc_info:
        serve_crop(bad, None)
    assert exc_info.value.path == bad


# ── prep_img_b64 success path ─────────────────────────────────────────────────


def test_prep_img_b64_success(tmp_path: Path) -> None:
    path = _make_png(tmp_path)
    b64, mime = prep_img_b64(path)
    assert mime == "image/png"
    assert len(b64) > 0


def test_prep_img_b64_with_crop(tmp_path: Path) -> None:
    path = _make_png(tmp_path)
    b64, mime = prep_img_b64(path, crop_frac=(0.0, 0.0, 0.5, 0.5))
    assert mime == "image/png"
    assert len(b64) > 0


# ── Config exception attribute contracts ──────────────────────────────────────


def test_config_not_loaded_error() -> None:
    exc = ConfigNotLoadedError()
    assert "load_config" in str(exc)


def test_config_file_error() -> None:
    path = Path("config/missing.yaml")
    exc = ConfigFileError(path, "file not found")
    assert exc.path == path
    assert exc.reason == "file not found"
    assert "missing.yaml" in str(exc)
    assert "file not found" in str(exc)


def test_config_validation_error() -> None:
    exc = ConfigValidationError("unexpected field 'foo'")
    assert exc.reason == "unexpected field 'foo'"
    assert "unexpected field" in str(exc)


# ── Config loading errors ─────────────────────────────────────────────────────


def test_load_config_raises_on_invalid_yaml(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    import config as config_module

    cfg_dir = tmp_path / "config"
    cfg_dir.mkdir()
    (cfg_dir / "credentials.default.yaml").write_text(": invalid: yaml: {\n")
    # write empty valid files for other categories
    for cat in ["models", "functions", "ui"]:
        (cfg_dir / f"{cat}.default.yaml").write_text(f"{cat}: {{}}\n")

    monkeypatch.setattr(config_module, "_CONFIG_DIR", cfg_dir)
    with pytest.raises(ConfigFileError) as exc_info:
        config_module.load_config()
    assert exc_info.value.path == cfg_dir / "credentials.default.yaml"
    assert exc_info.value.reason


def test_load_config_raises_on_schema_mismatch(tmp_path: Path, monkeypatch: pytest.MonkeyPatch) -> None:
    import config as config_module

    cfg_dir = tmp_path / "config"
    cfg_dir.mkdir()
    # credentials expects CredentialConfig but we give it a non-dict value
    (cfg_dir / "credentials.default.yaml").write_text("credentials:\n  openrouter: not_a_dict\n")
    for cat in ["models", "functions", "ui"]:
        (cfg_dir / f"{cat}.default.yaml").write_text("")

    monkeypatch.setattr(config_module, "_CONFIG_DIR", cfg_dir)
    with pytest.raises(ConfigValidationError) as exc_info:
        config_module.load_config()
    assert exc_info.value.reason


def test_get_config_raises_if_not_loaded(monkeypatch: pytest.MonkeyPatch) -> None:
    import config as config_module

    # Clear the holder to simulate unloaded state
    original = list(config_module.config_holder)
    config_module.config_holder.clear()
    try:
        with pytest.raises(ConfigNotLoadedError):
            config_module.get_config()
    finally:
        config_module.config_holder.extend(original)


# ── Image exception string representation ─────────────────────────────────────


def test_image_file_not_found_str() -> None:
    exc = ImageFileNotFoundError(Path("/data/images/img.jpg"))
    assert exc.path == Path("/data/images/img.jpg")
    assert "img.jpg" in str(exc)


def test_image_read_error_str() -> None:
    exc = ImageReadError(Path("/data/images/img.jpg"), "cannot identify image file")
    assert exc.path == Path("/data/images/img.jpg")
    assert exc.reason == "cannot identify image file"
    assert "img.jpg" in str(exc)
    assert "cannot identify image file" in str(exc)