"""Tests for the library-validation sweep.

Covers: scanning a fake library, ignoring the _quarantine subtree,
counting suspect files by format, and capping suspect_paths.
"""
from pathlib import Path

import pytest

from app.services.file_validator import (
    GIF_HEAD_89A,
    JPEG_HEAD,
    JPEG_TAIL,
    PNG_HEAD,
    PNG_TAIL,
)
from app.tasks.maintenance import scan_library_for_corruption


def _good_jpeg(p: Path) -> None:
    p.parent.mkdir(parents=True, exist_ok=True)
    p.write_bytes(JPEG_HEAD + b"\x00" * 32 + JPEG_TAIL)


def _bad_jpeg(p: Path) -> None:
    p.parent.mkdir(parents=True, exist_ok=True)
    p.write_bytes(JPEG_HEAD + b"\x00" * 32)  # no EOI


def _bad_png(p: Path) -> None:
    p.parent.mkdir(parents=True, exist_ok=True)
    p.write_bytes(PNG_HEAD + b"\x00" * 32)  # no IEND


def test_scan_finds_truncated_files(tmp_path):
    _good_jpeg(tmp_path / "Artist" / "patreon" / "01.jpg")
    _bad_jpeg(tmp_path / "Artist" / "patreon" / "02.jpg")
    _bad_png(tmp_path / "Artist" / "patreon" / "03.png")
    # JSON sidecars must not be scanned
    (tmp_path / "Artist" / "patreon" / "01.json").write_bytes(b"{}")

    report = scan_library_for_corruption(tmp_path)

    assert report["scanned"] == 3
    assert report["suspect_count"] == 2
    assert report["by_format"] == {"jpeg": 1, "png": 1}
    paths = {entry["path"] for entry in report["suspect_paths"]}
    assert any("02.jpg" in p for p in paths)
    assert any("03.png" in p for p in paths)
    assert not report["truncated"]


def test_scan_skips_quarantine_subtree(tmp_path):
    """Files already moved to _quarantine are known-bad; don't re-scan them."""
    _bad_jpeg(tmp_path / "_quarantine" / "Artist" / "patreon" / "01.jpg")
    _good_jpeg(tmp_path / "Artist" / "patreon" / "02.jpg")

    report = scan_library_for_corruption(tmp_path)

    assert report["scanned"] == 1
    assert report["suspect_count"] == 0


def test_scan_caps_suspect_paths(tmp_path):
    """suspect_count is the true total; suspect_paths is capped + truncated flag set."""
    for i in range(7):
        _bad_jpeg(tmp_path / "Artist" / "patreon" / f"{i:02d}.jpg")

    report = scan_library_for_corruption(tmp_path, max_suspect_paths=3)

    assert report["scanned"] == 7
    assert report["suspect_count"] == 7
    assert len(report["suspect_paths"]) == 3
    assert report["truncated"] is True


def test_scan_missing_root_returns_empty_report(tmp_path):
    report = scan_library_for_corruption(tmp_path / "does_not_exist")
    assert report["scanned"] == 0
    assert report["suspect_count"] == 0
    assert report["suspect_paths"] == []