test_file_utils.py

"""Tests for file utilities."""

import random
import string
import sys
from pathlib import Path

import pytest

from basic_memory.config import BasicMemoryConfig
from basic_memory.file_utils import (
    FileError,
    FileWriteError,
    ParseError,
    compute_checksum,
    format_file,
    format_markdown_builtin,
    has_frontmatter,
    parse_frontmatter,
    remove_frontmatter,
    sanitize_for_filename,
    sanitize_for_directory,
    write_file_atomic,
)

# Skip marker for tests that use Unix-specific commands (cat, sh, sleep, /dev/null)
skip_on_windows = pytest.mark.skipif(
    sys.platform == "win32", reason="Test uses Unix-specific commands not available on Windows"
)


def get_random_word(length: int = 12, necessary_char: str | None = None) -> str:
    letters = string.ascii_lowercase
    word_chars = [random.choice(letters) for i in range(length)]

    if necessary_char and length > 0:
        # Replace a character at a random position with the necessary character
        random_pos = random.randint(0, length - 1)
        word_chars[random_pos] = necessary_char

    return "".join(word_chars)


@pytest.mark.asyncio
async def test_compute_checksum():
    """Test checksum computation."""
    content = "test content"
    checksum = await compute_checksum(content)
    assert isinstance(checksum, str)
    assert len(checksum) == 64  # SHA-256 produces 64 char hex string


@pytest.mark.asyncio
async def test_compute_checksum_error():
    """Test checksum error handling."""
    with pytest.raises(FileError):
        # Try to hash an object that can't be encoded
        await compute_checksum(object())  # pyright: ignore [reportArgumentType]


@pytest.mark.asyncio
async def test_write_file_atomic(tmp_path: Path):
    """Test atomic file writing."""
    test_file = tmp_path / "test.txt"
    content = "test content"

    await write_file_atomic(test_file, content)
    assert test_file.exists()
    assert test_file.read_text(encoding="utf-8") == content

    # Temp file should be cleaned up
    assert not test_file.with_suffix(".tmp").exists()


@pytest.mark.asyncio
async def test_write_file_atomic_error(tmp_path: Path):
    """Test atomic write error handling."""
    # Try to write to a directory that doesn't exist
    test_file = tmp_path / "nonexistent" / "test.txt"

    with pytest.raises(FileWriteError):
        await write_file_atomic(test_file, "test content")


def test_has_frontmatter():
    """Test frontmatter detection."""
    # Valid frontmatter
    assert has_frontmatter("""---
title: Test
---
content""")

    # Just content
    assert not has_frontmatter("Just content")

    # Empty content
    assert not has_frontmatter("")

    # Just delimiter
    assert not has_frontmatter("---")

    # Delimiter not at start
    assert not has_frontmatter("""
Some text
---
title: Test
---""")

    # Invalid format
    assert not has_frontmatter("--title: test--")


def test_parse_frontmatter():
    """Test parsing frontmatter."""
    # Valid frontmatter
    content = """---
title: Test
tags:
  - a
  - b
---
content"""

    result = parse_frontmatter(content)
    assert result == {"title": "Test", "tags": ["a", "b"]}

    # Empty frontmatter
    content = """---
---
content"""
    result = parse_frontmatter(content)
    assert result == {} or result == {}  # Handle both None and empty dict cases

    # Invalid YAML syntax
    with pytest.raises(ParseError) as exc:
        parse_frontmatter("""---
[: invalid yaml syntax :]
---
content""")
    assert "Invalid YAML in frontmatter" in str(exc.value)

    # Non-dict YAML content
    with pytest.raises(ParseError) as exc:
        parse_frontmatter("""---
- just
- a
- list
---
content""")
    assert "Frontmatter must be a YAML dictionary" in str(exc.value)

    # No frontmatter
    with pytest.raises(ParseError):
        parse_frontmatter("Just content")

    # Incomplete frontmatter
    with pytest.raises(ParseError):
        parse_frontmatter("""---
title: Test""")


def test_remove_frontmatter():
    """Test removing frontmatter."""
    # With frontmatter
    content = """---
title: Test
---
test content"""
    assert remove_frontmatter(content) == "test content"

    # No frontmatter
    content = "test content"
    assert remove_frontmatter(content) == "test content"

    # Only frontmatter
    content = """---
title: Test
---
"""
    assert remove_frontmatter(content) == ""

    # Invalid frontmatter - missing closing delimiter
    with pytest.raises(ParseError) as exc:
        remove_frontmatter("""---
title: Test""")
    assert "Invalid frontmatter format" in str(exc.value)


def test_sanitize_for_filename_removes_invalid_characters():
    # Test all invalid characters listed in the regex
    invalid_chars = '<>:"|?*'

    # All invalid characters should be replaced
    for char in invalid_chars:
        text = get_random_word(length=12, necessary_char=char)
        sanitized_text = sanitize_for_filename(text)

        assert char not in sanitized_text


def test_sanitize_for_filename_strips_trailing_periods():
    """Trailing periods cause double-dot filenames like 'hi-everyone..md'.

    This was a production bug where title "Hi everyone." produced file path
    "hi-everyone..md" which failed path traversal validation.
    """
    assert sanitize_for_filename("Hi everyone.") == "Hi everyone"
    assert sanitize_for_filename("test...") == "test"
    assert sanitize_for_filename(".hidden") == "hidden"
    assert sanitize_for_filename("...dots...") == "dots"
    assert sanitize_for_filename("normal title") == "normal title"


@pytest.mark.parametrize(
    "input_directory,expected",
    [
        ("", ""),  # Empty string
        ("   ", ""),  # Whitespace only
        ("my-directory", "my-directory"),  # Simple directory
        ("my/directory", "my/directory"),  # Nested directory
        ("my//directory", "my/directory"),  # Double slash compressed
        ("my\\\\directory", "my/directory"),  # Windows-style double backslash compressed
        ("my/directory/", "my/directory"),  # Trailing slash removed
        ("/my/directory", "my/directory"),  # Leading slash removed
        ("./my/directory", "my/directory"),  # Leading ./ removed
        ("my<>directory", "mydirectory"),  # Special chars removed
        ("my:directory|test", "mydirectorytest"),  # More special chars removed
        ("my_directory-1", "my_directory-1"),  # Allowed chars preserved
        ("my directory", "my directory"),  # Space preserved
        ("my/directory//sub//", "my/directory/sub"),  # Multiple compressions and trims
        ("my\\directory\\sub", "my/directory/sub"),  # Windows-style separators normalized
        ("my/directory<>:|?*sub", "my/directorysub"),  # All invalid chars removed
        ("////my////directory////", "my/directory"),  # Excessive leading/trailing/multiple slashes
    ],
)
def test_sanitize_for_directory_edge_cases(input_directory, expected):
    assert sanitize_for_directory(input_directory) == expected


# =============================================================================
# format_file tests
# =============================================================================


@pytest.mark.asyncio
async def test_format_file_disabled_by_default(tmp_path: Path):
    """Test that format_file returns None when format_on_save is False (default)."""
    test_file = tmp_path / "test.md"
    test_file.write_text("# Test\n")

    config = BasicMemoryConfig()
    assert config.format_on_save is False

    result = await format_file(test_file, config)
    assert result is None


@pytest.mark.asyncio
async def test_format_file_no_formatter_uses_builtin_for_markdown(tmp_path: Path):
    """Test that format_file uses built-in mdformat for markdown when no external formatter configured."""
    test_file = tmp_path / "test.md"
    test_file.write_text("# Test\n")

    # No external formatter configured - should use built-in mdformat for markdown
    config = BasicMemoryConfig(format_on_save=True, formatter_command=None)

    result = await format_file(test_file, config, is_markdown=True)
    # mdformat should return formatted content
    assert result is not None
    assert "# Test" in result


@pytest.mark.asyncio
async def test_format_file_no_formatter_for_non_markdown(tmp_path: Path):
    """Test that format_file returns None for non-markdown files when no formatter configured."""
    test_file = tmp_path / "test.txt"
    test_file.write_text("Some text\n")

    # No external formatter configured - should return None for non-markdown
    config = BasicMemoryConfig(format_on_save=True, formatter_command=None)

    result = await format_file(test_file, config, is_markdown=False)
    assert result is None


@skip_on_windows
@pytest.mark.asyncio
async def test_format_file_with_global_formatter(tmp_path: Path):
    """Test formatting with global formatter_command."""
    test_file = tmp_path / "test.md"
    original_content = "# Test\n"
    test_file.write_text(original_content)

    # Use a simple formatter that just echoes content (cat)
    config = BasicMemoryConfig(
        format_on_save=True,
        formatter_command="cat {file}",  # This doesn't modify the file but runs successfully
    )

    result = await format_file(test_file, config)
    assert result == original_content


@skip_on_windows
@pytest.mark.asyncio
async def test_format_file_with_extension_specific_formatter(tmp_path: Path):
    """Test formatting with extension-specific formatter."""
    test_file = tmp_path / "test.json"
    original_content = '{"key": "value"}'
    test_file.write_text(original_content)

    config = BasicMemoryConfig(
        format_on_save=True,
        formatter_command="echo global",  # This should NOT be used
        formatters={"json": "cat {file}"},  # Extension-specific should be used
    )

    result = await format_file(test_file, config)
    assert result == original_content


@skip_on_windows
@pytest.mark.asyncio
async def test_format_file_extension_specific_overrides_global(tmp_path: Path):
    """Test that extension-specific formatter takes precedence over global."""
    test_file = tmp_path / "test.md"
    original_content = "# Test\n"
    test_file.write_text(original_content)

    # Use different commands to verify which one is used
    # Since cat just reads the file, we can tell which was used by the content
    config = BasicMemoryConfig(
        format_on_save=True,
        formatter_command="cat /dev/null",  # Would return empty
        formatters={"md": "cat {file}"},  # Should return original content
    )

    result = await format_file(test_file, config)
    assert result == original_content


@skip_on_windows
@pytest.mark.asyncio
async def test_format_file_falls_back_to_global(tmp_path: Path):
    """Test that global formatter is used when no extension-specific one exists."""
    test_file = tmp_path / "test.txt"  # No extension-specific formatter for .txt
    original_content = "Some text\n"
    test_file.write_text(original_content)

    config = BasicMemoryConfig(
        format_on_save=True,
        formatter_command="cat {file}",
        formatters={"md": "echo wrong"},  # Only for .md, not .txt
    )

    result = await format_file(test_file, config)
    assert result == original_content


@pytest.mark.asyncio
async def test_format_file_handles_nonexistent_formatter(tmp_path: Path):
    """Test that format_file handles missing formatter executable gracefully."""
    test_file = tmp_path / "test.md"
    test_file.write_text("# Test\n")

    config = BasicMemoryConfig(
        format_on_save=True,
        formatter_command="nonexistent_formatter_executable_12345 {file}",
    )

    result = await format_file(test_file, config)
    assert result is None  # Should return None on error


@skip_on_windows
@pytest.mark.asyncio
async def test_format_file_handles_timeout(tmp_path: Path):
    """Test that format_file handles formatter timeout gracefully."""
    test_file = tmp_path / "test.md"
    test_file.write_text("# Test\n")

    config = BasicMemoryConfig(
        format_on_save=True,
        formatter_command="sleep 10",  # Will timeout
        formatter_timeout=0.1,  # Very short timeout
    )

    result = await format_file(test_file, config)
    assert result is None  # Should return None on timeout


@skip_on_windows
@pytest.mark.asyncio
async def test_format_file_handles_nonzero_exit(tmp_path: Path):
    """Test that format_file handles non-zero exit codes gracefully."""
    test_file = tmp_path / "test.md"
    original_content = "# Test\n"
    test_file.write_text(original_content)

    config = BasicMemoryConfig(
        format_on_save=True,
        formatter_command="sh -c 'exit 1'",  # Non-zero exit
    )

    result = await format_file(test_file, config)
    # Should still return file content even with non-zero exit
    assert result == original_content


@skip_on_windows
@pytest.mark.asyncio
async def test_format_file_returns_modified_content(tmp_path: Path):
    """Test that format_file returns the modified file content after formatting."""
    test_file = tmp_path / "test.md"
    original_content = "original content"
    test_file.write_text(original_content)

    # This formatter modifies the file to contain different content
    config = BasicMemoryConfig(
        format_on_save=True,
        formatter_command="sh -c 'echo modified > {file}'",
    )

    result = await format_file(test_file, config)
    assert result == "modified\n"
    assert test_file.read_text() == "modified\n"


@skip_on_windows
@pytest.mark.asyncio
async def test_format_file_with_spaces_in_path(tmp_path: Path):
    """Test formatting files with spaces in path."""
    subdir = tmp_path / "path with spaces"
    subdir.mkdir()
    test_file = subdir / "my file.md"
    original_content = "# Test\n"
    test_file.write_text(original_content)

    config = BasicMemoryConfig(
        format_on_save=True,
        formatter_command="cat {file}",
    )

    result = await format_file(test_file, config)
    assert result == original_content


# =============================================================================
# format_markdown_builtin tests
# =============================================================================


@pytest.mark.asyncio
async def test_format_markdown_builtin_formats_content(tmp_path: Path):
    """Test that format_markdown_builtin formats markdown content."""
    test_file = tmp_path / "test.md"
    # Markdown with inconsistent formatting
    test_file.write_text("# Title\n\n*emphasis*  and  **bold**\n")

    result = await format_markdown_builtin(test_file)

    assert result is not None
    assert "# Title" in result
    assert "*emphasis*" in result or "_emphasis_" in result


@pytest.mark.asyncio
async def test_format_markdown_builtin_preserves_frontmatter(tmp_path: Path):
    """Test that format_markdown_builtin preserves YAML frontmatter."""
    test_file = tmp_path / "test.md"
    content = """---
title: Test Note
tags:
  - test
  - markdown
---

# Content

Some text here.
"""
    test_file.write_text(content)

    result = await format_markdown_builtin(test_file)

    assert result is not None
    assert "---" in result
    assert "title: Test Note" in result
    assert "# Content" in result


@pytest.mark.asyncio
async def test_format_markdown_builtin_handles_gfm_tables(tmp_path: Path):
    """Test that format_markdown_builtin handles GFM tables."""
    test_file = tmp_path / "test.md"
    content = """# Table Test

| Column 1 | Column 2 |
|----------|----------|
| A | B |
| C | D |
"""
    test_file.write_text(content)

    result = await format_markdown_builtin(test_file)

    assert result is not None
    assert "Column 1" in result
    assert "|" in result


@pytest.mark.asyncio
async def test_format_markdown_builtin_only_writes_if_changed(tmp_path: Path):
    """Test that format_markdown_builtin only writes if content changed."""
    test_file = tmp_path / "test.md"
    # Already well-formatted content
    content = "# Title\n\nSome text.\n"
    test_file.write_text(content)
    test_file.stat().st_mtime

    result = await format_markdown_builtin(test_file)

    assert result is not None
    # File should not have been rewritten if content didn't change
    # (This is a best-effort check - mtime may or may not change depending on OS)


# =============================================================================
# BOM handling tests
# =============================================================================


class TestBOMHandling:
    """Test handling of Byte Order Mark (BOM) in frontmatter.

    BOM characters can be present in files created on Windows or copied
    from certain sources. They should not break frontmatter detection
    or parsing. See issue #452.
    """

    def test_has_frontmatter_with_bom(self):
        """Test that has_frontmatter handles BOM correctly."""
        # Content with UTF-8 BOM
        content_with_bom = "\ufeff---\ntitle: Test\n---\nContent"
        assert has_frontmatter(content_with_bom), "Should detect frontmatter even with BOM"

    def test_has_frontmatter_with_bom_and_windows_crlf(self):
        """Test BOM with Windows line endings."""
        content = "\ufeff---\r\ntitle: Test\r\n---\r\nContent"
        assert has_frontmatter(content), "Should detect frontmatter with BOM and CRLF"

    def test_parse_frontmatter_with_bom(self):
        """Test that parse_frontmatter handles BOM correctly."""
        content_with_bom = "\ufeff---\ntitle: Test Title\ntype: note\n---\nContent"
        result = parse_frontmatter(content_with_bom)
        assert result["title"] == "Test Title"
        assert result["type"] == "note"

    def test_remove_frontmatter_with_bom(self):
        """Test that remove_frontmatter handles BOM correctly."""
        content_with_bom = "\ufeff---\ntitle: Test\n---\nContent here"
        result = remove_frontmatter(content_with_bom)
        assert result == "Content here"