utils.py

"""Utility functions for basic-memory."""

import os

import logging
import re
import sys
from pathlib import Path
from typing import Optional, Protocol, Union, runtime_checkable, List

from loguru import logger
from unidecode import unidecode


@runtime_checkable
class PathLike(Protocol):
    """Protocol for objects that can be used as paths."""

    def __str__(self) -> str: ...


# In type annotations, use Union[Path, str] instead of FilePath for now
# This preserves compatibility with existing code while we migrate
FilePath = Union[Path, str]

# Disable the "Queue is full" warning
logging.getLogger("opentelemetry.sdk.metrics._internal.instrument").setLevel(logging.ERROR)


def generate_permalink(file_path: Union[Path, str, PathLike]) -> str:
    """Generate a stable permalink from a file path.

    Args:
        file_path: Original file path (str, Path, or PathLike)

    Returns:
        Normalized permalink that matches validation rules. Converts spaces and underscores
        to hyphens for consistency. Preserves non-ASCII characters like Chinese.

    Examples:
        >>> generate_permalink("docs/My Feature.md")
        'docs/my-feature'
        >>> generate_permalink("specs/API (v2).md")
        'specs/api-v2'
        >>> generate_permalink("design/unified_model_refactor.md")
        'design/unified-model-refactor'
        >>> generate_permalink("中文/测试文档.md")
        '中文/测试文档'
    """
    # Convert Path to string if needed
    path_str = str(file_path)

    # Remove extension
    base = os.path.splitext(path_str)[0]

    # Check if we have CJK characters that should be preserved
    # CJK ranges: \u4e00-\u9fff (CJK Unified Ideographs), \u3000-\u303f (CJK symbols), 
    # \u3400-\u4dbf (CJK Extension A), \uff00-\uffef (Fullwidth forms)
    has_cjk_chars = any(
        '\u4e00' <= char <= '\u9fff' or 
        '\u3000' <= char <= '\u303f' or 
        '\u3400' <= char <= '\u4dbf' or
        '\uff00' <= char <= '\uffef'
        for char in base
    )
    
    if has_cjk_chars:
        # For text with CJK characters, selectively transliterate only Latin accented chars
        result = ""
        for char in base:
            if ('\u4e00' <= char <= '\u9fff' or 
                '\u3000' <= char <= '\u303f' or 
                '\u3400' <= char <= '\u4dbf'):
                # Preserve CJK ideographs and symbols
                result += char
            elif ('\uff00' <= char <= '\uffef'):
                # Remove Chinese fullwidth punctuation entirely (like ，！？)
                continue
            else:
                # Transliterate Latin accented characters to ASCII
                result += unidecode(char)
        
        # Insert hyphens between CJK and Latin character transitions
        # Match: CJK followed by Latin letter/digit, or Latin letter/digit followed by CJK
        result = re.sub(r'([\u4e00-\u9fff\u3000-\u303f\u3400-\u4dbf])([a-zA-Z0-9])', r'\1-\2', result)
        result = re.sub(r'([a-zA-Z0-9])([\u4e00-\u9fff\u3000-\u303f\u3400-\u4dbf])', r'\1-\2', result)
        
        # Insert dash between camelCase
        result = re.sub(r"([a-z0-9])([A-Z])", r"\1-\2", result)
        
        # Convert ASCII letters to lowercase, preserve CJK
        lower_text = "".join(c.lower() if c.isascii() and c.isalpha() else c for c in result)
        
        # Replace underscores with hyphens
        text_with_hyphens = lower_text.replace("_", "-")
        
        # Remove apostrophes entirely (don't replace with hyphens)
        text_no_apostrophes = text_with_hyphens.replace("'", "")
        
        # Replace unsafe chars with hyphens, but preserve CJK characters
        clean_text = re.sub(
            r"[^a-z0-9\u4e00-\u9fff\u3000-\u303f\u3400-\u4dbf/\-]", "-", text_no_apostrophes
        )
    else:
        # Original ASCII-only processing for backward compatibility
        # Transliterate unicode to ascii
        ascii_text = unidecode(base)

        # Insert dash between camelCase
        ascii_text = re.sub(r"([a-z0-9])([A-Z])", r"\1-\2", ascii_text)

        # Convert to lowercase
        lower_text = ascii_text.lower()

        # replace underscores with hyphens
        text_with_hyphens = lower_text.replace("_", "-")

        # Remove apostrophes entirely (don't replace with hyphens)
        text_no_apostrophes = text_with_hyphens.replace("'", "")

        # Replace remaining invalid chars with hyphens
        clean_text = re.sub(r"[^a-z0-9/\-]", "-", text_no_apostrophes)

    # Collapse multiple hyphens
    clean_text = re.sub(r"-+", "-", clean_text)

    # Clean each path segment
    segments = clean_text.split("/")
    clean_segments = [s.strip("-") for s in segments]

    return "/".join(clean_segments)


def setup_logging(
    env: str,
    home_dir: Path,
    log_file: Optional[str] = None,
    log_level: str = "INFO",
    console: bool = True,
) -> None:  # pragma: no cover
    """
    Configure logging for the application.

    Args:
        env: The environment name (dev, test, prod)
        home_dir: The root directory for the application
        log_file: The name of the log file to write to
        log_level: The logging level to use
        console: Whether to log to the console
    """
    # Remove default handler and any existing handlers
    logger.remove()

    # Add file handler if we are not running tests and a log file is specified
    if log_file and env != "test":
        # Setup file logger
        log_path = home_dir / log_file
        logger.add(
            str(log_path),
            level=log_level,
            rotation="10 MB",
            retention="10 days",
            backtrace=True,
            diagnose=True,
            enqueue=True,
            colorize=False,
        )

    # Add console logger if requested or in test mode
    if env == "test" or console:
        logger.add(sys.stderr, level=log_level, backtrace=True, diagnose=True, colorize=True)

    logger.info(f"ENV: '{env}' Log level: '{log_level}' Logging to {log_file}")

    # Reduce noise from third-party libraries
    noisy_loggers = {
        # HTTP client logs
        "httpx": logging.WARNING,
        # File watching logs
        "watchfiles.main": logging.WARNING,
    }

    # Set log levels for noisy loggers
    for logger_name, level in noisy_loggers.items():
        logging.getLogger(logger_name).setLevel(level)


def parse_tags(tags: Union[List[str], str, None]) -> List[str]:
    """Parse tags from various input formats into a consistent list.

    Args:
        tags: Can be a list of strings, a comma-separated string, or None

    Returns:
        A list of tag strings, or an empty list if no tags

    Note:
        This function strips leading '#' characters from tags to prevent
        their accumulation when tags are processed multiple times.
    """
    if tags is None:
        return []

    # Process list of tags
    if isinstance(tags, list):
        # First strip whitespace, then strip leading '#' characters to prevent accumulation
        return [tag.strip().lstrip("#") for tag in tags if tag and tag.strip()]

    # Process comma-separated string of tags
    if isinstance(tags, str):
        # Split by comma, strip whitespace, then strip leading '#' characters
        return [tag.strip().lstrip("#") for tag in tags.split(",") if tag and tag.strip()]

    # For any other type, try to convert to string and parse
    try:  # pragma: no cover
        return parse_tags(str(tags))
    except (ValueError, TypeError):  # pragma: no cover
        logger.warning(f"Couldn't parse tags from input of type {type(tags)}: {tags}")
        return []


def normalize_file_path_for_comparison(file_path: str) -> str:
    """Normalize a file path for conflict detection.
    
    This function normalizes file paths to help detect potential conflicts:
    - Converts to lowercase for case-insensitive comparison
    - Normalizes Unicode characters
    - Handles path separators consistently
    
    Args:
        file_path: The file path to normalize
        
    Returns:
        Normalized file path for comparison purposes
    """
    import unicodedata
    
    # Convert to lowercase for case-insensitive comparison
    normalized = file_path.lower()
    
    # Normalize Unicode characters (NFD normalization)
    normalized = unicodedata.normalize('NFD', normalized)
    
    # Replace path separators with forward slashes
    normalized = normalized.replace('\\', '/')
    
    # Remove multiple slashes
    normalized = re.sub(r'/+', '/', normalized)
    
    return normalized


def detect_potential_file_conflicts(file_path: str, existing_paths: List[str]) -> List[str]:
    """Detect potential conflicts between a file path and existing paths.
    
    This function checks for various types of conflicts:
    - Case sensitivity differences
    - Unicode normalization differences
    - Path separator differences
    - Permalink generation conflicts
    
    Args:
        file_path: The file path to check
        existing_paths: List of existing file paths to check against
        
    Returns:
        List of existing paths that might conflict with the given file path
    """
    conflicts = []
    
    # Normalize the input file path
    normalized_input = normalize_file_path_for_comparison(file_path)
    input_permalink = generate_permalink(file_path)
    
    for existing_path in existing_paths:
        # Skip identical paths
        if existing_path == file_path:
            continue
            
        # Check for case-insensitive path conflicts
        normalized_existing = normalize_file_path_for_comparison(existing_path)
        if normalized_input == normalized_existing:
            conflicts.append(existing_path)
            continue
            
        # Check for permalink conflicts
        existing_permalink = generate_permalink(existing_path)
        if input_permalink == existing_permalink:
            conflicts.append(existing_path)
            continue
    
    return conflicts


def validate_project_path(path: str, project_path: Path) -> bool:
    """Ensure path stays within project boundaries."""
    # Allow empty strings as they resolve to the project root
    if not path:
        return True

    # Check for obvious path traversal patterns first
    if ".." in path or "~" in path:
        return False

    # Check for Windows-style path traversal (even on Unix systems)
    if "\\.." in path or path.startswith("\\"):
        return False

    # Block absolute paths (Unix-style starting with / or Windows-style with drive letters)
    if path.startswith("/") or (len(path) >= 2 and path[1] == ":"):
        return False

    # Block paths with control characters (but allow whitespace that will be stripped)
    if path.strip() and any(ord(c) < 32 and c not in [" ", "\t"] for c in path):
        return False

    try:
        resolved = (project_path / path).resolve()
        return resolved.is_relative_to(project_path.resolve())
    except (ValueError, OSError):
        return False