"""
Cross-platform compatibility utilities for prism
"""

import os
import sys
from pathlib import Path


def normalize_path(path):
    """Normalize path separators for cross-platform compatibility"""
    return str(Path(path).as_posix()) if path else path


def safe_path_join(*args):
    """Safe path joining that works across platforms"""
    return str(Path(*args))


def get_platform_info():
    """Get platform-specific information"""
    return {
        "platform": sys.platform,
        "is_windows": sys.platform.startswith("win"),
        "is_posix": os.name == "posix",
        "path_separator": os.sep,
        "line_separator": os.linesep,
    }


def normalize_line_endings(text):
    """Normalize line endings for cross-platform compatibility"""
    # Convert to Unix-style line endings, then to platform-appropriate
    return text.replace("\r\n", "\n").replace("\r", "\n").replace("\n", os.linesep)


def get_executable_extension():
    """Get the appropriate executable extension for the platform"""
    return ".exe" if sys.platform.startswith("win") else ""


def case_insensitive_glob(pattern, path="."):
    """Case-insensitive file globbing for Windows compatibility"""
    from pathlib import Path
    import fnmatch

    path_obj = Path(path)
    if not path_obj.exists():
        return []

    # On Windows, filesystem is case-insensitive anyway
    # On Unix, we need to do case-insensitive matching manually
    if sys.platform.startswith("win"):
        return list(path_obj.glob(pattern))
    else:
        # Manual case-insensitive matching for Unix systems
        results = []
        for item in path_obj.rglob("*"):
            if fnmatch.fnmatch(item.name.lower(), pattern.lower()):
                results.append(item)
        return results


class CrossPlatformFile:
    """File operations that work consistently across platforms"""

    @staticmethod
    def read_text(filepath, encoding="utf-8"):
        """Read text file with proper encoding handling"""
        try:
            # Try UTF-8 first (most common)
            with open(filepath, "r", encoding=encoding, newline="") as f:
                content = f.read()
            return normalize_line_endings(content)
        except UnicodeDecodeError:
            # Fallback to system default encoding
            with open(
                filepath, "r", encoding=sys.getdefaultencoding(), newline=""
            ) as f:
                content = f.read()
            return normalize_line_endings(content)

    @staticmethod
    def write_text(filepath, content, encoding="utf-8"):
        """Write text file with proper encoding"""
        # Ensure directory exists
        Path(filepath).parent.mkdir(parents=True, exist_ok=True)

        with open(filepath, "w", encoding=encoding, newline="") as f:
            f.write(content)


def get_temp_dir():
    """Get platform-appropriate temporary directory"""
    import tempfile

    return tempfile.gettempdir()


def is_case_sensitive_filesystem(path="."):
    """Check if the filesystem is case-sensitive"""
    import tempfile
    import os

    # Create a temporary file with lowercase name
    with tempfile.NamedTemporaryFile(
        mode="w", delete=False, dir=path, suffix=".tmp"
    ) as f:
        temp_path = f.name
        f.write("test")

    try:
        # Try to access it with uppercase name
        uppercase_path = temp_path.replace(temp_path[-8:-4], temp_path[-8:-4].upper())
        case_sensitive = not os.path.exists(uppercase_path)
        return case_sensitive
    finally:
        # Clean up
        try:
            os.unlink(temp_path)
        except OSError:
            pass


def validate_filename_cross_platform(filename):
    """Validate filename for cross-platform compatibility"""
    issues = []

    # Windows filename restrictions
    if sys.platform.startswith("win"):
        # Reserved names in Windows
        reserved_names = {
            "CON",
            "PRN",
            "AUX",
            "NUL",
            "COM1",
            "COM2",
            "COM3",
            "COM4",
            "COM5",
            "COM6",
            "COM7",
            "COM8",
            "COM9",
            "LPT1",
            "LPT2",
            "LPT3",
            "LPT4",
            "LPT5",
            "LPT6",
            "LPT7",
            "LPT8",
            "LPT9",
        }

        name_without_ext = os.path.splitext(filename)[0].upper()
        if name_without_ext in reserved_names:
            issues.append(f"Filename '{filename}' uses Windows reserved name")

        # Invalid characters in Windows
        invalid_chars = '<>:"|?*'
        for char in invalid_chars:
            if char in filename:
                issues.append(
                    f"Filename '{filename}' contains invalid character '{char}' for Windows"
                )

        # Trailing spaces or dots
        if filename.endswith(" ") or filename.endswith("."):
            issues.append(
                f"Filename '{filename}' ends with space or dot (invalid on Windows)"
            )

    # General cross-platform issues
    if len(filename) > 255:
        issues.append(f"Filename '{filename}' too long (>255 characters)")

    return issues