"""Language detection utilities for Local Code Assistant."""

from pathlib import Path
from typing import Optional


class LanguageSettings:
    """Language configuration settings."""

    def __init__(
        self,
        extensions: list[str],
        patterns: list[str],
        comment: str,
        testing_framework: str,
    ):
        self.extensions = extensions
        self.patterns = patterns
        self.comment = comment
        self.testing_framework = testing_framework


LANGUAGE_MAP: dict[str, LanguageSettings] = {
    "python": LanguageSettings(
        extensions=[".py", ".pyw", ".pyi"],
        patterns=["def ", "import ", "from ", "class ", "if __name__"],
        comment="#",
        testing_framework="pytest",
    ),
    "javascript": LanguageSettings(
        extensions=[".js", ".mjs", ".cjs"],
        patterns=["function ", "const ", "let ", "var ", "=>"],
        comment="//",
        testing_framework="jest",
    ),
    "typescript": LanguageSettings(
        extensions=[".ts", ".tsx"],
        patterns=[": string", ": number", "interface ", "type "],
        comment="//",
        testing_framework="jest",
    ),
    "go": LanguageSettings(
        extensions=[".go"],
        patterns=["func ", "package ", "import (", "type "],
        comment="//",
        testing_framework="testing",
    ),
    "rust": LanguageSettings(
        extensions=[".rs"],
        patterns=["fn ", "let ", "struct ", "impl ", "pub "],
        comment="//",
        testing_framework="test",
    ),
    "java": LanguageSettings(
        extensions=[".java"],
        patterns=["public class", "public static", "import java"],
        comment="//",
        testing_framework="junit",
    ),
    "cpp": LanguageSettings(
        extensions=[".cpp", ".cc", ".hpp", ".h"],
        patterns=["#include", "std::", "using namespace"],
        comment="//",
        testing_framework="catch2",
    ),
    "c": LanguageSettings(
        extensions=[".c", ".h"],
        patterns=["#include", "int main()", "struct "],
        comment="//",
        testing_framework="unity",
    ),
}


def detect_language_from_extension(file_path: Path) -> Optional[str]:
    """Detect programming language from file extension.

    Args:
        file_path: Path to the file.

    Returns:
        Detected language or None.
    """
    suffix = file_path.suffix.lower()
    for language, config in LANGUAGE_MAP.items():
        if suffix in config.extensions:
            return language
    return None


def detect_language_from_content(content: str) -> Optional[str]:
    """Detect programming language from file content.

    Args:
        content: File content to analyze.

    Returns:
        Detected language or None.
    """
    for language, config in LANGUAGE_MAP.items():
        for pattern in config.patterns:
            if pattern in content:
                return language
    return None


def detect_language(file_path: Path, content: Optional[str] = None) -> str:
    """Detect programming language from file path and optionally content.

    Args:
        file_path: Path to the file.
        content: Optional file content for additional detection.

    Returns:
        Detected language (defaults to 'python').
    """
    ext_lang = detect_language_from_extension(file_path)
    if ext_lang:
        return ext_lang

    if content:
        content_lang = detect_language_from_content(content)
        if content_lang:
            return content_lang

    return "python"


def get_language_config(language: str) -> LanguageSettings:
    """Get configuration for a specific language.

    Args:
        language: Language name.

    Returns:
        Language configuration object.
    """
    if language in LANGUAGE_MAP:
        return LANGUAGE_MAP[language]
    return LanguageSettings(
        extensions=[".txt"],
        patterns=[],
        comment="#",
        testing_framework="pytest",
    )


def get_supported_languages() -> list[str]:
    """Get list of supported programming languages.

    Returns:
        List of language names.
    """
    return list(LANGUAGE_MAP.keys())


def is_language_supported(language: str) -> bool:
    """Check if a language is supported.

    Args:
        language: Language name to check.

    Returns:
        True if supported, False otherwise.
    """
    return language.lower() in LANGUAGE_MAP


def get_file_extension(language: str) -> str:
    """Get file extension for a language.

    Args:
        language: Language name.

    Returns:
        File extension with leading dot.
    """
    config = get_language_config(language)
    return config.extensions[0] if config.extensions else ".txt"


def get_comment_style(language: str) -> str:
    """Get comment style for a language.

    Args:
        language: Language name.

    Returns:
        Comment prefix string.
    """
    config = get_language_config(language)
    return config.comment


def get_testing_framework(language: str) -> str:
    """Get default testing framework for a language.

    Args:
        language: Language name.

    Returns:
        Testing framework name.
    """
    config = get_language_config(language)
    return config.testing_framework