"""Configuration system for depcheck."""

import fnmatch
import os
from dataclasses import dataclass, field
from pathlib import Path
from typing import Optional

import yaml

from depcheck.models import Severity


@dataclass
class Config:
    """Configuration for depcheck."""

    ignore_patterns: list[str] = field(default_factory=list)
    ignore_packages: list[str] = field(default_factory=list)
    fail_level: Severity = Severity.MEDIUM
    output_format: str = "terminal"
    verbose: bool = False
    quiet: bool = False
    include_dev: bool = True
    package_managers: list[str] = field(default_factory=list)


def load_config(config_path: Optional[Path] = None) -> Config:
    """Load configuration from file."""
    config = Config()

    if config_path is None:
        config_path = _find_config_file()

    if config_path and config_path.exists():
        try:
            content = config_path.read_text()
            data = yaml.safe_load(content) or {}
        except (yaml.YAMLError, OSError):
            return config
    else:
        return config

    if "ignore_patterns" in data:
        config.ignore_patterns = data["ignore_patterns"]

    if "ignore_packages" in data:
        config.ignore_packages = data["ignore_packages"]

    if "fail_level" in data:
        try:
            config.fail_level = Severity(data["fail_level"])
        except ValueError:
            pass

    if "output" in data:
        output = data["output"]
        if "format" in output:
            config.output_format = output["format"]
        if "verbose" in output:
            config.verbose = output["verbose"]
        if "quiet" in output:
            config.quiet = output["quiet"]

    if "include_dev" in data:
        config.include_dev = data["include_dev"]

    if "package_managers" in data:
        config.package_managers = data["package_managers"]

    return config


def _find_config_file() -> Optional[Path]:
    """Find config file in current dir or XDG locations."""
    current_dir = Path.cwd()
    config_path = current_dir / ".depcheck.yaml"
    if config_path.exists():
        return config_path

    xdg_config = os.environ.get("XDG_CONFIG_HOME", str(Path.home() / ".config"))
    xdg_config_path = Path(xdg_config) / "depcheck" / ".depcheck.yaml"
    if xdg_config_path.exists():
        return xdg_config_path

    return None


def should_ignore_package(config: Config, package_name: str) -> bool:
    """Check if a package should be ignored."""
    for pattern in config.ignore_packages:
        if fnmatch.fnmatch(package_name, pattern):
            return True
    return False


def should_ignore_file(config: Config, file_path: Path) -> bool:
    """Check if a file should be ignored."""
    for pattern in config.ignore_patterns:
        if pattern in str(file_path):
            return True
    return False