"""Configuration loader."""
from pathlib import Path
from typing import List, Optional
import yaml
from ..models import Rule

class ConfigLoader:
    def __init__(self):
        self._config_paths = [
            Path.cwd() / ".shell-safe-validator.yaml",
            Path.home() / ".config" / "shell-safe-validator" / "rules.yaml",
        ]
        self._default_config_path = Path(__file__).parent.parent.parent / "config" / "default_rules.yaml"

    def load_default_rules(self):
        if self._default_config_path.exists():
            return self.load_from_file(self._default_config_path)
        return []

    def load_from_file(self, path):
        rules = []
        try:
            with open(path, "r") as f:
                config = yaml.safe_load(f)
            if config and "rules" in config:
                for rule_data in config["rules"]:
                    if rule_data.get("enabled", True):
                        rules.append(Rule.from_dict(rule_data))
        except yaml.YAMLError as e:
            raise ValueError(f"Invalid YAML syntax: {e}")
        return rules

    def load_user_rules(self):
        rules = []
        for config_path in self._config_paths:
            if config_path.exists():
                rules.extend(self.load_from_file(config_path))
        return rules

    def load_merged_rules(self, custom_rules=None):
        rules = self.load_default_rules()
        user_rules = self.load_user_rules()
        rule_dict = {r.id: r for r in rules}
        for r in user_rules:
            rule_dict[r.id] = r
        return list(rule_dict.values())

def load_rules(config_path=None):
    loader = ConfigLoader()
    if config_path:
        return loader.load_from_file(Path(config_path))
    return loader.load_merged_rules()