"""Configuration loader for AUR-Shield."""
from __future__ import annotations

import os
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any

import yaml


@dataclass
class OllamaConfig:
    url: str = "http://localhost:11434"
    model: str = "qwen2.5:latest"
    timeout: int = 120


@dataclass
class ServerConfig:
    host: str = "0.0.0.0"
    port: int = 8443
    repo_dir: str = "/var/cache/aur-shield/repo"
    work_dir: str = "/var/cache/aur-shield/build"
    build_user: str = "nobody"
    scan_only: bool = False


@dataclass
class SecurityConfig:
    block_patterns: list[str] = field(default_factory=lambda: [
        r"curl.*\|.*bash",
        r"wget.*/tmp/.*\|.*sh",
        r"eval.*base64",
        r"nc\s+-.*\d+",
        r"/dev/tcp/",
        r"systemctl.*enable.*--now",
    ])
    max_pkg_size_mb: int = 500
    allowed_source_schemes: list[str] = field(default_factory=lambda: [
        "https", "http", "git", "ftp", "file",
    ])


@dataclass
class CacheConfig:
    ttl_hours: int = 168
    max_cache_gb: int = 10


@dataclass
class BuildConfig:
    use_devtools: bool = True
    timeout: int = 600


@dataclass
class Config:
    ollama: OllamaConfig = field(default_factory=OllamaConfig)
    server: ServerConfig = field(default_factory=ServerConfig)
    security: SecurityConfig = field(default_factory=SecurityConfig)
    cache: CacheConfig = field(default_factory=CacheConfig)
    build: BuildConfig = field(default_factory=BuildConfig)

    @classmethod
    def load(cls, path: str | Path | None = None) -> "Config":
        """Load config from YAML file, falling back to defaults."""
        if path is None:
            path = Path(os.environ.get(
                "AUR_SHIELD_CONFIG",
                "config.yaml",
            ))

        path = Path(path)
        if not path.exists():
            return cls()

        with open(path) as f:
            raw: dict[str, Any] = yaml.safe_load(f) or {}

        cfg = cls()
        if "ollama" in raw:
            cfg.ollama = OllamaConfig(**raw["ollama"])
        if "server" in raw:
            cfg.server = ServerConfig(**raw["server"])
        if "security" in raw:
            cfg.security = SecurityConfig(**raw["security"])
        if "cache" in raw:
            cfg.cache = CacheConfig(**raw["cache"])
        if "build" in raw:
            cfg.build = BuildConfig(**raw["build"])
        return cfg