"""Host client configuration loader.

Loads host_config.yaml (multi-host mode) or keyring.yaml (standalone mode).

Fields:
- NODE_ID, DISPLAY_NAME
- ROUTER_URL, ROUTER_SECRET
- OPENAI_BASE_URL, OPENAI_API_KEY, OPENAI_MODEL
- WORKING_DIR, METASO_API_KEY
- SERVES_USERS / ALLOWED_OPEN_IDS, CAPABILITIES
"""

from __future__ import annotations

from pathlib import Path
from typing import Optional

import yaml


def _load_yaml(path: Path) -> dict:
    if not path.exists():
        raise FileNotFoundError(f"Config file not found: {path}")
    with open(path, "r", encoding="utf-8") as f:
        return yaml.safe_load(f) or {}


class HostConfig:
    """Configuration for a host client node."""

    def __init__(
        self,
        data: dict,
        *,
        serves_users_key: str = "SERVES_USERS",
        default_node_id: str = "unknown-node",
        default_display_name: str = "",
    ):
        self.node_id: str = data.get("NODE_ID", default_node_id)
        self.display_name: str = data.get("DISPLAY_NAME", default_display_name or self.node_id)
        self.router_url: str = data.get("ROUTER_URL", "ws://127.0.0.1:8000/ws/node")
        self.router_secret: str = data.get("ROUTER_SECRET", "")

        self.openai_base_url: str = data.get(
            "OPENAI_BASE_URL", "https://open.bigmodel.cn/api/paas/v4/"
        )
        self.openai_api_key: str = data.get("OPENAI_API_KEY", "")
        self.openai_model: str = data.get("OPENAI_MODEL", "glm-4.7")

        self.working_dir: str = data.get("WORKING_DIR", str(Path.home() / "projects"))
        self.metaso_api_key: Optional[str] = data.get("METASO_API_KEY")

        serves_users = data.get(serves_users_key, [])
        self.serves_users: list[str] = serves_users if isinstance(serves_users, list) else []

        capabilities = data.get("CAPABILITIES", ["claude_code", "shell", "file_ops", "web", "scheduler"])
        self.capabilities: list[str] = capabilities if isinstance(capabilities, list) else []

        if not self.openai_api_key:
            raise ValueError("OPENAI_API_KEY is required in config but was not set")

    @classmethod
    def from_file(cls, config_path: Optional[Path] = None) -> "HostConfig":
        """Load from host_config.yaml (multi-host mode)."""
        path = config_path or Path(__file__).parent.parent / "host_config.yaml"
        return cls(_load_yaml(path), serves_users_key="SERVES_USERS", default_node_id="unknown-node")

    @classmethod
    def from_keyring(cls, keyring_path: Optional[Path] = None) -> "HostConfig":
        """Load from keyring.yaml (standalone mode)."""
        path = keyring_path or Path(__file__).parent.parent / "keyring.yaml"
        return cls(
            _load_yaml(path),
            serves_users_key="ALLOWED_OPEN_IDS",
            default_node_id="local-node",
            default_display_name="Local Machine",
        )


_host_config: Optional[HostConfig] = None


def get_host_config() -> HostConfig:
    """Get the global host config instance (multi-host mode)."""
    global _host_config
    if _host_config is None:
        _host_config = HostConfig.from_file()
    return _host_config