"""
System agents 配置加载工具

从 system_agents.yaml 加载配置并构建 RuntimeConfig
"""

from pathlib import Path

import yaml
from pydantic import ValidationError

from schemas.agent.system_agent import SystemAgentLLMConfig
from schemas.agent.runtime_config import (
    ContextSource,
    ContextWindowMode,
    MessageContextConfig,
    RuntimeConfig,
)
from utils.paths import get_system_agents_config_path


def _default_system_agents_path() -> Path:
    return get_system_agents_config_path()


def _load_system_agents_yaml(path: Path | None = None) -> dict[str, object]:
    target_path = path or _default_system_agents_path()
    with target_path.open("r", encoding="utf-8") as f:
        loaded = yaml.safe_load(f) or {}
    if not isinstance(loaded, dict):
        raise ValueError(f"Invalid system agents format: {target_path}")
    return loaded


def _parse_context_messages_config(
    yaml_config: dict[str, object] | None,
) -> MessageContextConfig:
    if not yaml_config:
        return MessageContextConfig()
    raw_mode = yaml_config.get("mode", "day")
    mode_str = raw_mode if isinstance(raw_mode, str) else "day"
    raw_count = yaml_config.get("count", 2)
    count = raw_count if isinstance(raw_count, int) else 2
    try:
        source = ContextSource.LATEST_CHAT
    except ValueError:
        source = ContextSource.LATEST_CHAT
    try:
        window_mode = ContextWindowMode(mode_str)
    except ValueError:
        window_mode = ContextWindowMode.DAY
    return MessageContextConfig(
        source=source,
        window_mode=window_mode,
        window_count=count,
    )


def build_runtime_config_from_system_agents(
    yaml_path: Path | None = None,
) -> RuntimeConfig:
    """
    从 system_agents.yaml 构建 RuntimeConfig

    仅使用 worker 配置:
    - worker.context_messages 配置上下文窗口
    - enabled_tools 固定为空（eryao 不启用自定义工具）
    """
    raw = _load_system_agents_yaml(yaml_path)
    raw_agents = raw.get("agents", [])
    agents_list = raw_agents if isinstance(raw_agents, list) else []

    worker_config: SystemAgentLLMConfig | None = None

    for agent in agents_list:
        if not isinstance(agent, dict):
            continue
        agent_type = str(agent.get("agent_type", "")).strip().lower()
        if agent_type == "worker":
            config_dict = agent.get("config") or {}
            try:
                worker_config = SystemAgentLLMConfig.model_validate(config_dict)
            except ValidationError:
                worker_config = SystemAgentLLMConfig()

    context_cfg = _parse_context_messages_config(
        worker_config.context_messages.model_dump() if worker_config else None
    )

    return RuntimeConfig(
        enabled_tools=[],
        context=context_cfg,
    )