"""子智能体提示词构建。

所有 prompt 正文均从 prompts/sub_agent/ 下的文本文件加载，避免在代码中硬编码。
"""
from __future__ import annotations

import platform
from datetime import datetime
from pathlib import Path
from typing import Optional

try:
    from config import PROMPTS_DIR
except ImportError:
    import sys

    project_root = Path(__file__).resolve().parents[2]
    if str(project_root) not in sys.path:
        sys.path.insert(0, str(project_root))
    from config import PROMPTS_DIR


_SUB_AGENT_PROMPTS_DIR = Path(PROMPTS_DIR) / "sub_agent"
_TEMPLATE_CACHE: dict[str, str] = {}


def _load_template(name: str) -> str:
    """从 prompts/sub_agent/<name>.txt 加载模板，带缓存。"""
    cached = _TEMPLATE_CACHE.get(name)
    if cached is not None:
        return cached

    template_path = _SUB_AGENT_PROMPTS_DIR / f"{name}.txt"
    if not template_path.exists():
        raise FileNotFoundError(f"子智能体 prompt 模板缺失: {template_path}")

    content = template_path.read_text(encoding="utf-8")
    _TEMPLATE_CACHE[name] = content
    return content


def _format_template(name: str, **kwargs) -> str:
    """加载模板并用 str.format 填充占位符。"""
    template = _load_template(name)
    return template.format(**kwargs)


def build_user_message(
    agent_id: int,
    summary: str,
    task: str,
    deliverables_path: str,
    timeout_seconds: int,
) -> str:
    """构建发送给子智能体的用户消息。"""
    return _format_template(
        "user_message",
        agent_id=agent_id,
        summary=summary,
        task=task,
        deliverables_path=deliverables_path,
        timeout_seconds=timeout_seconds,
    )


def build_system_prompt(workspace_path: str) -> str:
    """构建子智能体的系统提示。"""
    system_info = f"{platform.system()} {platform.release()}"
    current_time = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
    return _format_template(
        "system",
        workspace_path=workspace_path,
        system_info=system_info,
        current_time=current_time,
    )