# -*- coding: utf-8 -*-
"""从 prompts.yaml 加载报告 LLM 提示词，供 llm_analyzer 使用。"""
from __future__ import annotations

import logging
from functools import lru_cache
from pathlib import Path
from typing import Any, Dict, Optional

import yaml

logger = logging.getLogger("voc.prompt_loader")

PROMPTS_FILE = Path(__file__).resolve().parent / "prompts.yaml"


def _render(template: str, **kwargs: Any) -> str:
    """将 {{key}} 替换为值；模板内 JSON 示例的花括号无需转义。"""
    out = template
    for key, val in kwargs.items():
        out = out.replace("{{" + key + "}}", str(val))
    return out


@lru_cache(maxsize=1)
def load_prompts(path: Optional[str] = None) -> Dict[str, Any]:
    fp = Path(path) if path else PROMPTS_FILE
    if not fp.is_file():
        raise FileNotFoundError(f"提示词文件不存在: {fp}")
    with fp.open(encoding="utf-8") as f:
        data = yaml.safe_load(f) or {}
    logger.debug("已加载提示词: %s", fp)
    return data


def reload_prompts() -> None:
    load_prompts.cache_clear()


def get_section(name: str, path: Optional[str] = None) -> Dict[str, Any]:
    prompts = load_prompts(path)
    sec = prompts.get(name)
    if not sec:
        raise KeyError(f"prompts.yaml 缺少段落: {name}")
    return sec


def system_prompt(name: str, path: Optional[str] = None) -> str:
    return (get_section(name, path).get("system") or "").strip()


def llm_params(name: str, path: Optional[str] = None) -> Dict[str, Any]:
    sec = get_section(name, path)
    return {
        "temperature": float(sec.get("temperature", 0.3)),
        "max_tokens": int(sec.get("max_tokens", 8000)),
    }


def user_prompt(name: str, path: Optional[str] = None, **kwargs: Any) -> str:
    tpl = (get_section(name, path).get("user_template") or "").strip()
    return _render(tpl, **kwargs)


def optional_block(name: str, block_key: str, path: Optional[str] = None, **kwargs: Any) -> str:
    """加载可选子模板（如差评主题 extra 块）。"""
    sec = get_section(name, path)
    tpl = (sec.get(block_key) or "").strip()
    if not tpl:
        return ""
    return _render(tpl, **kwargs)