from __future__ import annotations

from pathlib import Path
from typing import Dict


class PersonaEngine:
    def __init__(self, plugin_path: str, config: Dict):
        self.plugin_path = Path(plugin_path)
        self.config = config or {}
        self.persona_text = self._load_persona()

    def build_system_prompt(self) -> str:
        name = self.config.get("name", "小牛")
        style = self.config.get("style", "")
        familiarity = self.config.get("familiarity_hint", "")
        max_sentences = self.config.get("max_reply_sentences", 3)
        return (
            f"{self.persona_text}\n\n"
            f"补充约束：\n"
            f"- 你当前对外名称固定为{name}\n"
            f"- 整体风格：{style}\n"
            f"- 熟悉感边界：{familiarity}\n"
            f"- 一般最多输出{max_sentences}句\n"
            f"- 优先根据场景决定是答疑、接话还是不说话\n"
        )

    def _load_persona(self) -> str:
        persona_file = self.config.get("persona_file", "persona/xiaoniu.txt")
        persona_path = self.plugin_path / persona_file
        if persona_path.exists():
            return persona_path.read_text(encoding="utf-8").strip()
        return "你叫小牛，是一个自然、靠谱、会看场合的群聊成员。"