import os
import re

class SkillLoader:
    """从 skills/ 目录加载 SKILL.md 技能"""
    def __init__(self, skills_dir: str = "./skills"):
        self.skills_dir = skills_dir
        self.index = {}   # name -> (description, full_text)

    def scan(self):
        """扫描所有技能，建立索引"""
        for entry in os.listdir(self.skills_dir):
            skill_path = os.path.join(self.skills_dir, entry, "SKILL.md")
            if not os.path.isfile(skill_path):
                continue
            with open(skill_path, "r", encoding="utf-8") as f:
                text = f.read()
            # 解析 front matter 里的 name 和 description
            m = re.search(r"^---\s*\n(.*?)\n---", text, re.DOTALL)
            meta = {}
            if m:
                for line in m.group(1).splitlines():
                    if ":" in line:
                        key, _, value = line.partition(":")
                        meta[key.strip()] = value.strip()
            self.index[meta.get("name", entry)] = (meta.get("description", ""), text)
        return self.index

    def match(self, task: str, top_k: int = 2) -> list:
        """根据任务文本粗匹配技能（真实项目可用 Embedding 语义匹配）"""
        scored = []
        for name, (desc, text) in self.index.items():
            score = 0
            for kw in task.split():
                if kw in desc or kw in name:
                    score += 1
            scored.append((score, name, text))
        scored.sort(key=lambda x: x[0], reverse=True)
        return [item for item in scored if item[0] > 0][:top_k]

    def build_system_prompt(self, task: str) -> str:
        """把匹配到的技能注入系统提示词"""
        parts = ["你是智能助手，请按照用户提供的技能规范工作。"]
        for score, name, text in self.match(task):
            parts.append(f"\n===== 技能：{name} =====\n{text}")
        return "\n".join(parts)

# 使用
loader = SkillLoader("./skills")
loader.scan()
system_prompt = loader.build_system_prompt("帮我审查这段 Python 代码")
print(system_prompt[:200])