from __future__ import annotations

from pathlib import Path
from typing import Iterable


class SkillStore:
    """Minimal skill loader kept for the same extension point as the reference project."""

    def __init__(self, skill_dirs: Iterable[str | Path] | None = None) -> None:
        self.skill_dirs = [Path(path) for path in (skill_dirs or [])]

    def build_prompt_fragment(self, active_skills: Iterable[str]) -> str:
        fragments: list[str] = []
        active = set(active_skills)
        if not active:
            return ""
        for directory in self.skill_dirs:
            if not directory.exists():
                continue
            for skill_file in directory.glob("*/SKILL.md"):
                if skill_file.parent.name in active:
                    fragments.append(skill_file.read_text(encoding="utf-8"))
        return "\n\n".join(fragments)