"""Skills Scanner — Scan skills/ directory and generate SKILLS_SNAPSHOT.md."""

from pathlib import Path
from hashlib import sha256

import yaml


def discover_skills(base_dir: Path) -> list[dict]:
    """Read the native Skills catalog without changing its generated snapshot."""
    root = (base_dir / "skills").resolve()
    entries = []
    for file in sorted(root.rglob("SKILL.md")):
        resolved = file.resolve()
        if not resolved.is_relative_to(root):
            continue
        try:
            content = file.read_text(encoding="utf-8")
            if not content.startswith("---"):
                continue
            parts = content.split("---", 2)
            meta = yaml.safe_load(parts[1]) if len(parts) == 3 else None
            if not isinstance(meta, dict):
                continue
            legacy_id = file.relative_to(root).as_posix()
            entries.append({
                "id": legacy_id,
                "component_id": str(meta.get("id", legacy_id)),
                "legacy_id": legacy_id,
                "kind": str(meta.get("kind", "skill")),
                "version": str(meta.get("version", "legacy")),
                "schema_version": int(meta.get("schema_version", 1)),
                "status": str(meta.get("status", "published")),
                "name": str(meta.get("name", file.parent.name)),
                "description": str(meta.get("description", "")),
                "content_hash": sha256(content.encode("utf-8")).hexdigest(),
                "content": content,
            })
        except (OSError, ValueError, TypeError, yaml.YAMLError):
            continue
    return entries


def scan_skills(base_dir: Path) -> str:
    """Scan all SKILL.md files and generate SKILLS_SNAPSHOT.md."""
    skills_dir = base_dir / "skills"
    snapshot_path = base_dir / "SKILLS_SNAPSHOT.md"

    if not skills_dir.exists():
        skills_dir.mkdir(parents=True)

    skills = [{**s, "location":f"./backend/skills/{s['legacy_id']}"} for s in discover_skills(base_dir)]

    # Build XML-style snapshot
    lines = ["<available_skills>"]
    for s in skills:
        lines.append("  <skill>")
        lines.append(f"    <name>{s['name']}</name>")
        lines.append(f"    <description>{s['description']}</description>")
        lines.append(f"    <location>{s['location']}</location>")
        lines.append("  </skill>")
    lines.append("</available_skills>")

    snapshot = "\n".join(lines)
    snapshot_path.write_text(snapshot, encoding="utf-8")
    print(f"📋 Skills snapshot: {len(skills)} skills found")
    return snapshot