#!/usr/bin/env python3
"""Quick validation for a Codex skill directory."""

from __future__ import annotations

import re
import sys
from pathlib import Path

import yaml


MAX_SKILL_NAME_LENGTH = 64


def validate_skill(skill_path: Path) -> tuple[bool, str]:
    skill_md = skill_path / "SKILL.md"
    if not skill_md.exists():
        return False, "SKILL.md not found"

    content = skill_md.read_text(encoding="utf-8")
    if not content.startswith("---"):
        return False, "No YAML frontmatter found"

    match = re.match(r"^---\n(.*?)\n---", content, re.DOTALL)
    if not match:
        return False, "Invalid frontmatter format"

    try:
        frontmatter = yaml.safe_load(match.group(1))
    except yaml.YAMLError as exc:
        return False, f"Invalid YAML in frontmatter: {exc}"

    if not isinstance(frontmatter, dict):
        return False, "Frontmatter must be a YAML dictionary"

    allowed_keys = {"name", "description"}
    unexpected_keys = set(frontmatter) - allowed_keys
    if unexpected_keys:
        return False, "Unexpected frontmatter key(s): " + ", ".join(
            sorted(unexpected_keys)
        )

    name = frontmatter.get("name")
    if not isinstance(name, str) or not name.strip():
        return False, "Missing or invalid 'name' in frontmatter"
    if not re.fullmatch(r"[a-z0-9-]+", name):
        return False, "Name must use lowercase letters, digits, and hyphens only"
    if name.startswith("-") or name.endswith("-") or "--" in name:
        return False, "Name cannot start/end with hyphen or contain consecutive hyphens"
    if len(name) > MAX_SKILL_NAME_LENGTH:
        return False, f"Name exceeds {MAX_SKILL_NAME_LENGTH} characters"

    description = frontmatter.get("description")
    if not isinstance(description, str) or not description.strip():
        return False, "Missing or invalid 'description' in frontmatter"
    if "<" in description or ">" in description:
        return False, "Description cannot contain angle brackets"
    if len(description) > 1024:
        return False, "Description exceeds 1024 characters"

    return True, "Skill is valid!"


def main(argv: list[str]) -> int:
    if len(argv) != 1:
        print("Usage: python scripts/quick_validate.py <skill-directory>", file=sys.stderr)
        return 2

    valid, message = validate_skill(Path(argv[0]))
    print(message)
    return 0 if valid else 1


if __name__ == "__main__":
    raise SystemExit(main(sys.argv[1:]))