from __future__ import annotations

from dataclasses import dataclass
from typing import Any, Dict, Optional

import yaml
from .hook_manifest_core import parse_hook_manifest


@dataclass(frozen=True, slots=True)
class ParsedHookFrontmatter:
    frontmatter: Dict[str, Any]
    body: str


def parse_frontmatter(markdown: str) -> ParsedHookFrontmatter:
    """
    Parse YAML frontmatter delimited by leading '---' lines.
    Returns (frontmatter_dict, remaining_body).
    """
    text = markdown.lstrip("\ufeff")
    if not text.startswith("---"):
        return ParsedHookFrontmatter(frontmatter={}, body=markdown)

    lines = text.splitlines(keepends=True)
    if not lines:
        return ParsedHookFrontmatter(frontmatter={}, body=markdown)

    # first line is '---'
    if not lines[0].strip().startswith("---"):
        return ParsedHookFrontmatter(frontmatter={}, body=markdown)

    fm_lines = []
    end_idx = None
    for i in range(1, len(lines)):
        if lines[i].strip().startswith("---"):
            end_idx = i
            break
        fm_lines.append(lines[i])

    if end_idx is None:
        return ParsedHookFrontmatter(frontmatter={}, body=markdown)

    fm_raw = "".join(fm_lines)
    body = "".join(lines[end_idx + 1 :])

    try:
        parsed = yaml.safe_load(fm_raw) or {}
        if not isinstance(parsed, dict):
            parsed = {}
    except Exception:
        parsed = {}
    return ParsedHookFrontmatter(frontmatter=parsed, body=body)


def resolve_oclaw_metadata(frontmatter: Dict[str, Any]) -> Optional[Dict[str, Any]]:
    parsed = parse_hook_manifest(frontmatter=frontmatter, default_name="hook")
    out = parsed.metadata.as_dict()
    return out if out else None


def resolve_hook_invocation_policy(frontmatter: Dict[str, Any]) -> Dict[str, bool]:
    parsed = parse_hook_manifest(frontmatter=frontmatter, default_name="hook")
    return {"enabled": bool(parsed.invocation_enabled)}


def resolve_hook_key(name: str, entry: Dict[str, Any]) -> str:
    # Oclaw's TS resolves a config key with possible explicit hookKey; keep it simple.
    md = entry.get("metadata") if isinstance(entry, dict) else None
    if isinstance(md, dict):
        hook_key = md.get("hookKey")
        if isinstance(hook_key, str) and hook_key.strip():
            return hook_key.strip()
    return name