"""Loader for the shared fixture corpus — seeds and tests draw from it.

The corpus is product content (German knowledge documents of the fictional
SME "Nordwind Maschinenbau GmbH"). PyYAML is available through
uvicorn[standard]; it becomes a declared dependency with the template
import in M6.
"""

from dataclasses import dataclass, field
from pathlib import Path
from typing import Any

import yaml

FIXTURES_DIR = Path(__file__).resolve().parent
CORPUS_DIR = FIXTURES_DIR / "corpus"


@dataclass
class CorpusDoc:
    slug: str
    title: str
    department: str
    visibility: str
    content_md: str
    grants: list[str] = field(default_factory=list)


def load_corpus() -> list[CorpusDoc]:
    docs: list[CorpusDoc] = []
    for path in sorted(CORPUS_DIR.glob("*.md")):
        text = path.read_text()
        if not text.startswith("---\n"):
            raise ValueError(f"corpus file without frontmatter: {path.name}")
        _, frontmatter, body = text.split("---\n", 2)
        meta = yaml.safe_load(frontmatter)
        docs.append(
            CorpusDoc(
                slug=meta["id"],
                title=meta["title"],
                department=meta["department"],
                visibility=meta["visibility"],
                grants=list(meta.get("grants", [])),
                content_md=body.strip() + "\n",
            )
        )
    return docs


def load_golden_queries() -> list[dict[str, Any]]:
    return yaml.safe_load((FIXTURES_DIR / "golden_queries.yaml").read_text())


def load_conversation_snippets() -> list[dict[str, Any]]:
    """Short chats whose LAST message is a topic-losing follow-up, with the
    corpus slug the conversation is really about — for comparing topic-summary
    retrieval against retrieval over the raw last message."""
    return yaml.safe_load((FIXTURES_DIR / "conversation_snippets.yaml").read_text())