from __future__ import annotations

import hashlib
import uuid
from dataclasses import dataclass
from pathlib import Path

SUPPORTED_LANGUAGES = ("nl-BE", "en-GB", "fr-BE")

# Stable across runs (and across which language ships first) so a document's RAGcore
# source_id never changes just because the sync ran on a different day or in a
# different order -- required for RAGcore's upload idempotency to work per document.
_SOURCE_ID_NAMESPACE = uuid.uuid5(
    uuid.NAMESPACE_URL, "https://mobilityops.internal/knowledge/procedures"
)


def parse_frontmatter(raw: str) -> tuple[dict[str, str], str]:
    if not raw.startswith("---"):
        return {}, raw
    end = raw.find("\n---", 3)
    if end == -1:
        return {}, raw
    block = raw[3:end].strip()
    body = raw[end + 4 :].lstrip("\n")
    meta: dict[str, str] = {}
    for line in block.splitlines():
        if ":" not in line:
            continue
        key, _, value = line.partition(":")
        meta[key.strip()] = value.strip().strip('"')
    return meta, body


@dataclass(frozen=True)
class ProcedureDocument:
    source_id: str
    language: str
    document_id: str
    title: str
    version: str
    content: str
    content_hash: str


def iter_procedure_documents(knowledge_dir: Path) -> list[ProcedureDocument]:
    """Read every procedure Markdown file Fleet Ops ships, across every supported
    language, as a flat list ready for external sync (e.g. into RAGcore). Frontmatter
    fields (title, version) come from the same files the demo knowledge provider
    already reads -- see parse_frontmatter -- so the two never drift apart."""

    documents: list[ProcedureDocument] = []
    for language in SUPPORTED_LANGUAGES:
        language_dir = knowledge_dir / language
        if not language_dir.is_dir():
            continue
        for path in sorted(language_dir.glob("*.md")):
            raw = path.read_text(encoding="utf-8")
            meta, body = parse_frontmatter(raw)
            document_id = meta.get("document_id", path.stem)
            content = body.strip()
            documents.append(
                ProcedureDocument(
                    source_id=str(uuid.uuid5(_SOURCE_ID_NAMESPACE, f"{language}:{document_id}")),
                    language=language,
                    document_id=document_id,
                    title=meta.get("title", path.stem),
                    version=meta.get("version", "1.0"),
                    content=content,
                    content_hash=hashlib.sha256(content.encode("utf-8")).hexdigest(),
                )
            )
    return documents