import base64


def _encode_key(key: str) -> str:
    return base64.urlsafe_b64encode(key.encode("utf-8")).decode("ascii").rstrip("=")


class SearchClient:
    def __init__(self, client, index_name: str):
        self._client = client
        self._index_name = index_name

    def index_document(self, key: str, path: str, title: str, content: str) -> None:
        index = self._client.index(self._index_name)
        index.add_documents([{
            "id": _encode_key(key),
            "key": key,
            "path": path,
            "title": title,
            "content": content,
        }])

    def delete_document(self, key: str) -> None:
        index = self._client.index(self._index_name)
        index.delete_document(_encode_key(key))

    def delete_all_documents(self) -> None:
        index = self._client.index(self._index_name)
        index.delete_all_documents()

    def search(self, query: str) -> list[dict]:
        index = self._client.index(self._index_name)
        response = index.search(query, {
            "attributesToHighlight": ["content"],
            "highlightPreTag": "<em>",
            "highlightPostTag": "</em>",
            "attributesToCrop": ["content"],
            "cropLength": 30,
            "showMatchesPosition": True,
        })
        results = []
        for hit in response.get("hits", []):
            formatted = hit.get("_formatted", {})
            line_number = None
            matches = hit.get("_matchesPosition", {}).get("content", [])
            if matches and hit.get("content"):
                start = matches[0]["start"]
                line_number = hit["content"][:start].count("\n") + 1
            results.append({
                "key": hit["key"],
                "title": hit["title"],
                "path": hit["path"],
                "snippet": formatted.get("content", hit.get("content", "")),
                "lineNumber": line_number,
            })
        return results