import logging

logger = logging.getLogger(__name__)

MAX_HISTORY_FETCH_LIMIT = 100
MAX_HISTORY_BODY_CHARS = 2000


async def fetch_chat_history(
    client,
    chat_guid: str,
    limit: int = 50,
    before_guid: str | None = None,
) -> list[dict]:
    params = {"limit": min(limit, MAX_HISTORY_FETCH_LIMIT)}
    if before_guid:
        params["before"] = before_guid

    for path, extra_params in _history_api_paths(chat_guid):
        merged = {**params, **extra_params}
        try:
            resp = await client.get(path, params=merged)
            if resp.status_code < 300:
                data = _extract_message_list(resp.json())
                return [_normalize_history_message(m) for m in data]
        except Exception as e:
            logger.debug("History fetch failed for %s: %s", path, e)
            continue

    return []


def _history_api_paths(chat_guid: str) -> list[tuple[str, dict]]:
    return [
        (f"/api/v1/chat/{chat_guid}/messages", {"sort": "DESC"}),
        ("/api/v1/messages", {"chatGuid": chat_guid}),
        (f"/api/v1/chat/{chat_guid}/message", {}),
    ]


def _extract_message_list(response_data) -> list[dict]:
    if isinstance(response_data, list):
        return response_data
    if isinstance(response_data, dict):
        for key in ("data", "messages", "results"):
            val = response_data.get(key)
            if isinstance(val, list):
                return val
    return []


def _normalize_history_message(msg: dict) -> dict:
    body = msg.get("text", msg.get("message", msg.get("body", "")))
    return {
        "guid": msg.get("guid", ""),
        "text": body[:MAX_HISTORY_BODY_CHARS],
        "sender": msg.get("sender", msg.get("handle", {}).get("id", "")),
        "date": msg.get("dateDelivered", msg.get("date_delivered", msg.get("date", 0))),
        "is_from_me": msg.get("isFromMe", msg.get("is_from_me", False)),
        "chat_guid": msg.get("chatGuid", msg.get("chat_guid", "")),
        "attachments": msg.get("attachments", []),
    }