import { invoke } from "@tauri-apps/api/core";
import type { WebsocketConnection, WebsocketEvent } from "@yaakapp-internal/models";
import {
  mergeModelsInStore,
  replaceModelsInStore,
  websocketConnectionsAtom,
  websocketEventsAtom,
} from "@yaakapp-internal/models";
import { atom, useAtomValue } from "jotai";
import { useEffect, useMemo } from "react";
import { fireAndForget } from "../lib/fireAndForget";
import { atomWithKVStorage } from "../lib/atoms/atomWithKVStorage";
import { jotaiStore } from "../lib/jotai";
import { activeRequestIdAtom } from "./useActiveRequestId";

const pinnedWebsocketConnectionIdAtom = atomWithKVStorage<Record<string, string | null>>(
  "pinned-websocket-connection-ids",
  {},
);

function recordKey(activeRequestId: string | null, latestConnection: WebsocketConnection | null) {
  return `${activeRequestId}-${latestConnection?.id ?? "none"}`;
}

export const activeWebsocketConnectionsAtom = atom<WebsocketConnection[]>((get) => {
  const activeRequestId = get(activeRequestIdAtom) ?? "n/a";
  return get(websocketConnectionsAtom).filter((c) => c.requestId === activeRequestId) ?? [];
});

export const activeWebsocketConnectionAtom = atom<WebsocketConnection | null>((get) => {
  const activeRequestId = get(activeRequestIdAtom) ?? "n/a";
  const activeConnections = get(activeWebsocketConnectionsAtom);
  const latestConnection = activeConnections[0] ?? null;
  const pinnedConnectionId = get(pinnedWebsocketConnectionIdAtom)[
    recordKey(activeRequestId, latestConnection)
  ];
  return activeConnections.find((c) => c.id === pinnedConnectionId) ?? activeConnections[0] ?? null;
});

export function setPinnedWebsocketConnectionId(id: string | null) {
  const activeRequestId = jotaiStore.get(activeRequestIdAtom);
  const activeConnections = jotaiStore.get(activeWebsocketConnectionsAtom);
  const latestConnection = activeConnections[0] ?? null;
  if (activeRequestId == null) return;
  jotaiStore.set(pinnedWebsocketConnectionIdAtom, (prev) => {
    return { ...prev, [recordKey(activeRequestId, latestConnection)]: id };
  });
}

export function useWebsocketEvents(connectionId: string | null) {
  const allEvents = useAtomValue(websocketEventsAtom);

  useEffect(() => {
    if (connectionId == null) {
      replaceModelsInStore("websocket_event", []);
      return;
    }

    // Fetch events from database, filtering out events from other connections and merging atomically
    fireAndForget(
      invoke<WebsocketEvent[]>("models_websocket_events", { connectionId }).then((events) =>
        mergeModelsInStore("websocket_event", events, (e) => e.connectionId === connectionId),
      ),
    );
  }, [connectionId]);

  return useMemo(
    () => allEvents.filter((e) => e.connectionId === connectionId),
    [allEvents, connectionId],
  );
}