"use client";

import { useEffect } from "react";
import { useRouter } from "next/navigation";
import { sse } from "@/lib/realtime/sse";
import { startRealtimeRefresh } from "@/lib/realtime/realtime-refresh";

type FormRealtimeRefreshProps = {
  topic: "forms" | "submissions";
  formId?: string;
  debounceMs?: number;
};

type UploadRealtimeRefreshProps = {
  topic: "uploads";
  debounceMs?: number;
};

type LeaderboardRealtimeRefreshProps =
  | {
      topic: "leaderboards";
      leaderboard: "xp";
      channelId?: never;
      debounceMs?: number;
    }
  | {
      topic: "leaderboards";
      leaderboard: "vc";
      channelId?: string;
      debounceMs?: number;
    }
  | {
      topic: "leaderboards";
      leaderboard: "profile";
      channelId?: never;
      debounceMs?: number;
    };

type RealtimeRefreshProps =
  | FormRealtimeRefreshProps
  | UploadRealtimeRefreshProps
  | LeaderboardRealtimeRefreshProps;

export function RealtimeRefresh(props: RealtimeRefreshProps) {
  const router = useRouter();
  const topic = props.topic;
  const formId = topic === "forms" || topic === "submissions" ? props.formId : undefined;
  const leaderboard = topic === "leaderboards" ? props.leaderboard : undefined;
  const channelId = topic === "leaderboards" ? props.channelId : undefined;
  const debounceMs = props.debounceMs ?? (topic === "leaderboards" ? 500 : 150);

  useEffect(() => {
    const filter = topic === "leaderboards"
      ? leaderboard === "profile"
        ? { kind: "profile" as const }
        : leaderboard === "xp"
        ? { kind: "xp" as const }
        : { kind: "vc" as const, channelId }
      : topic === "uploads"
        ? { kind: "uploads" as const }
        : { kind: "form" as const, formId };

    return startRealtimeRefresh({
      filter,
      debounceMs,
      refresh: () => router.refresh(),
      subscribe(emit) {
        const options = { onopen: () => emit({ kind: "open" }) };

        if (topic === "forms") {
          return sse.forms.sub(
            "update",
            (event) => emit({ kind: "form", formId: event.formId }),
            options,
          );
        }
        if (topic === "submissions") {
          return sse.submissions.sub(
            "update",
            (event) => emit({ kind: "form", formId: event.formId }),
            options,
          );
        }
        if (topic === "uploads") {
          return sse.uploads.sub("update", () => emit({ kind: "upload" }), options);
        }
        return sse.leaderboards.subMany({
          xp: () => emit({ kind: "xp" }),
          vc: (event) => emit({ kind: "vc", channelId: event.channelId }),
        }, options);
      },
    });
  }, [channelId, debounceMs, formId, leaderboard, router, topic]);

  return null;
}