import { useEffect, useState, useCallback } from "react";
import { supabase } from "@/integrations/supabase/client";
import { useAuth } from "@/lib/auth";

interface Counts {
  messages: number;
  tasks: number;
  notifications: number;
}

export function useBubbleCounts(): Counts {
  const { user } = useAuth();
  const [counts, setCounts] = useState<Counts>({ messages: 0, tasks: 0, notifications: 0 });

  const load = useCallback(async () => {
    if (!user) {
      setCounts({ messages: 0, tasks: 0, notifications: 0 });
      return;
    }
    const [memberRes, msgRes, taskRes, notifRes] = await Promise.all([
      supabase.from("conversation_members").select("conversation_id, last_read_at").eq("user_id", user.id),
      // unread messages: query per-convo handled below
      Promise.resolve(null),
      supabase
        .from("task_assignees")
        .select("task_id, tasks!inner(status, due_date)")
        .eq("user_id", user.id)
        .eq("tasks.status", "incomplete"),
      supabase
        .from("notifications")
        .select("id", { count: "exact", head: true })
        .eq("user_id", user.id)
        .is("read_at", null),
    ]);

    let unreadMessages = 0;
    const memberRows = memberRes.data ?? [];
    if (memberRows.length) {
      // For each conversation, count messages newer than last_read_at and not from self
      const results = await Promise.all(
        memberRows.map(async (m) => {
          const { count } = await supabase
            .from("messages")
            .select("id", { count: "exact", head: true })
            .eq("conversation_id", m.conversation_id)
            .gt("created_at", m.last_read_at)
            .neq("sender_id", user.id);
          return count ?? 0;
        }),
      );
      unreadMessages = results.reduce((a, b) => a + b, 0);
    }

    const taskCount = (taskRes.data ?? []).length;
    setCounts({
      messages: unreadMessages,
      tasks: taskCount,
      notifications: notifRes.count ?? 0,
    });
  }, [user]);

  useEffect(() => {
    if (!user) return;
    load();
    const ch = supabase
      .channel(`bubbles-${user.id}-${Math.random().toString(36).slice(2)}`)
      .on("postgres_changes", { event: "*", schema: "public", table: "messages" }, () => load())
      .on("postgres_changes", { event: "*", schema: "public", table: "task_assignees" }, () => load())
      .on("postgres_changes", { event: "*", schema: "public", table: "tasks" }, () => load())
      .on("postgres_changes", { event: "*", schema: "public", table: "notifications", filter: `user_id=eq.${user.id}` }, () => load())
      .on("postgres_changes", { event: "*", schema: "public", table: "conversation_members", filter: `user_id=eq.${user.id}` }, () => load())
      .subscribe();
    return () => {
      supabase.removeChannel(ch);
    };
  }, [user, load]);

  return counts;
}