"use client";

import { useEffect, useRef, useState } from "react";
import Link from "next/link";
import { api } from "@/lib/api";
import { useAuth } from "@/lib/auth";
import { useI18n } from "@/lib/i18n";
import { useToast } from "@/lib/toast";
import type { ChatMessage, ConversationItem } from "@/lib/types";
import RingNext from "@/components/RingNext";
import { useRingSteps } from "@/lib/rings";
import { clearDraft, loadDraft, saveDraft } from "@/lib/localDraft";

export default function ChatThreadClient({ convId }: { convId: string }) {
  const { token, user } = useAuth();
  const { t } = useI18n();
  const { toast } = useToast();
  const rings = useRingSteps();
  const [messages, setMessages] = useState<ChatMessage[]>([]);
  const [conv, setConv] = useState<ConversationItem | null>(null);
  const [text, setText] = useState("");
  const [sending, setSending] = useState(false);
  const [loading, setLoading] = useState(Boolean(token));
  const [draftReady, setDraftReady] = useState(false);
  const bottomRef = useRef<HTMLDivElement>(null);
  const draftKey = `nomadro-chat-draft:${convId}`;

  const load = () => {
    if (!token) return;
    api
      .getMessages(token, convId)
      .then(setMessages)
      .catch(() => setMessages([]))
      .finally(() => setLoading(false));
  };

  useEffect(() => {
    if (!token) {
      setLoading(false);
      return;
    }
    api.getConversation(token, convId).then(setConv).catch(() => setConv(null));
    load();
    const id = setInterval(load, 4000);
    return () => clearInterval(id);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [token, convId]);

  useEffect(() => {
    const draft = loadDraft<{ text?: string }>(draftKey);
    if (draft?.text?.trim()) {
      setText(draft.text);
      toast(t.chat.draftRestored, "info");
    }
    setDraftReady(true);
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [convId]);

  useEffect(() => {
    if (!draftReady || !token) return;
    const id = window.setTimeout(() => {
      if (!text.trim()) {
        clearDraft(draftKey);
        return;
      }
      saveDraft(draftKey, { text });
    }, 400);
    return () => window.clearTimeout(id);
  }, [text, draftReady, token, draftKey]);

  useEffect(() => {
    bottomRef.current?.scrollIntoView({ behavior: "smooth" });
  }, [messages]);

  const send = async () => {
    if (!token || !text.trim() || sending) return;
    setSending(true);
    try {
      await api.sendMessage(token, convId, text.trim());
      setText("");
      clearDraft(draftKey);
      load();
    } catch {
      toast(t.chat.sendFail, "error");
    } finally {
      setSending(false);
    }
  };

  const peer = conv?.peer;
  const peerHref = peer?.userId ? `/members/${peer.userId}` : peer?.id ? `/members/${peer.id}` : "/dating";

  if (!user || !token) {
    return (
      <div className="chat-thread-page">
        <div className="container">
          <div className="dating-gate reveal">
            <h2>{t.chat.loginTitle}</h2>
            <p>{t.chat.loginDesc}</p>
            <div className="dating-empty-actions">
              <Link href={`/login?next=/chat/${convId}`} className="btn btn-primary">
                {t.nav.login}
              </Link>
              <Link href="/meetups" className="btn btn-ghost">
                {t.dating.meetAtEvents}
              </Link>
              <Link href="/dating" className="btn btn-ghost">
                {t.nav.dating}
              </Link>
            </div>
          </div>
        </div>
      </div>
    );
  }

  return (
    <div className="chat-thread-page">
      <div className="container chat-thread-wrap">
        <nav className="detail-nav">
          <Link href="/chat">← {t.chat.back}</Link>
          <span> · </span>
          <Link href="/dating">{t.nav.dating}</Link>
          <span> · </span>
          <Link href="/meetups">{t.nav.meetups}</Link>
        </nav>

        {peer && (
          <div className="chat-thread-peer reveal">
            <Link href={peerHref} className="chat-thread-peer-link">
              <span className="chat-avatar">{peer.photo || peer.name?.[0] || "💬"}</span>
              <div>
                <strong>{peer.name}</strong>
                <p className="dating-meta">{peer.location || t.dating.globalNomad}</p>
              </div>
            </Link>
            <Link href={peerHref} className="btn btn-ghost btn-sm">
              {t.dating.viewProfile}
            </Link>
          </div>
        )}

        <div className="chat-thread-messages">
          {loading && messages.length === 0 && <p className="dest-empty">{t.chat.loadingMessages}</p>}
          {!loading && messages.length === 0 && (
            <div className="notif-empty">
              <p className="dest-empty">{t.chat.sayHi}</p>
              <div className="dating-empty-actions">
                <Link href="/meetups" className="btn btn-sm">
                  {t.dating.meetAtEvents}
                </Link>
                <Link href="/dating" className="btn btn-sm">
                  {t.nav.dating}
                </Link>
              </div>
            </div>
          )}
          {messages.map((m) => (
            <div key={m.id} className={`chat-bubble${m.mine ? " mine" : ""}`}>
              {m.body}
            </div>
          ))}
          <div ref={bottomRef} />
        </div>
        <div className="chat-compose">
          <input
            value={text}
            onChange={(e) => setText(e.target.value)}
            placeholder={t.chat.placeholder}
            onKeyDown={(e) => e.key === "Enter" && void send()}
            disabled={sending}
          />
          <button type="button" className="btn btn-primary" disabled={sending || !text.trim()} onClick={() => void send()}>
            {sending ? "…" : t.chat.send}
          </button>
        </div>
        <RingNext steps={rings.afterDating} />
      </div>
    </div>
  );
}