import { Download, MessageCircle, Wrench } from "lucide-react";
import { memo, useEffect, useRef, useState } from "react";

import { initials } from "../lib/context";
import type { ConnectionStatus } from "../lib/contracts";
import { displayTime, exportConversation, renderMarkdown, type Message } from "../lib/messages";
import { LIVE_STATES } from "../realtime/controller";

const MessageRow = memo(function MessageRow({ message, userName }: { message: Message; userName: string }) {
  const [expanded, setExpanded] = useState(false);
  const time = displayTime(message.timestamp);
  if (message.role === "tool") {
    return (
      <div className="hist-msg tool">
        <div className="hist-role">Llamada a herramienta</div>
        <button
          className="hist-tool-header"
          type="button"
          aria-expanded={expanded}
          onClick={() => {
            setExpanded(!expanded);
          }}
        >
          <Wrench className="hist-tool-icon" />
          <span className="hist-tool-name">{message.toolName}</span>
        </button>
        <div className={`hist-tool-body ${expanded ? "open" : ""}`}>
          <div className="hist-tool-label">Entrada</div>
          <pre className="hist-tool-block">{message.toolArguments}</pre>
          <div className="hist-tool-label">Salida</div>
          <pre className="hist-tool-block hist-tool-output">{message.text}</pre>
        </div>
      </div>
    );
  }
  const data = {
    "data-user-name": userName,
    "data-user-initials": initials(userName),
    "data-asst-name": "Vocero",
    "data-timestamp": time,
  };
  return (
    <div className={`hist-msg ${message.role} ${message.interrupted ? "interrupted" : ""}`} {...data}>
      <div className="hist-role">{message.role === "user" ? userName : "Vocero"}</div>
      {message.role === "assistant" ? (
        <div
          className={`hist-body markdown-content ${message.partial ? "partial" : ""}`}
          {...data}
          dangerouslySetInnerHTML={{ __html: renderMarkdown(message.text) }}
        />
      ) : (
        <div className={`hist-body ${message.partial ? "partial" : ""}`} {...data}>
          {message.text}
        </div>
      )}
      {message.interrupted && <div className="hist-note">Interrumpido</div>}
    </div>
  );
});
export const Conversation = memo(function Conversation({
  messages,
  userName,
  status,
  white,
}: {
  messages: Message[];
  userName: string;
  status: ConnectionStatus;
  white: boolean;
}) {
  const history = useRef<HTMLDivElement>(null);
  const atBottom = useRef(true);
  useEffect(() => {
    const element = history.current;
    if (element && atBottom.current) {
      element.scrollTop = element.scrollHeight;
    }
  }, [messages]);
  const live = LIVE_STATES.has(status);
  const waiting = ["connecting", "queued", "your-turn"].includes(status);
  return (
    <section id="chat-panel" className="chat-panel chat-panel-inline" aria-label="Transcripción de la conversación">
      <div className="chat-panel-inner">
        <header className="chat-panel-header">
          <h2>Conversación</h2>
          <div className="chat-header-actions" role="group" aria-label="Acciones de la conversación">
            {white && (
              <span
                className="chat-status-pill"
                data-status={live ? "online" : status === "error" ? "error" : waiting ? "waiting" : "idle"}
                role="status"
              >
                <span className="chat-status-dot" aria-hidden="true" />
                <span>
                  {live ? "En línea" : status === "error" ? "Sin conexión" : waiting ? "Conectando" : "Sin sesión"}
                </span>
              </span>
            )}
            <button
              className="chat-export-btn icon-btn"
              type="button"
              aria-label="Descargar conversación"
              title="Descargar conversación (JSON + TXT)"
              disabled={!messages.length}
              onClick={() => {
                exportConversation(messages, userName);
              }}
            >
              <Download size={18} />
            </button>
          </div>
        </header>
        <div
          ref={history}
          id="chat-history"
          className="chat-history"
          role="log"
          aria-live="polite"
          aria-atomic="false"
          onScroll={() => {
            const element = history.current;
            if (element) {
              atBottom.current = element.scrollHeight - element.scrollTop - element.clientHeight < 60;
            }
          }}
        >
          {messages.length ? (
            messages.map((message) => <MessageRow key={message.id} message={message} userName={userName} />)
          ) : (
            <div className="chat-empty">
              <MessageCircle aria-hidden="true" />
              <span className="chat-empty-title">Aún no hay mensajes</span>
              <span className="chat-empty-hint">Toca el círculo y empieza a hablar</span>
            </div>
          )}
        </div>
      </div>
    </section>
  );
});