import { useRef, useState } from 'react';
import { renderRichText } from '../rich-text';
import { PopoverPortal } from './popover-portal';
import type { Attachment } from '../types';
import type { UiMessage } from '../hooks/use-messages';

const REACTION_EMOJIS = ['👍', '❤️', '😂', '🎉', '👀'];

const isImage = (mime: string): boolean => mime.startsWith('image/');

/** Slack-style message time: today shows the clock, then "Yesterday", weekday, else a date. */
function messageTime(iso: string): string {
  const d = new Date(iso);
  if (Number.isNaN(+d)) return '';
  const now = new Date();
  const time = d.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' });
  if (d.toDateString() === now.toDateString()) return time;
  const yesterday = new Date(now);
  yesterday.setDate(now.getDate() - 1);
  if (d.toDateString() === yesterday.toDateString()) return `Yesterday ${time}`;
  if (now.getTime() - d.getTime() < 7 * 86400000) return `${d.toLocaleDateString([], { weekday: 'short' })} ${time}`;
  return `${d.toLocaleDateString([], { month: 'short', day: 'numeric' })} ${time}`;
}

function AttachmentView({ att }: { att: Attachment }) {
  if (isImage(att.mime)) {
    return (
      <a href={att.url} target="_blank" rel="noreferrer" className="miu-att-img-link">
        <img src={att.url} alt={att.name} className="miu-att-img" />
      </a>
    );
  }
  return (
    <a href={att.url} target="_blank" rel="noreferrer" className="miu-att-file">
      📎 {att.name}
    </a>
  );
}

/** One rendered message: bubble (with @mention highlighting), attachment, reactions, seen tick,
 *  and — in the main thread only — a thread/reply affordance. */
export function MessageItem({
  message,
  memberNames,
  canReact,
  onReact,
  seen,
  replyCount,
  onOpenThread,
}: {
  message: UiMessage;
  memberNames: string[];
  canReact: boolean;
  onReact: (messageId: string, emoji: string) => void;
  seen: boolean;
  /** Present only in the main thread (not inside the pane). undefined => no thread affordance. */
  replyCount?: number;
  onOpenThread?: (messageId: string) => void;
}) {
  const [pickerOpen, setPickerOpen] = useState(false);
  const reactBtnRef = useRef<HTMLButtonElement>(null);
  const m = message;

  return (
    <div className={`miu-msg${message.mine ? ' is-mine' : ''}${message.pending ? ' is-pending' : ''}`}>
      <div className="miu-bubble-row">
        <div className="miu-bubble">
          {m.text ? renderRichText(m.text, memberNames) : null}
          {m.attachment ? <AttachmentView att={m.attachment} /> : null}
        </div>
        <time className="miu-msg-time" dateTime={m.at} title={Number.isNaN(+new Date(m.at)) ? '' : new Date(m.at).toLocaleString()}>
          {messageTime(m.at)}
        </time>
        <div className="miu-msg-actions">
          {canReact ? (
            <div className="miu-react-wrap">
              <button ref={reactBtnRef} type="button" className="miu-react-btn" title="React" onClick={() => setPickerOpen((p) => !p)}>
                🙂
              </button>
              {pickerOpen ? (
                <PopoverPortal anchorRef={reactBtnRef} onClose={() => setPickerOpen(false)}>
                  <div className="miu-react-picker">
                    {REACTION_EMOJIS.map((e) => (
                      <button
                        key={e}
                        type="button"
                        className="miu-react-emoji"
                        onClick={() => {
                          onReact(m.id, e);
                          setPickerOpen(false);
                        }}
                      >
                        {e}
                      </button>
                    ))}
                  </div>
                </PopoverPortal>
              ) : null}
            </div>
          ) : null}
          {onOpenThread ? (
            <button type="button" className="miu-react-btn" title="Reply in thread" onClick={() => onOpenThread(m.id)}>
              💬
            </button>
          ) : null}
        </div>
      </div>

      {m.reactions && m.reactions.length > 0 ? (
        <div className="miu-reactions">
          {m.reactions.map((r) => (
            <button key={r.emoji} type="button" className={`miu-reaction${r.mine ? ' is-mine' : ''}`} onClick={() => canReact && onReact(m.id, r.emoji)}>
              {r.emoji} {r.count}
            </button>
          ))}
        </div>
      ) : null}

      {replyCount !== undefined && replyCount > 0 && onOpenThread ? (
        <button type="button" className="miu-thread-link" onClick={() => onOpenThread(m.id)}>
          💬 {replyCount} {replyCount === 1 ? 'reply' : 'replies'}
        </button>
      ) : null}

      {message.mine && seen ? <span className="miu-seen">Seen</span> : null}
    </div>
  );
}