import { useState, useEffect, useMemo } from 'react';
import { DocContent } from '../api';
import { cleanDisplayText } from '../presentation';
import { renderKnowledgeMarkdown } from '../markdown';

interface Props {
  doc: DocContent;
  onSave: (title: string, body: string) => void;
  onWikiSelect?: (target: string) => void;
}

export function Editor({ doc, onSave, onWikiSelect }: Props) {
  const [editing, setEditing] = useState(false);
  const [title, setTitle] = useState(doc.meta.title);
  const [body, setBody] = useState(doc.body);

  // 切换文档时重置
  useEffect(() => {
    setTitle(doc.meta.title);
    setBody(doc.body);
    setEditing(false);
  }, [doc.meta.id]);

  const rendered = useMemo(() => {
    try {
      return renderKnowledgeMarkdown(body);
    } catch {
      return '<p>渲染失败</p>';
    }
  }, [body]);

  const handleSave = () => {
    onSave(title, body);
    setEditing(false);
  };

  const handleCancel = () => {
    setTitle(doc.meta.title);
    setBody(doc.body);
    setEditing(false);
  };
  const displayPath = doc.meta.id.split('/').map(cleanDisplayText).join(' / ');

  const handleRenderedClick = (event: React.MouseEvent<HTMLDivElement>) => {
    const anchor = (event.target as HTMLElement).closest<HTMLAnchorElement>('a[data-hololake-wiki="true"]');
    if (!anchor) return;
    event.preventDefault();
    const prefix = 'hololake://knowledge/';
    const rawTarget = anchor.href.startsWith(prefix) ? anchor.href.slice(prefix.length) : anchor.title;
    if (rawTarget) onWikiSelect?.(decodeURIComponent(rawTarget));
  };

  return (
    <div className="kb-editor">
      <div className="kb-page-symbol" aria-hidden="true">◇</div>
      {/* 元信息栏 */}
      <div className="kb-editor-meta">
        <span className="kb-editor-path">HoloLake / {displayPath}</span>
        <span className="kb-editor-date">
          更新于 {new Date(doc.meta.updatedAt).toLocaleString('zh-CN')}
        </span>
        <span className="kb-editor-author">by {doc.meta.author}</span>
      </div>

      {/* 标题 */}
      {editing ? (
        <input
          className="kb-editor-title-input"
          value={title}
          onChange={e => setTitle(e.target.value)}
          placeholder="文档标题"
        />
      ) : (
        <h1 className="kb-editor-title" onClick={() => setEditing(true)}>
          {cleanDisplayText(doc.meta.title)}
        </h1>
      )}

      {/* 操作栏 */}
      <div className="kb-editor-toolbar">
        {editing ? (
          <>
            <button className="kb-btn-primary" onClick={handleSave}>保存</button>
            <button className="kb-btn-secondary" onClick={handleCancel}>取消</button>
          </>
        ) : (
          <button className="kb-btn-primary" onClick={() => setEditing(true)}>编辑页面</button>
        )}
      </div>

      {/* 内容区 */}
      {editing ? (
        <div className="kb-editor-edit-pane">
          <textarea
            className="kb-editor-textarea"
            value={body}
            onChange={e => setBody(e.target.value)}
            placeholder="用 Markdown 写作..."
            spellCheck={false}
          />
          <div className="kb-editor-preview-pane">
            <div
              className="kb-markdown-render"
              onClick={handleRenderedClick}
              dangerouslySetInnerHTML={{ __html: rendered }}
            />
          </div>
        </div>
      ) : (
        <div className="kb-editor-read-pane">
          <div
            className="kb-markdown-render"
            onClick={handleRenderedClick}
            dangerouslySetInnerHTML={{ __html: rendered }}
          />
        </div>
      )}
    </div>
  );
}