import React, { useState, useRef, useMemo } from 'react';
import CodeMirror from '@uiw/react-codemirror';
import { markdown, markdownLanguage } from '@codemirror/lang-markdown';
import { EditorView } from '@codemirror/view';
import { 
  Space, Button, Tooltip, Card, 
  Divider, Dropdown, Typography 
} from 'antd';
import { 
  BoldOutlined, ItalicOutlined, FontSizeOutlined, 
  MessageOutlined, CodeOutlined, LinkOutlined, 
  TableOutlined, PictureOutlined, OrderedListOutlined, 
  UnorderedListOutlined, LineOutlined, EyeOutlined, 
  EditOutlined 
} from '@ant-design/icons';
import MarkdownRenderer from './MarkdownRenderer';

const { Text } = Typography;

const MarkdownEditor = ({
  value,
  onChange,
  onImageUpload,
  placeholder = '在这里编写内容...',
  height = 400,
  showImageUpload = true
}) => {
  const editorRef = useRef(null);
  const imageInputRef = useRef(null);
  const [showPreview, setShowPreview] = useState(false);

  const editorExtensions = useMemo(() => [
    markdown({ base: markdownLanguage }),
    EditorView.lineWrapping,
    EditorView.theme({
      "&": {
        fontSize: "14px",
        border: "1px solid #d9d9d9",
        borderRadius: "0 0 8px 8px",
        borderTop: "none",
      },
      ".cm-content": {
        fontFamily: "var(--ant-font-family-code), monospace",
        padding: "16px",
        minHeight: `${height}px`,
      },
      "&.cm-focused": {
        outline: "none",
        borderColor: "#1677ff",
        boxShadow: "0 0 0 2px rgba(22, 119, 255, 0.1)",
      }
    })
  ], [height]);

  const insertMarkdown = (before, after = '', placeholder = '') => {
    if (!editorRef.current?.view) return;
    const view = editorRef.current.view;
    const selection = view.state.selection.main;
    const selectedText = view.state.doc.sliceString(selection.from, selection.to);
    const text = selectedText || placeholder;
    const newText = `${before}${text}${after}`;
    view.dispatch({
      changes: { from: selection.from, to: selection.to, insert: newText },
      selection: { anchor: selection.from + before.length, head: selection.from + before.length + text.length }
    });
    view.focus();
  };

  const toolbarActions = {
    bold: () => insertMarkdown('**', '**', '粗体'),
    italic: () => insertMarkdown('*', '*', '斜体'),
    heading: (level) => insertMarkdown('#'.repeat(level) + ' ', '', '标题'),
    quote: () => insertMarkdown('> ', '', '引用'),
    code: () => insertMarkdown('`', '`', '代码'),
    link: () => insertMarkdown('[', '](url)', '链接'),
    unorderedList: () => insertMarkdown('- ', '', '列表项'),
    orderedList: () => insertMarkdown('1. ', '', '列表项'),
    table: () => insertMarkdown('\n| 列1 | 列2 |\n| --- | --- |\n| 单元格 | 单元格 |\n', '', ''),
    hr: () => insertMarkdown('\n---\n', '', ''),
    image: () => imageInputRef.current?.click(),
  };

  const headingMenu = {
    items: [1, 2, 3, 4, 5, 6].map(level => ({
      key: level,
      label: `标题 ${level}`,
      onClick: () => toolbarActions.heading(level)
    }))
  };

  return (
    <div className="markdown-editor-modern">
      <Card 
        size="small" 
        bodyStyle={{ padding: '4px 8px', background: '#f5f5f5', borderBottom: '1px solid #d9d9d9', borderRadius: '8px 8px 0 0' }}
        bordered={false}
      >
        <Space split={<Divider type="vertical" />} size={4}>
          <Space size={2}>
            <Tooltip title="粗体"><Button type="text" size="small" icon={<BoldOutlined />} onClick={toolbarActions.bold} /></Tooltip>
            <Tooltip title="斜体"><Button type="text" size="small" icon={<ItalicOutlined />} onClick={toolbarActions.italic} /></Tooltip>
            <Dropdown menu={headingMenu} placement="bottomLeft">
              <Button type="text" size="small" icon={<FontSizeOutlined />} />
            </Dropdown>
          </Space>
          
          <Space size={2}>
            <Tooltip title="引用"><Button type="text" size="small" icon={<MessageOutlined />} onClick={toolbarActions.quote} /></Tooltip>
            <Tooltip title="代码"><Button type="text" size="small" icon={<CodeOutlined />} onClick={toolbarActions.code} /></Tooltip>
            <Tooltip title="链接"><Button type="text" size="small" icon={<LinkOutlined />} onClick={toolbarActions.link} /></Tooltip>
            <Tooltip title="表格"><Button type="text" size="small" icon={<TableOutlined />} onClick={toolbarActions.table} /></Tooltip>
            {showImageUpload && (
              <Tooltip title="图片"><Button type="text" size="small" icon={<PictureOutlined />} onClick={toolbarActions.image} /></Tooltip>
            )}
          </Space>

          <Space size={2}>
            <Tooltip title="无序列表"><Button type="text" size="small" icon={<UnorderedListOutlined />} onClick={toolbarActions.unorderedList} /></Tooltip>
            <Tooltip title="有序列表"><Button type="text" size="small" icon={<OrderedListOutlined />} onClick={toolbarActions.orderedList} /></Tooltip>
            <Tooltip title="分隔线"><Button type="text" size="small" icon={<LineOutlined />} onClick={toolbarActions.hr} /></Tooltip>
          </Space>

          <Button 
            type={showPreview ? "primary" : "text"} 
            size="small" 
            icon={showPreview ? <EditOutlined /> : <EyeOutlined />} 
            onClick={() => setShowPreview(!showPreview)}
          >
            {showPreview ? "编辑" : "预览"}
          </Button>
        </Space>
      </Card>

      {showPreview ? (
        <Card bordered bodyStyle={{ padding: 16, minHeight: height, overflowY: 'auto' }} style={{ borderRadius: '0 0 8px 8px' }}>
          <MarkdownRenderer content={value} />
        </Card>
      ) : (
        <CodeMirror
          ref={editorRef}
          value={value}
          onChange={onChange}
          extensions={editorExtensions}
          placeholder={placeholder}
          basicSetup={{ lineNumbers: false, foldGutter: false }}
        />
      )}

      <input ref={imageInputRef} type="file" accept="image/*" onChange={(e) => {
        const file = e.target.files[0];
        if (file && onImageUpload) {
          onImageUpload(file).then(url => url && insertMarkdown(`![${file.name}](${url})`, '', ''));
        }
        e.target.value = '';
      }} style={{ display: 'none' }} />
    </div>
  );
};

export default MarkdownEditor;