import React, { useState, useMemo, useCallback } from 'react';
import { Button, Tooltip, Toast } from '@douyinfe/semi-ui';
import { Copy, ChevronDown, ChevronUp } from 'lucide-react';
import { useTranslation } from 'react-i18next';
import { copy } from '../../helpers/utils';

const PERFORMANCE_CONFIG = {
  MAX_DISPLAY_LENGTH: 50000, // 最大显示字符数
  PREVIEW_LENGTH: 5000, // 预览长度
  VERY_LARGE_MULTIPLIER: 2, // 超大内容倍数
};

const codeThemeStyles = {
  container: {
    backgroundColor: '#1e1e1e',
    color: '#d4d4d4',
    fontFamily: 'Consolas, "Courier New", Monaco, "SF Mono", monospace',
    fontSize: '13px',
    lineHeight: '1.4',
    borderRadius: '8px',
    border: '1px solid #3c3c3c',
    position: 'relative',
    overflow: 'hidden',
    boxShadow: '0 2px 8px rgba(0, 0, 0, 0.15)',
  },
  content: {
    height: '100%',
    overflowY: 'auto',
    overflowX: 'auto',
    padding: '16px',
    margin: 0,
    whiteSpace: 'pre',
    wordBreak: 'normal',
    background: '#1e1e1e',
  },
  actionButton: {
    position: 'absolute',
    zIndex: 10,
    backgroundColor: 'rgba(45, 45, 45, 0.9)',
    border: '1px solid rgba(255, 255, 255, 0.1)',
    color: '#d4d4d4',
    borderRadius: '6px',
    transition: 'all 0.2s ease',
  },
  actionButtonHover: {
    backgroundColor: 'rgba(60, 60, 60, 0.95)',
    borderColor: 'rgba(255, 255, 255, 0.2)',
    transform: 'scale(1.05)',
  },
  noContent: {
    display: 'flex',
    alignItems: 'center',
    justifyContent: 'center',
    height: '100%',
    color: '#666',
    fontSize: '14px',
    fontStyle: 'italic',
    backgroundColor: 'var(--semi-color-fill-0)',
    borderRadius: '8px',
  },
  performanceWarning: {
    padding: '8px 12px',
    backgroundColor: 'rgba(255, 193, 7, 0.1)',
    border: '1px solid rgba(255, 193, 7, 0.3)',
    borderRadius: '6px',
    color: '#ffc107',
    fontSize: '12px',
    marginBottom: '8px',
    display: 'flex',
    alignItems: 'center',
    gap: '8px',
  },
};

const highlightJson = (str) => {
  return str.replace(
    /("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+-]?\d+)?)/g,
    (match) => {
      let color = '#b5cea8';
      if (/^"/.test(match)) {
        color = /:$/.test(match) ? '#9cdcfe' : '#ce9178';
      } else if (/true|false|null/.test(match)) {
        color = '#569cd6';
      }
      return `<span style="color: ${color}">${match}</span>`;
    }
  );
};

const isJsonLike = (content, language) => {
  if (language === 'json') return true;
  const trimmed = content.trim();
  return (trimmed.startsWith('{') && trimmed.endsWith('}')) ||
    (trimmed.startsWith('[') && trimmed.endsWith(']'));
};

const formatContent = (content) => {
  if (!content) return '';

  if (typeof content === 'object') {
    try {
      return JSON.stringify(content, null, 2);
    } catch (e) {
      return String(content);
    }
  }

  if (typeof content === 'string') {
    try {
      const parsed = JSON.parse(content);
      return JSON.stringify(parsed, null, 2);
    } catch (e) {
      return content;
    }
  }

  return String(content);
};

const CodeViewer = ({ content, title, language = 'json' }) => {
  const { t } = useTranslation();
  const [copied, setCopied] = useState(false);
  const [isHoveringCopy, setIsHoveringCopy] = useState(false);
  const [isExpanded, setIsExpanded] = useState(false);
  const [isProcessing, setIsProcessing] = useState(false);

  const formattedContent = useMemo(() => formatContent(content), [content]);

  const contentMetrics = useMemo(() => {
    const length = formattedContent.length;
    const isLarge = length > PERFORMANCE_CONFIG.MAX_DISPLAY_LENGTH;
    const isVeryLarge = length > PERFORMANCE_CONFIG.MAX_DISPLAY_LENGTH * PERFORMANCE_CONFIG.VERY_LARGE_MULTIPLIER;
    return { length, isLarge, isVeryLarge };
  }, [formattedContent.length]);

  const displayContent = useMemo(() => {
    if (!contentMetrics.isLarge || isExpanded) {
      return formattedContent;
    }
    return formattedContent.substring(0, PERFORMANCE_CONFIG.PREVIEW_LENGTH) +
      '\n\n// ... 内容被截断以提升性能 ...';
  }, [formattedContent, contentMetrics.isLarge, isExpanded]);

  const highlightedContent = useMemo(() => {
    if (contentMetrics.isVeryLarge && !isExpanded) {
      return displayContent;
    }

    if (isJsonLike(displayContent, language)) {
      return highlightJson(displayContent);
    }

    return displayContent;
  }, [displayContent, language, contentMetrics.isVeryLarge, isExpanded]);

  const handleCopy = useCallback(async () => {
    try {
      const textToCopy = typeof content === 'object' && content !== null
        ? JSON.stringify(content, null, 2)
        : content;

      const success = await copy(textToCopy);
      setCopied(true);
      Toast.success(t('已复制到剪贴板'));
      setTimeout(() => setCopied(false), 2000);

      if (!success) {
        throw new Error('Copy operation failed');
      }
    } catch (err) {
      Toast.error(t('复制失败'));
      console.error('Copy failed:', err);
    }
  }, [content, t]);

  const handleToggleExpand = useCallback(() => {
    if (contentMetrics.isVeryLarge && !isExpanded) {
      setIsProcessing(true);
      setTimeout(() => {
        setIsExpanded(true);
        setIsProcessing(false);
      }, 100);
    } else {
      setIsExpanded(!isExpanded);
    }
  }, [isExpanded, contentMetrics.isVeryLarge]);

  if (!content) {
    const placeholderText = {
      preview: t('正在构造请求体预览...'),
      request: t('暂无请求数据'),
      response: t('暂无响应数据')
    }[title] || t('暂无数据');

    return (
      <div style={codeThemeStyles.noContent}>
        <span>{placeholderText}</span>
      </div>
    );
  }

  const warningTop = contentMetrics.isLarge ? '52px' : '12px';
  const contentPadding = contentMetrics.isLarge ? '52px' : '16px';

  return (
    <div style={codeThemeStyles.container} className="h-full">
      {/* 性能警告 */}
      {contentMetrics.isLarge && (
        <div style={codeThemeStyles.performanceWarning}>
          <span>⚡</span>
          <span>
            {contentMetrics.isVeryLarge
              ? t('内容较大，已启用性能优化模式')
              : t('内容较大，部分功能可能受限')}
          </span>
        </div>
      )}

      {/* 复制按钮 */}
      <div
        style={{
          ...codeThemeStyles.actionButton,
          ...(isHoveringCopy ? codeThemeStyles.actionButtonHover : {}),
          top: warningTop,
          right: '12px',
        }}
        onMouseEnter={() => setIsHoveringCopy(true)}
        onMouseLeave={() => setIsHoveringCopy(false)}
      >
        <Tooltip content={copied ? t('已复制') : t('复制代码')}>
          <Button
            icon={<Copy size={14} />}
            onClick={handleCopy}
            size="small"
            theme="borderless"
            style={{
              backgroundColor: 'transparent',
              border: 'none',
              color: copied ? '#4ade80' : '#d4d4d4',
              padding: '6px',
            }}
          />
        </Tooltip>
      </div>

      {/* 代码内容 */}
      <div
        style={{
          ...codeThemeStyles.content,
          paddingTop: contentPadding,
        }}
        className="model-settings-scroll"
      >
        {isProcessing ? (
          <div style={{
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center',
            height: '200px',
            color: '#888'
          }}>
            <div style={{
              width: '20px',
              height: '20px',
              border: '2px solid #444',
              borderTop: '2px solid #888',
              borderRadius: '50%',
              animation: 'spin 1s linear infinite',
              marginRight: '8px'
            }} />
            {t('正在处理大内容...')}
          </div>
        ) : (
          <div dangerouslySetInnerHTML={{ __html: highlightedContent }} />
        )}
      </div>

      {/* 展开/收起按钮 */}
      {contentMetrics.isLarge && !isProcessing && (
        <div style={{
          ...codeThemeStyles.actionButton,
          bottom: '12px',
          left: '50%',
          transform: 'translateX(-50%)',
        }}>
          <Tooltip content={isExpanded ? t('收起内容') : t('显示完整内容')}>
            <Button
              icon={isExpanded ? <ChevronUp size={14} /> : <ChevronDown size={14} />}
              onClick={handleToggleExpand}
              size="small"
              theme="borderless"
              style={{
                backgroundColor: 'transparent',
                border: 'none',
                color: '#d4d4d4',
                padding: '6px 12px',
              }}
            >
              {isExpanded ? t('收起') : t('展开')}
              {!isExpanded && (
                <span style={{ fontSize: '11px', opacity: 0.7, marginLeft: '4px' }}>
                  (+{Math.round((contentMetrics.length - PERFORMANCE_CONFIG.PREVIEW_LENGTH) / 1000)}K)
                </span>
              )}
            </Button>
          </Tooltip>
        </div>
      )}
    </div>
  );
};

export default CodeViewer; 