import { marked, Renderer, walkTokens } from 'marked';
import type { Tokens } from 'marked';
import katex from 'katex';
// [perf-base-v1] 卡6: DOMPurify 消毒实现迁到公共 util，本文件转调避免两处漂移
import { sanitizeHtml } from '/@/utils/markdownSafe';
import { getToken } from '/@/utils/auth';
import type { AttachedFile, ThinkingStep } from './types';

const mdRenderer = new Renderer();
const defaultLinkRenderer = mdRenderer.link.bind(mdRenderer);
mdRenderer.link = (token: Tokens.Link): string => {
  const html = defaultLinkRenderer(token);
  return html.replace(/^<a\s/, '<a target="_blank" rel="noopener" ');
};

const renderLatexInHtml = (html: string): string => {
  // 匹配块级公式（$$...$$）
  html = html.replace(/\$\$(.*?)\$\$/gs, (_match, formula) => {
    return katex.renderToString(formula.trim(), {
      displayMode: true,
      throwOnError: false,
      strict: false,
      trust: true,
    });
  });
  // 匹配行内公式（$...$）
  html = html.replace(/\$(.*?)\$/g, (_match, formula) => {
    return katex.renderToString(formula.trim(), {
      displayMode: false,
      throwOnError: false,
      strict: false,
    });
  });
  return html;
};

const processFootnotes = (html: string, maxId?: number): string => {
  if (maxId === undefined) {
    // 无 citations 上下文，剥离所有 [^n] 标记
    return html.replace(/\[\^\d+\]/g, '');
  }
  // 有效编号范围 [1, maxId]，范围外的剥离
  return html.replace(/\[\^(\d+)\]/g, (_match, n) => {
    const id = parseInt(n, 10);
    if (id >= 1 && id <= maxId) {
      return `<sup class="footnote-ref" data-n="${id}">[${n}]</sup>`;
    }
    return '';
  });
};

export const renderMarkdown = (
  text: string,
  icons?: { copy: string; download: string; preview: string; copySuccess: string },
  maxCitationId?: number
): string => {
  if (!text) return '';
  const processed = text.replace(/<br\s*\/?>/gi, '  \n');
  let html = marked.parse(processed, { renderer: mdRenderer }) as string;
  html = processFootnotes(html, maxCitationId);
  html = renderLatexInHtml(html);
  // Sanitize HTML to prevent XSS attacks
  // [perf-base-v1] 卡6: 转调公共 sanitizeHtml（DOMPurify，ADD_TAGS:['img']），保留本模块额外交互属性白名单
  html = sanitizeHtml(html, ['target', 'data-action', 'data-table', 'data-icon', 'data-icon-success', 'data-n']);
  // 原始 HTML 锚点不经过 marked link renderer，统一补 target/rel
  html = html.replace(/<a\b[^>]*>/gi, (tag) => {
    let attrs = '';
    if (!/\btarget\s*=/i.test(tag)) attrs += ' target="_blank"';
    if (!/\brel\s*=/i.test(tag)) attrs += ' rel="noopener"';
    return attrs ? tag.replace(/^<a\b/i, '<a' + attrs) : tag;
  });
  return icons ? wrapTables(html, icons) : html;
};

// 从 markdown 文本中提取链接（与 renderMarkdown 共用同一套 marked 解析，
// 仅收集 link token，代码块/图片等不会被误收）
export const extractMarkdownLinks = (text: string): Array<{ title: string; href: string }> => {
  if (!text) return [];
  const links: Array<{ title: string; href: string }> = [];
  try {
    const tokens = marked.lexer(text);
    walkTokens(tokens, (token) => {
      if (token.type === 'link') {
        const linkToken = token as Tokens.Link;
        const href = linkToken.href || '';
        if (href) {
          links.push({ title: linkToken.text || href, href });
        }
      }
    });
  } catch {
    // 文本解析异常时返回已收集到的部分链接
  }
  return links;
};

export interface AgentGroup {
  agent: string;
  agentId?: string;
  steps: ThinkingStep[];
}

// 按智能体聚合思考步骤（与思考卡片、右侧详情面板的分组语义一致：优先按 agentId 分组）
export const groupStepsByAgent = (steps: ThinkingStep[]): AgentGroup[] => {
  const groupMap = new Map<string, AgentGroup>();
  for (const step of steps) {
    const agentName = step.agent || '系统';
    const groupKey = step.agentId || agentName;
    if (!groupMap.has(groupKey)) {
      groupMap.set(groupKey, { agent: agentName, agentId: step.agentId, steps: [] });
    }
    groupMap.get(groupKey)!.steps.push(step);
  }
  return Array.from(groupMap.values());
};

export const wrapTables = (html: string, icons: { copy: string; download: string; preview: string; copySuccess: string }): string => {
  return html.replace(/<table>([\s\S]*?)<\/table>/g, (match) => {
    const encodedTable = encodeURIComponent(match);
    return `<div class="markdown-table-wrapper">
      <div class="table-actions">
        <span class="table-action-btn" data-action="copy" data-table="${encodedTable}" data-icon="${icons.copy}" data-icon-success="${icons.copySuccess}" title="复制Markdown">
          <img src="${icons.copy}" width="14" height="14" />
        </span>
        <span class="table-action-btn" data-action="csv" data-table="${encodedTable}" title="下载">
          <img src="${icons.download}" width="14" height="14" />
        </span>
        <span class="table-action-btn" data-action="preview" data-table="${encodedTable}" title="预览">
          <img src="${icons.preview}" width="14" height="14" />
        </span>
      </div>
      ${match}
    </div>`;
  });
};

const decodeHtmlEntities = (escaped: string): string => {
  const textarea = document.createElement('textarea');
  textarea.innerHTML = escaped;
  return textarea.value;
};

// 给渲染后 HTML 中的 ```markdown / ```md 代码块加上操作工具栏（复制/下载/预览）
export const wrapMarkdownCodeBlocks = (html: string, icons: { copy: string; download: string; preview: string; copySuccess: string }): string => {
  return html.replace(/<pre><code class="[^"]*language-(?:markdown|md)[^"]*">([\s\S]*?)<\/code><\/pre>/g, (match, escaped: string) => {
    const encoded = encodeURIComponent(decodeHtmlEntities(escaped));
    return `<div class="markdown-code-wrapper">
      <div class="table-actions">
        <span class="table-action-btn" data-action="copy-md" data-content="${encoded}" data-icon="${icons.copy}" data-icon-success="${icons.copySuccess}" title="复制内容">
          <img src="${icons.copy}" width="14" height="14" />
        </span>
        <span class="table-action-btn" data-action="download-md" data-content="${encoded}" title="下载.md文件">
          <img src="${icons.download}" width="14" height="14" />
        </span>
        <span class="table-action-btn" data-action="preview-md" data-content="${encoded}" title="预览渲染效果">
          <img src="${icons.preview}" width="14" height="14" />
        </span>
      </div>
      ${match}
    </div>`;
  });
};

export const tableHtmlToMarkdown = (tableHtml: string): string => {
  const parser = new DOMParser();
  const doc = parser.parseFromString(tableHtml, 'text/html');
  const table = doc.querySelector('table');
  if (!table) return tableHtml;

  const rows: string[][] = [];
  table.querySelectorAll('tr').forEach((tr) => {
    const cells: string[] = [];
    tr.querySelectorAll('th, td').forEach((cell) => {
      cells.push(cell.textContent?.trim() || '');
    });
    rows.push(cells);
  });

  if (rows.length === 0) return tableHtml;

  const colCount = Math.max(...rows.map((r) => r.length));
  const normalized = rows.map((r) => {
    while (r.length < colCount) r.push('');
    return r;
  });

  const lines: string[] = [];
  lines.push('| ' + normalized[0].join(' | ') + ' |');
  lines.push('| ' + normalized[0].map(() => '---').join(' | ') + ' |');
  for (let i = 1; i < normalized.length; i++) {
    lines.push('| ' + normalized[i].join(' | ') + ' |');
  }
  return lines.join('\n');
};

export const tableHtmlToCsv = (tableHtml: string): string => {
  const parser = new DOMParser();
  const doc = parser.parseFromString(tableHtml, 'text/html');
  const table = doc.querySelector('table');
  if (!table) return '';

  const rows: string[] = [];
  table.querySelectorAll('tr').forEach((tr) => {
    const cells: string[] = [];
    tr.querySelectorAll('th, td').forEach((cell) => {
      const text = (cell.textContent?.trim() || '').replace(/"/g, '""');
      cells.push(`"${text}"`);
    });
    rows.push(cells.join(','));
  });

  return '' + rows.join('\n');
};

export const formatFileSize = (bytes: number): string => {
  if (bytes < 1024) return bytes + ' B';
  if (bytes < 1024 * 1024) return (bytes / 1024).toFixed(2) + ' KB';
  return (bytes / (1024 * 1024)).toFixed(2) + ' MB';
};

export const isImageFile = (filename: string): boolean => /\.(jpg|jpeg|png|gif|bmp|webp|svg|ico|tiff|tif)$/i.test(filename);

export const isPdfFile = (filename: string): boolean => /\.pdf$/i.test(filename);

export const isVideoFile = (filename: string): boolean => /\.(mp4|webm|ogg|mov|avi|mkv|flv|wmv|m4v)$/i.test(filename);

export const isAudioFile = (filename: string): boolean => /\.(mp3|wav|ogg|aac|flac|wma|m4a|opus)$/i.test(filename);

export const isMdFile = (filename: string): boolean => /\.md$/i.test(filename);

export const isWordFile = (filename: string): boolean => /\.(doc|docx)$/i.test(filename);

export const isOldDocFile = (filename: string): boolean => /\.doc$/i.test(filename) && !/\.docx$/i.test(filename);

export const isExcelFile = (filename: string): boolean => /\.(xls|xlsx)$/i.test(filename);

export const isCsvFile = (filename: string): boolean => /\.csv$/i.test(filename);

export const isTextFile = (filename: string): boolean =>
  /\.(txt|md|json|csv|xml|yaml|yml|log|ini|toml|cfg|conf|env|gitignore|dockerignore|editorconfig|prettierrc|eslintrc|babelrc|properties|sh|bat|ps1|cmd|bash|zsh|fish|sql|graphql|proto|js|ts|jsx|tsx|vue|css|scss|sass|less|html|htm|svelte|py|java|kt|kts|c|cpp|h|hpp|cc|cxx|cs|go|rs|rb|php|swift|m|mm|r|R|lua|pl|pm|hs|ex|exs|erl|clj|scala|dart|zig|nim|v|sol|tf|hcl|gradle|cmake|makefile|mk)$/i.test(
    filename
  );

export const getFileExtension = (filename: string): string => {
  const match = filename.match(/\.([^.]+)$/);
  return match ? `.${match[1]}`.toUpperCase() : '';
};

export const getFileIconVar = (filename: string): string => {
  if (isMdFile(filename)) return 'var(--img-chat-file-md-icon)';
  if (isPdfFile(filename)) return 'var(--img-chat-file-pdf-icon)';
  if (isWordFile(filename)) return 'var(--img-chat-file-word-icon)';
  if (isExcelFile(filename) || isCsvFile(filename)) return 'var(--img-chat-file-excel-icon)';
  if (isImageFile(filename)) return 'var(--img-chat-file-img-icon)';
  if (isTextFile(filename)) return 'var(--img-chat-file-txt-icon)';
  return 'var(--img-chat-attach-icon)';
};

// 按文件类型拉取远端文件内容并构造右侧面板预览对象（消息内文件卡片与胶囊面板共用）。
// 不支持的格式返回 null，由调用方回退为直接下载
export const fetchPreviewFile = async (url: string, filename: string): Promise<AttachedFile | null> => {
  const resp = await fetch(url, { headers: { 'X-Access-Token': getToken() } });
  if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
  const ext = filename.split('.').pop()?.toLowerCase() || '';
  const mimeMap: Record<string, string> = {
    md: 'text/markdown',
    txt: 'text/plain',
    json: 'application/json',
    xml: 'text/xml',
    yaml: 'text/yaml',
    yml: 'text/yaml',
    csv: 'text/csv',
  };
  const id = `report-${url}`;
  const uploadTime = new Date().toISOString();

  if (mimeMap[ext]) {
    const content = await resp.text();
    return { id, name: filename, size: content.length, type: mimeMap[ext], content, uploadTime };
  }
  if (isWordFile(filename) || isExcelFile(filename)) {
    const arrayBuffer = await resp.arrayBuffer();
    return { id, name: filename, size: arrayBuffer.byteLength, type: 'application/octet-stream', arrayBuffer, uploadTime };
  }
  if (isImageFile(filename) || isPdfFile(filename)) {
    const blob = await resp.blob();
    const dataUrl = await new Promise<string>((resolve, reject) => {
      const reader = new FileReader();
      reader.onload = () => resolve(reader.result as string);
      reader.onerror = () => reject(reader.error);
      reader.readAsDataURL(blob);
    });
    return { id, name: filename, size: blob.size, type: blob.type, preview: dataUrl, uploadTime };
  }
  return null;
};