import React, { useState } from "react";
import { motion, AnimatePresence } from "framer-motion";
import {
  Download,
  Braces,
  FileCode2,
  Check,
  Share2,
  FileText,
  Link2,
  Mail,
} from "lucide-react";
import { Button } from "@/components/ui/button";
import {
  DropdownMenu,
  DropdownMenuContent,
  DropdownMenuItem,
  DropdownMenuSeparator,
  DropdownMenuTrigger,
} from "@/components/ui/dropdown-menu";
import { cn } from "@/lib/utils";
import ShareModal from "@/components/ShareModal";
import ShareLinkModal from "@/components/ShareLinkModal";
import { shareExtraction, createShareLink } from "@/services/api";

// Helper functions from ExtractionOutput
function prepareFieldsForOutput(fields, format = "json") {
  if (!fields || typeof fields !== "object") {
    return fields;
  }
  
  const output = { ...fields };
  
  // Extract Fields from root level if it exists
  const rootFields = output.Fields;
  // Remove Fields from output temporarily (will be added back at top)
  delete output.Fields;
  
  // Remove full_text from top-level if pages array exists (to avoid duplication)
  if (output.pages && Array.isArray(output.pages) && output.pages.length > 0) {
    delete output.full_text;
    
    // Clean up each page: remove full_text from page.fields (it duplicates page.text)
    output.pages = output.pages.map(page => {
      const cleanedPage = { ...page };
      if (cleanedPage.fields && typeof cleanedPage.fields === "object") {
        const cleanedFields = { ...cleanedPage.fields };
        // Remove full_text from page fields (duplicates page.text)
        delete cleanedFields.full_text;
        cleanedPage.fields = cleanedFields;
      }
      return cleanedPage;
    });
  }
  
  // For JSON and XML: restructure pages into separate top-level fields (page_1, page_2, etc.)
  if ((format === "json" || format === "xml") && output.pages && Array.isArray(output.pages)) {
    // Get top-level field keys (these are merged from all pages - avoid duplicating in page fields)
    const topLevelKeys = new Set(Object.keys(output).filter(k => k !== "pages" && k !== "full_text" && k !== "Fields"));
    
    output.pages.forEach((page, idx) => {
      const pageNum = page.page_number || idx + 1;
      const pageFields = page.fields || {};
      
      // Remove duplicate fields from page.fields:
      // 1. Remove full_text (duplicates page.text)
      // 2. Remove fields that match top-level fields (already shown at root)
      const cleanedPageFields = {};
      for (const [key, value] of Object.entries(pageFields)) {
        // Skip full_text and fields that match top-level exactly
        if (key !== "full_text" && (!topLevelKeys.has(key) || (value !== output[key]))) {
          cleanedPageFields[key] = value;
        }
      }
      
      const pageObj = {
        text: page.text || "",
        confidence: page.confidence || 0,
        doc_type: page.doc_type || "other"
      };
      
      // Add table and footer_notes if they exist
      if (page.table && Array.isArray(page.table) && page.table.length > 0) {
        pageObj.table = page.table;
      }
      if (page.footer_notes && Array.isArray(page.footer_notes) && page.footer_notes.length > 0) {
        pageObj.footer_notes = page.footer_notes;
      }
      
      // Only add fields if there are unique page-specific fields
      if (Object.keys(cleanedPageFields).length > 0) {
        pageObj.fields = cleanedPageFields;
      }
      
      output[`page_${pageNum}`] = pageObj;
    });
    // Remove pages array - we now have page_1, page_2, etc. as separate fields
    delete output.pages;
  }
  
  // Handle page_X structure (from backend) - remove Fields from page objects if they exist
  if (output && typeof output === "object") {
    const pageKeys = Object.keys(output).filter(k => k.startsWith("page_"));
    for (const pageKey of pageKeys) {
      const pageData = output[pageKey];
      if (pageData && typeof pageData === "object") {
        // Remove Fields from page objects (it's now at root level)
        delete pageData.Fields;
        delete pageData.metadata;
      }
    }
  }
  
  // Rebuild output with Fields at the top (only if it exists and is not empty)
  const finalOutput = {};
  if (rootFields && typeof rootFields === "object" && Object.keys(rootFields).length > 0) {
    finalOutput.Fields = rootFields;
  }
  
  // Add all other keys
  Object.keys(output).forEach(key => {
    finalOutput[key] = output[key];
  });
  
  return finalOutput;
}

function escapeXML(str) {
  return str
    .replace(/&/g, "&")
    .replace(/</g, "&lt;")
    .replace(/>/g, "&gt;")
    .replace(/"/g, "&quot;")
    .replace(/'/g, "&apos;");
}

function objectToXML(obj, rootName = "extraction") {
  // Prepare fields - remove full_text if pages exist
  const preparedObj = prepareFieldsForOutput(obj, "xml");
  
  let xml = `<?xml version="1.0" encoding="UTF-8"?>\n<${rootName}>\n`;
  
  const convert = (obj, indent = "  ") => {
    for (const [key, value] of Object.entries(obj)) {
      if (value === null || value === undefined) continue;
      
      // Skip full_text if pages exist (already handled in prepareFieldsForOutput)
      if (key === "full_text" && obj.pages && Array.isArray(obj.pages) && obj.pages.length > 0) {
        continue;
      }
      
      if (Array.isArray(value)) {
        value.forEach((item) => {
          xml += `${indent}<${key}>\n`;
          if (typeof item === "object") {
            convert(item, indent + "  ");
          } else {
            xml += `${indent}  ${escapeXML(String(item))}\n`;
          }
          xml += `${indent}</${key}>\n`;
        });
      } else if (typeof value === "object") {
        xml += `${indent}<${key}>\n`;
        convert(value, indent + "  ");
        xml += `${indent}</${key}>\n`;
      } else {
        xml += `${indent}<${key}>${escapeXML(String(value))}</${key}>\n`;
      }
    }
  };
  
  convert(preparedObj);
  xml += `</${rootName}>`;
  return xml;
}

export default function ExportButtons({ isComplete, extractionResult }) {
  const [downloading, setDownloading] = useState(null);
  const [copied, setCopied] = useState(false);
  const [isShareModalOpen, setIsShareModalOpen] = useState(false);
  const [isShareLinkModalOpen, setIsShareLinkModalOpen] = useState(false);
  const [shareLink, setShareLink] = useState("");
  const [isGeneratingLink, setIsGeneratingLink] = useState(false);

  // Helper function to extract text from fields (same as in ExtractionOutput)
  const extractTextFromFields = (fields) => {
    if (!fields || typeof fields !== "object") {
      return "";
    }
    
    // Check for page_X structure first (preferred format)
    const pageKeys = Object.keys(fields).filter(key => key.startsWith("page_"));
    if (pageKeys.length > 0) {
      // Get text from first page (or combine all pages)
      const pageTexts = pageKeys.map(key => {
        const page = fields[key];
        if (page && page.text) {
          return page.text;
        }
        return "";
      }).filter(text => text);
      
      if (pageTexts.length > 0) {
        return pageTexts.join("\n\n");
      }
    }
    
    // Fallback to full_text
    if (fields.full_text) {
      return fields.full_text;
    }
    
    return "";
  };

  // Helper function to escape HTML
  const escapeHtml = (text) => {
    if (!text) return '';
    const div = document.createElement('div');
    div.textContent = text;
    return div.innerHTML;
  };

  // Helper function to convert pipe-separated tables to HTML tables
  const convertPipeTablesToHTML = (text) => {
    if (!text) return text;
    
    const lines = text.split('\n');
    const result = [];
    let i = 0;
    
    while (i < lines.length) {
      const line = lines[i];
      
      // Check if this line looks like a table row (has multiple pipes)
      if (line.includes('|') && line.split('|').length >= 3) {
        // Check if it's a separator line (only |, -, :, spaces)
        const isSeparator = /^[\s|\-:]+$/.test(line.trim());
        
        if (!isSeparator) {
          // Start of a table - collect all table rows
          const tableRows = [];
          let j = i;
          
          // Collect header row
          const headerLine = lines[j];
          const headerCells = headerLine.split('|').map(cell => cell.trim()).filter(cell => cell || cell === '');
          // Remove empty cells at start/end
          if (headerCells.length > 0 && !headerCells[0]) headerCells.shift();
          if (headerCells.length > 0 && !headerCells[headerCells.length - 1]) headerCells.pop();
          
          if (headerCells.length >= 2) {
            tableRows.push(headerCells);
            j++;
            
            // Skip separator line if present
            if (j < lines.length && /^[\s|\-:]+$/.test(lines[j].trim())) {
              j++;
            }
            
            // Collect data rows
            while (j < lines.length) {
              const rowLine = lines[j];
              if (!rowLine.trim()) break; // Empty line ends table
              
              // Check if it's still a table row
              if (rowLine.includes('|') && rowLine.split('|').length >= 2) {
                const isRowSeparator = /^[\s|\-:]+$/.test(rowLine.trim());
                if (!isRowSeparator) {
                  const rowCells = rowLine.split('|').map(cell => cell.trim());
                  // Remove empty cells at start/end
                  if (rowCells.length > 0 && !rowCells[0]) rowCells.shift();
                  if (rowCells.length > 0 && !rowCells[rowCells.length - 1]) rowCells.pop();
                  tableRows.push(rowCells);
                  j++;
                } else {
                  j++;
                }
              } else {
                break; // Not a table row anymore
              }
            }
            
            // Convert to HTML table
            if (tableRows.length > 0) {
              let htmlTable = '<table class="border-collapse border border-gray-300 w-full my-4">\n<thead>\n<tr>';
              
              // Header row
              tableRows[0].forEach(cell => {
                htmlTable += `<th class="border border-gray-300 px-4 py-2 bg-gray-100 font-semibold text-left">${escapeHtml(cell)}</th>`;
              });
              htmlTable += '</tr>\n</thead>\n<tbody>\n';
              
              // Data rows
              for (let rowIdx = 1; rowIdx < tableRows.length; rowIdx++) {
                htmlTable += '<tr>';
                tableRows[rowIdx].forEach((cell, colIdx) => {
                  // Use header cell count to ensure alignment
                  const cellContent = cell || '';
                  htmlTable += `<td class="border border-gray-300 px-4 py-2">${escapeHtml(cellContent)}</td>`;
                });
                htmlTable += '</tr>\n';
              }
              
              htmlTable += '</tbody>\n</table>';
              result.push(htmlTable);
              i = j;
              continue;
            }
          }
        }
      }
      
      // Not a table row, add as-is
      result.push(line);
      i++;
    }
    
    return result.join('\n');
  };

  // Helper function to render markdown to HTML (same as in ExtractionOutput)
  const renderMarkdownToHTML = (text) => {
    if (!text) return "";
    
    let html = text;
    
    // FIRST: Convert pipe-separated tables to HTML tables
    html = convertPipeTablesToHTML(html);
    
    // Convert LaTeX-style superscripts/subscripts FIRST
    html = html.replace(/\$\s*\^\s*\{([^}]+)\}\s*\$/g, '<sup>$1</sup>');
    html = html.replace(/\$\s*\^\s*([^\s$<>]+)\s*\$/g, '<sup>$1</sup>');
    html = html.replace(/\$\s*_\s*\{([^}]+)\}\s*\$/g, '<sub>$1</sub>');
    html = html.replace(/\$\s*_\s*([^\s$<>]+)\s*\$/g, '<sub>$1</sub>');
    
    // Protect HTML table blocks
    const htmlBlocks = [];
    let htmlBlockIndex = 0;
    
    html = html.replace(/<table[\s\S]*?<\/table>/gi, (match) => {
      const placeholder = `__HTML_BLOCK_${htmlBlockIndex}__`;
      htmlBlocks[htmlBlockIndex] = match;
      htmlBlockIndex++;
      return placeholder;
    });
    
    // Convert markdown headers
    html = html.replace(/^### (.*$)/gim, '<h3>$1</h3>');
    html = html.replace(/^## (.*$)/gim, '<h2>$1</h2>');
    html = html.replace(/^# (.*$)/gim, '<h1>$1</h1>');
    
    // Convert markdown bold/italic
    html = html.replace(/\*\*(.*?)\*\*/g, '<strong>$1</strong>');
    html = html.replace(/\*(.*?)\*/g, '<em>$1</em>');
    
    // Convert markdown links
    html = html.replace(/\[([^\]]+)\]\(([^)]+)\)/g, '<a href="$2">$1</a>');
    
    // Process line breaks
    const parts = html.split(/(__HTML_BLOCK_\d+__)/);
    const processedParts = parts.map((part) => {
      if (part.match(/^__HTML_BLOCK_\d+__$/)) {
        const blockIndex = parseInt(part.match(/\d+/)[0]);
        return htmlBlocks[blockIndex];
      } else {
        let processed = part;
        processed = processed.replace(/\n\n+/g, '</p><p>');
        processed = processed.replace(/([^\n>])\n([^\n<])/g, '$1<br>$2');
        if (processed.trim() && !processed.trim().startsWith('<')) {
          processed = '<p>' + processed + '</p>';
        }
        return processed;
      }
    });
    
    html = processedParts.join('');
    html = html.replace(/<p><\/p>/g, '');
    html = html.replace(/<p>\s*<br>\s*<\/p>/g, '');
    html = html.replace(/<p>\s*<\/p>/g, '');
    
    return html;
  };

  const handleDownload = async (format) => {
    if (!extractionResult || !extractionResult.fields) {
      console.error("No extraction data available");
      return;
    }

    setDownloading(format);
    
    try {
      const fields = extractionResult.fields;
      let content = "";
      let filename = "";
      let mimeType = "";

      if (format === "json") {
        const preparedFields = prepareFieldsForOutput(fields, "json");
        content = JSON.stringify(preparedFields, null, 2);
        filename = `extraction_${new Date().toISOString().split('T')[0]}.json`;
        mimeType = "application/json";
      } else if (format === "xml") {
        content = objectToXML(fields);
        filename = `extraction_${new Date().toISOString().split('T')[0]}.xml`;
        mimeType = "application/xml";
      } else if (format === "docx") {
        // For DOCX, create a Word-compatible HTML document that preserves layout
        // Extract text and convert to HTML (same as text viewer)
        const textContent = extractTextFromFields(fields);
        const htmlContent = renderMarkdownToHTML(textContent);
        
        // Create a Word-compatible HTML document with proper MIME type
        // Word can open HTML files with .docx extension if we use the right MIME type
        const wordHTML = `<!DOCTYPE html>
<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40">
<head>
  <meta charset="UTF-8">
  <meta name="ProgId" content="Word.Document">
  <meta name="Generator" content="Microsoft Word">
  <meta name="Originator" content="Microsoft Word">
  <!--[if gte mso 9]><xml>
   <w:WordDocument>
    <w:View>Print</w:View>
    <w:Zoom>100</w:Zoom>
    <w:DoNotOptimizeForBrowser/>
   </w:WordDocument>
  </xml><![endif]-->
  <title>Document Extraction</title>
  <style>
    @page {
      size: 8.5in 11in;
      margin: 1in;
    }
    body {
      font-family: 'Calibri', 'Arial', sans-serif;
      font-size: 11pt;
      line-height: 1.6;
      margin: 0;
      color: #333;
    }
    h1 {
      font-size: 18pt;
      font-weight: bold;
      color: #0f172a;
      margin-top: 24pt;
      margin-bottom: 12pt;
      page-break-after: avoid;
    }
    h2 {
      font-size: 16pt;
      font-weight: 600;
      color: #0f172a;
      margin-top: 20pt;
      margin-bottom: 10pt;
      page-break-after: avoid;
    }
    h3 {
      font-size: 14pt;
      font-weight: 600;
      color: #1e293b;
      margin-top: 16pt;
      margin-bottom: 8pt;
      page-break-after: avoid;
    }
    p {
      margin-top: 6pt;
      margin-bottom: 6pt;
    }
    table {
      width: 100%;
      border-collapse: collapse;
      margin: 12pt 0;
      font-size: 10pt;
      page-break-inside: avoid;
    }
    table th {
      background-color: #f8fafc;
      border: 1pt solid #cbd5e1;
      padding: 6pt;
      text-align: left;
      font-weight: 600;
      color: #0f172a;
    }
    table td {
      border: 1pt solid #cbd5e1;
      padding: 6pt;
      color: #334155;
    }
    table tr:nth-child(even) {
      background-color: #f8fafc;
    }
    sup {
      font-size: 0.75em;
      vertical-align: super;
      line-height: 0;
    }
    sub {
      font-size: 0.75em;
      vertical-align: sub;
      line-height: 0;
    }
    strong {
      font-weight: 600;
    }
    em {
      font-style: italic;
    }
    a {
      color: #4f46e5;
      text-decoration: underline;
    }
  </style>
</head>
<body>
${htmlContent}
</body>
</html>`;
        
        content = wordHTML;
        filename = `extraction_${new Date().toISOString().split('T')[0]}.doc`;
        mimeType = "application/msword";
      }

      // Create blob and download
      const blob = new Blob([content], { type: mimeType });
      const url = URL.createObjectURL(blob);
      const link = document.createElement("a");
      link.href = url;
      link.download = filename;
      document.body.appendChild(link);
      link.click();
      document.body.removeChild(link);
      URL.revokeObjectURL(url);

      setDownloading(null);
    } catch (error) {
      console.error("Download error:", error);
      setDownloading(null);
    }
  };

  const handleCopyLink = async () => {
    if (!extractionResult?.id) return;
    
    setIsGeneratingLink(true);
    setIsShareLinkModalOpen(true);
    setShareLink("");
    
    try {
      const result = await createShareLink(extractionResult.id);
      if (result.success && result.share_link) {
        setShareLink(result.share_link);
      } else {
        throw new Error("Failed to generate share link");
      }
    } catch (err) {
      console.error("Failed to create share link:", err);
      setShareLink("");
      // Still show modal but with error state
    } finally {
      setIsGeneratingLink(false);
    }
  };

  const handleShare = async (extractionId, recipientEmail) => {
    await shareExtraction(extractionId, recipientEmail);
  };

  if (!isComplete) return null;

  return (
    <motion.div
      initial={{ opacity: 0, y: 20 }}
      animate={{ opacity: 1, y: 0 }}
      className="flex items-center gap-3"
    >
      {/* Export Options Dropdown */}
      <DropdownMenu>
        <DropdownMenuTrigger asChild>
          <Button 
            variant="ghost" 
            className="h-11 w-11 rounded-xl hover:bg-slate-100"
            disabled={downloading !== null}
          >
            {downloading ? (
              <motion.div
                animate={{ rotate: 360 }}
                transition={{ duration: 1, repeat: Infinity, ease: "linear" }}
              >
                <Download className="h-4 w-4" />
              </motion.div>
            ) : (
              <Share2 className="h-4 w-4" />
            )}
          </Button>
        </DropdownMenuTrigger>
        <DropdownMenuContent align="end" className="w-56 rounded-xl p-2">
          <DropdownMenuItem
            className="rounded-lg cursor-pointer"
            onClick={() => setIsShareModalOpen(true)}
          >
            <Mail className="h-4 w-4 mr-2 text-indigo-600" />
            Share output
          </DropdownMenuItem>
          <DropdownMenuItem
            className="rounded-lg cursor-pointer"
            onClick={handleCopyLink}
          >
            <Link2 className="h-4 w-4 mr-2 text-indigo-600" />
            Copy share link
          </DropdownMenuItem>
          <DropdownMenuSeparator />
          <DropdownMenuItem
            className="rounded-lg cursor-pointer"
            onClick={() => handleDownload("docx")}
            disabled={downloading === "docx"}
          >
            {downloading === "docx" ? (
              <motion.div
                animate={{ rotate: 360 }}
                transition={{ duration: 1, repeat: Infinity, ease: "linear" }}
                className="h-4 w-4 mr-2"
              >
                <Download className="h-4 w-4" />
              </motion.div>
            ) : (
              <FileText className="h-4 w-4 mr-2 text-blue-600" />
            )}
            Download Docx
          </DropdownMenuItem>
          <DropdownMenuItem
            className="rounded-lg cursor-pointer"
            onClick={() => handleDownload("json")}
            disabled={downloading === "json"}
          >
            {downloading === "json" ? (
              <motion.div
                animate={{ rotate: 360 }}
                transition={{ duration: 1, repeat: Infinity, ease: "linear" }}
                className="h-4 w-4 mr-2"
              >
                <Download className="h-4 w-4" />
              </motion.div>
            ) : (
              <Braces className="h-4 w-4 mr-2 text-indigo-600" />
            )}
            Download JSON
          </DropdownMenuItem>
          <DropdownMenuItem
            className="rounded-lg cursor-pointer"
            onClick={() => handleDownload("xml")}
            disabled={downloading === "xml"}
          >
            {downloading === "xml" ? (
              <motion.div
                animate={{ rotate: 360 }}
                transition={{ duration: 1, repeat: Infinity, ease: "linear" }}
                className="h-4 w-4 mr-2"
              >
                <Download className="h-4 w-4" />
              </motion.div>
            ) : (
              <FileCode2 className="h-4 w-4 mr-2 text-slate-600" />
            )}
            Download XML
          </DropdownMenuItem>
        </DropdownMenuContent>
      </DropdownMenu>

      {/* Share Modal */}
      <ShareModal
        isOpen={isShareModalOpen}
        onClose={() => setIsShareModalOpen(false)}
        onShare={handleShare}
        extractionId={extractionResult?.id}
      />

      {/* Share Link Modal */}
      <ShareLinkModal
        isOpen={isShareLinkModalOpen}
        onClose={() => {
          setIsShareLinkModalOpen(false);
          setShareLink("");
        }}
        shareLink={shareLink}
        isLoading={isGeneratingLink}
      />
    </motion.div>
  );
}