"use client";

import BackToMC from "@/components/mission-control/BackToMC";
import { useState } from "react";

export default function PdfViewerPage() {
  const [pdfData, setPdfData] = useState<string | null>(null);
  const [pdfName, setPdfName] = useState<string>("");
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [viewMode, setViewMode] = useState<"embed" | "download">("embed");

  const handleFileUpload = async (e: React.ChangeEvent<HTMLInputElement>) => {
    const file = e.target.files?.[0];
    if (!file) return;

    if (file.type !== "application/pdf") {
      setError("Please select a PDF file");
      return;
    }

    setLoading(true);
    setError(null);
    setPdfName(file.name);

    const reader = new FileReader();
    reader.onload = (event) => {
      const base64 = event.target?.result as string;
      setPdfData(base64);
      setLoading(false);
    };
    reader.onerror = () => {
      setError("Failed to read file");
      setLoading(false);
    };
    reader.readAsDataURL(file);
  };

  const handleUrlSubmit = async () => {
    const input = prompt("Enter PDF URL:");
    if (!input) return;

    setLoading(true);
    setError(null);

    try {
      new URL(input);
      // Use Google Docs viewer for external URLs
      const googleViewerUrl = `https://docs.google.com/gview?url=${encodeURIComponent(input)}&embedded=true`;
      setPdfData(googleViewerUrl);
      setPdfName(input.split("/").pop() || "document.pdf");
      setLoading(false);
    } catch {
      setError("Invalid URL");
      setLoading(false);
    }
  };

  const handleDownload = () => {
    if (!pdfData) return;
    const link = document.createElement("a");
    link.href = pdfData;
    link.download = pdfName || "document.pdf";
    link.click();
  };

  return (
    <div className="min-h-screen bg-slate-950 text-white flex flex-col">
      {/* Header */}
      <div className="bg-slate-900 border-b border-slate-800 px-6 py-4 flex-shrink-0">
        <h1 className="text-2xl font-bold text-white">📄 PDF Viewer</h1>
        <p className="text-slate-400 text-sm">View and analyze PDF documents</p>
      </div>

      {/* Toolbar */}
      <div className="bg-slate-900/50 border-b border-slate-800 px-6 py-3 flex-shrink-0">
        <div className="flex items-center gap-4 flex-wrap">
          <label className="cursor-pointer bg-blue-600 hover:bg-blue-500 text-white px-4 py-2 rounded-lg text-sm font-medium transition-colors">
            📁 Upload PDF
            <input
              type="file"
              accept="application/pdf"
              onChange={handleFileUpload}
              className="hidden"
            />
          </label>
          
          <button
            onClick={handleUrlSubmit}
            className="bg-slate-700 hover:bg-slate-600 text-white px-4 py-2 rounded-lg text-sm font-medium transition-colors"
          >
            🔗 Load from URL
          </button>

          {pdfData && (
            <>
              <button
                onClick={handleDownload}
                className="bg-green-700 hover:bg-green-600 text-white px-4 py-2 rounded-lg text-sm font-medium transition-colors"
              >
                ⬇️ Download
              </button>
              
              {pdfData.startsWith("data:") && (
                <a
                  href={pdfData}
                  target="_blank"
                  rel="noopener noreferrer"
                  className="bg-slate-700 hover:bg-slate-600 text-white px-4 py-2 rounded-lg text-sm font-medium transition-colors"
                >
                  ↗ Open in New Tab
                </a>
              )}
            </>
          )}
        </div>
      </div>

      {/* Content */}
      <div className="flex-1 overflow-hidden flex flex-col">
        {error && (
          <div className="bg-red-900/50 border border-red-700 rounded-lg p-4 m-4 max-w-md">
            <h3 className="text-red-400 font-bold mb-2">Error</h3>
            <p className="text-red-300">{error}</p>
            <button
              onClick={() => setError(null)}
              className="mt-2 bg-red-700 hover:bg-red-600 text-white px-4 py-1 rounded text-sm"
            >
              Dismiss
            </button>
          </div>
        )}

        {!pdfData && !loading && (
          <div className="flex-1 flex items-center justify-center">
            <div className="text-center">
              <div className="text-8xl mb-6 opacity-50">📄</div>
              <h2 className="text-xl font-bold text-white mb-2">No PDF Loaded</h2>
              <p className="text-slate-400 mb-6">Upload a PDF or enter a URL to view it</p>
              <div className="text-slate-500 text-sm space-y-1">
                <p>• Upload your resume to let Horus analyze it</p>
                <p>• Supports PDF files up to 50MB</p>
                <p>• Or load from any public PDF URL</p>
              </div>
            </div>
          </div>
        )}

        {loading && (
          <div className="flex-1 flex items-center justify-center">
            <div className="text-center">
              <div className="animate-spin text-6xl mb-4">⏳</div>
              <p className="text-slate-400">Loading PDF...</p>
            </div>
          </div>
        )}

        {pdfData && !loading && (
          <div className="flex-1 overflow-auto bg-slate-800 p-4">
            {pdfData.startsWith("data:") ? (
              // For uploaded files, show download prompt since browser PDF rendering in iframe is blocked
              <div className="flex flex-col items-center justify-center h-full">
                <div className="text-8xl mb-6">📄</div>
                <h2 className="text-xl font-bold text-white mb-2">{pdfName}</h2>
                <p className="text-slate-400 mb-6">PDF loaded successfully</p>
                <div className="flex gap-4">
                  <button
                    onClick={handleDownload}
                    className="bg-blue-600 hover:bg-blue-500 text-white px-6 py-3 rounded-lg font-medium"
                  >
                    ⬇️ Download PDF
                  </button>
                  <a
                    href={pdfData}
                    target="_blank"
                    rel="noopener noreferrer"
                    className="bg-slate-700 hover:bg-slate-600 text-white px-6 py-3 rounded-lg font-medium"
                  >
                    ↗ Open in New Tab
                  </a>
                </div>
              </div>
            ) : (
              // For external URLs, use Google Docs viewer
              <iframe
                src={pdfData}
                className="w-full h-full min-h-[700px] bg-white shadow-2xl rounded"
                title="PDF Viewer"
              />
            )}
          </div>
        )}
      </div>

      {/* Instructions */}
      <div className="bg-slate-900/50 border-t border-slate-800 px-6 py-2 flex-shrink-0">
        <p className="text-slate-500 text-xs">
          💡 Tip: Upload your resume PDF and Horus can analyze the design to recreate it
        </p>
      </div>
    </div>
  );
}