/**
 * Document Uploader Component
 * Agent 3: File Upload & Storage System
 *
 * Upload interface for documents (PDF, DOC, etc.)
 */

import React, { useState, useCallback, useRef } from 'react';
import type { FileCategory } from '../../lib/storage/types';
import ProgressBar from './ProgressBar';

interface UploadedDocument {
  id: string;
  url: string;
  size: number;
  mimeType: string;
  originalName: string;
}

interface DocumentUploaderProps {
  category?: FileCategory;
  plantId?: string;
  farmId?: string;
  userId?: string;
  onUpload?: (file: UploadedDocument) => void;
  onError?: (error: string) => void;
  accept?: string;
  className?: string;
}

export function DocumentUploader({
  category = 'document',
  plantId,
  farmId,
  userId,
  onUpload,
  onError,
  accept = '.pdf,.doc,.docx',
  className = '',
}: DocumentUploaderProps) {
  const [isUploading, setIsUploading] = useState(false);
  const [progress, setProgress] = useState(0);
  const [error, setError] = useState<string>();
  const [uploadedFile, setUploadedFile] = useState<UploadedDocument | null>(null);
  const fileInputRef = useRef<HTMLInputElement>(null);

  const uploadFile = async (file: File) => {
    setIsUploading(true);
    setProgress(10);
    setError(undefined);

    const formData = new FormData();
    formData.append('file', file);
    formData.append('category', category);
    if (plantId) formData.append('plantId', plantId);
    if (farmId) formData.append('farmId', farmId);
    if (userId) formData.append('userId', userId);

    try {
      setProgress(30);

      const response = await fetch('/api/upload/document', {
        method: 'POST',
        body: formData,
      });

      setProgress(80);

      const data = await response.json();

      if (!data.success) {
        throw new Error(data.error || 'Upload failed');
      }

      setProgress(100);
      setUploadedFile(data.file);
      onUpload?.(data.file);
    } catch (error) {
      const message = error instanceof Error ? error.message : 'Upload failed';
      setError(message);
      onError?.(message);
    } finally {
      setIsUploading(false);
    }
  };

  const handleFileChange = useCallback(
    async (e: React.ChangeEvent<HTMLInputElement>) => {
      const file = e.target.files?.[0];
      if (file) {
        await uploadFile(file);
      }
    },
    []
  );

  const handleClick = () => {
    fileInputRef.current?.click();
  };

  const handleRemove = () => {
    setUploadedFile(null);
    setProgress(0);
    setError(undefined);
    if (fileInputRef.current) {
      fileInputRef.current.value = '';
    }
  };

  const getFileIcon = (mimeType: string) => {
    if (mimeType === 'application/pdf') {
      return (
        <svg className="w-8 h-8 text-red-500" fill="currentColor" viewBox="0 0 24 24">
          <path d="M14 2H6a2 2 0 00-2 2v16a2 2 0 002 2h12a2 2 0 002-2V8l-6-6zm-1 2l5 5h-5V4zm-3 9.5c0 .83-.67 1.5-1.5 1.5s-1.5-.67-1.5-1.5.67-1.5 1.5-1.5 1.5.67 1.5 1.5zm3 3c0 .83-.67 1.5-1.5 1.5s-1.5-.67-1.5-1.5.67-1.5 1.5-1.5 1.5.67 1.5 1.5z" />
        </svg>
      );
    }

    return (
      <svg className="w-8 h-8 text-blue-500" fill="currentColor" viewBox="0 0 24 24">
        <path d="M14 2H6a2 2 0 00-2 2v16a2 2 0 002 2h12a2 2 0 002-2V8l-6-6zm4 18H6V4h7v5h5v11z" />
      </svg>
    );
  };

  const formatFileSize = (bytes: number): string => {
    if (bytes < 1024) return `${bytes} B`;
    if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
    return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
  };

  return (
    <div className={className}>
      <input
        ref={fileInputRef}
        type="file"
        accept={accept}
        onChange={handleFileChange}
        className="hidden"
      />

      {uploadedFile ? (
        <div className="flex items-center p-4 border rounded-lg bg-gray-50">
          {getFileIcon(uploadedFile.mimeType)}
          <div className="ml-3 flex-1 min-w-0">
            <p className="text-sm font-medium text-gray-900 truncate">
              {uploadedFile.originalName}
            </p>
            <p className="text-xs text-gray-500">
              {formatFileSize(uploadedFile.size)}
            </p>
          </div>
          <div className="flex items-center space-x-2">
            <a
              href={uploadedFile.url}
              target="_blank"
              rel="noopener noreferrer"
              className="text-green-600 hover:text-green-700"
              title="Download"
            >
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path
                  strokeLinecap="round"
                  strokeLinejoin="round"
                  strokeWidth={2}
                  d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-4l-4 4m0 0l-4-4m4 4V4"
                />
              </svg>
            </a>
            <button
              onClick={handleRemove}
              className="text-red-500 hover:text-red-600"
              title="Remove"
            >
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path
                  strokeLinecap="round"
                  strokeLinejoin="round"
                  strokeWidth={2}
                  d="M6 18L18 6M6 6l12 12"
                />
              </svg>
            </button>
          </div>
        </div>
      ) : (
        <button
          onClick={handleClick}
          disabled={isUploading}
          className={`
            w-full border-2 border-dashed rounded-lg p-6 text-center
            transition-colors duration-200
            ${isUploading
              ? 'border-gray-200 bg-gray-50 cursor-not-allowed'
              : 'border-gray-300 hover:border-green-400 hover:bg-gray-50 cursor-pointer'
            }
          `}
        >
          <svg
            className="mx-auto h-10 w-10 text-gray-400"
            fill="none"
            stroke="currentColor"
            viewBox="0 0 24 24"
          >
            <path
              strokeLinecap="round"
              strokeLinejoin="round"
              strokeWidth={1.5}
              d="M9 13h6m-3-3v6m5 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"
            />
          </svg>
          <p className="mt-2 text-sm text-gray-600">
            <span className="text-green-600 font-medium">Click to upload</span>
            {' '}a document
          </p>
          <p className="mt-1 text-xs text-gray-500">
            PDF, DOC, DOCX up to 10MB
          </p>
        </button>
      )}

      {isUploading && (
        <div className="mt-3">
          <ProgressBar progress={progress} />
          <p className="text-xs text-gray-500 mt-1 text-center">Uploading...</p>
        </div>
      )}

      {error && (
        <p className="mt-2 text-sm text-red-500 text-center">{error}</p>
      )}
    </div>
  );
}

export default DocumentUploader;