import { useRef } from 'react';
import { Download, Upload, Save, FolderOpen } from 'lucide-react';
import { formatWeekRange } from '../utils/dateUtils';

const ImportExport = ({ weekDays, timeEntries, customHomeowners, onImport }) => {
  const fileInputRef = useRef(null);

  const handleExport = () => {
    try {
      const exportData = {
        version: '1.0',
        exportDate: new Date().toISOString(),
        weekRange: formatWeekRange(weekDays),
        weekStart: weekDays[0].toISOString().split('T')[0],
        weekEnd: weekDays[6].toISOString().split('T')[0],
        timeEntries,
        customHomeowners
      };

      const dataStr = JSON.stringify(exportData, null, 2);
      const dataBlob = new Blob([dataStr], { type: 'application/json' });
      
      const url = URL.createObjectURL(dataBlob);
      const link = document.createElement('a');
      link.href = url;
      link.download = `Coastal_Timesheet_${formatWeekRange(weekDays).replace(/[^\w\s-]/g, '').replace(/\s+/g, '_')}.json`;
      document.body.appendChild(link);
      link.click();
      document.body.removeChild(link);
      URL.revokeObjectURL(url);

      // Show success message
      const notification = document.createElement('div');
      notification.className = 'fixed top-4 left-1/2 transform -translate-x-1/2 bg-green-600 text-white px-4 py-2 rounded-md shadow-lg z-50';
      notification.textContent = 'Timesheet exported successfully!';
      document.body.appendChild(notification);
      setTimeout(() => {
        if (document.body.contains(notification)) {
          document.body.removeChild(notification);
        }
      }, 3000);

    } catch (error) {
      console.error('Error exporting timesheet:', error);
      alert('Error exporting timesheet. Please try again.');
    }
  };

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

  const handleFileSelect = (event) => {
    const file = event.target.files?.[0];
    if (!file) return;

    if (file.type !== 'application/json') {
      alert('Please select a valid JSON file.');
      return;
    }

    const reader = new FileReader();
    reader.onload = (e) => {
      try {
        const importData = JSON.parse(e.target.result);
        
        // Validate the imported data structure
        if (!importData.version || !importData.timeEntries) {
          alert('Invalid timesheet file format.');
          return;
        }

        // Validate data structure
        const isValidStructure = Object.values(importData.timeEntries).every(dayEntries =>
          Array.isArray(dayEntries) && dayEntries.every(entry =>
            typeof entry === 'object' &&
            'id' in entry &&
            'workDescription' in entry &&
            'hoursWorked' in entry &&
            'homeowner' in entry
          )
        );

        if (!isValidStructure) {
          alert('Invalid timesheet data structure.');
          return;
        }

        // Confirm import
        const confirmImport = confirm(
          `Import timesheet data from ${importData.weekRange || 'unknown week'}?\n\nThis will replace your current timesheet data for this week.`
        );

        if (confirmImport) {
          onImport(importData);
          
          // Show success message
          const notification = document.createElement('div');
          notification.className = 'fixed top-4 left-1/2 transform -translate-x-1/2 bg-blue-600 text-white px-4 py-2 rounded-md shadow-lg z-50';
          notification.textContent = 'Timesheet imported successfully!';
          document.body.appendChild(notification);
          setTimeout(() => {
            if (document.body.contains(notification)) {
              document.body.removeChild(notification);
            }
          }, 3000);
        }

      } catch (error) {
        console.error('Error importing timesheet:', error);
        alert('Error reading timesheet file. Please check the file format.');
      }
    };

    reader.readAsText(file);
    
    // Reset file input
    event.target.value = '';
  };

  const hasData = Object.values(timeEntries).some(dayEntries => 
    dayEntries.some(entry => entry.workDescription || entry.hoursWorked || entry.homeowner)
  );

  return (
    <div className="flex items-center gap-3">
      {/* Export Button */}
      <button
        onClick={handleExport}
        disabled={!hasData}
        className={`flex items-center gap-2 px-4 py-2 rounded-lg font-medium transition-colors ${
          hasData
            ? 'bg-blue-600 hover:bg-blue-700 text-white'
            : 'bg-gray-300 dark:bg-gray-600 text-gray-500 dark:text-gray-400 cursor-not-allowed'
        }`}
        title={hasData ? 'Export timesheet data' : 'No data to export'}
      >
        <Save className="h-4 w-4" />
        Export
      </button>

      {/* Import Button */}
      <button
        onClick={handleImportClick}
        className="flex items-center gap-2 px-4 py-2 bg-purple-600 hover:bg-purple-700 text-white rounded-lg font-medium transition-colors"
        title="Import timesheet data"
      >
        <FolderOpen className="h-4 w-4" />
        Import
      </button>

      {/* Hidden File Input */}
      <input
        ref={fileInputRef}
        type="file"
        accept=".json"
        onChange={handleFileSelect}
        className="hidden"
      />
    </div>
  );
};

export default ImportExport;