@extends('layouts.admin')

@section('title', 'Upload Training Calendar')

@section('content_header')
    <h1>Upload Training Calendar</h1>
@stop

@section('content')
    <div class="card card-primary">
        <div class="card-header">
            <h3 class="card-title">Upload Training Calendar Excel Sheet</h3>
        </div>
        <div class="card-body">
                    @if($errors->any())
                        <div class="alert alert-danger alert-dismissible fade show" role="alert">
                            <ul class="mb-0">
                                @foreach($errors->all() as $error)
                                    <li>{{ $error }}</li>
                                @endforeach
                            </ul>
                            <button type="button" class="close" data-dismiss="alert" aria-label="Close">
                                <span aria-hidden="true">&times;</span>
                            </button>
                        </div>
                    @endif

                                         <div class="alert alert-info" data-auto-hide="false">
                         <h6><i class="fas fa-info-circle"></i> CSV File Requirements (Indian Format Compatible):</h6>
                         <ul class="mb-0">
                             <li>File format: .csv only</li>
                             <li>Maximum file size: 10MB</li>
                             <li>First row should contain headers (will be skipped)</li>
                             <li><strong>Required columns:</strong> Course Type, Training Course</li>
                             <li><strong>Optional columns:</strong> Batch Type, Duration, From Date, To Date, Holidays, Standard Price, Promotional Offer, Note</li>
                             <li><strong>Indian Date Format:</strong> DD/MM/YYYY or DD-MM-YYYY (e.g., "15/01/2024", "15-01-2024")</li>
                             <li><strong>Indian Price Format:</strong> ₹15,000.00, ₹2,50,000, Rs.15000, or plain numbers</li>
                             <li><strong>Holidays Format:</strong> Multiple dates separated by commas (e.g., "03/09/2025,11/09/2025,12/09/2025")</li>
                             <li><strong>Price Validation:</strong> Must be between ₹100 and ₹50,00,000</li>
                             <li><strong>Date Validation:</strong> From Date cannot be after To Date, dates must be valid (2020-2035)</li>
                             <li><strong>Duplicate Handling:</strong> If a record with the same Course Type + Training Course + From Date + To Date exists, it will be <strong>updated</strong> instead of creating a duplicate</li>
                             <li><strong>Data Replacement:</strong> Records not present in the new CSV will be <strong>soft deleted</strong> to maintain data consistency</li>
                             <li><strong>Upload Strategy:</strong> Each CSV upload completely replaces the training calendar data</li>
                             <li><strong>Database Protection:</strong> Unique constraint prevents duplicate entries at database level</li>
                         </ul>
                     </div>

                     <div class="alert alert-warning" data-auto-hide="false">
                         <h6><i class="fas fa-exclamation-triangle"></i> Important Notes:</h6>
                         <ul class="mb-0">
                             <li><strong>Data Replacement:</strong> Each upload completely replaces the training calendar - records not in the CSV will be soft deleted</li>
                             <li><strong>Soft Delete Safety:</strong> Soft deleted records can be restored if needed - data is not permanently lost</li>
                             <li><strong>Transaction Safety:</strong> All operations are wrapped in a database transaction - if upload fails, no changes are made</li>
                             <li>Check upload logs for detailed processing information including create/update/delete counts</li>
                         </ul>
                     </div>

                    <form action="{{ route('admin.training.upload.excel') }}" method="POST" enctype="multipart/form-data" id="uploadForm">
                        @csrf
                        <div class="form-group">
                            <label for="excel_file">Select CSV File <span class="text-danger">*</span></label>
                            <div class="input-group">
                                <div class="custom-file">
                                    <input type="file" class="custom-file-input @error('excel_file') is-invalid @enderror" 
                                           id="excel_file" name="excel_file" accept=".csv" required>
                                    <label class="custom-file-label" for="excel_file">Choose file</label>
                                </div>
                            </div>
                            @error('excel_file')
                                <span class="invalid-feedback" role="alert"><strong>{{ $message }}</strong></span>
                            @enderror
                            <small class="form-text text-muted">Only .csv files are allowed. Maximum size: 10MB</small>
                        </div>

                        <div class="form-group">
                            <button type="submit" class="btn btn-primary" id="uploadBtn">
                                <i class="fas fa-upload"></i> Upload & Process
                            </button>
                            <a href="{{ route('admin.training.index') }}" class="btn btn-default float-right">Cancel</a>
                        </div>
                    </form>

                    <hr>

                                         <div class="mt-4">
                         <h6>Sample CSV Format:</h6>
                         <div class="table-responsive">
                             <table class="table table-bordered table-sm">
                                 <thead class="thead-light">
                                     <tr>
                                         <th>Course Type</th>
                                         <th>Training Course</th>
                                         <th>Batch Type</th>
                                         <th>Duration</th>
                                         <th>From Date</th>
                                         <th>To Date</th>
                                         <th>Holidays</th>
                                         <th>Standard Price</th>
                                         <th>Promotional Offer</th>
                                         <th>Note</th>
                                     </tr>
                                 </thead>
                                 <tbody>
                                     <tr>
                                         <td>ISO 9001</td>
                                         <td>Quality Management System</td>
                                         <td>Weekend</td>
                                         <td>3 Days</td>
                                         <td>15/01/2024</td>
                                         <td>17/01/2024</td>
                                         <td>16/01/2024</td>
                                         <td>₹15,000.00</td>
                                         <td>₹12,000.00</td>
                                         <td>Early bird discount available</td>
                                     </tr>
                                     <tr>
                                         <td>ISO 14001</td>
                                         <td>Environmental Management</td>
                                         <td>Weekday</td>
                                         <td>2 Days</td>
                                         <td>20/01/2024</td>
                                         <td>21/01/2024</td>
                                         <td></td>
                                         <td>₹12,000.00</td>
                                         <td></td>
                                         <td></td>
                                     </tr>
                                     <tr>
                                         <td>ISO 45001</td>
                                         <td>Occupational Health & Safety</td>
                                         <td>Weekend</td>
                                         <td>5 Days</td>
                                         <td>15-03-2024</td>
                                         <td>19-03-2024</td>
                                         <td>17/03/2024,18/03/2024</td>
                                         <td>₹2,50,000</td>
                                         <td>Rs.2,25,000</td>
                                         <td>Corporate training</td>
                                     </tr>
                                 </tbody>
                             </table>
                         </div>
                         <div class="mt-3">
                             <h6>Download Sample CSV:</h6>
                             <a href="#" onclick="downloadSampleCSV()" class="btn btn-outline-primary btn-sm">
                                 <i class="fas fa-download"></i> Download Sample CSV
                             </a>
                         </div>
                     </div>
                </div>
                <div class="card-footer">
                    <a href="{{ route('admin.training.index') }}" class="btn btn-default float-right">Cancel</a>
                </div>
            </div>
        </div>
    </div>
@endsection

@push('css')
<style>
.table-sm td, .table-sm th {
    padding: 0.25rem;
    font-size: 0.875rem;
}
</style>
@endpush

@push('js')
<script>
// Bootstrap custom file input functionality with validation
$(document).ready(function() {
    // File input change handler - updates filename and validates
    $('.custom-file-input').on('change', function() {
        const file = this.files[0];
        const $label = $(this).next('.custom-file-label');
        
        if (file) {
            // Check file extension instead of MIME type for better compatibility
            if (!file.name.toLowerCase().endsWith('.csv')) {
                alert('Please select a valid CSV file (.csv extension)');
                $(this).val('');
                $label.removeClass("selected").html('Choose file');
                return;
            }
            
            if (file.size > 10 * 1024 * 1024) {
                alert('File size must be less than 10MB');
                $(this).val('');
                $label.removeClass("selected").html('Choose file');
                return;
            }
            
            // Update label with filename if validation passes
            $label.addClass("selected").html(file.name);
        } else {
            $label.removeClass("selected").html('Choose file');
        }
    });
    
    // Form submit validation
    $('#uploadForm').on('submit', function(e) {
        const fileInput = document.getElementById('excel_file');
        const uploadBtn = document.getElementById('uploadBtn');
        
        if (!fileInput.files[0]) {
            e.preventDefault();
            alert('Please select a file to upload.');
            return;
        }
        
        const file = fileInput.files[0];
        
        // Check file extension instead of MIME type for better compatibility
        if (!file.name.toLowerCase().endsWith('.csv')) {
            e.preventDefault();
            alert('Please select a valid CSV file (.csv extension)');
            return;
        }
        
        if (file.size > 10 * 1024 * 1024) { // 10MB
            e.preventDefault();
            alert('File size must be less than 10MB');
            return;
        }
        
        // Show loading state
        uploadBtn.disabled = true;
        uploadBtn.innerHTML = '<i class="fas fa-spinner fa-spin"></i> Processing...';
    });
});

// Download sample CSV function
function downloadSampleCSV() {
    const csvContent = `Course Type,Training Course,Batch Type,Duration,From Date,To Date,Holidays,Standard Price,Promotional Offer,Note
ISO 27001,Information Security Management Systems,Weekday Batch,40 Hours,15/09/2024,19/09/2024,17/09/2024,₹28,000.00,,
ISO 27001,Information Security Management Systems,Weekday Batch,40 Hours,22/09/2024,26/09/2024,,₹28,000.00,,
ISO 27001,Information Security Management Systems,Weekend Batch,40 Hours,13/09/2024,21/09/2024,15/09/2024,₹28,000.00,,
ISO 9001,Quality Management Systems,Evening Batch,40 Hours,06/09/2024,10/09/2024,,₹26,000.00,,
ISO 9001,Quality Management Systems,Evening Batch,40 Hours,11/09/2024,15/09/2024,12/09/2024,₹26,000.00,,
ISO 9001,Quality Management Systems,Weekday Batch,40 Hours,15/09/2024,19/09/2024,16/09/2024,18/09/2024,₹26,000.00,,
ISO 14001,Environmental Management Systems,Evening Batch,40 Hours,15/09/2024,19/09/2024,,₹26,000.00,,
ISO 14001,Environmental Management Systems,Weekday Batch,40 Hours,22/09/2024,26/09/2024,23/09/2024,₹26,000.00,,
ISO 45001,Occupational Health & Safety Management Systems,Weekday Batch,40 Hours,15/09/2024,19/09/2024,,₹26,000.00,,
ISO 45001,Occupational Health & Safety Management Systems,Evening Batch,40 Hours,22/09/2024,26/09/2024,25/09/2024,₹26,000.00,,
Integrated Management System,Integrated Management System,Weekday Batch,24 Hours,24/09/2024,26/09/2024,,₹18,000.00,,
ISO 9001,Quality Management Systems,Weekday Batch,16 Hours,25/08/2024,26/08/2024,,₹12,000.00,,`;
    
    const blob = new Blob([csvContent], { type: 'text/csv' });
    const url = window.URL.createObjectURL(blob);
    const a = document.createElement('a');
    a.href = url;
    a.download = 'training_calendar_sample.csv';
    document.body.appendChild(a);
    a.click();
    document.body.removeChild(a);
    window.URL.revokeObjectURL(url);
}
</script>
@endpush