<?php
session_start();
if (!isset($_SESSION['logged_in']) || $_SESSION['logged_in'] !== true) {
    header('HTTP/1.1 403 Forbidden');
    exit('Access denied');
}

class FileUploader {
    private $uploadDir = '../../uploads/claims/';
    private $allowedTypes = ['jpg', 'jpeg', 'png', 'pdf', 'doc', 'docx'];
    private $maxSize = 5 * 1024 * 1024; // 5MB

    public function __construct() {
        // Create upload directory if it doesn't exist
        if (!file_exists($this->uploadDir)) {
            mkdir($this->uploadDir, 0755, true);
        }
    }

    public function upload($file) {
        try {
            // Check for errors
            if ($file['error'] !== UPLOAD_ERR_OK) {
                throw new Exception('Upload error: ' . $file['error']);
            }

            // Check file size
            if ($file['size'] > $this->maxSize) {
                throw new Exception('File size exceeds maximum limit of 5MB');
            }

            // Check file type
            $fileExtension = strtolower(pathinfo($file['name'], PATHINFO_EXTENSION));
            if (!in_array($fileExtension, $this->allowedTypes)) {
                throw new Exception('Invalid file type. Allowed types: ' . implode(', ', $this->allowedTypes));
            }

            // Generate unique filename
            $filename = uniqid() . '_' . time() . '.' . $fileExtension;
            $filepath = $this->uploadDir . $filename;

            // Move uploaded file
            if (!move_uploaded_file($file['tmp_name'], $filepath)) {
                throw new Exception('Failed to move uploaded file');
            }

            return $filename;

        } catch (Exception $e) {
            error_log("File Upload Error: " . $e->getMessage());
            return false;
        }
    }
}

// Handle file upload via AJAX
if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_FILES['evidence_file'])) {
    $uploader = new FileUploader();
    $filename = $uploader->upload($_FILES['evidence_file']);
    
    if ($filename) {
        echo json_encode(['success' => true, 'filename' => $filename]);
    } else {
        echo json_encode(['success' => false, 'message' => 'File upload failed']);
    }
    exit;
}
?>