<?php
require_once 'includes/config.php';
require_once 'includes/functions.php';
require_once 'includes/auth.php';
require_once 'includes/db.php';

$auth = new Auth();

// Check if user is logged in
if (!$auth->isLoggedIn()) {
    die('Unauthorized');
}

$db = Database::getInstance();

// Get selection ID from URL
$selection_id = isset($_GET['id']) ? (int)$_GET['id'] : 0;

if (!$selection_id) {
    die('Invalid selection ID');
}

// Get selection details
$stmt = $db->prepare("
    SELECT s.*, p.project_id as project_code, p.title as project_title
    FROM selections s
    JOIN projects p ON s.project_id = p.id
    WHERE s.id = ? AND p.created_by = ?
");
$stmt->bind_param('ii', $selection_id, $_SESSION['user_id']);
$stmt->execute();
$selection = $stmt->get_result()->fetch_assoc();

if (!$selection) {
    die('Selection not found or access denied');
}

// Get selection members
$stmt = $db->prepare("
    SELECT sm.panelist_id, pd.attribute_values
    FROM selection_members sm
    LEFT JOIN panel_data pd ON sm.panelist_id = pd.panelist_id
    WHERE sm.selection_id = ?
    ORDER BY sm.id ASC
");
$stmt->bind_param('i', $selection_id);
$stmt->execute();
$members_result = $stmt->get_result();

// Get all attributes
$attributes = [];
$attr_query = $db->query("SELECT id, name FROM attributes ORDER BY created_at ASC");
while ($attr = $attr_query->fetch_assoc()) {
    $attributes[$attr['id']] = $attr['name'];
}

// Set headers for CSV download
header('Content-Type: text/csv; charset=utf-8');
header('Content-Disposition: attachment; filename="selection_' . $selection_id . '_' . date('Y-m-d') . '.csv"');

// Create output stream
$output = fopen('php://output', 'w');

// Add BOM for Excel UTF-8 compatibility
fprintf($output, chr(0xEF).chr(0xBB).chr(0xBF));

// Write headers
$headers = ['#', 'Panelist ID'];
foreach ($attributes as $attr_name) {
    $headers[] = $attr_name;
}
fputcsv($output, $headers);

// Write data rows
$counter = 1;
while ($member = $members_result->fetch_assoc()) {
    $row = [$counter++, $member['panelist_id']];
    
    $attribute_values = json_decode($member['attribute_values'], true);
    foreach ($attributes as $attr_id => $attr_name) {
        $row[] = isset($attribute_values[$attr_id]) ? $attribute_values[$attr_id] : '';
    }
    
    fputcsv($output, $row);
}

fclose($output);
exit;