<?php
session_start();

if (!isset($_SESSION['user_id'])) {
    header("Location: login.php");
    exit();
}

require_once 'db_connection.php';

try {
    // Set headers for CSV download
    header('Content-Type: text/csv; charset=utf-8');
    header('Content-Disposition: attachment; filename="buyers_' . date('Y-m-d') . '.csv"');
    
    // Create output stream
    $output = fopen('php://output', 'w');
    
    // Add BOM for Excel UTF-8 support
    fprintf($output, chr(0xEF).chr(0xBB).chr(0xBF));
    
    // Add header
    fputcsv($output, array('Name', 'Phone', 'Tilapia Rate', 'Small Fish Rate', 'Big Fish Rate', 'Delivery Rate', 'Harvesting Fee Tilapia', 'Harvesting Fee Small Fish', 'Harvesting Fee Big Fish'));
    
    // Fetch all buyers
    $query = "SELECT * FROM buyers ORDER BY name";
    $result = $conn->query($query);
    
    while ($row = $result->fetch_assoc()) {
        fputcsv($output, array(
            $row['name'],
            $row['phone'],
            number_format($row['rate_tilapia'], 2),
            number_format($row['rate_small_fish'], 2),
            number_format($row['rate_big_fish'], 2),
            number_format($row['delivery_rate'], 2),
            number_format($row['harvesting_fee_tilapia'], 2),
            number_format($row['harvesting_fee_small_fish'], 2),
            number_format($row['harvesting_fee_big_fish'], 2)
        ));
    }

    fclose($output);
    $conn->close();
} catch (Exception $e) {
    header('Content-Type: text/plain');
    echo "An error occurred while exporting data.";
    error_log("Buyer export error: " . $e->getMessage());
}

exit();
?>