<?php
session_start();

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

require_once 'db_connection.php';

try {
    header('Content-Type: text/csv; charset=utf-8');
    header('Content-Disposition: attachment; filename="sales_' . date('Y-m-d') . '.csv"');
    
    $output = fopen('php://output', 'w');
    fprintf($output, chr(0xEF).chr(0xBB).chr(0xBF));
    
    fputcsv($output, array('Date', 'Buyer', 'Weight Tilapia (kg)', 'Weight Small Fish (kg)', 'Weight Big Fish (kg)', 'Include Delivery', 'Final Amount'));
    
    $query = "SELECT s.*, b.name as buyer_name FROM sales s JOIN buyers b ON s.buyer_id = b.id ORDER BY s.date DESC";
    $result = $conn->query($query);
    
    while ($row = $result->fetch_assoc()) {
        // Use override amount if set, otherwise use final_amount
        $display_amount = ($row['final_amount_override'] != null && $row['final_amount_override'] > 0) ? $row['final_amount_override'] : $row['final_amount'];
        
        fputcsv($output, array(
            $row['date'],
            $row['buyer_name'],
            number_format($row['weight_tilapia'], 2),
            number_format($row['weight_small_fish'], 2),
            number_format($row['weight_big_fish'], 2),
            $row['include_delivery'] ? 'Yes' : 'No',
            number_format($display_amount, 2)
        ));
    }

    fclose($output);
    $conn->close();
} catch (Exception $e) {
    header('Content-Type: text/plain');
    echo "Export error";
    error_log("Sales export error: " . $e->getMessage());
}

exit();
?>