<?php
require_once 'db/config.php';

header('Content-Type: application/json');

$p_start_date = date('Y-m-d', strtotime('-6 days'));
$p_end_date = date('Y-m-d');

$sql = "SELECT 
            d.sale_date, 
            COALESCE(SUM(s.total_amount), 0) AS daily_total
        FROM 
            (SELECT CURDATE() - INTERVAL (a.a + (10 * b.a) + (100 * c.a)) DAY AS sale_date
            FROM (SELECT 0 AS a UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS a
            CROSS JOIN (SELECT 0 AS a UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS b
            CROSS JOIN (SELECT 0 AS a UNION ALL SELECT 1 UNION ALL SELECT 2 UNION ALL SELECT 3 UNION ALL SELECT 4 UNION ALL SELECT 5 UNION ALL SELECT 6 UNION ALL SELECT 7 UNION ALL SELECT 8 UNION ALL SELECT 9) AS c
            ) AS d
        LEFT JOIN 
            sales s ON d.sale_date = DATE(s.sale_date)
        WHERE 
            d.sale_date BETWEEN :start_date AND :end_date
        GROUP BY 
            d.sale_date
        ORDER BY 
            d.sale_date ASC;";

$stmt = db()->prepare($sql);
$stmt->bindParam(':start_date', $p_start_date, PDO::PARAM_STR);
$stmt->bindParam(':end_date', $p_end_date, PDO::PARAM_STR);
$stmt->execute();

$sales_data = $stmt->fetchAll(PDO::FETCH_ASSOC);

$labels = [];
$data = [];

foreach ($sales_data as $row) {
    $labels[] = date('M d', strtotime($row['sale_date']));
    $data[] = $row['daily_total'];
}

echo json_encode(['labels' => $labels, 'data' => $data]);