data-inventory-purchases.php

<?php

    header("Content-Type: text/plain");

    //echo "sales_id,customer_id,product_id,product_type,unit_cost,quantity,unit_cost\r\n";

    echo "PONumber,SupplierID,ProductID,Quantity,OrderDate,ReceivedDate,ReceivedQuantity\r\n";

    $start      = "1 January 2018";
    $end        = "31 December 2018";
    $dateStart  = strtotime($start);
    $dateEnd    = strtotime($end);

    $days       = round(($dateEnd - $dateStart) / (60 * 60 * 24));

    // 2017: CNY, Qingming, Lunar 7th Month, Mid Autumn

    $counter = 1;

    $holidays = [
        '6 February 2019',
        '5 April 2019',
        '15 August 2019'
    ];

    $products = [
        ['P0001', 'P0002', 'P0003', 'P0004', 'P0005'],
        ['P0006', 'P0007'],
        ['P0008', 'P0009', 'P0010'],
        ['P0011'],
        ['P0012', 'P0013', 'P0014'],
        ['P0015', 'P0016'],
        ['P0017', 'P0018'],
        ['P0019', 'P0020'],
        ['P0021', 'P0022', 'P0023']
    ];

    $productsAll = call_user_func_array('array_merge', $products);
    
    for ($i = 0; $i <= $days; $i++) {
        // each day.
        $currentDate = strtotime($start . " +{$i} days");
        $format = date("Ym", $currentDate);
        
        $inRangeOfHoliday = false;
        foreach ($holidays as $holiday) {
            $oneMonthBefore = strtotime($holiday . " -1 month");
            $holiday = strtotime($holiday);
            
            if ($oneMonthBefore <= $currentDate and $currentDate <= $holiday) {
                $inRangeOfHoliday = true;
            }
        }

        if ($inRangeOfHoliday) {
            $orders = mt_rand(14, 22); // No. of orders in a day.
        }
        else {
            $orders = mt_rand(8, 14); // No. of orders in a day.
        }
        
        if (date('j', $currentDate) === '1') {
            $counter = 1;
        }

        $supplierIds = randomGen(1, 40, $orders);
        
        for ($j = 1; $j <= $orders; $j++) {
            // each order. $inRangeOfHoliday
            $receivedDate = strtotime(date("Y-m-d", $currentDate) . " +" . mt_rand(1, 2) . " days");
            $noOfProducts = mt_rand(1, 5);

            $supplierId = $supplierIds[0];
            $supplierIds = array_slice($supplierIds, 1);

            $productIds = randomGenProducts($noOfProducts, $inRangeOfHoliday); //$productsAll

            for ($k = 1; $k <= $noOfProducts; $k++) {
                // each product
                $data = "PO" . $format . sprintf('%03d', $counter) . ",";
                $data .= "SUP" . sprintf('%08d', $supplierId) . ",";
                $productId = $productsAll[$productIds[0]];
                $data .= $productId . ",";
                $productIds = array_slice($productIds, 1);

                if (in_array($productId, ['P0001', 'P0002', 'P0003', 'P0004', 'P0005'])) {
                    $prob = mt_rand(1, 100);

                    if ($prob < 75) {
                        $quantity = mt_rand(1, 5);
                    }
                    else {
                        $quantity = mt_rand(6, 10);
                    }
                }
                else if (in_array($productId, ['P0006', 'P0007'])) {
                    $prob = mt_rand(1, 100);

                    if ($prob < 75) {
                        $quantity = mt_rand(1, 5);
                    }
                    else {
                        $quantity = mt_rand(6, 10);
                    }
                }
                else if (in_array($productId, ['P0008', 'P0009', 'P0010'])) {
                    $prob = mt_rand(1, 100);

                    if ($prob < 75) {
                        $quantity = mt_rand(ceil(10/5), floor(40/5))*5;
                    }
                    else {
                        $quantity = mt_rand(ceil(40/5), floor(80/5))*5;   
                    }
                }
                else if (in_array($productId, ['P0011'])) {
                    $prob = mt_rand(1, 100);

                    if ($prob < 80) {
                        $quantity = mt_rand(ceil(10/5), floor(40/5))*5;
                    }
                    else {
                        $quantity = mt_rand(ceil(40/5), floor(80/5))*5;   
                    }
                }
                else if (in_array($productId, ['P0012', 'P0013', 'P0014'])) {
                    if ($inRangeOfHoliday) {
                        $quantity = mt_rand(1, 2);
                    }
                }
                else if (in_array($productId, ['P0015', 'P0016'])) {
                    $prob = mt_rand(1, 100);

                    if ($prob < 75) {
                        $quantity = mt_rand(2, 20)/2;
                    }
                    else {
                        $quantity = mt_rand(21, 40)/2;
                    }
                }
                else if (in_array($productId, ['P0017', 'P0018'])) {
                    $prob = mt_rand(1, 100);

                    if ($prob < 75) {
                        $quantity = mt_rand(2, 10)/2;
                    }
                    else {
                        $quantity = mt_rand(11, 20)/2;
                    }
                }
                else if (in_array($productId, ['P0019', 'P0020'])) {
                    $prob = mt_rand(1, 100);

                    if ($prob < 75) {
                        $quantity = mt_rand(2, 20)/2;
                    }
                    else {
                        $quantity = mt_rand(21, 40)/2;
                    }
                }
                else if (in_array($productId, ['P0021', 'P0022', 'P0023'])) {
                    $prob = mt_rand(1, 100);

                    if ($prob < 75) {
                        $quantity = mt_rand(2, 10)/2;
                    }
                    else {
                        $quantity = mt_rand(11, 20)/2;
                    }
                }

                $data .= $quantity . ",";
                $data .= date("Y-m-d", $currentDate) . ",";
                $data .= date("Y-m-d", $receivedDate) .",";
                $data .= $quantity;

                echo $data . "\r\n";
            }

            $counter++;
        }
    }


    function randomGen($min, $max, $quantity) {
        $numbers = range($min, $max);
        shuffle($numbers);
        return array_slice($numbers, 0, $quantity);
    }

    function randomGenProducts($quantity, $isHoliday) {
        if ($isHoliday) {
            $numbers = range(0, 21);
            shuffle($numbers);
            return array_slice($numbers, 0, $quantity);
        }
        else {
            $numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 14, 15, 16, 17, 18, 19, 20, 21];
            $prob = mt_rand(1, 100);

            if ($prob >= 95) {
                array_push($numbers, 11, 12, 13);
            }

            shuffle($numbers);
            return array_slice($numbers, 0, $quantity);
        }
    }