permutations.php

<?php
require 'vendor/autoload.php'; // Install the Shotstack SDK using: `composer require shotstack/shotstack-sdk-php`

use Shotstack\Client\Api\EditApi;
use Shotstack\Client\ApiException;
use Shotstack\Client\Configuration;
use Shotstack\Client\Model\Edit;
use Shotstack\Client\Model\Output;
use Shotstack\Client\Model\Timeline;
use Shotstack\Client\Model\Track;
use Shotstack\Client\Model\Clip;
use Shotstack\Client\Model\ImageAsset;
use Shotstack\Client\Model\VideoAsset;

function generatePermutations($items, $perms = [], &$all = [])
{
    if (empty($items)) {
        $all[] = $perms;
    } else {
        for ($i = count($items) - 1; $i >= 0; --$i) {
            $newitems = $items;
            $newperms = $perms;
            list($foo) = array_splice($newitems, $i, 1);
            array_unshift($newperms, $foo);
            generatePermutations($newitems, $newperms, $all);
        }
        return $all;
    }
}

$config = Configuration::getDefaultConfiguration()
    ->setHost('https://api.shotstack.io/v1')
    ->setApiKey('x-api-key', 'YOUR_API_KEY');

// Map mergeFields to their lengths
$mergeFields = [
    'https://shotstack-assets.s3-ap-southeast-2.amazonaws.com/footage/night-sky.mp4' => 13,
    'https://s3-ap-southeast-2.amazonaws.com/shotstack-assets/footage/skater.hd.mp4' => 27,
    'https://github.com/shotstack/test-media/raw/main/captioning/scott-ko.mp4' => 28,
    'https://cdn.shotstack.io/au/v1/gb0ckjoadi/18724ca5-d607-4171-920d-144270c9650d.mp4' => 16,
    'https://s3-ap-southeast-2.amazonaws.com/shotstack-assets/examples/images/pexels/pexels-photo-712850.jpeg' => 5
];

$client = new EditApi(null, $config);

// Generate all permutations of 5 clips
$permutations = generatePermutations(array_keys($mergeFields));

foreach ($permutations as $permutation) {
    $track = new Track();
    $clips = [];
    $startTime = 0;

    foreach ($permutation as $mergeField) {
        $asset = (strpos($mergeField, '.jpeg') !== false) ? new ImageAsset() : new VideoAsset();
        $asset->setSrc($mergeField);
        $length = $mergeFields[$mergeField];

        $clip = new Clip();
        $clip->setAsset($asset)->setStart($startTime)->setLength($length);
        $clips[] = $clip;

        $startTime += $length;
    }

    $track->setClips($clips);

    $timeline = new Timeline();
    $timeline->setTracks([$track]);

    $output = new Output();
    $output->setFormat('mp4')->setResolution('sd');

    $edit = new Edit();
    $edit->setTimeline($timeline)->setOutput($output);

    try {
        $response = $client->postRender($edit)->getResponse();
        echo $response->getMessage() . PHP_EOL;
    } catch (ApiException $e) {
        die('Request failed: ' . $e->getMessage() . $e->getResponseBody());
    }
}
?>