Get all the changesets in Nightly between the current build and the previous one

today_in_nightly.php

<?php

function getBuilId(string $raw_build_id): array {
    return [
        'year'   => substr($raw_build_id, 0, 4),
        'month'  => substr($raw_build_id, 4, 2),
        'day'    => substr($raw_build_id, 6, 2),
        'hour'   => substr($raw_build_id, 8, 2),
        'minute' => substr($raw_build_id, 10, 2),
        'second' => substr($raw_build_id, 12, 2),
    ];
}

function getRemoteJSON(string $url): array {
    return json_decode(file_get_contents($url), true);
}

function extractLinksFromHTML(string $html): array {
    $regexp = "<a\s[^>]*href=(\"??)([^\" >]*?)\\1[^>]*>(.*)<\/a>";
    if (preg_match_all("/$regexp/siU", $html, $matches)) {
        return $matches[2];
    }
    return [];
}

$nightly_version = getRemoteJSON('https://product-details.mozilla.org/1.0/firefox_versions.json')['FIREFOX_NIGHTLY'];
$nightly_archive = 'https://archive.mozilla.org/pub/firefox/nightly/';
$file_name = 'firefox-' . $nightly_version . '.en-US.win64.json';
$latest_metadata = getRemoteJSON($nightly_archive . 'latest-mozilla-central/' . $file_name);

$latest_build_id   = getBuilId($latest_metadata['buildid']);
$latest_changeset  = $latest_metadata['moz_source_stamp'];
$latest_build_date = new DateTime(implode(array_slice($latest_build_id, 0, 3), '/'));
$yesterday = $latest_build_date->add(DateInterval::createFromDateString('yesterday'))->format('Y/m/');

// Get all the links from yesterday
$links = extractLinksFromHTML(file_get_contents($nightly_archive . $yesterday));
$links = preg_grep("/mozilla-central\//", $links);
$links = preg_grep("/" . $latest_build_date->format('Y-m-d') ."/", $links);

// We often have 2 builds a day, we want the first one (not taskcluster-based, they are built later)
$yesterday_build    = 'https://archive.mozilla.org' . array_shift($links) . $file_name;
$previous_changeset = getRemoteJSON($yesterday_build)['moz_source_stamp'];

$target_url = 'https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=' 
    . $previous_changeset 
    . '&tochange=' 
    . $latest_changeset;

header('Location: ' . $target_url);
exit;