<?php

namespace App\Services;

/**
 * Pure semver arithmetic for the Release page: given the current version, what rc-target versions
 * may the operator cut? The dashboard computes the target X.Y.Z; the host bridge computes -rcN.
 */
class ReleasePlanner
{
    /**
     * Proposed target versions (bare X.Y.Z) for the current version. A release candidate also offers
     * continuing its own base (another release candidate of the same target).
     *
     * @return array{patch:string, minor:string, major:string, continueRc?:string}
     */
    public function proposedTargets(string $current): array
    {
        $current = ltrim($current, 'vV');
        $base = preg_replace('/-.*$/', '', $current);
        [$maj, $min, $pat] = array_map('intval', array_pad(explode('.', (string) $base), 3, '0'));

        $targets = [
            'patch' => "{$maj}.{$min}.".($pat + 1),
            'minor' => "{$maj}.".($min + 1).'.0',
            'major' => ($maj + 1).'.0.0',
        ];

        if (str_contains($current, '-rc')) {
            $targets['continueRc'] = "{$maj}.{$min}.{$pat}";
        }

        return $targets;
    }

    /**
     * The flat list of allowed target versions — the server-side allow-list for a posted target.
     *
     * @return array<int,string>
     */
    public function allowedTargets(string $current): array
    {
        return array_values($this->proposedTargets($current));
    }
}