<?php

namespace App\Services;

use Illuminate\Support\Str;

/**
 * The app side of the release bridge. requestStaging() writes a strictly-validated request to
 * run/release-request.json (a host watcher runs it); result() reads the host-written result for an
 * id this app issued. Validation here is the first gate — the host re-validates every value.
 * Reuses the same bind-mounted signal dir as the WireGuard/restart bridges.
 */
class ReleaseBridge
{
    private function dir(): string
    {
        return storage_path('app/restart-signal');
    }

    /**
     * Write a staging-release request for a bare X.Y.Z target; returns the request id, or null when
     * the signal dir is not writable. Throws on a non-semver target (defence-in-depth).
     */
    public function requestStaging(string $target): ?string
    {
        if (preg_match('/^\d+\.\d+\.\d+$/', $target) !== 1) {
            throw new \InvalidArgumentException('invalid target');
        }

        $id = Str::random(32);
        $payload = ['id' => $id, 'action' => 'stage', 'target' => $target, 'at' => time()];

        @mkdir($this->dir(), 0775, true);
        $ok = @file_put_contents($this->dir().'/release-request.json', json_encode($payload, JSON_UNESCAPED_SLASHES));

        return $ok === false ? null : $id;
    }

    /**
     * Read the host result for an id THIS app issued. Null until the result exists. Never throws.
     *
     * @return array{ok:bool, tag:?string, message:string}|null
     */
    public function result(string $id): ?array
    {
        if (preg_match('/^[A-Za-z0-9]{16,64}$/', $id) !== 1) {
            return null;
        }
        $file = $this->dir()."/release-result-{$id}.json";
        if (! is_file($file)) {
            return null;
        }
        $data = json_decode((string) @file_get_contents($file), true);
        if (! is_array($data) || ($data['id'] ?? null) !== $id) {
            return null;
        }

        return [
            'ok' => (bool) ($data['ok'] ?? false),
            'tag' => isset($data['tag']) && is_string($data['tag']) ? $data['tag'] : null,
            'message' => (string) ($data['message'] ?? ''),
        ];
    }
}