<?php

declare(strict_types=1);

// Status report to the manage server.
//
// Sent from cron (manage-client.php heartbeat) and after every update or
// backup, so the server dashboard shows the installed version, the last backup
// and any pending migrations without polling the instance.
//
// The response doubles as a cheap update check: one request is enough for a
// monitoring job to learn that an instance is behind.

function manageHeartbeatPayload(): array
{
    $lastBackupAt = "";
    $pendingMigrations = 0;

    try {
        $backups = manageBackupList();
        if ($backups !== []) {
            $lastBackupAt = (string) ($backups[0]["created_at"] ?? "");
        }
    } catch (Throwable $exception) {
        // A broken backup index must not stop the heartbeat; the server simply
        // keeps the previous value.
        manageClientLog("WARNING", "Heartbeat could not read backup index", [
            "error" => $exception->getMessage(),
        ]);
    }

    try {
        $pendingMigrations = count(manageUpdatePendingMigrations());
    } catch (Throwable $exception) {
        manageClientLog("WARNING", "Heartbeat could not read migrations", [
            "error" => $exception->getMessage(),
        ]);
    }

    $diskFree = 0;
    try {
        $free = @disk_free_space(manageClientAppRoot());
        if (is_float($free) || is_int($free)) {
            $diskFree = (int) $free;
        }
    } catch (Throwable $exception) {
        $diskFree = 0;
    }

    return [
        "version" => manageClientVersion(),
        "php_version" => PHP_VERSION,
        "disk_free" => $diskFree,
        "pending_migrations" => $pendingMigrations,
        "last_backup_at" => $lastBackupAt,
    ];
}

/**
 * Sends the heartbeat.
 *
 * @return array{success: bool, latest: string, update_available: bool, server_time: string}
 */
function manageHeartbeatSend(): array
{
    $decoded = manageClientRequestJson(
        "POST",
        "heartbeat.php",
        manageHeartbeatPayload(),
        (int) MANAGE_HTTP_TIMEOUT,
    );

    return [
        "success" => !empty($decoded["success"]),
        "latest" => (string) ($decoded["latest"] ?? ""),
        "update_available" => !empty($decoded["update_available"]),
        "server_time" => (string) ($decoded["server_time"] ?? ""),
    ];
}

/**
 * Heartbeat that never throws. For call sites inside a host application where
 * an unreachable server must not surface as an error.
 */
function manageHeartbeatSendQuietly(): ?array
{
    try {
        return manageHeartbeatSend();
    } catch (Throwable $exception) {
        manageClientLog("WARNING", "Heartbeat failed", ["error" => $exception->getMessage()]);

        return null;
    }
}