ProcessManager.h

/*
 * Copyright (c) 2026 Pavel Vainerman.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, version 2.1.
 */
// -------------------------------------------------------------------------
#ifndef ProcessManager_H_
#define ProcessManager_H_
// -------------------------------------------------------------------------
#include <memory>
#include <string>
#include <vector>
#include <map>
#include <mutex>
#include <atomic>
#include <thread>
#include <functional>
#include <iostream>
#include <Poco/Process.h>
#include "ProcessInfo.h"
#include "DependencyResolver.h"
#include "HealthChecker.h"
#include "Configuration.h"
#include "Debug.h"
// -------------------------------------------------------------------------
namespace uniset
{
    enum class BulkOperation : int
    {
        None = 0,
        Restart,
        Reload,
        Stop
    };
 
    class ProcessManager
    {
        public:
            explicit ProcessManager(std::shared_ptr<Configuration> conf = nullptr);
            ~ProcessManager();
 
            // Configuration
            void setNodeName(const std::string& name);
            std::string getNodeName() const;
 
            void setHealthCheckInterval(size_t msec);
            void setRestartWindow(size_t msec);
            void setStopTimeout(size_t msec);
            void setCommonArgs(const std::vector<std::string>& args);
            void setPassthroughArgs(const std::vector<std::string>& args);
            void setForwardArgs(const std::vector<std::string>& args);
 
            // Process registration
            void addProcess(const ProcessInfo& proc);
            void addGroup(const ProcessGroup& group);
 
            // Lifecycle management
            bool startAll();
            void stopAll();
            void restartAll();  
            void reloadAll();   
            void requestStop(); 

            void cancelStartup();
            bool isBulkOperationInProgress() const;
            BulkOperation currentBulkOperation() const;
            bool restartProcess(const std::string& name);
            bool stopProcess(const std::string& name);
            bool startProcess(const std::string& name);
 
            // Monitoring
            void startMonitoring();
            void stopMonitoring();
            bool isMonitoring() const;
 
            // State queries
            ProcessState getProcessState(const std::string& name) const;
            ProcessInfo getProcessInfo(const std::string& name) const;
            std::vector<ProcessInfo> getAllProcesses() const;
            std::vector<ProcessGroup> getAllGroups() const;
 
            bool allRunning() const;
            bool anyCriticalFailed() const;

            std::vector<std::string> getFullArgs(const std::string& name) const;

            void printRunList(std::ostream& out) const;
 
            // Callbacks
            using ProcessCallback = std::function<void(const ProcessInfo&)>;
            void setOnProcessStarted(ProcessCallback cb);
            void setOnProcessStopped(ProcessCallback cb);
            void setOnProcessFailed(ProcessCallback cb);
 
            // Debug
            std::shared_ptr<DebugStream> log();
 
        private:
            bool startProcessWithUnlock(ProcessInfo& proc, std::unique_lock<std::mutex>& lock);
            bool startOneshotWithUnlock(ProcessInfo& proc, std::unique_lock<std::mutex>& lock);
            void stopProcess(ProcessInfo& proc);
            void doStopAll();  
            void handleProcessExitByName(const std::string& name, int exitCode);
            void monitorLoop();
 
            // Helper methods for process startup
            std::vector<std::string> assembleArgs(const ProcessInfo& proc) const;
            std::vector<std::string> prepareProcessArgs(const ProcessInfo& proc);
            bool launchDaemonProcess(ProcessInfo& proc);

            static bool interruptibleSleep(size_t msec, const std::atomic<bool>& cancelFlag,
                                           size_t pollInterval_msec = 500);
 
            std::vector<std::string> resolveStartOrder();
            void expandEnvironment(std::vector<std::string>& args);
            std::string expandEnvVar(const std::string& s);
 
            std::shared_ptr<Configuration> conf_;
            std::unique_ptr<HealthChecker> healthChecker_;
            DependencyResolver depResolver_;
 
            std::string nodeName_;
            std::map<std::string, ProcessInfo> processes_;
            std::map<std::string, ProcessGroup> groups_;
 
            std::thread monitorThread_;
            std::atomic<bool> running_{false};
            std::atomic<bool> stopping_{false};
            std::atomic<bool> stopAllRunning_{false};
            std::atomic<bool> shutdownRequested_{false};  // monotonic: SIGINT/SIGTERM was received
            std::atomic<BulkOperation> currentBulkOp_{BulkOperation::None};
            mutable std::mutex mutex_;
 
            size_t healthCheckInterval_msec_ = 5000;
            size_t restartWindow_msec_ = 60000;
            size_t stopTimeout_msec_ = 5000;  // Time to wait for graceful shutdown before SIGKILL
            std::vector<std::string> commonArgs_;
            std::vector<std::string> passthroughArgs_;  // Arguments after "--" passed to all child processes
            std::vector<std::string> forwardArgs_;  // Unknown arguments forwarded to child processes
 
            ProcessCallback onStarted_;
            ProcessCallback onStopped_;
            ProcessCallback onFailed_;
 
            std::shared_ptr<DebugStream> mylog;
    };
 
} // end of namespace uniset
// -------------------------------------------------------------------------
#endif // ProcessManager_H_
// -------------------------------------------------------------------------