// Copyright (c) 2026 Ourpad Network
// See LICENSE file in the project root for full license text.

#pragma once

#include <string>
#include <thread>
#include <atomic>
#include "mixer/MixerEngine.hpp"

namespace mixer {

/// Unix domain socket JSON control server for the MixerEngine.
///
/// Listens on a Unix domain socket (default: /tmp/mixer-daemon.sock).
/// Each client connection sends one JSON command per line and receives
/// one JSON response per line.
///
/// Supported commands:
///   {"cmd":"getState"}                    → full mixer state snapshot
///   {"cmd":"getVU"}                        → VU levels for all channels
///   {"cmd":"setChannelVolume","channel":N,"volume":-6.0}
///   {"cmd":"setChannelPan","channel":N,"pan":0.0}
///   {"cmd":"setChannelMute","channel":N,"mute":true}
///   {"cmd":"setChannelSolo","channel":N,"solo":false}
///   {"cmd":"setChannelLabel","channel":N,"label":"Guitar"}
///   {"cmd":"setBusVolume","busId":N,"volume":0.0}
///   {"cmd":"setBusMute","busId":N,"mute":false}
///   {"cmd":"routeChannelToBus","channel":N,"busId":N,"level":0.0}
///   {"cmd":"routeBusToBus","sourceBusId":N,"targetBusId":N,"level":0.0}
///   {"cmd":"removeRoute","sourceId":N,"targetBusId":N}
///   {"cmd":"autoCreateChannels","inputs":N,"outputs":N}
///   {"cmd":"addChannel","physicalInput":N}    → {"status":"ok","channelIndex":N}
///   {"cmd":"removeChannel","channel":N}
class MixerControlServer {
public:
    MixerControlServer(MixerEngine* engine, const std::string& socketPath = "/tmp/mixer-daemon.sock");
    ~MixerControlServer();

    // Disable copy
    MixerControlServer(const MixerControlServer&) = delete;
    MixerControlServer& operator=(const MixerControlServer&) = delete;

    /// Start the control server in a background thread.
    /// Returns true if the socket was created successfully.
    bool start();

    /// Stop the control server and join the thread.
    void stop();

    /// True if the server is running.
    bool running() const { return running_.load(); }

private:
    MixerEngine* engine_;
    std::string socketPath_;
    int serverFd_ = -1;
    std::thread serverThread_;
    std::atomic<bool> running_{false};

    // Server thread main loop
    void serverLoop();

    // Handle one client connection
    void handleClient(int clientFd);

    // Process a single JSON command and return JSON response
    std::string processCommand(const std::string& commandJson);

    // Helper: build full state JSON
    std::string buildStateJson() const;

    // Helper: build VU JSON
    std::string buildVuJson() const;
};

} // namespace mixer