bridgetask.h

// Copyright (c) 2019 Internetstiftelsen
// Written by Göran Andersson <initgoran@gmail.com>
 
#pragma once
 
#include <string>
#include "task.h"
 
class BridgeTask : public Task {
 
public:
    BridgeTask(Task *agent = nullptr) : Task("Bridge"), the_agent(agent) {
        killChildTaskWhenFinished();
    }
 
    double start() override;
 
    void taskFinished(Task *task) override {
        if (task == the_agent) {
            if (!task->result().empty()) {
                log() << "Agent terminated";
                sendMsgToClient(agentTerminatedMessage(task->result()));
                the_agent = nullptr;
            }
            die();
        }
    }
 
    void setAgent(Task *agent) {
        if (!the_agent && !hasStarted())
            the_agent = agent;
        else
            err_log() << "cannot set agent";
    }
 
    void die() {
        setResult("");
    }
 
    virtual void sendMsgToClient(const std::string &msg) = 0;
 
    static std::string msgToAgent(const std::string &method,
                                  const std::string &jsonobj = "{}") {
        return "{\"method\": \"" + method + "\", \"args\": " + jsonobj + "}";
    }
 
    static bool isAgentTerminatedMessage(const std::string &msg) {
        return (msg.substr(0, 12) == "AGENT EXIT: ");
    }
 
    static std::string agentTerminatedMessage(const std::string &err_msg) {
        return "AGENT EXIT: " + err_msg;
    }
 
    void sendMsgToClient(const std::string &method, const std::string &jsonobj) {
        sendMsgToClient("{\"event\": \"" + method +
                        "\", \"args\": " + jsonobj + "}");
    }
 
    virtual ~BridgeTask() override;
 
protected:
    void sendMsgToAgent(const std::string &msg) {
        executeHandler(the_agent, msg);
        if (msg.substr(0, terminate_msg.size()) == terminate_msg)
            die();
    }
 
    void sendMsgToAgent(const std::string &method, const std::string &jsonobj) {
        sendMsgToAgent(msgToAgent(method, jsonobj));
    }
private:
    Task *the_agent;
    //const std::string quit_msg = "quit";
    const std::string terminate_msg = "{\"method\": \"terminate\"";
};