AuroraRuntime/Source/Console/ConsoleAsioStd/ConsoleAsioStd.cpp

/***
    Copyright (C) 2021 J Reece Wilson (a/k/a "Reece"). All rights reserved.

    File: ConsoleAsioStd.cpp
    Date: 2021-6-8
    Author: Reece
***/
#include <RuntimeInternal.hpp>
#include "ConsoleAsioStd.hpp"

namespace Aurora::Console::ConsoleAsioStd
{
#if defined(AURORA_PLATFORM_WIN32) || defined(AURORA_PLATFORM_LINUX) || defined(AURORA_PLATFORM_APPLE) 

#if defined(AURORA_PLATFORM_WIN32)
    using StreamDescriptor_t = asio::windows::stream_handle;
#else
    using StreamDescriptor_t = asio::posix::stream_descriptor;
#endif 

    static const AuMach        kLineBufferMax = 2048;

    static AuUInt8             gLineBuffer[kLineBufferMax] = { 0 };
    static AuString            gLineString = "";

    static StreamDescriptor_t *gInputStream = {};
    static StreamDescriptor_t *gOutputStream = {};

    static asio::io_context    gIOC;

    void Init()
    {
    #if defined(AURORA_PLATFORM_WIN32)

        if (GetConsoleWindow() == NULL)
        {
            if (!gRuntimeConfig.console.forceConsoleWindow)
            {
                return;
            }
            
            if (gRuntimeConfig.console.disableAll)
            {
                return;
            }

            auto ok = AllocConsole();
            SysAssert(ok, "Request of a Win32 console yielded nada, forceConsole wasn't respected");
        }
        else
        {
            // no always means no under UNIX targets; but on windows, if you're compiling a console app, dont be surprised to find console output
            // instead of attempting to detach from conhost, link as a WindowedApp and do not setup any windows, if you're looking for windowless
            // ignore gRuntimeConfig.console.disableAll
        }

        DWORD dwMode;
        bool ok;
        auto hOutput = GetStdHandle(STD_OUTPUT_HANDLE);
        SysAssert(hOutput != INVALID_HANDLE_VALUE, "Couldn't open STDOUT");

        ok = GetConsoleMode(hOutput, &dwMode);
        SysAssert(ok, "Couldn't get console mode");

        dwMode |= ENABLE_PROCESSED_OUTPUT | ENABLE_VIRTUAL_TERMINAL_PROCESSING;
        ok = SetConsoleMode(hOutput, dwMode);
        SysAssert(ok, "Couldn't set console mode");

        auto fileHandle = CreateFileA("CONIN$",
                                      GENERIC_READ,
                                      FILE_SHARE_READ,
                                      NULL,
                                      OPEN_EXISTING,
                                      FILE_FLAG_OVERLAPPED | FILE_FLAG_NO_BUFFERING,
                                      NULL);

        SysAssert(fileHandle != INVALID_HANDLE_VALUE, "Couldn't open CONIN");
        gInputStream = _new StreamDescriptor_t(gIOC, fileHandle);

        fileHandle = CreateFileA("CONOUT$",
                                 GENERIC_WRITE,
                                 FILE_SHARE_READ | FILE_SHARE_WRITE,
                                 NULL,
                                 OPEN_EXISTING,
                                 FILE_FLAG_OVERLAPPED | FILE_FLAG_NO_BUFFERING,
                                 NULL);

        SysAssert(fileHandle != INVALID_HANDLE_VALUE, "Couldn't open CONOUT");
        gOutputStream = _new StreamDescriptor_t(gIOC, fileHandle);

    #else
        
        // no always means no under UNIX targets
        // we *know* stdin/out should be available under these standards
        if (gRuntimeConfig.console.disableAll)
        {
            return;
        }

        gInputStream  = _new StreamDescriptor_t(gIOC, STDIN_FILENO);
        gOutputStream = _new StreamDescriptor_t(gIOC, STDOUT_FILENO);

    #endif 

        SysAssert(gInputStream, "Couldn't allocate input stream handler");
        SysAssert(gOutputStream, "Couldn't allocate output stream handler");

        Aurora::Console::Hooks::AddHook([](const Aurora::Console::ConsoleMessage &string) -> void
        {
        #if defined(DEBUG) && defined(AURORA_PLATFORM_WIN32)
            auto debugLine = string.ToSimplified() + "\r\n";
            OutputDebugStringA(debugLine.c_str());
        #endif 

            auto writeLine = string.ToConsole();

        #if defined(AURORA_PLATFORM_WIN32)
            writeLine += '\r';
        #endif 
            writeLine += '\n';

            asio::write(*gOutputStream, asio::buffer(writeLine));
        });
    }

    static void ProcessLines()
    {
        AuMach index = 0;

        while ((index = gLineString.find("\n")) != AuString::npos)
        {
            auto line   = gLineString.substr(0, index);
            gLineString = gLineString.substr(index + 1);

            if (line[line.size() - 1] == '\r')
            {
                line.pop_back();
            }

            if (line.size())
            {
                Aurora::Console::Commands::DispatchCommand(line);
            }
        }
    }

    static void StdInHandler(const asio::error_code &code, std::size_t bytesCopied)
    {
        if (bytesCopied == 0)
        {
            return;
        }

        gLineString.append(reinterpret_cast<const char *>(gLineBuffer), bytesCopied);

        ProcessLines();
    }

    void Pump()
    {
        if (!gInputStream) return;

        gInputStream->async_read_some(asio::buffer(gLineBuffer, kLineBufferMax), StdInHandler);

        gIOC.poll_one();
    }

    void Exit()
    {
        if (gInputStream)
        {
            delete gInputStream;
        }
        
        if (gOutputStream)
        {
            delete gOutputStream;
        }
    }

#else
    
    void Pump()
    {
    }
    
    void Init()
    {
    }

    void Exit()
    {
    }
    
#endif
}