/*----------------------------------------------------------------------------*/
/*                                                                            */
/* Copyright (c) 1995, 2004 IBM Corporation. All rights reserved.             */
/* Copyright (c) 2005-2020 Rexx Language Association. All rights reserved.    */
/*                                                                            */
/* This program and the accompanying materials are made available under       */
/* the terms of the Common Public License v1.0 which accompanies this         */
/* distribution. A copy is also available at the following address:           */
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/*                                                                            */
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/*                                                                            */
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/* notice, this list of conditions and the following disclaimer in            */
/* the documentation and/or other materials provided with the distribution.   */
/*                                                                            */
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/* of its contributors may be used to endorse or promote products             */
/* derived from this software without specific prior written permission.      */
/*                                                                            */
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/*                                                                            */
/*----------------------------------------------------------------------------*/
/******************************************************************************/
/* Implementation of the SysInterpreterInstance class                         */
/*                                                                            */
/******************************************************************************/

#include "RexxCore.h"
#include "InterpreterInstance.hpp"
#include "ListClass.hpp"
#include "SystemInterpreter.hpp"
#include "RexxActivation.hpp"

#include <fcntl.h>
#include <io.h>


BOOL __stdcall WinConsoleCtrlHandler(DWORD dwCtrlType)
/******************************************************************************/
/* Arguments:  Report record, registration record, context record,            */
/*             dispatcher context                                             */
/*                                                                            */
/* DESCRIPTION : For Control Break conditions issue a halt to activation      */
/*               Control-C or control-Break is pressed.                       */
/*                                                                            */
/*  Returned:  Action code                                                    */
/******************************************************************************/
{
    // check to condition for all threads of this process */

    if ((dwCtrlType == CTRL_CLOSE_EVENT) || (dwCtrlType == CTRL_SHUTDOWN_EVENT))
    {
        return false;  /* send to system */
    }

    /* if RXCTRLBREAK=NO then ignore SIGBREAK exception */
    if (dwCtrlType == CTRL_BREAK_EVENT || dwCtrlType == CTRL_LOGOFF_EVENT)
    {
        char envp[65];
        if (GetEnvironmentVariable("RXCTRLBREAK", envp, sizeof(envp)) > 0 && strcmp("NO",envp) == 0)
        {
            return true;    /* ignore signal */
        }
    }

    if (dwCtrlType == CTRL_LOGOFF_EVENT)
    {
        return false;    /* send to system */
    }

    // we need to do something about this one, let the system interpreter handle
    return SystemInterpreter::processSignal(dwCtrlType);
}


/**
 * Initialize the interpreter instance.
 *
 * @param i       Our interpreter instance container.
 * @param options The options used to initialize us.  We can add additional
 *                platform-specific options if we wish.
 */
void SysInterpreterInstance::initialize(InterpreterInstance *i, RexxOption *options)
{
    externalTraceEnabled = false;    // off by default
    TCHAR rxTraceBuf[8];

    // check the current environment for RXTRACE
    if (GetEnvironmentVariable("RXTRACE", rxTraceBuf, 8))
    {
        // if this is set to on, start with tracing enabled
        if (!Utilities::strCaselessCompare(rxTraceBuf, "ON"))
        {
            externalTraceEnabled = true;   // turn on tracing of top-level activations for this instance
        }
    }

    // Allow Rexx console output to use virtual terminal (VT) sequences.
    // This is based on the examples Microsoft gives in
    // https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequences
    // The Microsoft example shows
    // a) SetConsoleMode STD_OUTPUT_HANDLE or'ing in ENABLE_VIRTUAL_TERMINAL_PROCESSING and DISABLE_NEWLINE_AUTO_RETURN
    // b) SetConsoleMode STD_INPUT_HANDLE or'ing in ENABLE_VIRTUAL_TERMINAL_INPUT
    // In addition to a) we also run SetConsoleMode for STD_ERROR_HANDLE
    // but we don't do b) because this breaks PULL line editing (cursor
    // keys emit ANSI characters instead of moving around).

    // VT support was added around 10.0.10586, so we might or might not
    // have some of these defines.  If missing, make them nop's.
#ifndef ENABLE_VIRTUAL_TERMINAL_PROCESSING
#   define ENABLE_VIRTUAL_TERMINAL_PROCESSING 0
#endif
#ifndef DISABLE_NEWLINE_AUTO_RETURN
#   define DISABLE_NEWLINE_AUTO_RETURN 0
#endif

    DWORD mode;
    HANDLE h;

    h = GetStdHandle(STD_OUTPUT_HANDLE);
    if (h != NULL && h != INVALID_HANDLE_VALUE && GetConsoleMode(h, &mode) != 0)
    {
        SetConsoleMode(h, mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING | DISABLE_NEWLINE_AUTO_RETURN);
    }
    h = GetStdHandle(STD_ERROR_HANDLE);
    if (h != NULL && h != INVALID_HANDLE_VALUE && GetConsoleMode(h, &mode) != 0)
    {
        SetConsoleMode(h, mode | ENABLE_VIRTUAL_TERMINAL_PROCESSING | DISABLE_NEWLINE_AUTO_RETURN);
    }

    // Because of using the stand-alone runtime library or when using different compilers,
    // the std-streams of the calling program and the REXX.DLL might be located at different
    // addresses and therefore _file might be -1. If so, std-streams are reassigned to the
    // file standard handles returned by the system
    if ((_fileno(stdin) < 0) && (GetFileType(GetStdHandle(STD_INPUT_HANDLE)) != FILE_TYPE_UNKNOWN))
    {
        *stdin = *_fdopen(_open_osfhandle((intptr_t)GetStdHandle(STD_INPUT_HANDLE),_O_RDONLY), "r");
    }
    if ((_fileno(stdout) < 0) && (GetFileType(GetStdHandle(STD_OUTPUT_HANDLE)) != FILE_TYPE_UNKNOWN))
    {
        *stdout = *_fdopen(_open_osfhandle((intptr_t)GetStdHandle(STD_OUTPUT_HANDLE),_O_APPEND), "a");
    }
    if ((_fileno(stderr) < 0) && (GetFileType(GetStdHandle(STD_ERROR_HANDLE)) != FILE_TYPE_UNKNOWN))
    {
        *stderr = *_fdopen(_open_osfhandle((intptr_t)GetStdHandle(STD_ERROR_HANDLE),_O_APPEND), "a");
    }
    // enable trapping for CTRL_C exceptions
    SetConsoleCtrlHandler(&WinConsoleCtrlHandler, true);
    instance = i;

    // we never want to see a critical-error-handler message box.
    // according to MS docs: "Best practice is that all applications call
    // the process-wide SetErrorMode function with a parameter of
    // SEM_FAILCRITICALERRORS at startup
    SetErrorMode(SEM_FAILCRITICALERRORS);

    // add our default search extension
    addSearchExtension(".REX");
}


/**
 * Terminate the interpreter instance.
 */
void SysInterpreterInstance::terminate()
{
    SetConsoleCtrlHandler(&WinConsoleCtrlHandler, false);
}


/**
 * Append a system default extension to the extension search order.
 *
 * @param name   The name to add.
 */
void SysInterpreterInstance::addSearchExtension(const char *name)
{
    // if the extension is not already in the extension list, add it
    RexxString *ext = new_string(name);
    if (!instance->searchExtensions->hasItem(ext))
    {
        instance->searchExtensions->append(ext);
    }
}


/**
 * Do system specific program setup
 *
 * @param activation the activation starting up.
 */
void SysInterpreterInstance::setupProgram(RexxActivation *activation)
{
    // trace this activation if turned on externally when the instance was started
    if (externalTraceEnabled)
    {
        activation->enableExternalTrace();
    }
}


/**
 * Initialize a path searcher.
 *
 * @param parentDir The parent dirctory for the search.
 * @param extensionPath
 *                  The system extension path.
 */
SysSearchPath::SysSearchPath(const char *parentDir, const char *extensionPath)
{
    char temp[4];             // this is just a temp buffer to check component sizes

    // this is a little bit of a pain because this gets returned in a buffer. We need to
    // find the size so we can ensure our buffer is large enough before we start to
    // assemble it
    size_t pathSize = GetEnvironmentVariable("PATH", temp, sizeof(temp));
    size_t rexxPathSize = GetEnvironmentVariable("REXX_PATH", temp, sizeof(temp));
    size_t parentSize = parentDir == NULL ? 0 : strlen(parentDir);
    size_t extensionSize = extensionPath == NULL ? 0 : strlen(extensionPath);

    // enough room for separators and a terminating null
    path.ensureCapacity(pathSize + rexxPathSize + parentSize + extensionSize + 16);

    // parent directory
    addPath(parentDir);
    // add on the current directory
    addPath(".;");

    addPath(extensionPath);

    // add on the Rexx path, then the normal path
    GetEnvironmentVariable("REXX_PATH", (char *)path + path.length(), (DWORD)rexxPathSize + 1);
    if (!path.endsWith(';'))
    {
        path += ";";
    }

    GetEnvironmentVariable("PATH", (char *)path + path.length(), (DWORD)pathSize + 1);
    if (path.at(path.length() - 1) != ';')
    {
        path += ";";
    }
}