/*
     Copyright 2017 Wolfgang Thaller.

     This file is part of Retro68.

     Retro68 is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation, either version 3 of the License, or
     (at your option) any later version.

     Retro68 is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with Retro68.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "Elf2Mac.h"
#include "SegmentMap.h"

#include <gelf.h>

#include <err.h>

#include <string>
#include <vector>
#include <fstream>
#include <iostream>

#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

#include <boost/algorithm/string/predicate.hpp>

#include "Object.h"

using std::string;
using std::vector;
using std::ofstream;

string argvZero;

void RealLD(vector<string> args)
{
    vector<const char*> argv;
    string realLD = argvZero + ".real";
    argv.push_back(realLD.c_str());
    for(string& s : args)
        argv.push_back(s.c_str());
    argv.push_back(NULL);

    pid_t pid = fork();
    if(pid < 0)
    {
        perror("unable to fork");
        exit(-1);
    }
    else if(pid == 0)
    {
        execvp(argv[0], const_cast<char* const *> (argv.data()));
        perror("exec failed");
        exit(-1);
    }
    else
    {
        int wstatus;
        int result = 0;
        do
        {
            result = waitpid(pid, &wstatus, 0);
        } while(result == -1 && errno == EINTR);
        if(!WIFEXITED(wstatus))
        {
            errx(EXIT_FAILURE, "ld process did not exit properly");
        }
        else
        {
            int exitcode = WEXITSTATUS(wstatus);
            if(exitcode)
                exit(exitcode);
        }
    }

}

int main(int argc, char *argv[])
{
    vector<string> args;
    std::copy(argv + 1, argv+argc, std::back_inserter(args));
    argvZero = argv[0];

    if(boost::algorithm::ends_with(argv[0], "ld"))
    {
        string outputFile = "a.out";
        string entryPoint = "_start";
        bool elf2mac = false;
        bool flatoutput = false;
        bool segments = true;
        bool stripMacsbug = false;
        bool saveLdScript = false;

        SegmentMap segmentMap;

        vector<string> args2;
        for(auto p = args.begin(), e = args.end(); p != e; ++p)
        {
            if(*p == "-o")
            {
                ++p;
                if(p == e)
                    errx(EXIT_FAILURE, "-o missing argument");
                outputFile = *p;
            }
            else if(boost::algorithm::starts_with(*p, "-o"))
            {
                outputFile = (*p).substr(2);
            }
            else if(*p == "-elf2mac" || *p == "--elf2mac")
            {
                elf2mac = true;
            }
            else if(*p == "-e")
            {
                ++p;
                if(p == e)
                    errx(EXIT_FAILURE, "-e missing argument");
                entryPoint = *p;
            }
            else if(boost::algorithm::starts_with(*p, "-e"))
            {
                entryPoint = (*p).substr(2);
            }
            else if(*p == "--mac-flat")
            {
                elf2mac = true;
                flatoutput = true;
                segments = false;
            }
            else if(*p == "--mac-single")
            {
                elf2mac = true;
                flatoutput = false;
                segments = false;
            }
            else if(*p == "--mac-segments")
            {
                elf2mac = true;
                if(flatoutput)
                    errx(EXIT_FAILURE, "--mac-segments can't be used with --mac-flat");
                ++p;
                if(p == e)
                    errx(EXIT_FAILURE, "--mac-segments missing argument");
                segmentMap = SegmentMap(*p);
            }
            else if(*p == "--mac-strip-macsbug")
            {
                stripMacsbug = true;
            }
            else if(*p == "--mac-keep-ldscript")
            {
                saveLdScript = true;
            }
            else
            {
                args2.push_back(*p);
            }
        }

        if(elf2mac)
        {
            char tmpfile[] = "/tmp/ldscriptXXXXXX";
            int fd = mkstemp(tmpfile);
            if(fd < 0)
                errx(EXIT_FAILURE, "can't create temp file");

            {
                ofstream out(tmpfile);
                if(segments)
                {
                    segmentMap.CreateLdScript(out, entryPoint, stripMacsbug);
                }
                else
                {
                    CreateFlatLdScript(out, entryPoint, stripMacsbug);
                }
            }

            args2.push_back("-o");
            args2.push_back(outputFile + ".gdb");
            args2.push_back("-T");
            args2.push_back(tmpfile);
            RealLD(args2);
            if(saveLdScript)
                std::cerr << "Ld Script at: " << tmpfile << std::endl;
            else
                unlink(tmpfile);
            Object theObject(outputFile + ".gdb");
            if(flatoutput)
                theObject.FlatCode(outputFile);
            else if(segments)
                theObject.MultiSegmentApp(outputFile, segmentMap);
            else
                theObject.SingleSegmentApp(outputFile);
        }
        else
        {
            RealLD(args);
        }
        return 0;
    }
    else
    {
        if(argc != 2)
            errx(EXIT_FAILURE, "usage : %s file-name ", argv[0]);
        Object theObject(argv[1]);
        SegmentMap segmentMap;
        theObject.MultiSegmentApp("out.bin", segmentMap);
    }
    return 0;
}