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

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <fcntl.h>
#include <unistd.h>
#include <assert.h>

#include "PEF.h"

#include "ResourceFile.h"

#include <boost/filesystem.hpp>
#include <boost/filesystem/fstream.hpp>

namespace fs = boost::filesystem;


using std::cout;
using std::cerr;
using std::endl;
using std::pair;
using std::make_pair;
using std::vector;
using std::string;
using std::ofstream;
using std::ios_base;

void RunCommand(const char *command, std::vector<std::string> args)
{
	std::vector<const char*> ptrs;
	ptrs.push_back(command);
	for(auto& s : args)
		ptrs.push_back(s.c_str());
	ptrs.push_back(NULL);

	pid_t pid = fork();
	if(pid == -1)
	{
		perror(command);
		exit(1);
	}

	if(pid)
	{
		int status = 0;
		while(waitpid(pid, &status, 0) == -1 && errno == EINTR)
			;
		if(!WIFEXITED(status) || WEXITSTATUS(status) != 0)
		{
			std::cerr << command << " failed.\n";
			exit(1);
		}
	}
	else
	{
		execvp(command, const_cast<char *const*>(ptrs.data()));
		perror("exec");
		exit(1);
	}
}

void MakeImportLibrary(char *pefptr, size_t pefsize, fs::path dest, fs::path tmpdir)
{
	PEFContainerHeader *containerHeader = (PEFContainerHeader*) pefptr;
	eswap(containerHeader);

	assert(containerHeader->tag1 == 'Joy!');
	assert(containerHeader->tag2 == 'peff');

	PEFSectionHeader *sectionHeaders
		= (PEFSectionHeader*) (pefptr + kPEFFirstSectionHeaderOffset);

	PEFSectionHeader *loaderHeader = NULL;
	UInt16 n = containerHeader->sectionCount;
	for(UInt16 i=0; i < n; i++)
	{
		eswap(&sectionHeaders[i]);
		if(sectionHeaders[i].sectionKind == kPEFLoaderSection)
			loaderHeader = &sectionHeaders[i];
	}

	PEFLoaderInfoHeader *loaderInfoHeader
		= (PEFLoaderInfoHeader*) (pefptr + loaderHeader->containerOffset);
	eswap(loaderInfoHeader);
	
	UInt32 hashTableSize = 1;
	UInt32 hashTablePower = loaderInfoHeader->exportHashTablePower;
	while(hashTablePower--)
		hashTableSize *= 2;
	
	UInt32 nSymbols = loaderInfoHeader->exportedSymbolCount;
	
	const char *symbols	/* use char pointer to avoid packing issues */
		=	(pefptr	+ loaderHeader->containerOffset
					+ loaderInfoHeader->exportHashOffset
					+ hashTableSize * sizeof(PEFExportedSymbolHashSlot)
					+ nSymbols * sizeof(PEFExportedSymbolKey));
	
	const char *stringTable = pefptr
						+ loaderHeader->containerOffset
						+ loaderInfoHeader->loaderStringsOffset;
	/*const char *stringTableEnd = pefptr
					+ loaderHeader->containerOffset
					+ loaderInfoHeader->exportHashOffset;*/
	vector< pair< const char *, UInt8 > > classesAndNamePtrs;
	
	for(UInt32 i=0; i < nSymbols; i++)
	{
		PEFExportedSymbol *sym = (PEFExportedSymbol*) (symbols + 10*i);
		eswap(sym);

		UInt8 symclass = PEFExportedSymbolClass(sym->classAndName);
		UInt32 nameoffset = PEFExportedSymbolNameOffset(sym->classAndName);
		
		const char *nameptr
			= stringTable + nameoffset;
		
		classesAndNamePtrs.push_back( make_pair(nameptr, symclass) );
	}
	std::sort(classesAndNamePtrs.begin(), classesAndNamePtrs.end());
	
	vector< pair<string, UInt8> > exportedSymbols;
	for(UInt32 i=0; i < nSymbols; i++)
	{
		UInt8 symclass = classesAndNamePtrs[i].second;
		const char *namestart = classesAndNamePtrs[i].first;
		
		string name;
		if(i + 1 < nSymbols)
		{
			const char *nameend = classesAndNamePtrs[i+1].first;
			name = string(namestart,nameend);
		}
		else
			name = string(namestart);
			
		exportedSymbols.push_back( make_pair( name, symclass ) );
	}
	std::sort(exportedSymbols.begin(), exportedSymbols.end());
	
	fs::path	stub_exp(tmpdir / "__stub.exp"),
				stub_s(tmpdir / "__stub.s"),
				stub_o(tmpdir / "__stub.o");

	{
		fs::ofstream expFile(stub_exp);
		fs::ofstream sFile(stub_s);
		sFile << "\t.toc\n";
		for(UInt32 i=0; i< nSymbols; i++)
		{
			string& sym = exportedSymbols[i].first;
			if(exportedSymbols[i].second == kPEFTVectorSymbol)
			{
				expFile << sym << endl;
				sFile << ".text" << endl;
				sFile << "\t.globl " << sym << endl;
				sFile << "\t.globl ." << sym << endl;
				sFile << "\t.csect " << sym << "[DS]" << endl;
				sFile << sym << ':' << endl;
				sFile << ".long ." << sym << ", TOC[tc0], 0" << endl;
				sFile << ".text" << endl;
				sFile << '.' << sym << ':' << endl;
				sFile << "\tblr" << endl;
			}
			else if(exportedSymbols[i].second == kPEFDataSymbol)
			{
				expFile << sym << endl;
				sFile << "\t.globl " << sym << endl;
				sFile << "\t.csect .data[RW],3" << endl;
				sFile << "\t.align 2" << endl;
				sFile << sym << ':' << endl;
				sFile << "\t.long\t42" << endl;
			}
		}
		
		//cerr << "Generating: " << name << " -> " << libname << endl;
		RunCommand("powerpc-apple-macos-as", std::vector<std::string> {
					   stub_s.string(), "-o", stub_o.string()
				   });
		RunCommand("powerpc-apple-macos-ld", std::vector<std::string> {
					   "-shared", "--no-check-sections", "-bexport:" + stub_exp.string(),
					   "-o", dest.string(), stub_o.string()
				   });
	}
}

void MakeImportLibraryMulti(fs::path path, fs::path libname)
{
	ResourceFile resFile(path.string());
	assert(resFile.read());

	std::vector<char> data(resFile.data.begin(), resFile.data.end());

	char *dataPtr = data.data();
	Resource& cfrgRes = resFile.resources.resources[ResRef("cfrg",0)];

	fs::path tmpdir = libname.parent_path() / fs::unique_path("makeimport-tmp-%%%%-%%%%-%%%%-%%%%");
	fs::create_directory(tmpdir);
	try
	{
		CFragResource *cfrg = (CFragResource *)cfrgRes.getData().data();
		eswap(cfrg);

		CFragResourceMember *member = &(cfrg -> firstMember);

		fs::path archiveTmp(tmpdir / "__archive.a");
		std::vector<string> arArguments { "cq", archiveTmp.string() };

		for(UInt16 i = 0; i < cfrg->memberCount; i++)
		{
			eswap(member);
			string membername =
				string(member->name+1, member->name+1+member->name[0]);

			if(member->architecture == 'pwpc'
				|| member->architecture == '\?\?\?\?')
			{
				if(member->usage == 0	/* import library */
					|| member->usage == 3 /* stub library */)
					;
				else if(member->usage == 4 /* weak stub library */)
					membername += "__weak";
				else
				{
					std::cerr << "Inappropriate usage flag: "
							  << (int)member->usage << endl;
					continue;
				}

				fs::path shlib_file(tmpdir / (membername + ".o"));
				MakeImportLibrary(dataPtr + member->offset, member->length,
									shlib_file, tmpdir);
				arArguments.push_back(shlib_file.string());
			}

			member = (CFragResourceMember*)  (((char*)member) + member->memberSize);
		}

		RunCommand("powerpc-apple-macos-ar", arArguments);
		fs::rename(archiveTmp, libname);
	}
	catch(...)
	{
		fs::remove_all(tmpdir);
		throw;
	}
	fs::remove_all(tmpdir);
}

int main (int argc, char * const argv[])
{
	//printf("%d\n",argc);
	if(argc != 3)
	{
		cerr << "Usage: makeimport <peflib> <libname>" << endl;
		return 1;
	}
	
	int fd = open(argv[1], O_RDONLY, 0);
	if(fd < 0)
	{
		perror(argv[1]);
		return 1;
	}
	
	MakeImportLibraryMulti(argv[1], argv[2]);

	close(fd);
    return 0;
}