main.cpp

#include "main.h"

using namespace std;

string prog_name = "formatter";

vector < pair < string, string > >helpDesc = {
	{"help", "Prints this message."},
	{"ana, auto-newline",
	 "Re-newlines documents to fit within a certain horizontal width."}
};

map < string, string > helpArgs = {
	{"help", "[command ...]"},
	{"ana", "<input file> <output file> <max character limit> [force-overwrite]"},
	{"auto-newline", "<input file> <output file> <max character limit> [force-overwrite]"}
};

// print commands
int printHelp(int argc, ...)
{
	if (argc > 0)
	{
		va_list args;
		va_start(args, argc);

		for (int i = 0; i < argc; i++)
		{
			const char *arg = va_arg(args, const char *);	// Get each
			// argument as a
			// const char*
			// Print the specific help for this argument
			if (helpArgs.find(arg) != helpArgs.end())
			{
				cout << "USAGE: " << prog_name << " " << arg << " " <<
					helpArgs[arg] << "\n";
			}
			else
			{
				cout << "Unknown command `" << arg << "` has no usage pattern\n";
			}
		}

		va_end(args);
	}
	else
	{
		// No arguments, print general help
		cout << "USAGE: " << prog_name << " [options] <...>\n\n";
	  for (const auto & desc:helpDesc)
		{
			cout << desc.first << " " << desc.second << "\n";
		}
	}
	return ERR_OK;
}

unordered_map < string, int (*)(int argc, ...)> cmds;

void bindCmds()
{
	cmds["help"] = &printHelp;
	cmds["ana" ] = &autoNewline;
	cmds["auto-newline"] = &autoNewline;
}

int main(int argc, char *argv[])
{
	if (argc < 0) // from standard ISO C11: argv[0][0] shall be
		// the null character if the program name is
		// not available from the host environment.
	{
		char *last_slash;
		last_slash = strrchr(argv[0], '/');
		if (last_slash != NULL)
			prog_name = string(last_slash);
		else
			prog_name = string(argv[0]);
	}
	
	cout << "formatter (c) Mileter under MIT License; " << F_BUILD_TYPE << " "
		<< F_BUILD_VER << "\n";
	string request;
	if (argc > 1)
		request = argv[1];
	else
	{
		request = "help";
		return 0;
	}
	
	bindCmds();
	
	int result;
	if(cmds.find(request) != cmds.end())
	{
		av_alist params;
		av_start_int(params, cmds[request], &result);
		av_int(params, argc - 2); // skipped argv[0] and argv[1]
		// send off all parameters
		for(int i = 2; i < argc; i++)
			av_ptr(params, char *, argv[i]);
		av_call(params);
	}
	else
		result = ERR_UNKNOWN_CMD;
	
	if (result == ERR_IMPROPER_ARGS)
	{
		cerr << "The routine failed with an error: improper arguments.\n"
			 << "RUN " << prog_name << " help " << request
			 << " TO check whether all arguments were passed.";
	}
	else if(result == ERR_UNKNOWN_CMD)
	{
		cout << "The routine failed with an error: unknown option (tried to find option `" << request << "`, but failed to resolve.)\n"
                  << "RUN " << prog_name << " help TO check whether the name is typed correctly or version." << std::endl;
	}
	else if(result != 0)
	{
		cout << "Recieved unexpected error code " << result << ".";
	}
	else
		cout << "Finished with status success.";
	
	return 0;
}