src/commandline.cpp

/*
	Copyright 2014 Teemu Piippo
	All rights reserved.

	Redistribution and use in source and binary forms, with or without
	modification, are permitted provided that the following conditions
	are met:

	1. Redistributions of source code must retain the above copyright
	   notice, this list of conditions and the following disclaimer.
	2. Redistributions in binary form must reproduce the above copyright
	   notice, this list of conditions and the following disclaimer in the
	   documentation and/or other materials provided with the distribution.
	3. The name of the author may not be used to endorse or promote products
	   derived from this software without specific prior written permission.

	THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include "commandline.h"

// _________________________________________________________________________________________________
//
CommandLine::~CommandLine()
{
	for (CommandLineOption* opt : _options)
		delete opt;
}

// _________________________________________________________________________________________________
//
StringList CommandLine::process (int const argc, char* argv[])
{
	StringList args;

	for (int argn = 1; argn < argc; ++argn)
	{
		String const arg (argv[argn]);

		if (arg == "--")
		{
			// terminating option - write everything to args and be done with it.
			while (++argn < argc)
				args << argv[argn];

			break;
		}

		if (arg[0] != '-' or arg[1] == '\0')
		{
			// non-option argument - pass to result
			args << arg;
			continue;
		}

		if (arg[1] != '-' and arg[1] != '\0')
		{
			// short-form options
			for (int i = 1; i < arg.length(); ++i)
			{
				CommandLineOption** optionptr = _options.find ([&](CommandLineOption* const& a)
				{
					return arg[i] == a->shortform();
				});

				if (not optionptr)
					error ("unknown option -%1", arg[i]);

				CommandLineOption* option = *optionptr;

				if (option->isOfType<bool>())
				{
					// Bool options need no parameters
					option->handleValue ("");
				}
				else
				{
					// Ensure we got a valid parameter coming up
					if (argn == argc - 1)
						error ("option -%1 requires a parameter", option->describe());

					if (i != arg.length() - 1)
					{
						error ("option %1 requires a parameter but has option -%2 stacked on",
							option->describe(), arg[i + 1]);
					}

					option->handleValue (argv[++argn]);
				}
			}
		}
		else
		{
			// long-form options
			String name, value;
			{
				int idx = arg.firstIndexOf ("=", 2);

				if (idx != -1)
				{
					name = arg.mid (2, idx);
					value = arg.mid (idx + 1);
				}
				else
				{
					name = arg.mid (2);
				}
			}

			CommandLineOption** optionptr = _options.find ([&](CommandLineOption* const& a)
			{
				return a->longform() == name;
			});

			if (not optionptr)
				error ("unknown option --%1", name);

			if ((*optionptr)->isOfType<bool>() and not value.isEmpty())
				error ("option %1 does not take a value", (*optionptr)->describe());
 
			(*optionptr)->handleValue (value);
		}
	}

	return args;
}

// _________________________________________________________________________________________________
//
String CommandLine::describeOptions() const
{
	StringList lines;

	for (CommandLineOption* option : _options)
	{
		String line ("  ");

		if (option->shortform() != '\0')
			line += String ({'-', option->shortform(), '\0'});
		else
			line += "  ";

		line += "  ";

		if (not option->longform().isEmpty())
		{
			line += "--" + option->longform();
			String description (option->describeArgument());

			if (not description.isEmpty())
				line += "=" + description;
		}

		lines << line;
	}

	int maxlength (0);

	for (String& line : lines)
		maxlength = max (maxlength, line.length());

	maxlength += 2;
	ASSERT_EQ (lines.size(), _options.size());

	for (int i = 0; i < lines.size(); ++i)
	{
		while (lines[i].length() < maxlength)
			lines[i] += " ";

		lines[i] += _options[i]->description();
	}

	StringList extralines;

	for (CommandLineOption* option : _options)
	{
		String extradata = option->describeExtra();

		if (not extradata.isEmpty())
		{
			if (extralines.isEmpty())
				extralines << "";

			extralines << extradata;
		}
	}

	lines.merge (extralines);
	String result (lines.join ("\n"));
	return result;
}

// _________________________________________________________________________________________________
//
void CommandLineOption::handleValue (const String& a)
{
	if (isOfType<bool>())
	{
		pointer().setValue (true);
	}
	elif (isOfType<int>())
	{
		bool ok;
		pointer().setValue (a.toLong (&ok));

		if (not ok)
			error ("bad integral value passed to %1", describe());
	}
	elif (isOfType<String>())
	{
		pointer().setValue (a);
	}
	elif (isOfType<double>())
	{
		bool ok;
		pointer().setValue (a.toDouble (&ok));

		if (not ok)
			error ("bad floating-point value passed to %1", describe());
	}
	else
	{
		error ("OMGWTFBBQ: %1 has an invalid type index", describe());
	}
}

// _________________________________________________________________________________________________
//
String CommandLineOption::describeArgument() const
{
	if (isOfType<int>())
		return "INTEGER";
	elif (isOfType<String>())
		return "STRING";
	elif (isOfType<double>())
		return "FLOAT";

	return "";
}