/* -*- C++ -*-
 * Copyright ©2004 Hugo Mills <hugo@carfax.org.uk>
 *
 * This software is distributed under the terms of the GNU GPL v3
 * For more information on the GPL, see the file COPYING or 
 * visit http://www.gnu.org/
 *
 * This software is distributed without warranty
 */

#include "magellan/configlexer.h"
#include "magellan/options.h"

ConfigLexer* lex;

ConfigLexer* ConfigLexer::next(void)
{
//	std::cerr << "NEXT" << std::endl;
	while(true)
	{
		char ch = input->get();

		if(input->eof())
		{
			if(parsestate != WS)
				throw UnexpectedEOF();
			currentvalue.first = END;
			if(opts->debug_lexer() >= 1)
				std::cerr << "Lexer: next value "
						  << currentvalue.second << std::endl;
			return this;
		}

		// Keep track of the line numbers
		if(ch == 10)
			line++;

		switch(parsestate)
		{
		case WS:
			// More white space
			if(isspace(ch))
			{
				break;
			}
			// Comment handling
			if(ch == '#')
			{
				parsestate = PERLCOMMENT;
				break;
			}
			if(ch == '/')
			{
				parsestate = POSSCOMMENT;
				currentvalue.first = CHAR;
				currentvalue.second += ch;
				break;
			}
			// Quoted strings
			if(ch == '"')
			{
				parsestate = QUOTEDSTRING;
				currentvalue.first = STRING;
				currentvalue.second = "";
				break;
			}
			// Numbers
			if(isdigit(ch) || ch == '-' || ch == '+')
			{
				parsestate = NUMBER;
				currentvalue.first = INTEGER;
				currentvalue.second = ch;
				break;
			}
			// Unquoted strings/tokens
			if(ch == '_' || isalpha(ch))
			{
				parsestate = TEXT;
				currentvalue.first = TOKEN;
				currentvalue.second = ch;
				break;
			}
			currentvalue.first = CHAR;
			currentvalue.second = ch;
			if(opts->debug_lexer() >= 1)
				std::cerr << "Lexer: next value "
						  << currentvalue.second << std::endl;
			return this;
			break;
		case PERLCOMMENT:
		case CPPCOMMENT:
			if(ch == 10)
				parsestate = WS;
			break;
		case POSSCOMMENT:
			if(ch == '*')
				parsestate = CCOMMENT;
			else if(ch == '/')
			{
				currentvalue.second = "";
				parsestate = CPPCOMMENT;
			}
			else
			{
				parsestate = WS;
				input->unget();
                // We've already got something in the result string,
				// so keep this one for the "next token" request
				if(opts->debug_lexer() >= 1)
					std::cerr << "Lexer: next value "
							  << currentvalue.second << std::endl;
				return this;
			}
			break;
		case CCOMMENT:
			if(ch == '*')
				parsestate = POSSCOMMENTEND;
			break;
		case POSSCOMMENTEND:
			if(ch == '/')
				parsestate = WS;
			else
				parsestate = CCOMMENT;
			break;
		case TEXT:
			if(ch == '_' || ch == '-' || isalnum(ch))
				currentvalue.second += ch;
			else
			{
				parsestate = WS;
				input->unget();
				if(opts->debug_lexer() >= 1)
					std::cerr << "Lexer: next value "
							  << currentvalue.second << std::endl;
				return this;
			}
			break;
		case QUOTEDSTRING:
			if(ch == '"')
			{
				parsestate = WS;
				if(opts->debug_lexer() >= 1)
					std::cerr << "Lexer: next value "
							  << currentvalue.second << std::endl;
				return this;
			}
			currentvalue.second += ch;
			break;
		case NUMBER:
			if(ch == '.')
			{
				currentvalue.first = FLOAT;
				currentvalue.second += ch;
				parsestate = DECIMAL;
				break;
			}
			// No break here
		case DECIMAL:
			if(isdigit(ch))
				currentvalue.second += ch;
			else
			{
				parsestate = WS;
				input->unget();
				if(opts->debug_lexer() >= 1)
					std::cerr << "Lexer: next value "
							  << currentvalue.second << std::endl;
				return this;
			}
			break;
		}
	}
}

bool ConfigLexer::eos(void)
{
// 	std::cerr << "EOS: " << type() << " (" << CHAR << ")   "
// 			  << value() << std::endl;
	bool rv = (type() == CHAR && value() == "}");
	return rv;
}

ConfigLexer* ConfigLexer::section_next(void)
{
	while(!eos())
		next();
	next();
	return this;
}

ConfigLexer* ConfigLexer::directive_next(void)
{
	while(!(type() == CHAR && value() == ";"))
		next();
	next();
	return this;
}