/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * This program 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 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

#include "common/util.h"
#include "common/system.h"
#include "common/events.h"
#include "common/hashmap.h"
#include "common/hash-str.h"

#include "gui/ThemeParser.h"

/**

<drawdata = "background_default" cache = true>
	<draw func = "roundedsq" fill = "gradient" gradient_start = "255, 255, 128" gradient_end = "128, 128, 128" size = "auto">
	<draw func = "roundedsq" fill = "none" color = "0, 0, 0" size = "auto">
</drawdata>

*/

namespace GUI {

inline bool isValidNameChar(char c) {
	return isalnum(c) || c == '_';
}

void ThemeParser::debug_testEval() {
	static const char *debug_config_text =
		"<drawdata id = \"background_default\" cache = true>"
		"<draw func = \"roundedsq\" /*/fill = \"gradient\" gradient_start = \"255, 255, 128\" gradient_end = \"128, 128, 128\" size = \"auto\"/>"
		"<draw func = \"roundedsq\" fill = \"none\" color = \"0, 0, 0\" size = \"auto\"/>"
		"</drawdata>/* lol this is just a simple test*/";

	_text = strdup(debug_config_text);
	parse();
}
	

void ThemeParser::parserError(const char *error_string) {
	_state = kParserError;
	printf("PARSER ERROR: %s\n", error_string);
}

void ThemeParser::parserCallback_DRAW() {
	printf("Draw callback!\n");
}

void ThemeParser::parserCallback_DRAWDATA() {
	printf("Drawdata callback!\n");
}

void ThemeParser::parseActiveKey(bool closed) {
	printf("Parsed key %s.\n", _activeKey.top().c_str());

	if (!_callbacks.contains(_activeKey.top())) {
		parserError("Unhandled value inside key.");
		return;
	}

	// Don't you just love C++ syntax? Water clear.
	(this->*(_callbacks[_activeKey.top()]))();

	for (Common::StringMap::const_iterator t = _keyValues.top().begin(); t != _keyValues.top().end(); ++t)
		printf("    Key %s = %s\n", t->_key.c_str(), t->_value.c_str());

	if (closed) {
		_keyValues.pop();
		_activeKey.pop();
	}
}

void ThemeParser::parseKeyValue(Common::String &key_name) {
	assert(_text[_pos++] == '=');
	assert(_keyValues.empty() == false);

	if (_keyValues.top().contains(key_name)) {
		parserError("Repeated value inside key.");
		return;
	}

	skipSpaces();

	Common::String data;
	char string_start;

	if (_text[_pos] == '"' || _text[_pos] == '\'') {
		string_start = _text[_pos++];

		while (_text[_pos] != string_start)
			data += _text[_pos++];

		_pos++;
	} else {
		while (isValidNameChar(_text[_pos]))
			data += _text[_pos++];
	}

	_keyValues.top()[key_name] = data;
}

bool ThemeParser::parse() {

	_state = kParserNeedKey;
	_pos = 0;
	_keyValues.clear();
	_activeKey.clear();
	
	while (_text[_pos]) {
		if (_state == kParserError)
			break;

		skipSpaces();

		if (skipComments())
			continue;

		switch (_state) {
			case kParserNeedKey:
				if (_text[_pos++] != '<') {
					parserError("Expecting key start.");
					break;
				}

				if (_text[_pos] == '/') {
					_pos++;
					_token.clear();
					while (isValidNameChar(_text[_pos]))
						_token += _text[_pos++];

					if (_activeKey.empty() || _token != _activeKey.top())
						parserError("Unexpected closure.");
					else {
						_activeKey.pop();
						_keyValues.pop();

						skipSpaces();

						if (_text[_pos++] != '>')
							parserError("Malformed tag closure.");
					}
	
					break;
				}

				_keyValues.push(Common::StringMap());
				_state = kParserNeedKeyName;
				break;

			case kParserNeedKeyName:
				_token.clear();
				while (isValidNameChar(_text[_pos]))
					_token += _text[_pos++];

				if (!isspace(_text[_pos]) && _text[_pos] != '>') {
					parserError("Invalid character in token name.");
					break;
				}

				_state = kParserNeedKeyValues;
				_activeKey.push(_token);
				break;

			case kParserNeedKeyValues:
				_token.clear();

				if ((_text[_pos] == '/' && _text[_pos + 1] == '>') || _text[_pos] == '>') {
					bool closed = _text[_pos] == '/';
					parseActiveKey(closed);
					_pos += closed ? 2 : 1;
					_state = kParserNeedKey;
					break;
				}

				while (isValidNameChar(_text[_pos]))
					_token += _text[_pos++];

				skipSpaces();

				if (_text[_pos] != '=') {
					parserError("Unexpected character after key name.");
					break;
				}

				parseKeyValue(_token);
				break;

			default:
				break;
		}
	}

	if (_state == kParserError) {
		return false;
	}

	if (_state != kParserNeedKey || !_activeKey.empty()) {
		parserError("Unexpected end of file.");
	}

	return true;
}

}