/**
 * EQEmulator: Everquest Server Emulator
 * Copyright (C) 2001-2019 EQEmulator Development Team (https://github.com/EQEmu/Server)
 *
 * 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; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY except by those people which sell it, which
 * are required to give you total support for your newly bought product;
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */

#include "../common/global_define.h"
#include "../common/eqemu_logsys.h"
#include "config.h"

/**
 * Retrieves the variable we want from our title or theme
 * First gets the map from the title, then gets the argument from the map we got from title
 *
 * @param title
 * @param parameter
 * @return
 */
std::string Config::GetVariable(std::string title, std::string parameter)
{
	std::map<std::string, std::map<std::string, std::string> >::iterator iter = vars.find(title);
	if (iter != vars.end()) {
		std::map<std::string, std::string>::iterator arg_iter = iter->second.find(parameter);
		if (arg_iter != iter->second.end()) {
			return arg_iter->second;
		}
	}

	return std::string("");
}

/**
 * Opens a file and passes it to the tokenizer
 * Then it parses the tokens returned and puts them into titles and variables
 *
 * @param file_name
 */
void Config::Parse(const char *file_name)
{
	if (file_name == nullptr) {
		Error("Config::Parse(), file_name passed was null");
		return;
	}

	vars.clear();
	FILE *input = fopen(file_name, "r");
	if (input) {
		std::list<std::string> tokens;
		Tokenize(input, tokens);

		char        mode = 0;
		std::string title, param, arg;

		std::list<std::string>::iterator iter = tokens.begin();
		while (iter != tokens.end()) {
			if ((*iter).compare("[") == 0) {
				title.clear();
				bool first = true;
				++iter;
				if (iter == tokens.end()) {
					Error("Config::Parse(), EOF before title done parsing");
					fclose(input);
					vars.clear();
					return;
				}

				while ((*iter).compare("]") != 0 && iter != tokens.end()) {
					if (!first) {
						title += " ";
					}
					else {
						first = false;
					}

					title += (*iter);
					++iter;
				}
				++iter;
			}

			if (mode == 0) {
				param = (*iter);
				mode++;
			}
			else if (mode == 1) {
				mode++;
				if ((*iter).compare("=") != 0) {
					Error("Config::Parse(), invalid parse token where = should be");
					fclose(input);
					vars.clear();
					return;
				}
			}
			else {
				arg  = (*iter);
				mode = 0;
				std::map<std::string, std::map<std::string, std::string> >::iterator map_iter = vars.find(title);
				if (map_iter != vars.end()) {
					map_iter->second[param] = arg;
					vars[title]             = map_iter->second;
				}
				else {
					std::map<std::string, std::string> var_map;
					var_map[param] = arg;
					vars[title]    = var_map;
				}
			}
			++iter;
		}
		fclose(input);
	}
	else {
		Error("Config::Parse(), file was unable to be opened for parsing");
	}
}

/**
 * Pretty basic lexical analyzer
 * Breaks up the input character stream into tokens and puts them into the list provided
 * Ignores # as a line comment
 *
 * @param input
 * @param tokens
 */
void Config::Tokenize(FILE *input, std::list<std::string> &tokens)
{
	auto        c = fgetc(input);
	std::string lexeme;

	while (c != EOF) {
		if (isspace(c)) {
			if (lexeme.size() > 0) {
				tokens.push_back(lexeme);
				lexeme.clear();
			}
			c = fgetc(input);
			continue;
		}

		if (isalnum(c)) {
			lexeme += c;
			c = fgetc(input);
			continue;
		}

		switch (c) {
			case '#': {
				if (lexeme.size() > 0) {
					tokens.push_back(lexeme);
					lexeme.clear();
				}

				while (c != '\n' && c != EOF) {
					c = fgetc(input);
				}
				break;
			}
			case '[':
			case ']':
			case '=': {
				if (lexeme.size() > 0) {
					tokens.push_back(lexeme);
					lexeme.clear();
				}

				lexeme += c;
				tokens.push_back(lexeme);
				lexeme.clear();
				break;
			}
			default: {
				lexeme += c;
			}
		}

		c = fgetc(input);
	}

	if (lexeme.size() > 0) {
		tokens.push_back(lexeme);
	}
}