/*
 * This file is part of OpenTTD.
 * OpenTTD 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.
 * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file misc.cpp Misc functions that shouldn't be here. */

#include "stdafx.h"
#include "landscape.h"
#include "news_func.h"
#include "ai/ai.hpp"
#include "script/script_gui.h"
#include "newgrf.h"
#include "newgrf_house.h"
#include "economy_func.h"
#include "timer/timer_game_calendar.h"
#include "timer/timer_game_tick.h"
#include "texteff.hpp"
#include "gfx_func.h"
#include "gamelog.h"
#include "animated_tile_func.h"
#include "tilehighlight_func.h"
#include "network/network_func.h"
#include "window_func.h"
#include "core/pool_type.hpp"
#include "game/game.hpp"
#include "linkgraph/linkgraphschedule.h"
#include "station_kdtree.h"
#include "town_kdtree.h"
#include "viewport_kdtree.h"
#include "newgrf_profiling.h"
#include "3rdparty/md5/md5.h"

#include "safeguards.h"

std::string _savegame_id; ///< Unique ID of the current savegame.

extern TileIndex _cur_tileloop_tile;
extern void MakeNewgameSettingsLive();

void InitializeSound();
void InitializeMusic();
void InitializeVehicles();
void InitializeRailGui();
void InitializeRoadGui();
void InitializeAirportGui();
void InitializeDockGui();
void InitializeGraphGui();
void InitializeObjectGui();
void InitializeTownGui();
void InitializeIndustries();
void InitializeObjects();
void InitializeTrees();
void InitializeCompanies();
void InitializeCheats();
void InitializeNPF();
void InitializeOldNames();

/**
 * Generate an unique ID.
 *
 * It isn't as much of an unique ID as we would like, but our random generator
 * can only produce 32bit random numbers.
 * That is why we combine InteractiveRandom with the current (steady) clock.
 * The first to add a bit of randomness, the second to ensure you can't get
 * the same unique ID when you run it twice from the same state at different
 * times.
 *
 * This makes it unlikely that two users generate the same ID for different
 * subjects. But as this is not an UUID, so it can't be ruled out either.
 */
std::string GenerateUid(std::string_view subject)
{
	auto current_time = std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::steady_clock::now().time_since_epoch()).count();
	std::string coding_string = fmt::format("{}{}{}", InteractiveRandom(), current_time, subject);

	Md5 checksum;
	uint8 digest[16];
	checksum.Append(coding_string.c_str(), coding_string.length());
	checksum.Finish(digest);

	return MD5SumToString(digest);
}

/**
 * Generate an unique savegame ID.
 */
void GenerateSavegameId()
{
	_savegame_id = GenerateUid("OpenTTD Savegame ID");
}

void InitializeGame(uint size_x, uint size_y, bool reset_date, bool reset_settings)
{
	/* Make sure there isn't any window that can influence anything
	 * related to the new game we're about to start/load. */
	UnInitWindowSystem();

	Map::Allocate(size_x, size_y);

	_pause_mode = PM_UNPAUSED;
	_game_speed = 100;
	TimerGameTick::counter = 0;
	_cur_tileloop_tile = 1;
	_thd.redsq = INVALID_TILE;
	if (reset_settings) MakeNewgameSettingsLive();

	_newgrf_profilers.clear();

	if (reset_date) {
		TimerGameCalendar::SetDate(TimerGameCalendar::ConvertYMDToDate(_settings_game.game_creation.starting_year, 0, 1), 0);
		InitializeOldNames();
	}

	LinkGraphSchedule::Clear();
	PoolBase::Clean(PT_NORMAL);

	RebuildStationKdtree();
	RebuildTownKdtree();
	RebuildViewportKdtree();

	ResetPersistentNewGRFData();

	InitializeSound();
	InitializeMusic();

	InitializeVehicles();

	InitNewsItemStructs();
	InitializeLandscape();
	InitializeRailGui();
	InitializeRoadGui();
	InitializeAirportGui();
	InitializeDockGui();
	InitializeGraphGui();
	InitializeObjectGui();
	InitializeTownGui();
	InitializeScriptGui();
	InitializeTrees();
	InitializeIndustries();
	InitializeObjects();
	InitializeBuildingCounts();

	InitializeNPF();

	InitializeCompanies();
	AI::Initialize();
	Game::Initialize();
	InitializeCheats();

	InitTextEffects();
	NetworkInitChatMessage();
	InitializeAnimatedTiles();

	InitializeEconomy();

	ResetObjectToPlace();

	_gamelog.Reset();
	_gamelog.StartAction(GLAT_START);
	_gamelog.Revision();
	_gamelog.Mode();
	_gamelog.GRFAddList(_grfconfig);
	_gamelog.StopAction();
}