/*
** savegame.cpp
**
** common savegame utilities for all front ends.
** 
**---------------------------------------------------------------------------
** Copyright 2019 Christoph Oelckers
** 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 OFf
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/

#include "compositesaveame.h"
#include "savegamehelp.h"
#include "gstrings.h"
#include "i_specialpaths.h"
#include "cmdlib.h"
#include "filesystem.h"
#include "statistics.h"
#include "secrets.h"
#include "quotemgr.h"
#include "mapinfo.h"
#include "v_video.h"
#include "gamecontrol.h"
#include "m_argv.h"
#include "serializer.h"
#include "version.h"
#include "raze_music.h"
#include "raze_sound.h"
#include "gamestruct.h"
#include "automap.h"
#include "statusbar.h"
#include "gamestate.h"
#include "razemenu.h"
#include "interpolate.h"


sectortype sectorbackup[MAXSECTORS];
walltype wallbackup[MAXWALLS];

static CompositeSavegameWriter savewriter;
static FResourceFile *savereader;
void WriteSavePic(FileWriter* file, int width, int height);
extern FString BackupSaveGame;
void SerializeMap(FSerializer &arc);
FixedBitArray<MAXSPRITES> activeSprites;

CVAR(String, cl_savedir, "", CVAR_ARCHIVE|CVAR_GLOBALCONFIG)

//=============================================================================
//
//
//
//=============================================================================

static void SerializeGlobals(FSerializer& arc)
{
	if (arc.BeginObject("globals"))
	{
		arc("crouch_toggle", crouch_toggle)
		.EndObject();
	}
}

//=============================================================================
//
//
//
//=============================================================================

static void SerializeSession(FSerializer& arc)
{
	SerializeMap(arc);
	SerializeStatistics(arc);
	SECRET_Serialize(arc);
	Mus_Serialize(arc);
	quoteMgr.Serialize(arc);
	S_SerializeSounds(arc);
	SerializeAutomap(arc);
	SerializeHud(arc);
	SerializeGlobals(arc);
	gi->SerializeGameState(arc);
}

//=============================================================================
//
// This is for keeping my sanity while working with the horrible mess
// that is the savegame code in Duke Nukem.
// Without handling this in global variables it is a losing proposition
// to save custom data along with the regular snapshot. :(
// With this the savegame code can mostly pretend to load from and write
// to files while really using a composite archive.
//
// All global non-game dependent state is also saved right here for convenience.
//
//=============================================================================


bool OpenSaveGameForRead(const char *name)
{
	if (savereader) delete savereader;
	savereader = FResourceFile::OpenResourceFile(name, true, true);

	if (savereader != nullptr)
	{
		auto file = ReadSavegameChunk("info.json");
		if (!file.isOpen())
		{
			FinishSavegameRead();
			delete savereader;
			return false;
		}
		if (G_ValidateSavegame(file, nullptr, false) <= 0)
		{
			FinishSavegameRead();
			delete savereader;
			return false;
		}

		FResourceLump* info = savereader->FindLump("session.json");
		if (info == nullptr)
		{
			return false;
		}

		void* data = info->Lock();
		FSerializer arc;
		if (!arc.OpenReader((const char*)data, info->LumpSize))
		{
			info->Unlock();
			return false;
		}
		info->Unlock();

		// Load system-side data from savegames.
		loadMapBackup(currentLevel->fileName);
		SerializeSession(arc);
	}
	return savereader != nullptr;
}

FileWriter *WriteSavegameChunk(const char *name)
{
	return &savewriter.NewElement(name);
}

void AddCompressedSavegameChunk(const char* name, FCompressedBuffer& buffer)
{
	savewriter.AddCompressedElement(name, buffer);
}

FileReader ReadSavegameChunk(const char *name)
{
	if (!savereader) return FileReader();
	auto lump = savereader->FindLump(name);
	if (!lump) return FileReader();
	return lump->NewReader();
}

bool FinishSavegameWrite()
{
	return savewriter.WriteToFile();
}

void FinishSavegameRead()
{
	delete savereader;
	savereader = nullptr;
}

CVAR(Bool, save_formatted, false, 0)	// should be set to false once the conversion is done

//=============================================================================
//
// Creates the savegame and writes all cross-game content.
//
//=============================================================================

bool OpenSaveGameForWrite(const char* filename, const char *name)
{
	savewriter.Clear();
	savewriter.SetFileName(filename);

	FSerializer savegameinfo;		// this is for displayable info about the savegame.
	FSerializer savegamesession;	// saved game session settings.
	FSerializer savegameengine;		// saved play state.

	savegameinfo.OpenWriter(true);
	savegameengine.OpenWriter(save_formatted);

	char buf[100];
	mysnprintf(buf, countof(buf), GAMENAME " %s", GetVersionString());
	auto savesig = gi->GetSaveSig();
	auto gs = gi->getStats();
	FStringf timeStr("%02d:%02d", gs.timesecnd / 60, gs.timesecnd % 60);
	auto lev = currentLevel;

	savegameinfo.AddString("Software", buf)
		("Save Version", savesig.currentsavever)
		.AddString("Engine", savesig.savesig)
		.AddString("Game Resource", fileSystem.GetResourceFileName(1))
		.AddString("Map Name", lev->DisplayName())
		.AddString("Creation Time", myasctime())
		.AddString("Title", name)
		.AddString("Map File", lev->fileName)
		.AddString("Map Label", lev->labelName)
		.AddString("Map Time", timeStr);

	const char *fn = currentLevel->fileName;
	if (*fn == '/') fn++;
	if (strncmp(fn, "file://", 7) != 0) // this only has meaning for non-usermaps
	{
		auto fileno = fileSystem.FindFile(fn);
		auto mapfile = fileSystem.GetFileContainer(fileno);
		auto mapcname = fileSystem.GetResourceFileName(mapfile);
		if (mapcname) savegameinfo.AddString("Map Resource", mapcname);
		else
		{
			savewriter.Clear();
			return false; // this should never happen. Saving on a map that isn't present is impossible.
		}
	}

	auto buff = savegameinfo.GetCompressedOutput();
	AddCompressedSavegameChunk("info.json", buff);


	// Handle system-side modules that need to persist data in savegames here, in a central place.
	savegamesession.OpenWriter(save_formatted);
	SerializeSession(savegamesession);
	buff = savegamesession.GetCompressedOutput();
	AddCompressedSavegameChunk("session.json", buff);

	auto picfile = WriteSavegameChunk("savepic.png");
	WriteSavePic(picfile, 240, 180);
	mysnprintf(buf, countof(buf), GAMENAME " %s", GetVersionString());
	// put some basic info into the PNG so that this isn't lost when the image gets extracted.
	M_AppendPNGText(picfile, "Software", buf);
	M_AppendPNGText(picfile, "Title", name);
	M_AppendPNGText(picfile, "Current Map", lev->labelName);
	M_FinishPNG(picfile);

	return true;
}

//=============================================================================
//
//
//
//=============================================================================

static bool CheckSingleFile (const char *name, bool &printRequires, bool printwarn)
{
	if (name == NULL)
	{
		return true;
	}
	if (strncmp(name, "file://", 7) == 0)
	{
		return FileExists(name + 7);	// User maps  must be present to be validated.
	}
	if (fileSystem.CheckIfResourceFileLoaded(name) < 0)
	{
		if (printwarn)
		{
			if (!printRequires)
			{
				Printf ("%s:\n%s", GStrings("TXT_SAVEGAMENEEDS"), name);
			}
			else
			{
				Printf (", %s", name);
			}
		}
		printRequires = true;
		return false;
	}
	return true;
}

//=============================================================================
//
// Return false if not all the needed wads have been loaded.
//
//=============================================================================

static bool G_CheckSaveGameWads (const char *gamegrp, const char *mapgrp, bool printwarn)
{
	bool printRequires = false;
	CheckSingleFile (gamegrp, printRequires, printwarn);
	CheckSingleFile (mapgrp, printRequires, printwarn);

	if (printRequires)
	{
		if (printwarn)
		{
			Printf ("\n");
		}
		return false;
	}

	return true;
}

//=============================================================================
//
// Checks if the savegame is valid. Gets a reader to the included info.json
// Returns 1 if valid, 0 if invalid and -1 if old and -2 if content missing
//
//=============================================================================

int G_ValidateSavegame(FileReader &fr, FString *savetitle, bool formenu)
{
	auto data = fr.Read();
	FSerializer arc;
	if (!arc.OpenReader((const char*)data.Data(), data.Size()))
	{
		return -2;
	}

	int savever;
	FString engine, gamegrp, mapgrp, title, filename, label;

	arc("Save Version", savever)
		("Engine", engine)
		("Game Resource", gamegrp)
		("Map Resource", mapgrp)
		("Title", title)
		("Map Label", label)
		("Map File", filename);

	auto savesig = gi->GetSaveSig();

	if (savetitle) *savetitle = title;
	if (engine.Compare(savesig.savesig) != 0 || savever > savesig.currentsavever)
	{
		// different engine or newer version:
		// not our business. Leave it alone.
		return 0;
	}

	MapRecord *curLevel = FindMapByName(label);

	// If the map does not exist, check if it's a user map.
	if (!curLevel)
	{
		curLevel = AllocateMap();
		if (!formenu)
		{
			curLevel->name = "";
			curLevel->SetFileName(filename);
		}
	}
	if (!curLevel) return 0;
	if (!formenu) currentLevel = curLevel;
		

	if (savever < savesig.minsavever)
	{
		// old, incompatible savegame. List as not usable.
		return -1;
	}
	else
	{
		auto ggfn = ExtractFileBase(fileSystem.GetResourceFileName(1), true);
		if (gamegrp.CompareNoCase(ggfn) == 0)
		{
			return G_CheckSaveGameWads(gamegrp, mapgrp, false) ? 1 : -2;
		}
		else
		{
			// different game. Skip this.
			return 0;
		}
	}
	return 0;
}

//=============================================================================
//
//
//
//=============================================================================

FString G_BuildSaveName (const char *prefix)
{
	FString name;
	bool usefilter;

	if (const char *const dir = Args->CheckValue("-savedir"))
	{
		name = dir;
		usefilter = false;
	}
	else
	{
		name = **cl_savedir ? cl_savedir : M_GetSavegamesPath();
		usefilter = true;
	}

	const size_t len = name.Len();
	if (len > 0)
	{
		name.Substitute("\\", "/");
		if (name[len - 1] != '/')
			name << '/';
	}

	if (usefilter)
		name << LumpFilter << '/';

	CreatePath(name);

	name << prefix;
	if (!strchr(prefix, '.')) name << SAVEGAME_EXT; // only add an extension if the prefix doesn't have one already.
	name = NicePath(name);
	name.Substitute("\\", "/");
	return name;
}

#include "build.h"
#include "mmulti.h"

static const int magic = 0xbeefcafe;
void WriteMagic(FileWriter *fw)
{
	fw->Write(&magic, 4);
}

void CheckMagic(FileReader& fr)
{
	int m = 0;
	fr.Read(&m, 4);
	assert(m == magic);
#ifndef _DEBUG
	if (m != magic)  I_Error("Savegame corrupt");
#endif
}


#define V(x) x
static spritetype zsp;
static spriteext_t zspx;

FSerializer &Serialize(FSerializer &arc, const char *key, spritetype &c, spritetype *def)
{
	def = &zsp; // always delta against 0
	if (arc.BeginObject(key))
	{
		arc("x", c.x, def->x)
			("y", c.y, def->y)
			("z", c.z, def->z)
			("cstat", c.cstat, def->cstat)
			("picnum", c.picnum, def->picnum)
			("shade", c.shade, def->shade)
			("pal", c.pal, def->pal)
			("clipdist", c.clipdist, def->clipdist)
			("blend", c.blend, def->blend)
			("xrepeat", c.xrepeat, def->xrepeat)
			("yrepeat", c.yrepeat, def->yrepeat)
			("xoffset", c.xoffset, def->xoffset)
			("yoffset", c.yoffset, def->yoffset)
			("statnum", c.statnum)
			("sectnum", c.sectnum)
			("ang", c.ang, def->ang)
			("owner", c.owner, def->owner)
			("xvel", c.xvel, def->xvel)
			("yvel", c.yvel, def->yvel)
			("zvel", c.zvel, def->zvel)
			("lotag", c.lotag, def->lotag)
			("hitag", c.hitag, def->hitag)
			("extra", c.extra, def->extra)
			("detail", c.detail, def->detail)
			.EndObject();
	}
	return arc;
}

FSerializer& Serialize(FSerializer& arc, const char* key, spriteext_t& c, spriteext_t* def)
{
	if (arc.isWriting() && c.mdanimtims)
	{
		c.mdanimtims -= mdtims;
		if (c.mdanimtims == 0) c.mdanimtims++;
	}

	def = &zspx; // always delta against 0
	if (arc.BeginObject(key))
	{
		arc("mdanimtims", c.mdanimtims, def->mdanimtims)
			("mdanimcur", c.mdanimcur, def->mdanimcur)
			("angoff", c.angoff, def->angoff)
			("pitch", c.pitch, def->pitch)
			("roll", c.roll, def->roll)
			("pivot_offset", c.pivot_offset, def->pivot_offset)
			("position_offset", c.position_offset, def->position_offset)
			("flags", c.flags, def->flags)
			("alpha", c.alpha, def->alpha)
			.EndObject();
	}

	if (c.mdanimtims) c.mdanimtims += mdtims;
	return arc;
}

FSerializer &Serialize(FSerializer &arc, const char *key, sectortype &c, sectortype *def)
{
	if (arc.BeginObject(key))
	{
		arc("wallptr", c.wallptr, def->wallptr)
			("wallnum", c.wallnum, def->wallnum)
			("ceilingz", c.ceilingz, def->ceilingz)
			("floorz", c.floorz, def->floorz)
			("ceilingstat", c.ceilingstat, def->ceilingstat)
			("floorstat", c.floorstat, def->floorstat)
			("ceilingpicnum", c.ceilingpicnum, def->ceilingpicnum)
			("ceilingheinum", c.ceilingheinum, def->ceilingheinum)
			("ceilingshade", c.ceilingshade, def->ceilingshade)
			("ceilingpal", c.ceilingpal, def->ceilingpal)
			("ceilingxpanning", c.ceilingxpan_, def->ceilingxpan_)
			("ceilingypanning", c.ceilingypan_, def->ceilingypan_)
			("floorpicnum", c.floorpicnum, def->floorpicnum)
			("floorheinum", c.floorheinum, def->floorheinum)
			("floorshade", c.floorshade, def->floorshade)
			("floorpal", c.floorpal, def->floorpal)
			("floorxpanning", c.floorxpan_, def->floorxpan_)
			("floorypanning", c.floorypan_, def->floorypan_)
			("visibility", c.visibility, def->visibility)
			("fogpal", c.fogpal, def->fogpal)
			("lotag", c.lotag, def->lotag)
			("hitag", c.hitag, def->hitag)
			("extra", c.extra, def->extra)
			.EndObject();
	}
	return arc;
}

FSerializer &Serialize(FSerializer &arc, const char *key, walltype &c, walltype *def)
{
	if (arc.BeginObject(key))
	{
		arc("x", c.x, def->x)
			("y", c.y, def->y)
			("point2", c.point2, def->point2)
			("nextwall", c.nextwall, def->nextwall)
			("nextsector", c.nextsector, def->nextsector)
			("cstat", c.cstat, def->cstat)
			("picnum", c.picnum, def->picnum)
			("overpicnum", c.overpicnum, def->overpicnum)
			("shade", c.shade, def->shade)
			("pal", c.pal, def->pal)
			("xrepeat", c.xrepeat, def->xrepeat)
			("yrepeat", c.yrepeat, def->yrepeat)
			("xpanning", c.xpan_, def->xpan_)
			("ypanning", c.ypan_, def->ypan_)
			("lotag", c.lotag, def->lotag)
			("hitag", c.hitag, def->hitag)
			("extra", c.extra, def->extra)
			.EndObject();
	}
	return arc;
}


void SerializeMap(FSerializer& arc)
{
	// create a map of all used sprites so that we can use that elsewhere to only save what's needed.
	activeSprites.Zero();
	if (arc.isWriting())
	{
		for (int i=0; i<MAXSPRITES;i++)
		{
			if (sprite[i].statnum != MAXSTATUS)
			{
				activeSprites.Set(i);
			}
		}
		// simplify the data a bit for better compression. 
		for (int i = 0; i < MAXSPRITES; i++)
		{
			if (nextspritestat[i] == i + 1) nextspritestat[i] = -2;
			if (nextspritesect[i] == i + 1) nextspritesect[i] = -2;
			if (prevspritestat[i] == i - 1) prevspritestat[i] = -2;
			if (prevspritesect[i] == i - 1) prevspritesect[i] = -2;
		}

	}
	else
	{
		memset(sprite, 0, sizeof(sprite[0]) * MAXSPRITES);
		initspritelists();
		zsp = sprite[0];
	}

	if (arc.BeginObject("engine"))
	{
		arc.SerializeMemory("activesprites", activeSprites.Storage(), activeSprites.StorageSize())
			.SparseArray("sprites", sprite, MAXSPRITES, activeSprites)
			.SparseArray("spriteext", spriteext, MAXSPRITES, activeSprites)
			("numsectors", numsectors)
			.Array("sectors", sector, sectorbackup, numsectors)
			("numwalls", numwalls)
			.Array("walls", wall, wallbackup, numwalls)
			.Array("headspritestat", headspritestat, MAXSTATUS + 1)
			.Array("nextspritestat", nextspritestat, MAXSPRITES)
			.Array("prevspritestat", prevspritestat, MAXSPRITES)
			.Array("headspritesect", headspritesect, MAXSECTORS + 1)
			.Array("nextspritesect", nextspritesect, MAXSPRITES)
			.Array("prevspritesect", prevspritesect, MAXSPRITES)

			("tailspritefree", tailspritefree)
			("myconnectindex", myconnectindex)
			("connecthead", connecthead)
			.Array("connectpoint2", connectpoint2, countof(connectpoint2))
			("randomseed", randomseed)
			("numshades", numshades)	// is this really needed?
			("visibility", g_visibility)
			("parallaxtype", parallaxtype)
			("parallaxvisibility", parallaxvisibility)
			("parallaxyo", parallaxyoffs_override)
			("parallaxys", parallaxyscale_override)
			("pskybits", pskybits_override)
			("numsprites", Numsprites)
			("gamesetinput", gamesetinput);

		SerializeInterpolations(arc);

		if (arc.BeginArray("picanm")) // write this in the most compact form available.
		{
			for (int i = 0; i < MAXTILES; i++)
			{
				arc(nullptr, picanm[i].sf)
					(nullptr, picanm[i].extra);
			}
			arc.EndArray();
		}

		arc.EndObject();
	}


	// Undo the simplification.
	for (int i = 0; i < MAXSPRITES; i++)
	{
		if (nextspritestat[i] == -2) nextspritestat[i] = i + 1;
		if (nextspritesect[i] == -2) nextspritesect[i] = i + 1;
		if (prevspritestat[i] == -2) prevspritestat[i] = i - 1;
		if (prevspritesect[i] == -2) prevspritesect[i] = i - 1;
	}
}

//=============================================================================
//
//
//
//=============================================================================

CVAR(Bool, saveloadconfirmation, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)

CVAR(Int, autosavenum, 0, CVAR_NOSET | CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
static int nextautosave = -1;
CVAR(Int, disableautosave, 0, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
CUSTOM_CVAR(Int, autosavecount, 4, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
{
	if (self < 1)
		self = 1;
}

CVAR(Int, quicksavenum, 0, CVAR_NOSET | CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
static int nextquicksave = -1;
 CUSTOM_CVAR(Int, quicksavecount, 4, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
{
	if (self < 1)
		self = 1;
}

 void DoLoadGame(const char* name)
 {
	 if (OpenSaveGameForRead(name))
	 {
		 if (gi->LoadGame())
		 {
			 gameaction = ga_level;
		 }
		 else
		 {
			 I_Error("%s: Failed to load savegame", name);
		 }
	 }
	 else
	 {
		 I_Error("%s: Failed to open savegame", name);
	 }
 }


 void G_LoadGame(const char *filename)
 {
	 inputState.ClearAllInput();
	 gi->FreeLevelData();
	 DoLoadGame(filename);
	 BackupSaveGame = filename;
 }

 void G_SaveGame(const char *fn, const char *desc, bool ok4q, bool forceq)
 {
	 if (OpenSaveGameForWrite(fn, desc))
	 {
		 if (gi->SaveGame() && FinishSavegameWrite())
		 {
			 savegameManager.NotifyNewSave(fn, desc, ok4q, forceq);
			 Printf(PRINT_NOTIFY, "%s\n", GStrings("GAME SAVED"));
			 BackupSaveGame = fn;
		 }
	 }
 }


void M_Autosave()
{
	if (disableautosave) return;
	if (!gi->CanSave()) return;
	FString description;
	FString file;
	// Keep a rotating sets of autosaves
	UCVarValue num;
	const char* readableTime;
	int count = autosavecount != 0 ? autosavecount : 1;

	if (nextautosave == -1)
	{
		nextautosave = (autosavenum + 1) % count;
	}

	num.Int = nextautosave;
	autosavenum.ForceSet(num, CVAR_Int);

	auto Filename = G_BuildSaveName(FStringf("auto%04d", nextautosave));
	readableTime = myasctime();
	FStringf SaveTitle("Autosave %s", readableTime);
	nextautosave = (nextautosave + 1) % count;
	G_SaveGame(Filename, SaveTitle, false, false);
}

CCMD(autosave)
{
	gameaction = ga_autosave;
}

CCMD(rotatingquicksave)
{
	if (!gi->CanSave()) return;
	FString description;
	FString file;
	// Keep a rotating sets of quicksaves
	UCVarValue num;
	const char* readableTime;
	int count = quicksavecount != 0 ? quicksavecount : 1;

	if (nextquicksave == -1)
	{
		nextquicksave = (quicksavenum + 1) % count;
	}

	num.Int = nextquicksave;
	quicksavenum.ForceSet(num, CVAR_Int);

	FSaveGameNode sg;
	auto Filename = G_BuildSaveName(FStringf("quick%04d", nextquicksave));
	readableTime = myasctime();
	FStringf SaveTitle("Quicksave %s", readableTime);
	nextquicksave = (nextquicksave + 1) % count;
	G_SaveGame(Filename, SaveTitle, false, false);
}