/**

 * vim: set ts=4 :

 * =============================================================================

 * SourceMod

 * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.

 * =============================================================================

 *

 * This program is free software; you can redistribute it and/or modify it under

 * the terms of the GNU General Public License, version 3.0, as published by the

 * Free Software Foundation.

 * 

 * 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, see <http://www.gnu.org/licenses/>.

 *

 * As a special exception, AlliedModders LLC gives you permission to link the

 * code of this program (as well as its derivative works) to "Half-Life 2," the

 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

 * by the Valve Corporation.  You must obey the GNU General Public License in

 * all respects for all other code used.  Additionally, AlliedModders LLC grants

 * this exception to all derivative works.  AlliedModders LLC defines further

 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

 * or <http://www.sourcemod.net/license.php>.

 *

 * Version: $Id$

 */

#include <sh_list.h>

#include <sm_trie_tpl.h>

#include "common_logic.h"

#include "CellArray.h"

#include <IGameHelpers.h>

#include <ILibrarySys.h>

#include <ITextParsers.h>

#include <ISourceMod.h>

#include "stringutil.h"

using namespace SourceHook;

struct maplist_info_t

{

	bool bIsCompat;

	bool bIsPath;

	char name[PLATFORM_MAX_PATH];

	char path[PLATFORM_MAX_PATH];

	time_t last_modified_time;

	CellArray *pArray;

	int serial;

};

#define MAPLIST_FLAG_MAPSFOLDER		(1<<0)		/**< On failure, use all maps in the maps folder. */

#define MAPLIST_FLAG_CLEARARRAY		(1<<1)		/**< If an input array is specified, clear it before adding. */

#define MAPLIST_FLAG_NO_DEFAULT		(1<<2)		/**< Do not read "default" or "mapcyclefile" on failure. */

class MapLists : public SMGlobalClass, public ITextListener_SMC

{

public:

	enum MapListState

	{

		MPS_NONE,

		MPS_GLOBAL,

		MPS_MAPLIST,

	};

public:

	MapLists()

	{

		m_pMapCycleFile = NULL;

		m_ConfigLastChanged = 0;

		m_nSerialChange = 0;

	}

	void OnSourceModAllInitialized()

	{

		g_pSM->BuildPath(Path_SM, m_ConfigFile, sizeof(m_ConfigFile), "configs/maplists.cfg");

	}

	void OnSourceModShutdown()

	{

		DumpCache(NULL);

	}

	void GetMapCycleFilePath(char *pBuffer, int maxlen)

	{

		const char *pEngineName = smcore.GetSourceEngineName();

		const char *pMapCycleFileName = m_pMapCycleFile ? smcore.GetCvarString(m_pMapCycleFile) : "mapcycle.txt";

		if (strcmp(pEngineName, "tf2") == 0 || strcmp(pEngineName, "css") == 0

			|| strcmp(pEngineName, "dods") == 0 || strcmp(pEngineName, "hl2dm") == 0)

		{

			// These four games and Source SDK 2013 do a lookup in this order; so shall we.

			g_pSM->BuildPath(Path_Game,

				pBuffer,

				maxlen,

				"cfg/%s",

				pMapCycleFileName);

			if (!libsys->PathExists(pBuffer))

			{

				g_pSM->BuildPath(Path_Game,

					pBuffer,

					maxlen,

					"%s",

					pMapCycleFileName);

				if (!libsys->PathExists(pBuffer))

				{

					g_pSM->BuildPath(Path_Game,

						pBuffer,

						maxlen,

						"cfg/mapcycle_default.txt");

				}

			}

		}

		else

		{

			g_pSM->BuildPath(Path_Game,

				pBuffer,

				maxlen,

				"%s",

				pMapCycleFileName);

		}

	}

	void AddOrUpdateDefault(const char *name, const char *file)

	{

		char path[PLATFORM_MAX_PATH];

		maplist_info_t *pMapList, **ppMapList;

		if ((ppMapList = m_ListLookup.retrieve(name)) == NULL)

		{

			pMapList = new maplist_info_t;

			pMapList->bIsCompat = true;

			pMapList->bIsPath = true;

			pMapList->last_modified_time = 0;

			smcore.strncopy(pMapList->name, name, sizeof(pMapList->name));

			pMapList->pArray = NULL;

			g_pSM->BuildPath(Path_Game, pMapList->path, sizeof(pMapList->path), "%s", file);

			pMapList->serial = 0;

			m_ListLookup.insert(name, pMapList);

			m_MapLists.push_back(pMapList);

			return;

		}

		pMapList = *ppMapList;

		/* Don't modify if it's from the config file */

		if (!pMapList->bIsCompat)

		{

			return;

		}

		g_pSM->BuildPath(Path_Game, path, sizeof(path), "%s", file);

		/* If the path matches, don't reset the serial/time */

		if (strcmp(path, pMapList->path) == 0)

		{

			return;

		}

		smcore.strncopy(pMapList->path, path, sizeof(pMapList->path));

		pMapList->bIsPath = true;

		pMapList->last_modified_time = 0;

		pMapList->serial = 0;

	}

	void UpdateCache()

	{

		bool fileFound;

		SMCError error;

		time_t fileTime;

		SMCStates states = {0, 0};

		fileFound = libsys->FileTime(m_ConfigFile, FileTime_LastChange, &fileTime);

		/* If the file is found and hasn't changed, bail out now. */

		if (fileFound && fileTime == m_ConfigLastChanged)

		{

			return;

		}

		/* If the file wasn't found, and we already have entries, we bail out too. 

		 * This case lets us optimize when a user deletes the config file, so we 

		 * don't reparse every single time the function is called.

		 */

		if (!fileFound && m_MapLists.size() > 0)

		{

			return;

		}

		m_pMapCycleFile = smcore.FindConVar("mapcyclefile");

		/* Dump everything we know about. */

		List<maplist_info_t *> compat;

		DumpCache(&compat);

		/* All this is to add the default entry back in. */

		maplist_info_t *pDefList = new maplist_info_t;

		pDefList->bIsPath = true;

		smcore.strncopy(pDefList->name, "mapcyclefile", sizeof(pDefList->name));

		GetMapCycleFilePath(pDefList->path, sizeof(pDefList->path));

		pDefList->last_modified_time = 0;

		pDefList->pArray = NULL;

		pDefList->serial = 0;

		m_ListLookup.insert("mapcyclefile", pDefList);

		m_MapLists.push_back(pDefList);

		/* Now parse the config file even if we don't know about it.

		 * This will give us a nice error message.

		 */

		if ((error = textparser->ParseFile_SMC(m_ConfigFile, this, &states))

			!= SMCError_Okay)

		{

			const char *errmsg = textparser->GetSMCErrorString(error);

			if (errmsg == NULL)

			{

				errmsg = "Unknown error";

			}

			smcore.LogError("[SM] Could not parse file \"%s\"", m_ConfigFile);

			smcore.LogError("[SM] Error on line %d (col %d): %s", states.line, states.col, errmsg);

		}

		else

		{

			m_ConfigLastChanged = fileTime;

		}

		/* Now, re-add compat stuff back in if we can. */

		List<maplist_info_t *>::iterator iter = compat.begin();

		while (iter != compat.end())

		{

			if (m_ListLookup.retrieve((*iter)->name) != NULL)

			{

				/* The compatibility shim is no longer needed. */

				delete (*iter)->pArray;

				delete (*iter);

			}

			else

			{

				m_ListLookup.insert((*iter)->name, (*iter));

				m_MapLists.push_back((*iter));

			}

			iter = compat.erase(iter);

		}

	}

	void ReadSMC_ParseStart()

	{

		m_CurState = MPS_NONE;

		m_IgnoreLevel = 0;

		m_pCurMapList = NULL;

	}

	SMCResult ReadSMC_NewSection(const SMCStates *states, const char *name)

	{

		if (m_IgnoreLevel)

		{

			m_IgnoreLevel++;

			return SMCResult_Continue;

		}

		if (m_CurState == MPS_NONE)

		{

			if (strcmp(name, "MapLists") == 0)

			{

				m_CurState = MPS_GLOBAL;

			}

			else

			{

				m_IgnoreLevel = 1;

			}

		}

		else if (m_CurState == MPS_GLOBAL)

		{

			m_pCurMapList = new maplist_info_t;

			memset(m_pCurMapList, 0, sizeof(maplist_info_t));

			smcore.strncopy(m_pCurMapList->name, name, sizeof(m_pCurMapList->name));

			m_CurState = MPS_MAPLIST;

		}

		else if (m_CurState == MPS_MAPLIST)

		{

			m_IgnoreLevel++;

		}

		return SMCResult_Continue;

	}

	SMCResult ReadSMC_KeyValue(const SMCStates *states, const char *key, const char *value)

	{

		if (m_IgnoreLevel || m_pCurMapList == NULL)

		{

			return SMCResult_Continue;

		}

		if (strcmp(key, "file") == 0)

		{

			g_pSM->BuildPath(Path_Game, 

				m_pCurMapList->path,

				sizeof(m_pCurMapList->path),

				"%s",

				value);

			m_pCurMapList->bIsPath = true;

		}

		else if (strcmp(key, "target") == 0)

		{

			smcore.strncopy(m_pCurMapList->path, value, sizeof(m_pCurMapList->path));

			m_pCurMapList->bIsPath = false;

		}

		return SMCResult_Continue;

	}

	SMCResult ReadSMC_LeavingSection(const SMCStates *states)

	{

		if (m_IgnoreLevel)

		{

			m_IgnoreLevel--;

			return SMCResult_Continue;

		}

		if (m_CurState == MPS_MAPLIST)

		{

			if (m_pCurMapList != NULL

				&& m_pCurMapList->path[0] != '\0'

				&& m_ListLookup.retrieve(m_pCurMapList->name) == NULL)

			{

				m_ListLookup.insert(m_pCurMapList->name, m_pCurMapList);

				m_MapLists.push_back(m_pCurMapList);

				m_pCurMapList = NULL;

			}

			else

			{

				delete m_pCurMapList;

				m_pCurMapList = NULL;

			}

			m_CurState = MPS_GLOBAL;

		}

		else if (m_CurState == MPS_GLOBAL)

		{

			m_CurState = MPS_NONE;

		}

		return SMCResult_Continue;

	}

	void ReadSMC_ParseEnd(bool halted, bool failed)

	{

		delete m_pCurMapList;

		m_pCurMapList = NULL;

	}

	static int sort_maps_in_adt_array(const void *str1, const void *str2)

	{

		return strcmp((char *)str1, (char *)str2);

	}

	CellArray *UpdateMapList(CellArray *pUseArray, const char *name, int *pSerial, unsigned int flags)

	{

		int change_serial;

		CellArray *pNewArray = NULL;

		bool success, free_new_array;

		free_new_array = false;

		if ((success = GetMapList(&pNewArray, name, &change_serial)) == false)

		{

			if ((flags & MAPLIST_FLAG_NO_DEFAULT) != MAPLIST_FLAG_NO_DEFAULT)

			{

				/* If this list failed, and it's not the default, try the default. 

				 */

				if (strcmp(name, "default") != 0)

				{

					success = GetMapList(&pNewArray, name, &change_serial);

				}

				/* If either of the last two conditions failed, try again if we can. */

				if (!success && strcmp(name, "mapcyclefile") != 0)

				{

					success = GetMapList(&pNewArray, "mapcyclefile", &change_serial);

				}

			}

		}

		/* If there was a success, and the serial has not changed, bail out. */

		if (success && *pSerial == change_serial)

		{

			return NULL;

		}

		/**

		 * If there was a success but no map list, we need to look in the maps folder.

		 * If there was a failure and the flag is specified, we need to look in the maps folder.

		 */

		if ((success && pNewArray == NULL)

			|| (!success && ((flags & MAPLIST_FLAG_MAPSFOLDER) == MAPLIST_FLAG_MAPSFOLDER)))

		{

			pNewArray = new CellArray(64);

			free_new_array = true;

			cell_t *blk;

			FileFindHandle_t findHandle;

			const char *fileName = smcore.filesystem->FindFirstEx("maps/*.bsp", "GAME", &findHandle);

			while (fileName)

			{

				char buffer[PLATFORM_MAX_PATH];

				UTIL_StripExtension(fileName, buffer, sizeof(buffer));

				if (!engine->IsMapValid(buffer))

				{

					fileName = smcore.filesystem->FindNext(findHandle);

					continue;

				}

				if ((blk = pNewArray->push()) == NULL)

				{

					fileName = smcore.filesystem->FindNext(findHandle);

					continue;

				}

				smcore.strncopy((char *)blk, buffer, 255);

				fileName = smcore.filesystem->FindNext(findHandle);

			}

			smcore.filesystem->FindClose(findHandle);

			/* Remove the array if there were no items. */

			if (pNewArray->size() == 0)

			{

				delete pNewArray;

				pNewArray = NULL;

			}

			else

			{

				qsort(pNewArray->base(), 

					pNewArray->size(), 

					pNewArray->blocksize() * sizeof(cell_t), 

					sort_maps_in_adt_array);

			}

			change_serial = -1;

		}

		/* If there is still no array by this point, bail out. */

		if (pNewArray == NULL)

		{

			*pSerial = -1;

			return NULL;

		}

		*pSerial = change_serial;

		/* If there is no input array, return something temporary. */

		if (pUseArray == NULL)

		{

			if (free_new_array)

			{

				return pNewArray;

			}

			else

			{

				return pNewArray->clone();

			}

		}

		/* Clear the input array if necessary. */

		if ((flags & MAPLIST_FLAG_CLEARARRAY) == MAPLIST_FLAG_CLEARARRAY)

		{

			pUseArray->clear();

		}

		/* Copy. */

		cell_t *blk_dst;

		cell_t *blk_src;

		for (size_t i = 0; i < pNewArray->size(); i++)

		{

			blk_dst = pUseArray->push();

			blk_src = pNewArray->at(i);

			smcore.strncopy((char *)blk_dst, (char *)blk_src, pUseArray->blocksize() * sizeof(cell_t));

		}

		/* Free resources if necessary. */

		if (free_new_array)

		{

			delete pNewArray;

		}

		/* Return the array we were given. */

		return pUseArray;

	}

private:

	bool GetMapList(CellArray **ppArray, const char *name, int *pSerial)

	{

		time_t last_time;

		maplist_info_t *pMapList, **ppMapList;

		if ((ppMapList = m_ListLookup.retrieve(name)) == NULL)

		{

			return false;

		}

		pMapList = *ppMapList;

		if (!pMapList->bIsPath)

		{

			return GetMapList(ppArray, pMapList->path, pSerial);

		}

		/* If it is a path, and the path is "*", assume all files must be used. */

		if (strcmp(pMapList->path, "*") == 0)

		{

			*ppArray = NULL;

			return true;

		}

		if (m_pMapCycleFile != NULL && strcmp(name, "mapcyclefile") == 0)

		{

			char path[PLATFORM_MAX_PATH];

			GetMapCycleFilePath(path, sizeof(path));

			if (strcmp(path, pMapList->path) != 0)

			{

				smcore.strncopy(pMapList->path, path, sizeof(pMapList->path));

				pMapList->last_modified_time = 0;

			}

		}

		if (!libsys->FileTime(pMapList->path, FileTime_LastChange, &last_time)

			|| last_time > pMapList->last_modified_time)

		{

			/* Reparse */

			FILE *fp;

			cell_t *blk;

			char buffer[255];

			if ((fp = fopen(pMapList->path, "rt")) == NULL)

			{

				return false;

			}

			delete pMapList->pArray;

			pMapList->pArray = new CellArray(64);

			while (!feof(fp) && fgets(buffer, sizeof(buffer), fp) != NULL)

			{

				size_t len = strlen(buffer);

				char *ptr = smcore.TrimWhitespace(buffer, len);

				if (*ptr == '\0'

					|| *ptr == ';'

					|| strncmp(ptr, "//", 2) == 0)

				{

					continue;

				}

				if (!gamehelpers->IsMapValid(ptr))

				{

					continue;

				}

				if ((blk = pMapList->pArray->push()) != NULL)

				{

					smcore.strncopy((char *)blk, ptr, 255);

				}

			}

			fclose(fp);

			pMapList->last_modified_time = last_time;

			pMapList->serial = ++m_nSerialChange;

		}

		if (pMapList->pArray == NULL || pMapList->pArray->size() == 0)

		{

			return false;

		}

		*pSerial = pMapList->serial;

		*ppArray = pMapList->pArray;

		return true;

	}

	void DumpCache(List<maplist_info_t *> *compat_list)

	{

		m_ListLookup.clear();

		List<maplist_info_t *>::iterator iter = m_MapLists.begin();

		while (iter != m_MapLists.end())

		{

			if (compat_list != NULL && (*iter)->bIsCompat)