/**

  * vim: set ts=4 :

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

  * SourceMod Updater Extension

  * Copyright (C) 2004-2009 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 <sourcemod_version.h>

 #include <stdlib.h>

 #include "extension.h"

 #include "Updater.h"

 #include "md5.h"

 #define USTATE_NONE			0

 #define USTATE_FOLDERS		1

 #define USTATE_CHANGED		2

 #define USTATE_CHANGE_FILE	3

 #define USTATE_ERRORS		4

 using namespace SourceMod;

 UpdateReader::UpdateReader() : partFirst(NULL), partLast(NULL)

 {

 }

 UpdateReader::~UpdateReader()

 {

 }

 void UpdateReader::ReadSMC_ParseStart()

 {

 	ignoreLevel = 0;

 	ustate = USTATE_NONE;

 }

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

 {

 	if (ignoreLevel)

 	{

 		ignoreLevel++;

 		return SMCResult_Continue;

 	}

 	switch (ustate)

 	{

 	case USTATE_NONE:

 		{

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

 			{

 				ustate = USTATE_FOLDERS;

 			}

 			else if (strcmp(name, "Changed") == 0)

 			{

 				ustate = USTATE_CHANGED;

 			}

 			else if (strcmp(name, "Errors") == 0)

 			{

 				ustate = USTATE_ERRORS;

 			}

 			else

 			{

 				ignoreLevel++;

 			}

 			break;

 		}

 	case USTATE_FOLDERS:

 	case USTATE_CHANGE_FILE:

 		{

 			ignoreLevel++;

 			break;

 		}

 	case USTATE_CHANGED:

 		{

 			curfile.assign(name);

 			url.clear();

 			checksum[0] = '\0';

 			ustate = USTATE_CHANGE_FILE;

 			break;

 		}

 	}

 	return SMCResult_Continue;

 }

 SMCResult UpdateReader::ReadSMC_KeyValue(const SMCStates *states,

 										 const char *key,

 										 const char *value)

 {

 	if (ignoreLevel)

 	{

 		return SMCResult_Continue;

 	}

 	switch (ustate)

 	{

 	case USTATE_CHANGE_FILE:

 		{

 			if (strcmp(key, "md5sum") == 0)

 			{

 				if (strlen(value) != 32)

 				{

 					return SMCResult_Continue;

 				}

 				strcpy(checksum, value);

 			}

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

 			{

 				url.assign(update_url);

 				url.append(value);

 			}

 			break;

 		}

 	case USTATE_ERRORS:

 		{

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

 			{

 				AddUpdateError("%s", value);

 			}

 			break;

 		}

 	case USTATE_FOLDERS:

 		{

 			HandleFolder(value);

 			break;

 		}

 	}

 	return SMCResult_Continue;

 }

 SMCResult UpdateReader::ReadSMC_LeavingSection(const SMCStates *states)

 {

 	if (ignoreLevel)

 	{

 		ignoreLevel--;

 		return SMCResult_Continue;

 	}

 	switch (ustate)

 	{

 	case USTATE_FOLDERS:

 	case USTATE_CHANGED:

 	case USTATE_ERRORS:

 		{

 			ustate = USTATE_NONE;

 			break;

 		}

 	case USTATE_CHANGE_FILE:

 		{

 			if (url.size() != 0 && checksum[0] != '\0')

 			{

 				HandleFile();

 			}

 			else

 			{

 				AddUpdateError("Incomplete file definition in update manifest");

 			}

 			ustate = USTATE_CHANGED;

 			break;

 		}

 	}

 	return SMCResult_Continue;

 }

 void UpdateReader::LinkPart(UpdatePart *part)

 {

 	part->next = NULL;

 	if (partFirst == NULL)

 	{

 		partFirst = part;

 		partLast = part;

 	}

 	else

 	{

 		partLast->next = part;

 		partLast = part;

 	}

 }

 void UpdateReader::HandleFile()

 {

 	MD5 md5;

 	char real_checksum[33];

 	mdl.Reset();

 	if (!xfer->Download(url.c_str(), &mdl, NULL))

 	{

 		AddUpdateError("Could not download \"%s\"", url.c_str());

 		AddUpdateError("Error: %s", xfer->LastErrorMessage());

 		return;

 	}

 	md5.update((unsigned char *)mdl.GetBuffer(), mdl.GetSize());

 	md5.finalize();

 	md5.hex_digest(real_checksum);

 	if (mdl.GetSize() == 0)

 	{

 		AddUpdateError("Zero-length file returned for \"%s\"", curfile.c_str());

 		return;

 	}

 	if (strcasecmp(checksum, real_checksum) != 0)

 	{

 		AddUpdateError("Checksums for file \"%s\" do not match:", curfile.c_str());

 		AddUpdateError("Expected: %s Real: %s", checksum, real_checksum);

 		return;

 	}

 	UpdatePart *part = new UpdatePart;

 	part->data = (char*)malloc(mdl.GetSize());

 	memcpy(part->data, mdl.GetBuffer(), mdl.GetSize());

 	part->file = strdup(curfile.c_str());

 	part->length = mdl.GetSize();

 	LinkPart(part);

 }

 void UpdateReader::HandleFolder(const char *folder)

 {

 	UpdatePart *part = new UpdatePart;

 	part->data = NULL;

 	part->length = 0;

 	part->file = strdup(folder);

 	LinkPart(part);

 }

 static bool md5_file(const char *file, char checksum[33])

 {

 	MD5 md5;

 	FILE *fp;

 	long length;

 	void *fdata;

 	if ((fp = fopen(file, "rb")) == NULL)

 	{

 		return false;

 	}

 	fseek(fp, 0, SEEK_END);

 	length = ftell(fp);

 	fseek(fp, 0, SEEK_SET);

 	fdata = malloc(length);

 	if (fread(fdata, 1, length, fp) != size_t(length))

 	{

 		free(fdata);

 		fclose(fp);

 		return false;

 	}

 	fclose(fp);

 	md5.update((unsigned char*)fdata, length);

 	md5.finalize();

 	md5.hex_digest(checksum);

 	free(fdata);

 	return true;

 }

 /* Path should be sourcemod relative, not gamedata relative */

 static bool add_file(IWebForm *form, const char *file, unsigned int &num_files)

 {

 	char path[PLATFORM_MAX_PATH];

 	smutils->BuildPath(Path_SM, path, sizeof(path), "%s", file);

 	char checksum[33];

 	if (!md5_file(path, checksum))

 	{

 		return false;

 	}

 	char name[32];

 	smutils->Format(name, sizeof(name), "file_%d_name", num_files);

 	form->AddString(name, file);

 	smutils->Format(name, sizeof(name), "file_%d_md5", num_files);

 	form->AddString(name, checksum);

 	num_files++;

 	return true;

 }

 static void add_folders(IWebForm *form, const char *root, unsigned int &num_files)

 {

 	IDirectory *dir;

 	char path[PLATFORM_MAX_PATH];

 	char name[PLATFORM_MAX_PATH];

 	smutils->BuildPath(Path_SM, path, sizeof(path), "%s", root);

 	dir = libsys->OpenDirectory(path);

 	if (dir == NULL)

 	{

 		AddUpdateError("Could not open folder: %s", path);

 		return;

 	}

 	while (dir->MoreFiles())

 	{

 		if (strcmp(dir->GetEntryName(), ".") == 0 ||

 			strcmp(dir->GetEntryName(), "..") == 0)

 		{

 			dir->NextEntry();

 			continue;

 		}

 		smutils->Format(name, sizeof(name), "%s/%s", root, dir->GetEntryName());

 		if (dir->IsEntryDirectory())

 		{

 			add_folders(form, name, num_files);

 		}

 		else if (dir->IsEntryFile())

 		{

 			add_file(form, name, num_files);

 		}

 		dir->NextEntry();

 	}

 	libsys->CloseDirectory(dir);

 }

 void UpdateReader::PerformUpdate(const char *url)

 {

 	IWebForm *form;

 	MemoryDownloader master;

 	SMCStates states = {0, 0};

 	update_url = url;

 	form = webternet->CreateForm();

 	xfer = webternet->CreateSession();

 	xfer->SetFailOnHTTPError(true);

 	form->AddString("version", SM_VERSION_STRING);

 	unsigned int num_files = 0;

 	add_folders(form, "gamedata", num_files);

 	char temp[24];

 	smutils->Format(temp, sizeof(temp), "%d", num_files);

 	form->AddString("files", temp);

 	if (!xfer->PostAndDownload(url, form, &master, NULL))

 	{

 		AddUpdateError("Could not download \"%s\"", url);

 		AddUpdateError("Error: %s", xfer->LastErrorMessage());

 		goto cleanup;

 	}

 	SMCError error;

 	char errbuf[256];

 	error = textparsers->ParseSMCStream(master.GetBuffer(),

 										master.GetSize(),

 										this,

 										&states,

 										errbuf,

 										sizeof(errbuf));

 	if (error != SMCError_Okay)

 	{

 		AddUpdateError("Parse error in update manifest: %s", errbuf);

 		goto cleanup;

 	}

 cleanup:

 	delete xfer;

 	delete form;

 }

 UpdatePart *UpdateReader::DetachParts()

 {

 	UpdatePart *first;

 	first = partFirst;

 	partFirst = NULL;

 	partLast = NULL;

 	return first;

 }