//***********************************************
// Handles Message Folders
// A message folder is a directory in the file system
// This directory contains a message files (one for each message)
// and a special file called "messages"
// This file contains an identifier in the first place which identifies it as a messagefolder file
// If the folder does not exist it is created, If it exists it must contain a "messages" file
// else this is considered an inconsistent state of the messagefolder object.
// TODO:
//		Should be able to rebuild messages file
// ALTERNATE:
//		Store all messages in one file (like PINE).
// AUTHOR: Chris Wild
// DATE: July 25, 1997
// REVISED: January 22, 1999
//*************************************************
#include "MsgFolder.h"
#include <stdlib.h>	// for MAX_PATH
#include <iostream.h>
#include <stdio.h>
#include <windows.h>
#include "packet.h"

const int MAGIC_COOKIE=1234567;


CMsgFolder::CMsgFolder()
{
	messages = NULL;
	nextMsgNum = 0; 
	folderName = NULL;
}

// Construct folder and open it to folderName
CMsgFolder::CMsgFolder(const char* folderName)
{
	messages = NULL;
	nextMsgNum = 0; 
	folderName = NULL;
	OpenMsgFolder(folderName);
}

// Close folder if any
CMsgFolder::~CMsgFolder()
{
	if( messages != NULL)
		CloseMsgFolder();
}

// Puts a message in the folder
// Will save message in its own file
// Names are of the form "MSGxxx" where xxx is a number from
// 1 to max number of messages ever created.
// new messages are put at the end of the list of current messages
// Save maximum buffer sizes for topic and text fields.
bool CMsgFolder::PostMsg(CMessage& thisMsg)
{
	
	HANDLE fileHandle;
	Item thisItem;
	
	if (messages == NULL)	// no message folder opened
		return false;
	ZeroMemory(thisItem.fileName, sizeof(thisItem.fileName));
	ZeroMemory(thisItem.topic, sizeof(thisItem.topic));
	sprintf(thisItem.fileName, "MSG%d", ++nextMsgNum);

	fileHandle = client_CreateFile(thisItem.fileName,GENERIC_WRITE,0,0,CREATE_NEW,0,0);
	if(fileHandle == INVALID_HANDLE_VALUE) {
		cerr << "Error: " << GetLastError() <<
			" when creating file:" << thisItem.fileName << endl;
		return false;
	}
	if(!thisMsg.WriteMsg(fileHandle)) {
		return false;
	}
	client_CloseHandle(fileHandle);
	thisMsg.GetTopic(thisItem.topic);
	msgList.AddItem(msgList.length()+1,thisItem);
	return true;
}
// gets message with ID "messageId"
// returns true if successful else false
bool CMsgFolder::GetMsg(msgID messageId, CMessage & thisMsg) const
{
	if (messages == NULL)
		return NULL;
	Item msgHeader;
	HANDLE msgFile;
	if (msgList.GetItem(messageId, msgHeader)) {
		msgFile = client_CreateFile(msgHeader.fileName,GENERIC_READ,0,0,OPEN_EXISTING,0,0);
		if(msgFile == INVALID_HANDLE_VALUE) {
			cerr << "Error: " << GetLastError() <<
				" when opening file: " << msgHeader.fileName << endl;
			ExitProcess(1);
		}
		if(!thisMsg.ReadMsg(msgFile)) {
			client_CloseHandle(msgFile);
			return false;
		}
		client_CloseHandle(msgFile);
		return true;
	}
	else
		return NULL;
}

// Deletes message with msgID "messageID"
// removes from MsgList and deletes Message file
// returns false if 1) no folder open
// 2) message does not exists in list
// 3) file cannot be deleted
// returns true is successfull

bool CMsgFolder::DeleteMsg(msgID messageID)
{
	if(messages == NULL)
		return false;
	Item msgHeader;
	if(msgList.GetItem(messageID, msgHeader)) {
		if(!client_DeleteFile(msgHeader.fileName)) {
			cerr << "Error: " << GetLastError() <<
				" when deleting file: " << msgHeader.fileName << endl;
			ExitProcess(1);
		}
		if(msgList.DeleteItem(messageID))
			return true;
		else
			return false;
	}
	else return false;
}

// PRE: message with "messageID" exists
// topic points to a string big enough to hold topic string
// POST: if exists, returns true and topic of this message
//	else returns false
bool CMsgFolder::GetMsgTopic(msgID messageId, char* topic) const
{
	if(messages == NULL)
		return false;
	Item thisItem;
	if(msgList.GetItem(messageId, thisItem)) {
		strncpy(topic, thisItem.topic, SIZE_TOPIC+1);
		return true;
	}
	else
		return false;
}

int CMsgFolder::NumMsgs() const
{
	return msgList.length();
}

// ****
// verifyFolder - verifies then creates/opens message folder
bool CMsgFolder::verifyFolder(const char* name)
{
	DWORD nBytes;
	
	if(client_CreateDirectory(name,0)) {
		cout << "Created Directory:" <<  name << endl;
		if(!client_SetCurrentDirectory(name)) {
			cerr << "Could not set message folder" << name << GetLastError();
			return false;
		}
		// create "messages" file with magic cookie
		messages = client_CreateFile("messages",GENERIC_WRITE,0,0,CREATE_NEW,0,0);
		if(messages == INVALID_HANDLE_VALUE) {
			cerr << "Could not create messages file" << GetLastError();
			return false;
		}
		nextMsgNum = 0;
		return true;
	}
	else {
		if(!client_SetCurrentDirectory(name)) {
			cerr << "Could not set message folder" << name << GetLastError();
			return false;
		}
		// Now check if this folder contains a "messages" file with the magic cookie
		messages = client_CreateFile(
			"messages",
			GENERIC_READ|GENERIC_WRITE, // read then write this file
			0,0,
			OPEN_EXISTING,
			0,0);
		if(messages == INVALID_HANDLE_VALUE) {
			cerr << "Could not open messages file" << GetLastError();
			return false;
		}
		int cookie;
		if(!client_ReadFile(messages, (LPBYTE) &cookie, sizeof(cookie), &nBytes, NULL)) {
			cerr << "Could not read magic cookie!" << GetLastError();
			return false;
		}
		if(cookie != MAGIC_COOKIE) {
			cerr << "no magic cookie!\n";
			return false;
		}
		if(!client_ReadFile(messages, (LPBYTE) &nextMsgNum, sizeof(nextMsgNum), &nBytes, NULL)) {
			cerr << "Could not nMessages!" << GetLastError();
			return false;
		}
		
		// now read messages list
		if(!msgList.ReadListMsgs(messages)) {
			cerr << "Could not read message list\n";
			return false;
		}
		return true;
	}
	
}


//**** OpenMsgFolder: client/server implementation
// for simplicity, uses a flat folder naming scheme on server side

bool CMsgFolder::OpenMsgFolder(const char* folder)
{
	if( messages != NULL)
		CloseMsgFolder();
	folderName = new char[strlen(folder)+1];
	strcpy(folderName,folder);
	return verifyFolder(folderName);
	
}

bool CMsgFolder::CloseMsgFolder()
{
	DWORD nBytes;
	
	if (messages == NULL) return true;	// nothing to do
	delete folderName;
	folderName = NULL;

	client_SetFilePointer(messages,0,0,FILE_BEGIN); // rest pointer
	client_SetEndOfFile(messages); // truncate file
	if(!client_WriteFile(messages, (LPBYTE) &MAGIC_COOKIE, sizeof(int), &nBytes, NULL)) {
		cerr << "Could not write magic cookie!" << GetLastError();
		ExitProcess(1);
	}
	if(!client_WriteFile(messages, (LPBYTE) &nextMsgNum, sizeof(nextMsgNum), &nBytes, NULL)) {
		cerr << "Could not write nMessages!" << GetLastError();
		ExitProcess(1);
	}
	if(!msgList.WriteListMsgs(messages)) {
		cerr << "Could not write messages!\n" ;
		ExitProcess(1);
	}
	// delete list
	while(msgList.DeleteItem(1)) ; // delete first item continuously until done
	// now return to parent directory
	if(!client_SetCurrentDirectory("..")) {
		cerr << "Could not reset to parent directory" << GetLastError();
		return false;
	}

	if (client_CloseHandle(messages)){
		messages = NULL;
		return true;
	}
	else
		return false;
}