#include "stdafx.h"
#include "stdio.h"
#include "process.h"
#include "SenLink.h"

CSenNode::CSenNode()
{
	Sen.Empty();
	lSeek = 0;
	lLen = 0;
	pLast = NULL;
	pNext = NULL;
}

CSenNode::~CSenNode()
{
}

CSenLink::CSenLink()
{
	nSenNum = 0;
	nContainError = 0;
}

CSenLink::~CSenLink()
{
	if(nSenNum != 0)
		delete NewSeekBuf;
	fclose(fpIn);
}

//初始化SeekBuf
BOOL CSenLink::InitSeekBuf(char *sDicOut)
{
	char ch;

	fpIn = fopen(sDicIn,"rb");
	if( !fpIn ){
		strMsg.Format("Cann't open %s!",sDicIn);
		AfxMessageBox(strMsg);
		return FALSE;
	}

	//初始化SeekBuf數組
	//SeekBuf[2*n] -- 第n個詞條的起始位置
	//SeekBuf[2*n + 1] -- 第n個詞條的長度
	SeekBufPos = 0;
	SeekBuf[SeekBufPos++] = ftell(fpIn);	//第一句詞條的起始位置
	for( ; !feof(fpIn) ; ){
		ch = fgetc(fpIn);
		if( ch == 0x0d ){
			 ch = fgetc(fpIn);
			 if( ch == 0x0a ){
				 //本句詞條的長度
				 SeekBuf[SeekBufPos] = ftell(fpIn) - SeekBuf[SeekBufPos - 1];
				 SeekBufPos++;
				 //下一句詞條的起始位置
				 SeekBuf[SeekBufPos] = ftell(fpIn);
				 SeekBufPos++;				 
			}
		}
		if(SeekBufPos >= MAXBUFNUM){
			long lNum = MAXBUFNUM;
			strMsg.Format("您的詞典的詞條數已經超過%d,建索引失敗!",lNum/2);
			AfxMessageBox(strMsg);
			return FALSE;
		}
	}
	//最后一句詞條的長度
	SeekBuf[SeekBufPos] = ftell(fpIn) - SeekBuf[SeekBufPos - 1];
	
	//詞條數nSenNum
	nSenNum = (SeekBufPos+1) / 2;
	SeekBufPos = 0;
	NewSeekBuf = new long[nSenNum*2];
	NewSeekBufPos = 0;

	return TRUE;
}
//初始化鏈表
BOOL CSenLink::InitLink()
{
	CSenNode *pNewSenNode;

	pNewSenNode = &SenNodeBuf[0];
	GetNewSen(pNewSenNode,0);
	pHead = pNewSenNode;
	pEnd = pNewSenNode;
	pNewSenNode->pLast = pNewSenNode;
	pNewSenNode->pNext = pNewSenNode;
	for(int i=1; i < LINKNUM && i< nSenNum; i++)
	{
		pNewSenNode = &SenNodeBuf[i];	
		GetNewSen(pNewSenNode,i);
		InsertNewSen(pNewSenNode);
	}
	if(i >= nSenNum)	//如果詞條數小于等于鏈表長度
		return FALSE;
	return TRUE;
}

//將第nSenBuf句的詞條讀入pNewSenNode中
BOOL CSenLink::GetNewSen(CSenNode *pNewSenNode,int nBufNo)
{
	char SenBuf[300];
	
	pNewSenNode->Sen.Empty();
	pNewSenNode->pLast = NULL;
	pNewSenNode->pNext = NULL;
	pNewSenNode->lSeek = SeekBuf[2*nBufNo];
	pNewSenNode->lLen  = SeekBuf[2*nBufNo + 1];
	fseek(fpIn,pNewSenNode->lSeek,SEEK_SET);
	//fread(SenBuf,sizeof(char),pNewSenNode->lLen,fpIn);
	
	if(fgets(SenBuf,pNewSenNode->lLen,fpIn) == NULL)
		return FALSE;
	
	//fscanf(fpIn,"%s",SenBuf);
	pNewSenNode->Sen = SenBuf;	
	return TRUE;
}

BOOL CSenLink::InsertNewSen(CSenNode *pNewSenNode)
{
	BOOL bDone;
	CSenNode *pTmp;
	
	pTmp = pHead;
	bDone = FALSE;
	if(bOrderMethor ==TRUE)  //從大到小排序
	{
		if(pNewSenNode->Sen >= pHead->Sen)
			pHead = pNewSenNode;
		do{
			if(pNewSenNode->Sen >= pTmp->Sen)
			{
				AddNodeToLink(pNewSenNode,pTmp);			//將pNewSenNode加到pTmp前
				bDone = TRUE;
				break;
			}
			else
				pTmp = pTmp->pNext;
			
			//如果pNewSenNode小于鏈表中的所有節點
			if(pTmp == pHead){
				AddNodeToLink(pNewSenNode,pTmp);			//將pNewSenNode加到pTmp前
				pEnd = pNewSenNode;
				bDone = FALSE;
				//bContainError = TRUE;		//將包含錯誤標志設為真
				break;
			}
		}while(TRUE);
	}
	else				//從小到大排序
	{
		if(pNewSenNode->Sen <= pHead->Sen)
			pHead = pNewSenNode;
		do{
			if(pNewSenNode->Sen <= pTmp->Sen)
			{
				AddNodeToLink(pNewSenNode,pTmp);			//將pNewSenNode加到pTmp前
				bDone = TRUE;
				break;
			}
			else
				pTmp = pTmp->pNext;
			
			//如果pNewSenNode大于鏈表中的所有節點
			if(pTmp == pHead){
				AddNodeToLink(pNewSenNode,pTmp);			//將pNewSenNode加到pTmp前
				pEnd = pNewSenNode;
				bDone = FALSE;
				//bContainError = TRUE;		//將包含錯誤標志設為真
				break;
			}
		}while(TRUE);
	}

	return bDone;
}

void CSenLink::AddNodeToLink(CSenNode *pNew, CSenNode *pTmp)
{
	CSenNode *pLastNode;

	pLastNode = pTmp->pLast;
	pTmp->pLast = pNew;
	pLastNode->pNext = pNew;
	pNew->pLast = pLastNode;
	pNew->pNext = pTmp;
}

//將鏈表的末節點從鏈表中釋放,返回其指針
CSenNode *CSenLink::FreeNode()
{
	CSenNode *pNew = pEnd;
	pEnd = pEnd->pLast;
	
	pNew->pLast->pNext = pNew->pNext;
	pNew->pNext->pLast = pNew->pLast;
	pNew->Sen.Empty();
	pNew->lSeek = 0;
	pNew->lLen = 0;
	pNew->pLast = NULL;
	pNew->pNext = NULL;

	return pNew;
}

void CSenLink::SaveEndNode(CSenNode *pNode)
{
	NewSeekBuf[NewSeekBufPos++] = pNode->lSeek;
	NewSeekBuf[NewSeekBufPos++] = pNode->lLen;
}

void CSenLink::SaveLinkToNewBuf()
{
	CSenNode *pTmp;

	SaveEndNode(pEnd);
	for(pTmp = pEnd->pLast; pTmp !=pEnd; pTmp = pTmp->pLast)
		SaveEndNode(pTmp);
}
//若還需再次排序,則先將NewSeekBuf --> SeekBuf
void CSenLink::ChangeBuf()
{
	for(int i=0; i < 2*nSenNum; i++)
		SeekBuf[i] = NewSeekBuf[i];
	NewSeekBufPos = 0;	
}

BOOL CSenLink::SaveOrderResult(char *sDicOut)
{
	char SenBuf[500];

	fpOut = fopen(sDicOut,"wb");
	if( !fpOut ){
		strMsg.Format("無法創建臨時文件,建索引失敗!");
		AfxMessageBox(strMsg);
		return FALSE;
	}

	long lLen,lSeek,lRdLen,lWrLen;

	int SenNo,i;
	if(bSaveMethor == TRUE)
		i = 0;
	else
		i = 2*nSenNum - 1;
	for(SenNo = 0; SenNo < nSenNum; SenNo ++)
	{
		if(bSaveMethor == TRUE){
			lSeek = NewSeekBuf[i++];
			lLen = NewSeekBuf[i++];
		}
		else{
			lLen = NewSeekBuf[i--];
			lSeek = NewSeekBuf[i--];			
		}

		fseek(fpIn,lSeek,SEEK_SET);
		lRdLen = fread(SenBuf,sizeof(char),lLen,fpIn);
		
		//if( !fgets(SenBuf,lLen,fpIn) ){
		if( lRdLen != lLen ){
			strMsg.Format("讀臨時文件時發生錯誤,建索引失敗!");
			AfxMessageBox(strMsg);
			return FALSE;
		}
		lWrLen = fwrite(SenBuf,sizeof(char),lLen,fpOut);
		if( lWrLen != lLen){
			strMsg.Format("寫臨時文件時發生錯誤,磁盤已滿?");
			AfxMessageBox(strMsg);
			return FALSE;
		}
	}
	fclose(fpOut);

	return TRUE;
}

BOOL CSenLink::SortMain(char *sIn,char *sOut,BOOL bMethor)
{
	int nBufNo;

	strcpy(sDicIn,sIn);
	strcpy(sDicOut,sOut);
	bOrderMethor = bMethor;
	bSaveMethor = TRUE;		//排序結果按正常順序存儲

	if( !InitSeekBuf(sDicOut) )
		return FALSE;

	do{
		if (InitLink() == FALSE)		   //初始化鏈表
		{
			SaveLinkToNewBuf();			   //如果待排序內容數小于鏈表節點數,排序完畢
			break;
		}
		
		nContainError = 0;
		NewSeekBufPos = 0;
		pNewSenNode = &SenNodeBuf[LINKNUM];
		for(nBufNo = LINKNUM; nBufNo < nSenNum; nBufNo++)
		{			
			GetNewSen(pNewSenNode,nBufNo);
			if( !InsertNewSen(pNewSenNode) )
				nContainError ++;
			SaveEndNode(pEnd);		  //保存末節點
			pNewSenNode = FreeNode();
		}
		//如果待排序的內容基本上是按要求順序排序的
		if( nContainError < (int) (nSenNum - LINKNUM) / 2 )
		{
			SaveLinkToNewBuf();	//保存鏈表到NewSeekBuf 
			ChangeBuf();		//NewSeekBuf --> SeekBuf
		}
		//如果待排序的內容基本上是按要求順序反排序的
		else{
			bOrderMethor = !bOrderMethor;
			bSaveMethor = FALSE;
		}
	}while( nContainError );
	if( !SaveOrderResult(sDicOut) )
		return FALSE;
	
	return TRUE;
}