/*
 *    (c)Copyright 1992-1997 Obvious Implementations Corp.  Redistribution and
 *    use is allowed under the terms of the DICE-LICENSE FILE,
 *    DICE-LICENSE.TXT.
 */
#include	"defs.h"
#include	"dbug_protos.h"

// ************************************************************************

Prototype BOOL		DownDism(void);
Prototype BOOL		UpDism(void);
Prototype BOOL		PageDownDism(void);
Prototype BOOL		PageUpDism(void);
Prototype WORD		RefreshDism(short maxLines, BOOL fullRefresh);
Prototype ULONG 	PreviousInstruction(ULONG addr);

// ************************************************************************

BOOL	DownDism(void) {
	ULONG	val;

	val = Disassemble(CurDisplay->ds_WindowTop, CurDisplay->ds_WindowTop, LineBuf);
	CurDisplay->ds_WindowTop += val;

	if (CurDisplay->ds_DisplayMode != CurDisplay->ds_LastRefreshMode) {
		RefreshWindow(1);
		return TRUE;
	}
	CurDisplay->ds_LastRefreshTop = CurDisplay->ds_WindowTop;
	ScrScrollup();

	CurDisplay->ds_WindowBot += Disassemble(CurDisplay->ds_WindowBot, CurDisplay->ds_WindowBot, LineBuf);
	Disassemble(CurDisplay->ds_WindowBot, CurDisplay->ds_WindowBot, LineBuf);   // actual next inst

	if (CurDisplay->ds_WindowBot == programPC) ScrHighlight();
	if (IsBreakpoint(CurDisplay->ds_WindowBot)) ScrUnderline();
	PrintAddress(CurDisplay->ds_WindowBot);
	if (!CurDisplay->ds_DisplayOffsets) {
		char	*s;

		s = LookupValue(CurDisplay->ds_WindowBot);
		if (!s) s = "";
		ScrPrintf("%-16.16s %s", s, LineBuf);
	}
	else ScrPuts(LineBuf);
	ScrEOL();
	ScrPlain();
	RefreshWindow(FALSE);
	return TRUE;
}

BOOL	UpDism(void) {

	if (CurDisplay->ds_DisplayMode != CurDisplay->ds_LastRefreshMode) {
		RefreshWindow(TRUE);
		return TRUE;
	}

	CurDisplay->ds_LastRefreshTop = CurDisplay->ds_WindowTop = PreviousInstruction(CurDisplay->ds_WindowTop);

	ScrScrolldown();

	if (CurDisplay->ds_WindowTop == programPC) ScrHighlight();
	if (IsBreakpoint(CurDisplay->ds_WindowTop)) ScrUnderline();
	PrintAddress(CurDisplay->ds_WindowTop);
	if (!CurDisplay->ds_DisplayOffsets) {
		char	*s;

		s = LookupValue(CurDisplay->ds_WindowTop);
		if (!s) s = "";
		ScrPrintf("%-16.16s %s", s, LineBuf);
	}
	else ScrPuts(LineBuf);
	ScrEOL();
	ScrPlain();
	RefreshWindow(FALSE);
	return TRUE;
}


BOOL	PageUpDism(void) {
	ULONG address = CurDisplay->ds_WindowTop;
	int i, 	lines = CalcDisplayLines();

	if (CurDisplay->ds_DisplayMode != CurDisplay->ds_LastRefreshMode) {
		RefreshWindow(TRUE);
		return TRUE;
	}

	if(lines > 0) {
	    for(i=0; i<lines; i++)address = PreviousInstruction(address);
	    CurDisplay->ds_WindowTop = address;
	    CurDisplay->ds_WindowTopLine = 0;
	    RefreshWindow(1);
	}
	return TRUE;
}

BOOL	PageDownDism(void) {
	if (CurDisplay->ds_DisplayMode != CurDisplay->ds_LastRefreshMode) {
		RefreshWindow(TRUE);
		return TRUE;
	}
	CurDisplay->ds_WindowTop = CurDisplay->ds_WindowBot;
	CurDisplay->ds_WindowTopLine = 0;
	RefreshWindow(1);
	return TRUE;
}

WORD	RefreshDism(short maxLines, BOOL fullRefresh) {
	ULONG	address = CurDisplay->ds_WindowTop, size;
	WORD	count = 0;
	char	*s;
	BOOL	plotFlag;

	

	do_scroller();
//	if (fullRefresh) {
	    if (fullRefresh)SetTitle(NULL,NULL);
#if 0
	    ScrPlain();
	    ScrInverse();
	    ScrPuts("DISM MODE");
#endif
	    // add a seperation between register display and source

	    if(CurDisplay->ds_RegFlag) {
	    	++count;
	    	Newline();
	    	if (--maxLines == 0)return count;
	    }
//	}


	while (maxLines > 0) {
		plotFlag = fullRefresh;
		CurDisplay->ds_WindowBot = address;
		size = Disassemble(address, address, LineBuf);
		ScrPlain();

		plotFlag = TRUE; 

		if (address == programPC) { 
			plotFlag = TRUE; 
			ScrHighlight(); 
		}
		if (IsBreakpoint(address)) { 
			plotFlag = TRUE; 
			ScrUnderline(); 
		}
		if (address == lastPC) { 
			plotFlag = TRUE; 
			ScrPlain(); 
		}
		if (plotFlag) {
			PrintAddress(address);
			if (!CurDisplay->ds_DisplayOffsets) {
				s = LookupValue(address);
				if (!s) s = "";
				ScrPrintf("%-16.16s %s", s, LineBuf);
			}
			else ScrPuts(LineBuf);
			count++;
			ScrPutNewline(); 
			maxLines--;
		}
		else {
			count++;
			ScrPutNewline();
			maxLines--;
		}
		address += size;
	}
	return count;
}

/*  Attempt to find previous instruction. This is done by
 *  searching forward from the nearest label address or
 *  20 words back, whichever is closer.
 */

ULONG	PreviousInstruction(ULONG addr) {
	ULONG val;
	ULONG siz;
	char *s;

	if (s = NearestValue(addr-2)) {
		LookupSymbol(s, &val);
		if ((long)(addr - val) > 40 || (long)(addr - val) <= 0)
		    val = addr - 40;
	}
	else val = addr - 40;

	siz = 0;
	while (val + siz < addr) {
	    val = val + siz;
	    siz = Disassemble(val, val, LineBuf);
	    if ((long)siz <= 0)siz = 2; 	//  if siz is weird
	}
	return(val);
}