/*
 * textview.cc
 *
 * Turbo Vision - Version 2.0
 *
 * Copyright (c) 1994 by Borland International
 * All Rights Reserved.
 *
 * Modified by Sergio Sigala <sergio@sigala.it>
 * Modified by Max Okumoto <okumoto@ucsd.edu>
 */

#define Uses_TTextDevice
#define Uses_TTerminal
#define Uses_otstream
#include <tvision/tv.h>

#include <string.h>

using std::ostream;
using std::streamsize;

TTextDevice::TTextDevice( const TRect& bounds,
                          TScrollBar *aHScrollBar,
                          TScrollBar *aVScrollBar) :
    TScroller(bounds,aHScrollBar,aVScrollBar)
{
}

TTerminal::TTerminal( const TRect& bounds,
                      TScrollBar *aHScrollBar,
                      TScrollBar *aVScrollBar,
                      ushort aBufSize ) :
    TTextDevice(bounds, aHScrollBar, aVScrollBar),
    queFront( 0 ),
#ifndef __UNPATCHED
    queBack( 0 ),
    curLineWidth( 0 )       // Added for horizontal cursor tracking.
#else
    queBack( 0 )
#endif
{
    growMode = gfGrowHiX + gfGrowHiY;
    bufSize = min( 32000U, aBufSize );
    buffer = new char[ bufSize ];
    setLimit( 0, 1 );
    setCursor( 0, 0 );
    showCursor();
}


TTerminal::~TTerminal()
{
    delete buffer;
}

void TTerminal::bufDec( ushort& val )
{
    if (val == 0)
        val = bufSize - 1;
    else
        val--;
}

void TTerminal::bufInc( ushort& val )
{
    if( ++val >= bufSize )
        val = 0;
}

Boolean TTerminal::canInsert( ushort amount )
{
    long T = (queFront < queBack) ?
        ( queFront +  amount ) :
        ( long(queFront) - bufSize + amount);   // cast needed so we get
                                                // signed comparison
    return Boolean( queBack > T );
}

void TTerminal::draw()
{
    short  i;
    ushort begLine, endLine;
#ifndef __UNPATCHED
    char s[ maxViewWidth+1 ];  // KRW: Bug Fix/Enhancement: 95/01/05
                               // Do *NOT* attempt to display more
                               // than maxViewWidth chars
                               // ** assume size.x <= maxViewWidth **
#else
    char s[256];
#endif
    ushort bottomLine;

    bottomLine = size.y + delta.y;
    if( limit.y > bottomLine )
        {
        endLine = prevLines( queFront, limit.y - bottomLine );
        bufDec( endLine );
        }
    else
        endLine = queFront;

    if( limit.y > size.y )
        i = size.y - 1;
    else
        {
        for( i = limit.y; i <= size.y - 1; i++ )
            writeChar(0, i, ' ', 1, size.x);
        i =  limit.y -  1;
        }

    for( ; i >= 0; i-- )
        {
#ifndef __UNPATCHED
        // KRW: Bug fix/enhancement - handle any length line by only copying
        //   to s those characters to be displayed, which we assume will
        //   be < maxViewWidth
        //  This whole block rewritten
        memset( s, ' ', size.x ); // must display blanks if no characters!
        begLine = prevLines(endLine, 1);
        if (endLine >= begLine)
        {
            // Entire string to be displayed is in one fragment, not
            // wrapped around the end of the buffer
	    int fragmentLength = int( endLine - begLine );
            if (fragmentLength > delta.x)
                {
                fragmentLength -= delta.x;
                fragmentLength = min( size.x, fragmentLength );
                memcpy( s, &buffer[begLine+delta.x], fragmentLength );
                }
        }
        else
        {
            // Extract first fragment into s
            int deltaLeft = delta.x;
            int firstFragmentLength = int( bufSize - begLine );
            if (firstFragmentLength > delta.x)
            {
                deltaLeft = 0;
                firstFragmentLength -= delta.x;
                firstFragmentLength  = min( size.x, firstFragmentLength );
                memcpy( s, &buffer[begLine+delta.x], firstFragmentLength );
            }
            else
            {
                deltaLeft -= firstFragmentLength;
		firstFragmentLength = 0;
	    }
            // Extract second fragment into s
	    if ((endLine > deltaLeft) && (firstFragmentLength < size.x))
            {
                int secondFragmentLength = endLine - deltaLeft;
                secondFragmentLength =
                    min(size.x-firstFragmentLength,secondFragmentLength);
		    memcpy( &s[ firstFragmentLength ], &buffer[ deltaLeft ],
                    secondFragmentLength );
            }
        }

        s[ size.x ] = EOS;
        writeStr( 0, i, s, 1 );

        endLine = begLine;
        bufDec( endLine );
#else
        begLine = prevLines(endLine, 1);
        if (endLine >= begLine)
            {
            int T = int( endLine - begLine );
            memcpy( s, &buffer[begLine], T );
            s[T] = EOS;
            }
        else
            {
            int T = int( bufSize - begLine);
            memcpy( s, &buffer[begLine], T );
            memcpy( s+T, buffer, endLine );
            s[T+endLine] = EOS;
            }
        if( delta.x >= strlen(s) )
            *s = EOS;
        else
            strcpy( s, &s[delta.x] );

        writeStr( 0, i, s, 1 );
        writeChar( strlen(s), i, ' ', 1, size.x );
        endLine = begLine;
        bufDec( endLine );
#endif
        }
}

ushort TTerminal::nextLine( ushort pos )
{
    if( pos != queFront )
        {
        while( buffer[pos] != '\n' && pos != queFront )
            bufInc(pos);
        if( pos != queFront )
            bufInc( pos );
        }
    return pos;
}

int TTerminal::do_sputn( const char *s, int count )
{
#ifndef __UNPATCHED
    ushort screenWidth = limit.x;
    ushort screenLines = limit.y;

    // BUG FIX - Mon 07/25/94 - EFW: Made TTerminal adjust horizontal
    // scrollbar limit too.

    /* SS: stupid thing */

    ushort i;
    for(i = 0; i < count; i++, curLineWidth++)
        if(s[i] == '\n')
        {
            screenLines++;

            // Check width when an LF is seen.
            if(curLineWidth > screenWidth)
                screenWidth = curLineWidth;

            // Reset width for the next line.
            curLineWidth = 0;
        }

    // One last check for width for cases where whole lines aren't
    // received, maybe just a character or two.
    if(curLineWidth > screenWidth)
        screenWidth = curLineWidth;
#else
    ushort screenLines = limit.y;
    for( ushort i = 0; i < count; i++ )
        if( s[i] == '\n' )
            screenLines++;
#endif

    while( !canInsert( count ) )
        {
        queBack = nextLine( queBack );
        screenLines--;
        }

    if( queFront + count >= bufSize )
        {
        i = bufSize - queFront;
        memcpy( &buffer[queFront], s, i );
        memcpy( buffer, &s[i], count - i );
        queFront = count - i;
        }
    else
        {
        memcpy( &buffer[queFront], s, count );
        queFront += count;
        }

#ifndef __UNPATCHED
    setLimit( screenWidth, screenLines );
#else
    setLimit( limit.x, screenLines );
#endif
    scrollTo( 0, screenLines + 1 );
    i = prevLines( queFront, 1 );
    if( i <= queFront )
        i = queFront - i;
    else
        i = bufSize - (i - queFront);
    setCursor( i, screenLines - delta.y - 1 );
    drawView();
    return count;
}

Boolean TTerminal::queEmpty()
{
    return Boolean( queBack == queFront );
}

TerminalBuf::TerminalBuf(TTerminal *tt): term(tt)
{
}

int TerminalBuf::overflow(int c)
{
	streamsize n = pptr() - pbase();

	if (n > 0 && sync() == EOF) return EOF;
	if (c != EOF)
	{
		char b = c;

		term->do_sputn(&b, sizeof(b));
	}
	pbump(-n);
	return 0;
}

int TerminalBuf::sync()
{
	streamsize n = pptr() - pbase();

	if (n > 0) term->do_sputn(pbase(), n);
	return 0;
}

otstream::otstream( TTerminal *tt ):
	ostream(&buf),
	buf(tt)
{
}