// vt102em.cpp - vt102 emulator methods

// $Id: vt102em.cpp 2.3 1995/10/31 02:26:20 tsurace Beta $
// $Log: vt102em.cpp $// Revision 2.3  1995/10/31  02:26:20  tsurace// Fixed ret_val uninitialized in _SysMenuCommand.//
// Revision 2.2  1995/10/30  18:28:46  tsurace
// Added debug toggle and console mode switch to system menu.
//
// Revision 2.1  1995/10/24  15:52:51  tsurace
// Roll.
//
// Revision 1.8  1995/10/19  00:58:27  tsurace
// Changed title.
//
// Revision 1.7  1995/10/18  22:58:01  tsurace
// Made MY_SOCKET_LONG message globally accessible.
//
// Revision 1.6  1995/10/15  23:33:25  tsurace
// Added one line comment.
//
// Revision 1.5  1995/10/15  23:23:39  tsurace
// Fixed bug that caused all windows to resize on SIZE_MINIMIZE.
//
// Revision 1.4  1995/10/11  21:40:43  tsurace
// Modified the "select event" handling code.
// Modified resize functionality.
// Reflects changes to the scream_and_die function.
//
// Revision 1.3  1995/10/08  23:29:29  tsurace
// Modified code to update more quickly when scrolling.  It kind
// of sucks if you have a slow display card right now.
//
// Revision 1.2  1995/10/07  00:33:48  tsurace
// Added some cursor colors and the _Size function.  Scrolling
// optimization.
//
// (End of log)

// This is a simple VT102 emulator library for 32-bit
// programs only, but supportive of win32s.  This is intended to
// support the subset of vt102 required by VaporTalk, the best MUD
// client in the world.  It may also support ANSI color, someday.

#define  STRICT
#include <windows.h>
#pragma hdrstop

#include <stdlib.h>
#include <string.h>

#include "debug.hpp"
#include "esc_seq.hpp"
#include "global.hpp"
#include "keyev.hpp"
#include "vt102em.hpp"

extern "C" {
    // Functions from VT -- these define entry points into the
    // vt code to send keyboard events, check for remote input, and
    // so on.
    //
    // Be sure to check the type of these when updating
    // to a new version of VT!  I wanted to put these in a shared header
    // file, but it was getting to be a lot of trouble.  <frown>
    
    extern int io_check(long sec, long usec);  /* remote.c */
    extern int io_cycle();                     /* main.c */
    extern void process_incoming (char * str); /* keyboard input routine */
    extern void resize_screen(int new_rows, int new_cols);
    extern void curs_input();                  /* window.c */

    extern void console();                     /* console.c */
    extern int console_mode;                   /* console.c */
    extern int debug;                          /* vtc.c */
};

#define TEXT_FORE RGB(160,160,160)
#define TEXT_BACK RGB(0,0,0)
#define TEXT_BOLD RGB(40,255,100)
#define CURSOR_FORE RGB(255,255,255)
#define CURSOR_BACK RGB(128,0,128)
//
// >>>>> VT102Emulator class <<<<< //
//

char VT102Emulator::_szClassName[] = "VT102 Emulator Window";
static const char _TITLE[] = "VT-Win 1.1 $State: Beta $";

// ------------------------------------------------------------------------
// VT102Emulator constructor
// Do not create unless previously registered.
//
VT102Emulator::VT102Emulator(int nCmdShow)
: _screen(80,35,
          TEXT_FORE, // Normal foreground
          TEXT_BOLD,  // Bold foreground
          &VT102Emulator::InvalidateStaticCB,
          this,
          &VT102Emulator::ScrollAreaStaticCB,
          this),
  _font(0),
  _cursorColor(CURSOR_FORE),
  _cursorBackground(CURSOR_BACK),
  _cursorPen(0),
  _backgroundColor(TEXT_BACK),
  _fontSize(8,16),
  _lastPaintTickCount(0),
  _forceUpdateSoon(0),
  _initialized(0)
{
    // A Windows class should be registered with Windows before any windows
    // of that type are created.
    if (! Global::PrevInstance())      // Not already registered?
        _Register();              // Register!

    // Create a window, and Pass 'this' pointer in lpParam of CreateWindow()
    _hWnd = CreateWindow(_szClassName,
                         _TITLE,
                         WS_OVERLAPPEDWINDOW,
                         CW_USEDEFAULT,
                         0,
                         CW_USEDEFAULT,
                         0,
                         NULL,
                         NULL,
                         Global::Instance(),
                         (LPSTR) this );

    // Could not create window, might as well exit
    if (!_hWnd)
        scream_and_die(EC_FatalError, ERR_CreateWindow);

    // Load the monospace font, and initialize the "screen"
    _InitScreen();
    Show(nCmdShow);    // Show the window the correct/official way
    Update();
    _initialized = 1;  // Call after construction
};

VT102Emulator::~VT102Emulator()
{
    // _cursorPen is a stock object
    // _font is a stock object, maybe
}

// ------------------------------------------------------------------------
// ScrollAreaStaticCB - callback function, calls ScrollArea
//
int VT102Emulator::ScrollAreaStaticCB(int target,
                                      int source,
                                      int size,
                                      void * this_ptr)
{
    return ((VT102Emulator *)this_ptr)->ScrollArea(target, source, size);
}

// ------------------------------------------------------------------------
// ScrollArea - Scrolls the specified area of the screen
//
// Parameters:
//   top - first line to scroll (zero-indexed)
//   bottom - last line to scroll (also zero-indexed)
//   amount - amount to scroll, may be negative
//
// Returns:
//   nonzero if the row was successfully copied
//
int VT102Emulator::ScrollArea(int top, int bottom, int amount)
{
    ASSERT(bottom >= top, "No area to scroll");
    ASSERT(top >= 0, "Top is off screen");
    ASSERT(bottom < _screen.Height(), "Bottom is off screen");

    if (amount != 0)
    {
        RECT area;   
        area.top = top * _fontSize.Height();
        area.bottom = ((bottom + 1) * _fontSize.Height()) - 1;
        area.left = 0;
        area.right = (_screen.Width() * _fontSize.Width());

        ScrollWindow(Handle(),
                     0,         // No scroll of x
                     - (amount * _fontSize.Height()),  
                     NULL,      // Must be null so that exposed regions scroll
                     &area);     // Clip area

        _forceUpdateSoon = 1;
    };
    
    return 1;  // Successful scroll
}

// ------------------------------------------------------------------------
// _InvalidateStaticCB - invalidate rect - static callback calls builtin
void VT102Emulator::InvalidateStaticCB(const Pos & pos,
                                       const Size & size,
                                       void * this_ptr)
{
    ((VT102Emulator *)this_ptr)->Invalidate(pos, size);
}

void VT102Emulator::Invalidate(const Pos & pos, const Size & size)
{
    RECT area;
    area.left = pos.X() * _fontSize.Width();
    area.top = pos.Y() * _fontSize.Height();
    area.right = (pos.X() + size.Width()) * _fontSize.Width();
    area.bottom = (pos.Y() + size.Height()) * _fontSize.Height();
    
    // Don't clear, because it causes an annoying flicker, and the
    // textbackmode is opaque anyway
    InvalidateRect(Handle(), &area, TRUE);
}

// ------------------------------------------------------------------------
// NewSocket - tell windows about this new socket.
//
// Returns:
//   NULL on success or an error string on failure.
const char * VT102Emulator::NewSocket (SOCKET s, long events)
{
    // Select soctet messages
    if (SOCKET_ERROR == WSAAsyncSelect (s, Handle(), VT_SOCKET_MSG, events))
    {
        switch (WSAGetLastError())
        {
          case WSAENETDOWN: // Net is dead!
            return "The network is dead";

          case WSAEINPROGRESS:
            return "Blocking WinSock operation in progress";
            
          default:
            return "A horrible unknown WinSock error occurred";
        };
    };
    return NULL; // No problem
};


// ------------------------------------------------------------------------
void VT102Emulator::Output(char * str, int len)
{
    for (int i=0; i < len; i++)
    {
        _screen.Put(str[i]);   // Output the next character
        
        // Update screen at LEAST every quarter of a second, which is
        // generally accepted as the minimum acceptable delay.
        if (_forceUpdateSoon
            || ((GetTickCount() - _lastPaintTickCount) > 200))
        {
            Update();
        };
    };
}

// >>>>> PRIVATE and PROTECTED functions <<<<< //

// ------------------------------------------------------------------------
// This is the expose function, the critical heart of any graphic
// program!  :>
//
// Only call this in response to a WM_PAINT event!
//
void VT102Emulator::_Paint()
{
    _lastPaintTickCount = GetTickCount(); // Now
    _forceUpdateSoon = 0;                 // We are updating now.
    
    PAINTSTRUCT ps; // Begin paint, get info
    BeginPaint(Handle(), &ps);
    
    RECT clip_rect;
    GetClipBox(ps.hdc, &clip_rect);
    HRGN clip_reg = CreateRectRgnIndirect(&clip_rect);
    SelectClipRgn(ps.hdc, clip_reg);
    
    _PutText(ps.hdc, clip_reg);
    _PutCursor(ps.hdc);
    
    DeleteObject(clip_reg); // Don't need this region any more
    
    EndPaint(Handle(), &ps ); // Done, yay!
}

// ------------------------------------------------------------------------
// _PutTextOneLine - puts just this line of text on the screen
//
void VT102Emulator::_PutTextOneLine(HDC hdc, int row)
{
    ASSERT(_screen.Width() > 0, "Assuming the screen has width");
    
    // TextOut is very slow...count characters that are all the
    // same color and put them all at once.
    
    int y_pixel_location = row * _fontSize.Height();
    int x_text_location = 0;
    int start = _screen.IndexOf(0,row); // Start of string to put
    int row_end_marker = start + _screen.Width();
    int width = 0; // Width of current segment
    COLORREF thisColor = _screen.ForegroundElement(start);
    while(1)   // Loop forever
    {
        ++width;
        int end = start + width; // End of string
        if ((end >= row_end_marker)
            || (_screen.ForegroundElement(end) != thisColor))
        {
            // New color, flush text.
            SetTextColor(hdc, thisColor);
            TextOut(hdc,
                    x_text_location * _fontSize.Width(),
                    y_pixel_location,
                    &_screen.TextElement(start),
                    width);
            
            if (end >= row_end_marker) // Done with this line
                break;
            
            start += width; // Increment array offset
            x_text_location += width; // Increment column offset
            width = 0;        
            thisColor = _screen.ForegroundElement(end); // Save new color
        };
    };
}

// ------------------------------------------------------------------------
// _PutText - _Paint helper function that updates all modified text areas
//
// Parameters:
//   hdc - dc to paint to
//   clip_reg - current exposed region
//
void VT102Emulator::_PutText(HDC hdc, HRGN clip_reg)
{
    RECT exposeRect;
    GetRgnBox(clip_reg, &exposeRect); // What area of the screen to paint?
    
    int firstRow = (exposeRect.top+1) / _fontSize.Height();
    if (firstRow < 0) // Off top of screen?
        firstRow = 0;              
    else if (firstRow >= _screen.Height()) // Or bottom?
        firstRow = _screen.Height();
    
    int lastRow = (exposeRect.bottom) / _fontSize.Height();
    if (lastRow < 0) // Off top of screen
        lastRow = 0;
    else if (lastRow >= _screen.Height()) // Off bottom of screen?