/*
    CHAT:  A chat client using the SDL example network and GUI libraries
    Copyright (C) 1997-2009 Sam Lantinga

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    5635-34 Springhouse Dr.
    Pleasanton, CA 94588 (USA)
    slouken@devolution.com
*/

/* Note that this isn't necessarily the way to run a chat system.
   This is designed to excercise the network code more than be really
   functional.
*/

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

#include "SDL_net.h"
#ifdef macintosh
#include "GUI.h"
#include "GUI_widgets.h"
#else
#include <GUI/GUI.h>
#include <GUI/GUI_widgets.h>
#endif
#include "chat.h"


/* Global variables */
static TCPsocket tcpsock = NULL;
static UDPsocket udpsock = NULL;
static SDLNet_SocketSet socketset = NULL;
static UDPpacket **packets = NULL;
static struct {
	int active;
	Uint8 name[256+1];
} people[CHAT_MAXPEOPLE];

static GUI *gui = NULL;
static GUI_TermWin *termwin;
static GUI_TermWin *sendwin;
enum image_names {
	IMAGE_QUIT,
	IMAGE_SCROLL_UP,
	IMAGE_SCROLL_DN,
	NUM_IMAGES
};
char *image_files[NUM_IMAGES] = {
	"quit.bmp", "scroll_up.bmp", "scroll_dn.bmp"
};
SDL_Surface *images[NUM_IMAGES];


void SendHello(char *name)
{
	IPaddress *myip;
	char hello[1+1+256];
	int i, n;

	/* No people are active at first */
	for ( i=0; i<CHAT_MAXPEOPLE; ++i ) {
		people[i].active = 0;
	}
	if ( tcpsock != NULL ) {
		/* Get our chat handle */
		if ( (name == NULL) &&
		     ((name=getenv("CHAT_USER")) == NULL) &&
		     ((name=getenv("USER")) == NULL ) ) {
			name="Unknown";
		}
		termwin->AddText("Using name '%s'\n", name);

		/* Construct the packet */
		hello[0] = CHAT_HELLO;
		myip = SDLNet_UDP_GetPeerAddress(udpsock, -1);
		memcpy(&hello[CHAT_HELLO_PORT], &myip->port, 2);
		if ( strlen(name) > 255 ) {
			n = 255;
		} else {
			n = strlen(name);
		}
		hello[CHAT_HELLO_NLEN] = n;
		strncpy(&hello[CHAT_HELLO_NAME], name, n);
		hello[CHAT_HELLO_NAME+n++] = 0;

		/* Send it to the server */
		SDLNet_TCP_Send(tcpsock, hello, CHAT_HELLO_NAME+n);
	}
}

void SendBuf(char *buf, int len)
{
	int i;

	/* Redraw the prompt and add a newline to the buffer */
	sendwin->Clear();
	sendwin->AddText(CHAT_PROMPT);
	buf[len++] = '\n';

	/* Send the text to each of our active channels */
	for ( i=0; i < CHAT_MAXPEOPLE; ++i ) {
		if ( people[i].active ) {
			if ( len > packets[0]->maxlen ) {
				len = packets[0]->maxlen;
			}
			memcpy(packets[0]->data, buf, len);
			packets[0]->len = len;
			SDLNet_UDP_Send(udpsock, i, packets[0]);
		}
	}
}
void SendKey(SDLKey key, Uint16 unicode)
{
	static char keybuf[80-sizeof(CHAT_PROMPT)+1];
	static int  keypos = 0;
	unsigned char ch;

	/* We don't handle wide UNICODE characters yet */
	if ( unicode > 255 ) {
		return;
	}
	ch = (unsigned char)unicode;

	/* Add the key to the buffer, and send it if we have a line */
	switch (ch) {
		case '\0':
			break;
		case '\r':
		case '\n':
			/* Send our line of text */
			SendBuf(keybuf, keypos);
			keypos = 0;
			break;
		case '\b':
			/* If there's data, back up over it */
			if ( keypos > 0 ) {
				sendwin->AddText((char *)&ch, 1);
				--keypos;
			}
			break;
		default:
			/* If the buffer is full, send it */
			if ( keypos == (sizeof(keybuf)/sizeof(keybuf[0]))-1 ) {
				SendBuf(keybuf, keypos);
				keypos = 0;
			}
			/* Add the text to our send buffer */
			sendwin->AddText((char *)&ch, 1);
			keybuf[keypos++] = ch;
			break;
	}
}

int HandleServerData(Uint8 *data)
{
	int used;

	switch (data[0]) {
		case CHAT_ADD: {
			Uint8 which;
			IPaddress newip;

			/* Figure out which channel we got */
			which = data[CHAT_ADD_SLOT];
			if ((which >= CHAT_MAXPEOPLE) || people[which].active) {
				/* Invalid channel?? */
				break;
			}
			/* Get the client IP address */
			newip.host=SDLNet_Read32(&data[CHAT_ADD_HOST]);
			newip.port=SDLNet_Read16(&data[CHAT_ADD_PORT]);

			/* Copy name into channel */
			memcpy(people[which].name, &data[CHAT_ADD_NAME], 256);
			people[which].name[256] = 0;
			people[which].active = 1;

			/* Let the user know what happened */
			termwin->AddText(
	"* New client on %d from %d.%d.%d.%d:%d (%s)\n", which,
		(newip.host>>24)&0xFF, (newip.host>>16)&0xFF,
			(newip.host>>8)&0xFF, newip.host&0xFF,
					newip.port, people[which].name);

			/* Put the address back in network form */
			newip.host = SDL_SwapBE32(newip.host);
			newip.port = SDL_SwapBE16(newip.port);

			/* Bind the address to the UDP socket */
			SDLNet_UDP_Bind(udpsock, which, &newip);
		}
		used = CHAT_ADD_NAME+data[CHAT_ADD_NLEN];
		break;
		case CHAT_DEL: {
			Uint8 which;

			/* Figure out which channel we lost */
			which = data[CHAT_DEL_SLOT];
			if ( (which >= CHAT_MAXPEOPLE) ||
						! people[which].active ) {
				/* Invalid channel?? */
				break;
			}
			people[which].active = 0;

			/* Let the user know what happened */
			termwin->AddText(
	"* Lost client on %d (%s)\n", which, people[which].name);

			/* Unbind the address on the UDP socket */
			SDLNet_UDP_Unbind(udpsock, which);
		}
		used = CHAT_DEL_LEN;
		break;
		case CHAT_BYE: {
			termwin->AddText("* Chat server full\n");
		}
		used = CHAT_BYE_LEN;
		break;
		default: {
			/* Unknown packet type?? */;
		}
		used = 0;
		break;
	}
	return(used);
}

void HandleServer(void)
{
	Uint8 data[512];
	int pos, len;
	int used;

	/* Has the connection been lost with the server? */
	len = SDLNet_TCP_Recv(tcpsock, (char *)data, 512);
	if ( len <= 0 ) {
		SDLNet_TCP_DelSocket(socketset, tcpsock);
		SDLNet_TCP_Close(tcpsock);
		tcpsock = NULL;
		termwin->AddText("Connection with server lost!\n");
	} else {
		pos = 0;
		while ( len > 0 ) {
			used = HandleServerData(&data[pos]);
			pos += used;
			len -= used;
			if ( used == 0 ) {
				/* We might lose data here.. oh well,
				   we got a corrupt packet from server
				 */
				len = 0;
			}
		}
	}
}
void HandleClient(void)
{
	int n;

	n = SDLNet_UDP_RecvV(udpsock, packets);
	while ( n-- > 0 ) {
		if ( packets[n]->channel >= 0 ) {
			termwin->AddText("[%s] ", 
				people[packets[n]->channel].name);
			termwin->AddText((char *)packets[n]->data, packets[n]->len);
		}
	}
}

GUI_status HandleNet(void)
{
	SDLNet_CheckSockets(socketset, 0);
	if ( SDLNet_SocketReady(tcpsock) ) {
		HandleServer();
	}
	if ( SDLNet_SocketReady(udpsock) ) {
		HandleClient();
	}

	/* Redraw the screen if the window changed */
	if ( termwin->Changed() ) {
		return(GUI_REDRAW);
	} else {
		return(GUI_PASS);
	}
}

void InitGUI(SDL_Surface *screen)
{
	int x1, y1, y2;
	SDL_Rect empty_rect = { 0, 0, 0, 0 };
        GUI_Widget *widget;

	gui = new GUI(screen);

	/* Chat terminal window */
	termwin = new GUI_TermWin(0, 0, 80*8, 50*8, NULL,NULL,CHAT_SCROLLBACK);
	gui->AddWidget(termwin);

	/* Send-line window */
	y1 = termwin->H()+2;
	sendwin = new GUI_TermWin(0, y1, 80*8, 1*8, NULL, SendKey, 0);
	sendwin->AddText(CHAT_PROMPT);
	gui->AddWidget(sendwin);

	/* Add scroll buttons for main window */
	y1 += sendwin->H()+2;
	y2 = y1+images[IMAGE_SCROLL_UP]->h;
	widget = new GUI_ScrollButtons(2, y1, images[IMAGE_SCROLL_UP],
	                   empty_rect, 2, y2, images[IMAGE_SCROLL_DN],
					SCROLLBAR_VERTICAL, termwin);
	gui->AddWidget(widget);

	/* Add QUIT button */
	x1 = (screen->w-images[IMAGE_QUIT]->w)/2;
	y1 = sendwin->Y()+sendwin->H()+images[IMAGE_QUIT]->h/2;
	widget = new GUI_Button(NULL, x1, y1, images[IMAGE_QUIT], NULL);
	gui->AddWidget(widget);

	/* That's all folks */
	return;
}

extern "C"
void cleanup(int exitcode)
{
	int i;

	/* Clean up the GUI */
	if ( gui ) {
        	delete gui;
		gui = NULL;
	}
	/* Clean up any images we have */
	for ( i=0; i<NUM_IMAGES; ++i ) {
		if ( images[i] ) {
			SDL_FreeSurface(images[i]);
			images[i] = NULL;
		}
	}
	/* Close the network connections */
	if ( tcpsock != NULL ) {
		SDLNet_TCP_Close(tcpsock);
		tcpsock = NULL;
	}
	if ( udpsock != NULL ) {
		SDLNet_UDP_Close(udpsock);
		udpsock = NULL;
	}
	if ( socketset != NULL ) {
		SDLNet_FreeSocketSet(socketset);
		socketset = NULL;
	}
	if ( packets != NULL ) {
		SDLNet_FreePacketV(packets);
		packets = NULL;
	}
	SDLNet_Quit();
	SDL_Quit();
	exit(exitcode);
}

int main(int argc, char *argv[])
{
        SDL_Surface *screen;
	int i;
	char *server;
	IPaddress serverIP;

	/* Check command line arguments */
	if ( argv[1] == NULL ) {
		fprintf(stderr, "Usage: %s <server>\n", argv[0]);
		exit(1);
	}
	
        /* Initialize SDL */
        if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
                fprintf(stderr, "Couldn't initialize SDL: %s\n",SDL_GetError());
                exit(1);
	}

	/* Set a 640x480 video mode -- allows 80x50 window using 8x8 font */
	screen = SDL_SetVideoMode(640, 480, 0, SDL_SWSURFACE);
	if ( screen == NULL ) {
                fprintf(stderr, "Couldn't set video mode: %s\n",SDL_GetError());
		SDL_Quit();
                exit(1);
	}

	/* Initialize the network */
	if ( SDLNet_Init() < 0 ) {
		fprintf(stderr, "Couldn't initialize net: %s\n",
						SDLNet_GetError());
		SDL_Quit();
		exit(1);
	}

	/* Get ready to initialize all of our data */

	/* Load the display font and other images */
	for ( i=0; i<NUM_IMAGES; ++i ) {
		images[i] = NULL;
	}
	for ( i=0; i<NUM_IMAGES; ++i ) {
		images[i] = SDL_LoadBMP(image_files[i]);
		if ( images[i] == NULL ) {
			fprintf(stderr, "Couldn't load '%s': %s\n",
					image_files[i], SDL_GetError());
			cleanup(2);
		}
	}

	/* Go! */
	InitGUI(screen);

	/* Allocate a vector of packets for client messages */
	packets = SDLNet_AllocPacketV(4, CHAT_PACKETSIZE);
	if ( packets == NULL ) {
		fprintf(stderr, "Couldn't allocate packets: Out of memory\n");
		cleanup(2);
	}

	/* Connect to remote host and create UDP endpoint */
	server = argv[1];
	termwin->AddText("Connecting to %s ... ", server);
	gui->Display();
	SDLNet_ResolveHost(&serverIP, server, CHAT_PORT);
	if ( serverIP.host == INADDR_NONE ) {
		termwin->AddText("Couldn't resolve hostname\n");
	} else {
		/* If we fail, it's okay, the GUI shows the problem */
		tcpsock = SDLNet_TCP_Open(&serverIP);
		if ( tcpsock == NULL ) {
			termwin->AddText("Connect failed\n");
		} else {
			termwin->AddText("Connected\n");
		}
	}
	/* Try ports in the range {CHAT_PORT - CHAT_PORT+10} */
	for ( i=0; (udpsock == NULL) && i<10; ++i ) {
		udpsock = SDLNet_UDP_Open(CHAT_PORT+i);
	}
	if ( udpsock == NULL ) {
		SDLNet_TCP_Close(tcpsock);
		tcpsock = NULL;
		termwin->AddText("Couldn't create UDP endpoint\n");
	}

	/* Allocate the socket set for polling the network */
	socketset = SDLNet_AllocSocketSet(2);
	if ( socketset == NULL ) {
		fprintf(stderr, "Couldn't create socket set: %s\n",
						SDLNet_GetError());
		cleanup(2);
	}
	SDLNet_TCP_AddSocket(socketset, tcpsock);
	SDLNet_UDP_AddSocket(socketset, udpsock);

	/* Run the GUI, handling network data */
	SendHello(argv[2]);
	gui->Run(HandleNet);
	cleanup(0);

	/* Keep the compiler happy */
	return(0);
}
