/*
    This file is part of g15daemon.

    g15daemon 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.

    g15daemon 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 g15daemon; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    (c) 2006-2008 Mike Lampard, Philip Lawatsch, and others
    
    $Revision: 456 $ -  $Date: 2008-01-28 16:35:31 +1030 (Mon, 28 Jan 2008) $ $Author: mlampard $
        
    This daemon listens on localhost port 15550 for client connections,
    and arbitrates LCD display.  Allows for multiple simultaneous clients.
    Client screens can be cycled through by pressing the 'L1' key.
*/
#include <pthread.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <poll.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>

#include <errno.h>
#include <libg15.h>
#include <g15daemon.h>

static int leaving = 0;
static int server_events(plugin_event_t *myevent);

#ifndef SO_PRIORITY
#define SO_PRIORITY 12
#endif

/* tcp server defines */
#define LISTEN_PORT 15550
#define LISTEN_ADDR "127.0.0.1"

/* any more than this number of simultaneous clients will be rejected. */
#define MAX_CLIENTS 10

/* custom plugininfo for clients... */
plugin_info_t lcdclient_info[] = {
        /* TYPE, 	   name, 	initfunc, updatefreq, exitfunc, eventhandler, initfunc */
   {G15_PLUGIN_LCD_SERVER, "LCDclient"	, NULL, 500, NULL, (void*)server_events, NULL},
   {G15_PLUGIN_NONE,               ""   , NULL,   0, NULL,            NULL,      NULL}
};

static void process_client_cmds(lcdnode_t *lcdnode, int sock, unsigned int *msgbuf, unsigned int len)
{

    switch(msgbuf[0]){
    case CLIENT_CMD_SWITCH_PRIORITIES: {
        g15daemon_send_event(lcdnode,G15_EVENT_REQ_PRIORITY,1);
        break;
    }
    case CLIENT_CMD_NEVER_SELECT: { /* client can never be user-selected */
        pthread_mutex_lock(&lcdlist_mutex);
        lcdnode->lcd->never_select = 1;
        pthread_mutex_unlock(&lcdlist_mutex);
        break;
    }
    case CLIENT_CMD_IS_FOREGROUND:  { /* client wants to know if it's currently viewable */
        pthread_mutex_lock(&lcdlist_mutex);
        memset(msgbuf,0,2);
        if(lcdnode->list->current == lcdnode){
            msgbuf[0] = '1';
        }else{
            msgbuf[0] = '0';
        }
        pthread_mutex_unlock(&lcdlist_mutex);
        send(sock,msgbuf,1,MSG_OOB);
        break;
    } 
    case CLIENT_CMD_IS_USER_SELECTED: { /* client wants to know if it was set to foreground by the user */
        pthread_mutex_lock(&lcdlist_mutex);
        if(lcdnode->lcd->usr_foreground==1)  /* user manually selected this lcd */
            msgbuf[0] = 1;
        else
            msgbuf[0] = 0;
        pthread_mutex_unlock(&lcdlist_mutex);
        send(sock,msgbuf,1,MSG_OOB);
        break;
    } 
    default:
       if(msgbuf[0] & CLIENT_CMD_MKEY_LIGHTS) 
       { /* client wants to change the M-key backlights */
          lcdnode->lcd->mkey_state = msgbuf[0]-0x20;
          lcdnode->lcd->state_changed = 1;
          //if the client is the keyhandler, allow full, direct control over the mled status
          if(lcdnode->lcd->masterlist->remote_keyhandler_sock==lcdnode->lcd->connection)
            setLEDs(msgbuf[0]-0x20);
       } else if (msgbuf[0] & CLIENT_CMD_KEY_HANDLER) 
      { 
        g15daemon_log(LOG_WARNING, "Client is taking over keystate");
        
        lcdnode->list->remote_keyhandler_sock = sock;
        g15daemon_log(LOG_WARNING, "Client has taken over keystate");
      }
      else if (msgbuf[0] & CLIENT_CMD_BACKLIGHT) 
      {
        unsigned char retval = lcdnode->lcd->backlight_state;
        send(sock,&retval,1,MSG_OOB);
        lcdnode->lcd->backlight_state = msgbuf[0]-0x80;
        lcdnode->lcd->state_changed = 1;
      }
      else if (msgbuf[0] & CLIENT_CMD_KB_BACKLIGHT) 
      {
        setKBBrightness((unsigned int)msgbuf[0]-0x8);
      }
      else if (msgbuf[0] & CLIENT_CMD_CONTRAST) 
      { 
        send(sock,&lcdnode->lcd->contrast_state,1,MSG_OOB);
        lcdnode->lcd->contrast_state = msgbuf[0]-0x40;
        lcdnode->lcd->state_changed = 1;
      } 
    }
}

/* create and open a socket for listening */
static int init_sockserver(){
    int listening_socket;
    int yes=1;
    int tos = 0x18;

    struct    sockaddr_in servaddr; 

    if ((listening_socket = socket(AF_INET, SOCK_STREAM, 0)) < 0 ) {
        g15daemon_log(LOG_WARNING, "Unable to create socket.\n");
        return -1;
    }

    setsockopt(listening_socket, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
    setsockopt(listening_socket, SOL_SOCKET, SO_PRIORITY, &tos, sizeof(tos));
    
    memset(&servaddr, 0, sizeof(servaddr));
    servaddr.sin_family      = AF_INET;
    inet_aton (LISTEN_ADDR, &servaddr.sin_addr);
    servaddr.sin_port        = htons(LISTEN_PORT);

    if (bind(listening_socket, (struct sockaddr *) &servaddr, sizeof(servaddr)) < 0 ) {
        g15daemon_log(LOG_WARNING, "error calling bind()\n");
        return -1;
    }

    if (listen(listening_socket, MAX_CLIENTS) < 0 ) {
        g15daemon_log(LOG_WARNING, "error calling listen()\n");
        return -1;
    }

    return listening_socket;
}


static int g15_send(int sock, char *buf, unsigned int len)
{
    int total = 0;
    int retval = 0;
    int bytesleft = len;
    struct pollfd pfd[1];
    
    while(total < len && !leaving) {
        memset(pfd,0,sizeof(pfd));
        pfd[0].fd = sock;
        pfd[0].events = POLLOUT | POLLERR | POLLHUP | POLLNVAL;
        if(poll(pfd,1,500)>0) {
            if(pfd[0].revents & POLLOUT && !(pfd[0].revents & POLLERR || pfd[0].revents & POLLHUP || pfd[0].revents & POLLNVAL)) {
                retval = send(sock, buf+total, bytesleft, 0);
                if (retval == -1) { 
                    break; 
                }
                bytesleft -= retval;
                total += retval;
            }
            if((pfd[0].revents & POLLERR || pfd[0].revents & POLLHUP || pfd[0].revents & POLLNVAL)){
                retval=-1;
                break;
            }
        }
    }
    return retval==-1?-1:0;
} 


static int g15_recv(lcdnode_t *lcdnode, int sock, char *buf, unsigned int len)
{
    int total = 0;
    int retval = 0;
    int msgret = 0;
    int bytesleft = len; 
    struct pollfd pfd[1];
    unsigned int msgbuf[20];

    while(total < len  && !leaving) {
        memset(pfd,0,sizeof(pfd));
        pfd[0].fd = sock;
        pfd[0].events = POLLIN | POLLPRI | POLLERR | POLLHUP | POLLNVAL;
        if(poll(pfd,1,500)>0){
            if(pfd[0].revents & POLLPRI && !(pfd[0].revents & POLLERR || pfd[0].revents & POLLHUP || pfd[0].revents & POLLNVAL)) { /* receive out-of-band request from client and deal with it */
                memset(msgbuf,0,20);
                msgret = recv(sock, msgbuf, 10 , MSG_OOB);
                if (msgret < 1) {
                    break;
                }
           	process_client_cmds(lcdnode, sock, msgbuf,len);
            }
            else if(pfd[0].revents & POLLIN && !(pfd[0].revents & POLLERR || pfd[0].revents & POLLHUP || pfd[0].revents & POLLNVAL || pfd[0].revents & POLLPRI)) {

                retval = recv(sock, buf+total, bytesleft, 0);
                if (retval < 1) { 
                    break; 
                }
                total += retval;
                bytesleft -= retval;
            }
            if((pfd[0].revents & POLLERR || pfd[0].revents & POLLHUP || pfd[0].revents & POLLNVAL)){
               retval=-1;
               break;
            }
        }
    }
    return total;
} 


/* the client must send 6880 bytes for each lcd screen.  This thread will continue to copy data
* into the clients LCD buffer for as long as the connection remains open. 
* so, the client should open a socket, check to ensure that the server is a g15daemon,
* and send multiple 6880 byte packets (1 for each screen update) 
* once the client disconnects by closing the socket, the LCD buffer is 
* removed and will no longer be displayed.
*/
static void *lcd_client_thread(void *display) {

    lcdnode_t *g15node = display;
    lcd_t *client_lcd = g15node->lcd;
    int retval;
    unsigned int width, height, buflen,header=4;

    int client_sock = client_lcd->connection;
    char helo[]=SERV_HELO;
    unsigned char *tmpbuf=g15daemon_xmalloc(6880);
    
    if(g15_send(client_sock, (char*)helo, strlen(SERV_HELO))<0){
        goto exitthread;
    }
    /* check for requested buffer type.. we only handle pixel buffers atm */
    if(g15_recv(g15node, client_sock,(char*)tmpbuf,4)<4)
        goto exitthread;

    /* we will in the future handle txt buffers gracefully but for now we just hangup */
    if(tmpbuf[0]=='G') {
        while(!leaving) {
            retval = g15_recv(g15node, client_sock,(char *)tmpbuf,6880);
            if(retval!=6880){
                break;
            }
            pthread_mutex_lock(&lcdlist_mutex);
            memset(client_lcd->buf,0,1024);      
            g15daemon_convert_buf(client_lcd,tmpbuf);
            g15daemon_send_refresh(client_lcd);
            pthread_mutex_unlock(&lcdlist_mutex);
        }
    }
    else if (tmpbuf[0]=='R') { /* libg15render buffer */
        while(!leaving) {
            retval = g15_recv(g15node, client_sock, (char *)tmpbuf, 1048);
            if(retval != 1048) {
                break;
            }
            pthread_mutex_lock(&lcdlist_mutex);
            memcpy(client_lcd->buf,tmpbuf,sizeof(client_lcd->buf));
            g15daemon_send_refresh(client_lcd);
            pthread_mutex_unlock(&lcdlist_mutex);
        }
    }
    else if (tmpbuf[0]=='W'){ /* wbmp buffer - we assume (stupidly) that it's 160 pixels wide */
        while(!leaving) {
            retval = g15_recv(g15node, client_sock,(char*)tmpbuf, 865);
            if(!retval)
                break;

            if (tmpbuf[2] & 1) {
                width = ((unsigned char)tmpbuf[2] ^ 1) | (unsigned char)tmpbuf[3];
                height = tmpbuf[4];
                header = 5;
            } else {
                width = tmpbuf[2];
                height = tmpbuf[3];
                header = 4;
            }

            buflen = (width/8)*height;

            if(buflen>860){ /* grab the remainder of the image and discard excess bytes */
                /*  retval=g15_recv(client_sock,(char*)tmpbuf+865,buflen-860);  */
                retval=g15_recv(g15node, client_sock,NULL,buflen-860); 
                buflen = 860;
            }

            if(width!=160) /* FIXME - we ought to scale images I suppose */
                goto exitthread;

            pthread_mutex_lock(&lcdlist_mutex);
            memcpy(client_lcd->buf,tmpbuf+header,buflen+header);
            g15daemon_send_refresh(client_lcd);
            pthread_mutex_unlock(&lcdlist_mutex);
        }
    }
exitthread:
    if(client_lcd->masterlist->remote_keyhandler_sock==client_sock)
      client_lcd->masterlist->remote_keyhandler_sock=0;
    close(client_sock);
    free(tmpbuf);
    g15daemon_lcdnode_remove(display);
    
    pthread_exit(NULL);
}

/* poll the listening socket for connections, spawning new threads as needed to handle clients */
static int g15_clientconnect (g15daemon_t **g15daemon, int listening_socket) {

    int conn_s;
    struct pollfd pfd[1];
    pthread_t client_connection;
    pthread_attr_t attr;
    lcdnode_t *clientnode;

    memset(pfd,0,sizeof(pfd));
    pfd[0].fd = listening_socket;
    pfd[0].events = POLLIN;

    if (poll(pfd,1,500)>0){
        if (!(pfd[0].revents & POLLIN)){
            return 0;
        }

        if ( (conn_s = accept(listening_socket, NULL, NULL) ) < 0 ) {
            if(errno==EWOULDBLOCK || errno==EAGAIN){
            }else{
                g15daemon_log(LOG_WARNING, "error calling accept()\n");
                return -1;
            }
        }

        clientnode = g15daemon_lcdnode_add(g15daemon);
        clientnode->lcd->connection = conn_s;
        /* override the default (generic handler and use our own for our clients */
        clientnode->lcd->g15plugin->info=(void*)(&lcdclient_info);

        memset(&attr,0,sizeof(pthread_attr_t));
        pthread_attr_init(&attr);
        pthread_attr_setdetachstate(&attr,PTHREAD_CREATE_DETACHED);
        pthread_attr_setstacksize(&attr,256*1024); /* set stack to 768k - dont need 8Mb - this is probably rather excessive also */
        if (pthread_create(&client_connection, &attr, lcd_client_thread, clientnode) != 0) {
            g15daemon_log(LOG_WARNING,"Unable to create client thread.");
            if (close(conn_s) < 0 ) {
                g15daemon_log(LOG_WARNING, "error calling close()\n");
                return -1;
            }

        }
        pthread_detach(client_connection);
    }
    return 0;
}

/* this thread only listens for new connections. 
* sockserver_accept will spawn a new thread for each connected client
*/
static void lcdserver_thread(void *lcdlist){

    g15daemon_t *masterlist = (g15daemon_t*) lcdlist ;
    int g15_socket=-1;

    if((g15_socket = init_sockserver())<0){
        g15daemon_log(LOG_ERR,"Unable to initialise the server at port %i",LISTEN_PORT);
        return;
    }

    if (fcntl(g15_socket, F_SETFL, O_NONBLOCK) <0 ) {
        g15daemon_log(LOG_ERR,"Unable to set socket to nonblocking");
    }

    while ( !leaving ) {
        g15_clientconnect(&masterlist,g15_socket);
    }

    close(g15_socket);
    return;
}

/* incoming events */
static int server_events(plugin_event_t *event) {
    lcd_t *lcd = (lcd_t*) event->lcd;

    switch (event->event)
    {
        case G15_EVENT_KEYPRESS:{
            if(lcd->connection && lcd->masterlist->remote_keyhandler_sock!=lcd->connection) { /* server client */
                if((send(lcd->connection,(void *)&event->value,sizeof(event->value),0))<0) 
                    g15daemon_log(LOG_WARNING,"Error in send: %s\n",strerror(errno));
            }
            break;
        }
        case G15_EVENT_VISIBILITY_CHANGED:
        	break;
        case G15_EVENT_USER_FOREGROUND:
            lcd->usr_foreground = event->value;
            break;
	case G15_EVENT_MLED:
        case G15_EVENT_BACKLIGHT:
        case G15_EVENT_CONTRAST:
        /* should never receive these */
        default:
            break;
    }
    return G15_PLUGIN_OK;
}

static void g15plugin_net_exit() {

  leaving = 1;

}
    /* if no exitfunc or eventhandler, member should be NULL */
plugin_info_t g15plugin_info[] = {
        /* TYPE, name, initfunc, 				updatefreq, exitfunc, eventhandler, initfunc */
   {G15_PLUGIN_LCD_SERVER, "LCDServer"	, (void*)lcdserver_thread, 500, (void*)g15plugin_net_exit, (void*)server_events, NULL},
   {G15_PLUGIN_NONE,               ""          			, NULL,   0,   			NULL,            NULL,           NULL}
};