/*-
 * Copyright (c) 2012-2013 Jan Breuer,
 *
 * All Rights Reserved
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @file   main.c
 * @date   Thu Nov 15 10:58:45 UTC 2012
 * 
 * @brief  TCP/IP SCPI Server
 * 
 * 
 */

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

#include <netinet/in.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <arpa/inet.h>
#include <unistd.h>

#include "scpi/scpi.h"
#include "../common/scpi-def.h"

size_t SCPI_Write(scpi_t * context, const char * data, size_t len) {
    if (context->user_context != NULL) {
        int fd = *(int *)(context->user_context);
        return write(fd, data, len);
    }
    return 0;
}

scpi_result_t SCPI_Flush(scpi_t * context) {    
    return SCPI_RES_OK;
}

int SCPI_Error(scpi_t * context, int_fast16_t err) {
    (void) context;
    // BEEP
    fprintf(stderr, "**ERROR: %d, \"%s\"\r\n", (int16_t) err, SCPI_ErrorTranslate(err));
    return 0;
}

scpi_result_t SCPI_Control(scpi_t * context, scpi_ctrl_name_t ctrl, scpi_reg_val_t val) {
    if (SCPI_CTRL_SRQ == ctrl) {
        fprintf(stderr, "**SRQ: 0x%X (%d)\r\n", val, val);
    } else {
        fprintf(stderr, "**CTRL %02x: 0x%X (%d)\r\n", ctrl, val, val);
    }
    return SCPI_RES_OK;
}

scpi_result_t SCPI_Reset(scpi_t * context) {
    fprintf(stderr, "**Reset\r\n");
    return SCPI_RES_OK;
}

scpi_result_t SCPI_SystemCommTcpipControlQ(scpi_t * context) {
    return SCPI_RES_ERR;
}

static int createServer(int port) {
    int fd;
    int rc;
    int on = 1;
    struct sockaddr_in servaddr;
        
    /* Configure TCP Server */
    bzero(&servaddr, sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_addr.s_addr=htonl(INADDR_ANY);
    servaddr.sin_port=htons(port);
    
    /* Create socket */
    fd = socket(AF_INET,SOCK_STREAM, 0);
    if (fd < 0)
    {
        perror("socket() failed");
        exit(-1);
    }    
    
    /* Set address reuse enable */
    rc = setsockopt(fd, SOL_SOCKET,  SO_REUSEADDR, (char *)&on, sizeof(on));
    if (rc < 0)
    {
        perror("setsockopt() failed");
        close(fd);
        exit(-1);
    }
   
    /* Set non blocking */
    rc = ioctl(fd, FIONBIO, (char *)&on);
    if (rc < 0)
    {
        perror("ioctl() failed");
        close(fd);
        exit(-1);
    }    
    
    /* Bind to socket */
    rc = bind(fd, (struct sockaddr *)&servaddr, sizeof(servaddr));
    if (rc < 0)
    {
        perror("bind() failed");
        close(fd);
        exit(-1);
    }
    
    /* Listen on socket */
    listen(fd, 1);
    if (rc < 0)
    {
        perror("listen() failed");
        close(fd);
        exit(-1);
    }
    
    return fd;
}

static int waitServer(int fd) {
    fd_set fds;
    struct timeval timeout;
    int rc;
    int max_fd;
    
    FD_ZERO(&fds);
    max_fd = fd;
    FD_SET(fd, &fds);
    
    timeout.tv_sec  = 5;
    timeout.tv_usec = 0;
    
    rc = select(max_fd + 1, &fds, NULL, NULL, &timeout);
    
    return rc;
}

/*
 * 
 */
int main(int argc, char** argv) {
    (void) argc;
    (void) argv;
    int rc;

    int listenfd;
    char smbuffer[10];

    // user_context will be pointer to socket
    scpi_context.user_context = NULL;
    
    SCPI_Init(&scpi_context);

    listenfd = createServer(5025);
    
    while(1) {
        int clifd;
        struct sockaddr_in cliaddr;
        socklen_t clilen;

        clilen = sizeof(cliaddr);
        clifd = accept(listenfd, (struct sockaddr *)&cliaddr, &clilen);
        
        if (clifd < 0) continue;

        printf("Connection established %s\r\n", inet_ntoa(cliaddr.sin_addr));

        scpi_context.user_context = &clifd;

        while(1) {
            rc = waitServer(clifd);
            if (rc < 0) { // failed
                perror("  recv() failed");
                break;
            }
            if (rc == 0) { // timeout
                SCPI_Input(&scpi_context, NULL, 0);
            }
            if (rc > 0) { // something to read
                rc = recv(clifd, smbuffer, sizeof(smbuffer), 0);
                if (rc < 0) {
                    if (errno != EWOULDBLOCK) {
                        perror("  recv() failed");
                        break;
                    }
                } else if (rc == 0) {                
                    printf("Connection closed\r\n");
                    break;
                } else {
                    SCPI_Input(&scpi_context, smbuffer, rc);
                }
            }
        }

        close(clifd);
    }
    
    return (EXIT_SUCCESS);
}