/**

 * $Id$

 *

 * Host driver for a serial port attachment, that can be hooked to a character

 * device, fifo or named pipe.

 *

 * Copyright (c) 2009 Nathan Keynes.

 *

 * 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.

 */

#include <stdio.h>

#include <stdlib.h>

#include <fcntl.h>

#include <sys/stat.h>

#include "lxdream.h"

#include "config.h"

#include "ioutil.h"

#include "serial.h"

typedef struct serial_fd_device {

    struct serial_device dev;

    FILE *in;

    FILE *out;

    gboolean closeOnDestroy;

    io_listener_t listener;

} *serial_fd_device_t;

static void serial_fd_device_attach(serial_device_t dev);

static void serial_fd_device_detach(serial_device_t dev);

static void serial_fd_device_destroy(serial_device_t dev);

static void serial_fd_device_set_line_speed(struct serial_device *dev, uint32_t bps);

static void serial_fd_device_set_line_params(struct serial_device *dev, int flags);

static void serial_fd_device_receive_data(struct serial_device *dev, uint8_t value);

static gboolean serial_fd_device_transmit_data( int fd, void *dev);

static gboolean serial_config_changed(void *data, struct lxdream_config_group *group, unsigned item,

                                      const gchar *oldval, const gchar *newval);

struct lxdream_config_group serial_group =

    { "serial", serial_config_changed, NULL, NULL,

       {{ "device", N_("Serial device"), CONFIG_TYPE_FILE, "/dev/tty" },

        { NULL, CONFIG_TYPE_NONE }} };

void serial_init()

{

    const gchar *name = serial_group.params[0].value;

    if( name != NULL ) {

        serial_device_t dev = serial_fd_device_new_filename(name);

        if( dev != NULL ) {

            serial_attach_device( dev );

        }

    }

}

static gboolean serial_config_changed(void *data, struct lxdream_config_group *group, unsigned item,

                                      const gchar *oldval, const gchar *newval)

{

    if( item == 0 ) {

        serial_destroy_device(serial_detach_device());

        serial_device_t dev = serial_fd_device_new_filename(newval);

        if( dev != NULL ) {

            serial_attach_device( dev );

        }

    }

    return TRUE;

}

serial_device_t serial_fd_device_new_filename( const gchar *filename )

{

    FILE *out = fopen( filename, "w+" );

    FILE *in;

    struct stat st;

    if( out == NULL ) {

        return NULL;

    }

    if( fstat( fileno(out), &st ) != 0 ) {

        fclose(out);

        return NULL;

    }

    if( S_ISCHR(st.st_mode) || S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode) ) {

        in = out;

    } else {

        in = NULL;

    }

    return (serial_device_t)serial_fd_device_new_file(in, out, TRUE);

}

serial_device_t serial_fd_device_new_console()

{

    return serial_fd_device_new_file( stdin, stdout, FALSE );

}

serial_device_t serial_fd_device_new_file( FILE *in, FILE *out, gboolean closeOnDestroy )

{

    if( in != NULL )

        fcntl( fileno(in), F_SETFL, O_NONBLOCK );

    serial_fd_device_t dev = (serial_fd_device_t)malloc(sizeof(struct serial_fd_device));

    if( dev == NULL ) {

        if( closeOnDestroy ) {

            if( in != NULL )

                fclose(in);

            if( out != NULL && out != in )

                fclose(out);

        }

        return NULL;

    }

    dev->dev.attach = serial_fd_device_attach;

    dev->dev.detach = serial_fd_device_detach;

    dev->dev.destroy = serial_fd_device_destroy;

    dev->dev.set_line_speed = serial_fd_device_set_line_speed;

    dev->dev.set_line_params = serial_fd_device_set_line_params;

    dev->dev.receive_data = serial_fd_device_receive_data;

    dev->in = in;

    dev->out = out;

    dev->closeOnDestroy = closeOnDestroy;

    return (serial_device_t)dev;

}

static void serial_fd_device_attach(serial_device_t dev)

{

    serial_fd_device_t fddev = (serial_fd_device_t)dev;

    if( fddev->in != NULL )

        fddev->listener = io_register_listener( fileno(fddev->in), serial_fd_device_transmit_data, fddev, NULL );

}

static void serial_fd_device_detach(serial_device_t dev)

{

    serial_fd_device_t fddev = (serial_fd_device_t)dev;

    if( fddev->in != NULL )

        io_unregister_listener( fddev->listener );

}

static void serial_fd_device_destroy(serial_device_t dev)

{

    serial_fd_device_t fddev = (serial_fd_device_t)dev;

    if( fddev->closeOnDestroy ) {

        if( fddev->in != NULL )

            fclose(fddev->in);

        if( fddev->out != NULL && fddev->out != fddev->in )

            fclose(fddev->out);

    }

    fddev->in = NULL;

    fddev->out = NULL;

    free(fddev);

}

static void serial_fd_device_set_line_speed(struct serial_device *dev, uint32_t bps)

{

    /* Do nothing for now */

}

static void serial_fd_device_set_line_params(struct serial_device *dev, int flags)

{

    /* Do nothing for now */

}

static void serial_fd_device_receive_data(struct serial_device *dev, uint8_t value)

{

    serial_fd_device_t fddev = (serial_fd_device_t)dev;

    if( fddev->out != NULL )

        fputc( value, fddev->out );

}

static gboolean serial_fd_device_transmit_data( int fd, void *dev )

{

    serial_fd_device_t fddev = (serial_fd_device_t)dev;

    char buf[4096];

    size_t len = fread(buf, 1, sizeof(buf), fddev->in);

    if( len > 0 ) {

        serial_transmit_data(buf, len);

    }

    return TRUE;

}