/*
 * @author Hallyson Melo <hallyson.melo@indt.org.br>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser 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 Lesser 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
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <string.h>
#include <glib.h>
#include <math.h>

#include <libgnomevfs/gnome-vfs-module.h>
#include <libgnomevfs/gnome-vfs-utils.h>

#include "gmyth_file_transfer.h"

#define GST_MYTHTV_ID_NUM               1
#define MYTHTV_VERSION_DEFAULT          30

#define MYTHTV_BUFFER_SIZE		1024*64

static GnomeVFSResult do_read (GnomeVFSMethod *method,
                               GnomeVFSMethodHandle *method_handle,
                               gpointer buffer,
                               GnomeVFSFileSize num_bytes,
                               GnomeVFSFileSize *bytes_read,
                               GnomeVFSContext *context);

typedef struct {
    GMythFileTransfer *file_transfer;
    
    gint mythtv_version;
    guint64 content_size;
    guint64 bytes_read;

    GByteArray *buffer;
    gsize buffer_remain;
} MythtvHandle;



static GnomeVFSResult
do_open (GnomeVFSMethod *method,
         GnomeVFSMethodHandle **method_handle,
         GnomeVFSURI *uri,
         GnomeVFSOpenMode mode,
         GnomeVFSContext *context)
{

    const gchar *user, *password, *host, *transfer_uri;
    MythtvHandle *myth_handle;

    GString *uri_str;
    guint port;
    gchar *path;
    gboolean ret;

    _GNOME_VFS_METHOD_PARAM_CHECK (method_handle != NULL);
    _GNOME_VFS_METHOD_PARAM_CHECK (uri != NULL);

    g_debug ("[%s] Calling do_open function", __FUNCTION__);
	    
    myth_handle = g_new0 (MythtvHandle, 1);

    if (mode & GNOME_VFS_OPEN_WRITE) {
        return GNOME_VFS_ERROR_NOT_PERMITTED;
    }

    if ((host = gnome_vfs_uri_get_host_name (uri)) == NULL) {
	return GNOME_VFS_ERROR_INVALID_HOST_NAME;
    }

    /* Parse URI */
    path = gnome_vfs_unescape_string (uri->text, NULL);
    port = gnome_vfs_uri_get_host_port (uri);
    user = gnome_vfs_uri_get_user_name (uri);
    password = gnome_vfs_uri_get_password (uri);

    transfer_uri = gnome_vfs_uri_to_string (uri, 
		    GNOME_VFS_URI_HIDE_USER_NAME | GNOME_VFS_URI_HIDE_PASSWORD);
   
    /* Initialize mythtv handler*/
    myth_handle->file_transfer = NULL;
    myth_handle->mythtv_version = MYTHTV_VERSION_DEFAULT;
    myth_handle->bytes_read = 0;
    myth_handle->content_size = -1;

    /* Connect to the backend */
    myth_handle->file_transfer = gmyth_file_transfer_new ();

    g_return_val_if_fail (myth_handle->file_transfer != NULL, GNOME_VFS_ERROR_NOT_OPEN);

    /* sets the Playback monitor connection */
    uri_str = g_string_new (transfer_uri);
    ret = gmyth_file_transfer_open (myth_handle->file_transfer, uri_str);
    if (ret == FALSE) {
        g_printerr ("Mythtv FileTransfer open error\n");
        return GNOME_VFS_ERROR_NOT_OPEN;
    }
    g_string_free (uri_str, TRUE);

    // TODO: Verify if file exists in the backend

    myth_handle->content_size = myth_handle->file_transfer->filesize;
    
    myth_handle->buffer = g_byte_array_sized_new (MYTHTV_BUFFER_SIZE);
    myth_handle->buffer_remain = 0;

    *method_handle = (GnomeVFSMethodHandle *) myth_handle;

    return GNOME_VFS_OK;
}

static GnomeVFSResult
do_read (GnomeVFSMethod *method,
         GnomeVFSMethodHandle *method_handle,
         gpointer buffer,
         GnomeVFSFileSize num_bytes,
         GnomeVFSFileSize *bytes_read,
         GnomeVFSContext *context)
{
    MythtvHandle *myth_handle = (MythtvHandle *) method_handle;
    GnomeVFSFileSize bytes_to_read;

    g_debug ("do_read(): file size: %llu, already read: %llu, requested: %llu, buffer_remain: %du", 
		    myth_handle->content_size, myth_handle->bytes_read, num_bytes, 
				myth_handle->buffer_remain);

    *bytes_read = 0;

    if (myth_handle->bytes_read >= myth_handle->content_size)
        return GNOME_VFS_ERROR_EOF;

    // fixme: change this to min math function
    if (num_bytes > myth_handle->content_size - myth_handle->bytes_read)
	    bytes_to_read = myth_handle->content_size - myth_handle->bytes_read;
    else
	    bytes_to_read = num_bytes;

    /* Loop sending the Myth File Transfer request:
    * Retry whilst authentication fails and we supply it. */
  
  if ( bytes_to_read > myth_handle->buffer_remain ) {
  	GByteArray *tmp_buffer = g_byte_array_new();

    gint len = gmyth_file_transfer_read( myth_handle->file_transfer,
          tmp_buffer, MYTHTV_BUFFER_SIZE - myth_handle->buffer_remain, TRUE );

		if (len < 0)
		    return GNOME_VFS_ERROR_IO;

    myth_handle->buffer = g_byte_array_append( myth_handle->buffer, 
    				g_memdup( tmp_buffer->data, len ), len );

		myth_handle->buffer_remain += len;

		g_debug ( "Reading %d data from backend", MYTHTV_BUFFER_SIZE - myth_handle->buffer_remain );
	
    if ( tmp_buffer != NULL ) {
    	g_byte_array_free( tmp_buffer, TRUE );
    	tmp_buffer = NULL;    	
    }

  }
    
    bytes_to_read = (bytes_to_read > myth_handle->buffer_remain) ? myth_handle->buffer_remain : bytes_to_read;

    g_debug ("Returning %du bytes to gnomevfs", (gint) bytes_to_read);
	  /* gets the first buffer_size bytes from the byte array buffer variable */ 

	  g_memmove( buffer, myth_handle->buffer->data, bytes_to_read );

    myth_handle->bytes_read += bytes_to_read;
    myth_handle->buffer_remain -= bytes_to_read;    

  	/* flushs the newly buffer got from byte array */
  	myth_handle->buffer = g_byte_array_remove_range( myth_handle->buffer, 0, bytes_to_read );
    *bytes_read = bytes_to_read;
  
    return GNOME_VFS_OK;
}

static GnomeVFSResult
do_close (GnomeVFSMethod *method,
          GnomeVFSMethodHandle *method_handle,
          GnomeVFSContext *context)
{

    MythtvHandle *myth_handle = (MythtvHandle *) method_handle;

    if (myth_handle->file_transfer) {
	gmyth_file_transfer_close (myth_handle->file_transfer);
        g_object_unref (myth_handle->file_transfer);
	myth_handle->file_transfer = NULL;
    }
    
    if (myth_handle->buffer) {
			g_byte_array_free (myth_handle->buffer, TRUE);
			myth_handle->buffer = NULL;
    }

    g_free (myth_handle);

    return GNOME_VFS_OK;
}

static GnomeVFSResult
do_get_file_info (GnomeVFSMethod *method,
                  GnomeVFSURI *uri,
                  GnomeVFSFileInfo *file_info,
                  GnomeVFSFileInfoOptions options,
                  GnomeVFSContext *context)
{
    file_info->name = g_strdup ("fixme.txt");
    file_info->valid_fields = file_info->valid_fields
        | GNOME_VFS_FILE_INFO_FIELDS_TYPE
        | GNOME_VFS_FILE_INFO_FIELDS_MIME_TYPE
        | GNOME_VFS_FILE_INFO_FIELDS_PERMISSIONS;
    file_info->type = GNOME_VFS_FILE_TYPE_REGULAR;
    // fixme: get from file extension?
    file_info->mime_type = g_strdup ("video/x-nuv");
    file_info->permissions =
        GNOME_VFS_PERM_USER_READ |
        GNOME_VFS_PERM_OTHER_READ |
        GNOME_VFS_PERM_GROUP_READ;

    return GNOME_VFS_OK;
}

static gboolean
do_is_local (GnomeVFSMethod *method,
             const GnomeVFSURI *uri)
{
	return FALSE;
}

static GnomeVFSMethod method = {
	sizeof (GnomeVFSMethod),
	do_open,
	NULL,
	do_close,
	do_read,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	do_get_file_info,
	NULL,
	do_is_local,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
	NULL,
};


GnomeVFSMethod *
vfs_module_init (const char *method_name, const char *args)
{
	return &method;
}

void
vfs_module_shutdown (GnomeVFSMethod *method)
{
}