/*
Copyright 2011 Canonical Ltd.

Authors:
    Conor Curran <conor.curran@canonical.com>

This program is free software: you can redistribute it and/or modify it 
under the terms of the GNU General Public License version 3, as published 
by the Free Software Foundation.

This program is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranties of 
MERCHANTABILITY, SATISFACTORY QUALITY, 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, see <http://www.gnu.org/licenses/>.
*/

#include <gudev/gudev.h>

// TEMP
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>

#include "udev-mgr.h"
#include "sane-rules.h"

static void udevice_mgr_device_list_iterator (gpointer data,
                                              gpointer userdata);
static void udev_mgr_uevent_cb  (GUdevClient *client,
                                 gchar       *action,
                                 GUdevDevice *device,
                                 gpointer     user_data);   
static void udev_mgr_update_menuitems (UdevMgr* self);
static void udev_mgr_check_if_usb_device_is_supported (UdevMgr* self, 
                                                        GUdevDevice *device,
                                                        UdevMgrDeviceAction action);   
                                                                                                                                             
static void udev_mgr_check_if_scsi_device_is_supported (UdevMgr* self, 
                                                        GUdevDevice *device,
                                                        UdevMgrDeviceAction action);
static void udev_mgr_handle_webcam (UdevMgr* self,
                                    GUdevDevice* device,
                                    UdevMgrDeviceAction action);
                                                        
static void debug_device (UdevMgr* self,
                          GUdevDevice* device,
                          UdevMgrDeviceAction action);
                                                        

struct _UdevMgr
{
	GObject parent_instance;
  DbusmenuMenuitem* scanner_item;
  DbusmenuMenuitem* webcam_item;  
  GUdevClient* client;  
  GHashTable* supported_usb_scanners;
  GHashTable* scanners_present;
  GHashTable* webcams_present;
};

const char *subsystems[3] = {"usb", "scsi", "video4linux"};
const gchar* usb_subsystem = "usb";
const gchar* video4linux_subsystem = "video4linux";


G_DEFINE_TYPE (UdevMgr, udev_mgr, G_TYPE_OBJECT);

static void
udev_mgr_init (UdevMgr* self)
{
  self->client = NULL;
  self->supported_usb_scanners = NULL;
  self->scanners_present = NULL;
  self->webcams_present = NULL;
  
  self->client = g_udev_client_new (subsystems);  
  self->supported_usb_scanners = g_hash_table_new (g_str_hash, g_str_equal);
  self->scanners_present = g_hash_table_new (g_str_hash, g_str_equal);
  self->webcams_present = g_hash_table_new (g_str_hash, g_str_equal);
  
  // load into memory all supported scanners ...
  populate_usb_scanners(self->supported_usb_scanners);
  
  g_signal_connect (G_OBJECT (self->client),
                   "uevent",
                    G_CALLBACK (udev_mgr_uevent_cb),
                    self);
}

static void
udev_mgr_finalize (GObject *object)
{
  // TODO tidy up hashtables. 
	G_OBJECT_CLASS (udev_mgr_parent_class)->finalize (object);
}

static void
udev_mgr_class_init (UdevMgrClass *klass)
{
	GObjectClass* object_class = G_OBJECT_CLASS (klass);
	object_class->finalize = udev_mgr_finalize;
}

static void
udevice_mgr_device_list_iterator (gpointer data, gpointer userdata)
{
  g_return_if_fail (G_UDEV_IS_DEVICE (data));
  g_return_if_fail (UDEV_IS_MGR (userdata));
  
  UdevMgr* self = UDEV_MGR (userdata);
  
  GUdevDevice* device = G_UDEV_DEVICE (data);

  const gchar* subsystem = NULL;  
  subsystem = g_udev_device_get_subsystem (device);

  if (g_strcmp0 (subsystem, "usb") == 0){
    udev_mgr_check_if_usb_device_is_supported (self, device, ADD);
  }
  else if (g_strcmp0 (subsystem, "video4linux") == 0){
    udev_mgr_handle_webcam (self, device, ADD);    
  }
  g_object_unref (device);
}


static void udev_mgr_update_menuitems (UdevMgr* self)
{
  dbusmenu_menuitem_property_set_bool (self->scanner_item,
                                       DBUSMENU_MENUITEM_PROP_VISIBLE,
                                       g_hash_table_size (self->scanners_present) > 0);

  dbusmenu_menuitem_property_set_bool (self->webcam_item,
                                       DBUSMENU_MENUITEM_PROP_VISIBLE,
                                       g_hash_table_size (self->webcams_present) > 0);

}

static void udev_mgr_uevent_cb (GUdevClient *client,
                                gchar       *action,
                                GUdevDevice *device,
                                gpointer     user_data)   
{
  g_return_if_fail (UDEV_IS_MGR (user_data));
  UdevMgr* self = UDEV_MGR (user_data);
  g_return_if_fail (device != NULL);
  
  g_debug ("just received a UEVENT with an action :  %s", action);
 
  UdevMgrDeviceAction udev_mgr_action = ADD;

  if (g_strcmp0 (action, "remove") == 0){
    udev_mgr_action = REMOVE;
  }
  
  const gchar* subsystem = NULL;  
  subsystem = g_udev_device_get_subsystem (device);

  if (g_strcmp0 (subsystem, "usb") == 0){
    udev_mgr_check_if_usb_device_is_supported (self,
                                               device,
                                               udev_mgr_action);
  }
  else if (g_strcmp0 (subsystem, "video4linux") == 0){
    udev_mgr_handle_webcam (self, device, udev_mgr_action);
  }
  else if (g_strcmp0 (subsystem, "scsi") == 0){
    udev_mgr_check_if_scsi_device_is_supported (self, device, udev_mgr_action);    
  }
}

static void
udev_mgr_handle_webcam (UdevMgr* self,
                        GUdevDevice* device,
                        UdevMgrDeviceAction action)
{
  if (FALSE)
    debug_device (self, device, action);    
  
  const gchar* vendor;
  const gchar* product;
  
  vendor = g_udev_device_get_property (device, "ID_VENDOR_ID");
  product = g_udev_device_get_property (device, "ID_MODEL_ID");
  
  if (action == REMOVE){
    if (g_hash_table_lookup (self->webcams_present, product) == NULL){
      g_warning ("Got a remove event on a webcam device but we don't have that device in our webcam cache");
      return;                     
    }
    g_hash_table_remove (self->webcams_present,
                         g_strdup (product));
    
  }
  else {
    if (g_hash_table_lookup (self->webcams_present, product) != NULL){
      g_warning ("Got an ADD event on a webcam device but we already have that device in our webcam cache");
      return;                     
    }
    g_hash_table_insert (self->webcams_present,
                         g_strdup (product),
                         g_strdup (vendor));
                               
  }
  udev_mgr_update_menuitems (self);  
}                        

static void
debug_device (UdevMgr* self,
              GUdevDevice* device,
              UdevMgrDeviceAction action)
{
  const gchar* vendor;
  const gchar* product;
  const gchar* number;
  const gchar* name;
  
	vendor = g_udev_device_get_property (device, "ID_VENDOR_ID");
	product = g_udev_device_get_property (device, "ID_MODEL_ID");
  number = g_udev_device_get_number (device);
  name = g_udev_device_get_name (device);
  
  g_debug ("device vendor id %s , product id of %s , number of %s and name of %s",
           g_strdup(vendor),
           g_strdup(product),
           g_strdup(number),
           g_strdup(name));
           
  const gchar *const *list;
  const gchar *const *iter;  
  char propstr[500];
  guint32 namelen = 0, i;  
  
  list = g_udev_device_get_property_keys(device);
  
  for (iter = list; iter && *iter; iter++) {
    if (strlen(*iter) > namelen)
      namelen = strlen(*iter);
  }
  namelen++;

  for (iter = list; iter && *iter; iter++) {
    strcpy(propstr, *iter);
    strcat(propstr, ":");
    for (i = 0; i < namelen - strlen(*iter); i++)
           strcat(propstr, " ");
    strcat(propstr, g_udev_device_get_property(device, *iter));
    g_debug("%s", propstr);
  }   
}


static void
udev_mgr_check_if_scsi_device_is_supported (UdevMgr* self, 
                                            GUdevDevice *device,
                                            UdevMgrDeviceAction action)
{
}

static void
udev_mgr_check_if_usb_device_is_supported (UdevMgr* self, 
                                           GUdevDevice *device,
                                           UdevMgrDeviceAction action)
{
  const gchar* vendor = NULL;
  
	vendor = g_udev_device_get_property (device, "ID_VENDOR_ID");
  
  if (vendor == NULL)
    return;

  g_debug ("vendor = %s", vendor);
  
  GList* vendor_list = NULL;
  vendor_list = g_hash_table_lookup (self->supported_usb_scanners,
                                     (gpointer)vendor);
  if (vendor_list == NULL)
    return;

  const gchar* model_id = NULL;
	model_id = g_udev_device_get_property (device, "ID_MODEL_ID");
  
  if (model_id == NULL)
    return;
  
  GList* model_entry = NULL;
  model_entry = g_list_find_custom(vendor_list, model_id, (GCompareFunc)g_strcmp0);
    
  if (model_entry != NULL){
    if (action == REMOVE){
      if (g_hash_table_lookup (self->scanners_present, g_strdup(vendor)) == NULL){
        g_warning ("Got an REMOVE event on a scanner device but we dont have that device in our scanners cache");
      }
      else{
        g_hash_table_remove (self->scanners_present, g_strdup(vendor));
      }
    }
    else{      
      if (g_hash_table_lookup (self->scanners_present, g_strdup(vendor)) != NULL){
        g_warning ("Got an ADD event on a scanner device but we already have that device in our scanners cache");
      }
      else{
        g_hash_table_insert (self->scanners_present,
                             g_strdup(vendor),
                             g_strdup(model_id)); 
      }
    }
    udev_mgr_update_menuitems (self);
  }
}

UdevMgr* udev_mgr_new (DbusmenuMenuitem* scanner, 
                       DbusmenuMenuitem* webcam)
{
  UdevMgr* mgr = g_object_new (UDEV_TYPE_MGR, NULL);
  mgr->scanner_item = scanner;
  mgr->webcam_item = webcam;

  GList* usb_devices_available  = g_udev_client_query_by_subsystem (mgr->client,
                                                                usb_subsystem);
  g_list_foreach (usb_devices_available,
                  udevice_mgr_device_list_iterator,
                  mgr);
                  
  g_list_free (usb_devices_available);

  GList* video_devices_available  = g_udev_client_query_by_subsystem (mgr->client,
                                                                      video4linux_subsystem);
  g_list_foreach (video_devices_available,
                  udevice_mgr_device_list_iterator,
                  mgr);
  
  g_list_free (video_devices_available);

  //udev_mgr_update_menuitems (mgr);  
  return mgr;
}