//
// DapService.cs
//
// Authors:
//   Gabriel Burt <gburt@novell.com>
//   Aaron Bockover <abockover@novell.com>
//   Ruben Vermeersch <ruben@savanne.be>
//
// Copyright (C) 2007-2008 Novell, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using System.Collections.Generic;
using System.Linq;

using Mono.Unix;
using Mono.Addins;

using Hyena;
using Banshee.Base;
using Banshee.Kernel;
using Banshee.ServiceStack;
using Banshee.Sources;
using Banshee.Collection;
using Banshee.Collection.Database;
using Banshee.Hardware;

namespace Banshee.Dap
{
    public class DapService : IExtensionService, IDelayedInitializeService, IDisposable
    {
        private static SourceManager.GroupSource dap_group;
        private Dictionary<string, DapSource> sources;
        private List<DeviceCommand> unhandled_device_commands;
        private List<DapPriorityNode> supported_dap_types;
        private bool initialized;
        private object sync = new object ();

        static DapService ()
        {
            // This group source gives us a seperator for DAPs in the source view.
            // We add it when we get our first dap source, and then remove it when
            //we lose the last one.
            dap_group = new SourceManager.GroupSource ("Device", 400);
        }

        public void Initialize ()
        {
        }

        public void DelayedInitialize ()
        {
            lock (sync) {
                if (initialized || ServiceManager.HardwareManager == null)
                    return;

                sources = new Dictionary<string, DapSource> ();
                supported_dap_types = new List<DapPriorityNode> ();

                AddinManager.AddExtensionNodeHandler ("/Banshee/Dap/DeviceClass", OnExtensionChanged);

                ServiceManager.HardwareManager.DeviceAdded += OnHardwareDeviceAdded;
                ServiceManager.HardwareManager.DeviceRemoved += OnHardwareDeviceRemoved;
                ServiceManager.HardwareManager.DeviceCommand += OnDeviceCommand;
                ServiceManager.SourceManager.SourceRemoved += OnSourceRemoved;
                initialized = true;

                // Now that we've loaded all the enabled DAP providers, load the devices
                foreach (IDevice device in ServiceManager.HardwareManager.GetAllDevices ()) {
                    MapDevice (device);
                }
            }
        }

        private void OnExtensionChanged (object o, ExtensionNodeEventArgs args)
        {
            lock (sync) {
                var node = (DapPriorityNode)args.ExtensionNode;
                if (!node.Type.IsSubclassOf (typeof (DapSource)))
                    return;

                if (args.Change == ExtensionChange.Add) {
                    Log.DebugFormat ("Dap support extension loaded: {0}", node.Addin.Id);

                    supported_dap_types.Add (node);
                    supported_dap_types.Sort ((left, right) => right.Priority.CompareTo (left.Priority));

                    if (initialized) {
                        // See if any existing devices are handled by this new DAP support
                        foreach (IDevice device in ServiceManager.HardwareManager.GetAllDevices ()) {
                            MapDevice (device);
                        }
                    }
                } else if (args.Change == ExtensionChange.Remove) {
                    supported_dap_types.Remove ((DapPriorityNode) args.ExtensionNode);

                    Queue<DapSource> to_remove = new Queue<DapSource> ();
                    foreach (DapSource source in sources.Values) {
                        if (source.AddinId == node.Addin.Id) {
                            to_remove.Enqueue (source);
                        }
                    }

                    while (to_remove.Count > 0) {
                        UnmapDevice (to_remove.Dequeue ().Device.Uuid);
                    }
                }
            }
        }

        public void Dispose ()
        {
            Scheduler.Unschedule (typeof(MapDeviceJob));
            lock (sync) {
                if (!initialized)
                    return;

                AddinManager.RemoveExtensionNodeHandler ("/Banshee/Dap/DeviceClass", OnExtensionChanged);

                ServiceManager.HardwareManager.DeviceAdded -= OnHardwareDeviceAdded;
                ServiceManager.HardwareManager.DeviceRemoved -= OnHardwareDeviceRemoved;
                ServiceManager.HardwareManager.DeviceCommand -= OnDeviceCommand;
                ServiceManager.SourceManager.SourceRemoved -= OnSourceRemoved;

                List<DapSource> dap_sources = new List<DapSource> (sources.Values);
                foreach (DapSource source in dap_sources) {
                    UnmapDevice (source.Device.Uuid);
                }

                sources.Clear ();
                sources = null;
                supported_dap_types.Clear ();
                supported_dap_types = null;
                initialized = false;
            }
        }

        private DapSource FindDeviceSource (IDevice device)
        {
            foreach (TypeExtensionNode node in supported_dap_types) {
                try {
                    DapSource source = (DapSource)node.CreateInstance ();
                    source.DeviceInitialize (device);
                    source.LoadDeviceContents ();
                    source.AddinId = node.Addin.Id;
                    return source;
                } catch (InvalidDeviceException) {
                } catch (InvalidCastException e) {
                    Log.Exception ("Extension is not a DapSource as required", e);
                } catch (Exception e) {
                    Log.Exception (e);
                }
            }

            return null;
        }

        private void MapDevice (IDevice device)
        {
            Scheduler.Schedule (new MapDeviceJob (this, device));
        }

        private class MapDeviceJob : IJob
        {
            IDevice device;
            DapService service;

            public MapDeviceJob (DapService service, IDevice device)
            {
                this.device = device;
                this.service = service;
            }

            public string Uuid {
                get { return device.Uuid; }
            }

            public void Run ()
            {
                DapSource source = null;
                lock (service.sync) {
                    try {
                        if (service.sources.ContainsKey (device.Uuid)) {
                            return;
                        }

                        if (device is ICdromDevice || device is IDiscVolume) {
                            return;
                        }

                        if (device is IVolume && (device as IVolume).ShouldIgnore) {
                            return;
                        }

                        if (device.MediaCapabilities == null && !(device is IBlockDevice) && !(device is IVolume)) {
                            return;
                        }

                        source = service.FindDeviceSource (device);
                        if (source != null) {
                            Log.DebugFormat ("Found DAP support ({0}) for device {1} and Uuid {2}", source.GetType ().FullName,
                                             source.Name, device.Uuid);
                            service.sources.Add (device.Uuid, source);
                        }
                    } catch (Exception e) {
                        Log.Exception (e);
                    }
                }

                if (source != null) {
                    ThreadAssist.ProxyToMain (delegate {
                        if (!ServiceManager.SourceManager.ContainsSource (dap_group)) {
                            ServiceManager.SourceManager.AddSource (dap_group);
                        }

                        ServiceManager.SourceManager.AddSource (source);
                        source.NotifyUser ();

                        // If there are any queued device commands, see if they are to be
                        // handled by this new DAP (e.g. --device-activate=file:///media/disk)
                        try {
                            if (service.unhandled_device_commands != null) {
                                foreach (DeviceCommand command in service.unhandled_device_commands) {
                                    if (source.CanHandleDeviceCommand (command)) {
                                        service.HandleDeviceCommand (source, command.Action);
                                        service.unhandled_device_commands.Remove (command);
                                        if (service.unhandled_device_commands.Count == 0) {
                                            service.unhandled_device_commands = null;
                                        }
                                        break;
                                    }
                                }
                            }
                        } catch (Exception e) {
                            Log.Exception (e);
                        }
                    });
                }
            }
        }

        internal void UnmapDevice (string uuid)
        {
            DapSource source = null;
            lock (sync) {
                if (sources.ContainsKey (uuid)) {
                    Log.DebugFormat ("Unmapping DAP source ({0})", uuid);
                    source = sources[uuid];
                    sources.Remove (uuid);
                }
            }

            if (source != null) {
                try {
                    source.Dispose ();
                    ThreadAssist.ProxyToMain (delegate {
                        ServiceManager.SourceManager.RemoveSource (source);
                        if (ServiceManager.SourceManager.FindSources<DapSource> ().Count () < 1) {
                            ServiceManager.SourceManager.RemoveSource (dap_group);
                        }
                    });
                } catch (Exception e) {
                    Log.Exception (e);
                }
            }
        }

        private void OnSourceRemoved (SourceEventArgs args)
        {
            DapSource dap_source = args.Source as DapSource;
            if (dap_source != null) {
                UnmapDevice (dap_source.Device.Uuid);
            }
        }

        private void OnHardwareDeviceAdded (object o, DeviceAddedArgs args)
        {
            MapDevice (args.Device);
        }

        private void OnHardwareDeviceRemoved (object o, DeviceRemovedArgs args)
        {
            UnmapDevice (args.DeviceUuid);
        }


#region DeviceCommand Handling

        private void HandleDeviceCommand (DapSource source, DeviceCommandAction action)
        {
            if ((action & DeviceCommandAction.Activate) != 0) {
                ServiceManager.SourceManager.SetActiveSource (source);
            }
        }

        private void OnDeviceCommand (object o, DeviceCommand command)
        {
            lock (this) {
                // Check to see if we have an already mapped disc volume that should
                // handle this incoming command; if not, queue it for later devices
                foreach (DapSource source in sources.Values) {
                    if (source.CanHandleDeviceCommand (command)) {
                        HandleDeviceCommand (source, command.Action);
                        return;
                    }
                }

                if (unhandled_device_commands == null) {
                    unhandled_device_commands = new List<DeviceCommand> ();
                }
                unhandled_device_commands.Add (command);
            }
        }

#endregion

        string IService.ServiceName {
            get { return "DapService"; }
        }
    }
}
