using System;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.Threading.Tasks;
using EC.Onvif.Common;
using EC.Onvif.Device;
using EC.Onvif.Media;
using EC.Onvif.Imaging;
using EC.Onvif.PTZ;
using EC.Onvif.Security;

namespace EC.Onvif
{
	public static class OnvifClientFactory
	{
		static Binding CreateBinding()
		{
			var binding = new CustomBinding();
			var textBindingElement = new TextMessageEncodingBindingElement
			{
				MessageVersion = MessageVersion.CreateVersion(EnvelopeVersion.Soap12, AddressingVersion.None)
			};
			var httpBindingElement = new HttpTransportBindingElement
			{
				AllowCookies = true,
				MaxBufferSize = int.MaxValue,
				MaxReceivedMessageSize = int.MaxValue
			};

			binding.Elements.Add(textBindingElement);
			binding.Elements.Add(httpBindingElement);

			return binding;
		}

		public static async Task<DeviceClient> CreateDeviceClientAsync(string host, string username, string password)
		{
			return await CreateDeviceClientAsync(new Uri($"http://{host}/onvif/device_service"), username, password);
		}

		public static async Task<DeviceClient> CreateDeviceClientAsync(Uri uri, string username, string password)
		{
			var binding = CreateBinding();
			var endpoint = new EndpointAddress(uri);
			var device = new DeviceClient(binding, endpoint);
			var time_shift = await GetDeviceTimeShift(device);

			device = new DeviceClient(binding, endpoint);
			device.ChannelFactory.Endpoint.EndpointBehaviors.Clear();
			device.ChannelFactory.Endpoint.EndpointBehaviors.Add(new SoapSecurityHeaderBehavior(username, password, time_shift));

			// Connectivity Test
			await device.OpenAsync();

			return device;
		}

		public static async Task<MediaClient> CreateMediaClientAsync(string host, string username, string password)
		{
			var binding = CreateBinding();
			var device = await CreateDeviceClientAsync(host, username, password);
			var caps = await device.GetCapabilitiesAsync(new CapabilityCategory[] { CapabilityCategory.Media });
			var media = new MediaClient(binding, new EndpointAddress(new Uri(caps.Capabilities.Media.XAddr)));

			var time_shift = await GetDeviceTimeShift(device);
			media.ChannelFactory.Endpoint.EndpointBehaviors.Clear();
			media.ChannelFactory.Endpoint.EndpointBehaviors.Add(new SoapSecurityHeaderBehavior(username, password, time_shift));

			// Connectivity Test
			await media.OpenAsync();

			return media;
		}

		public static async Task<PTZClient> CreatePTZClientAsync(string host, string username, string password)
		{
			var binding = CreateBinding();
			var device = await CreateDeviceClientAsync(host, username, password);
			var caps = await device.GetCapabilitiesAsync(new CapabilityCategory[] { CapabilityCategory.PTZ });
			var ptz = new PTZClient(binding, new EndpointAddress(new Uri(caps.Capabilities.PTZ.XAddr)));

			var time_shift = await GetDeviceTimeShift(device);
			ptz.ChannelFactory.Endpoint.EndpointBehaviors.Clear();
			ptz.ChannelFactory.Endpoint.EndpointBehaviors.Add(new SoapSecurityHeaderBehavior(username, password, time_shift));

			// Connectivity Test
			await ptz.OpenAsync();

			return ptz;
		}

		public static async Task<ImagingClient> CreateImagingClientAsync(string host, string username, string password)
		{
			var binding = CreateBinding();
			var device = await CreateDeviceClientAsync(host, username, password);
			var caps = await device.GetCapabilitiesAsync(new CapabilityCategory[] { CapabilityCategory.Imaging });
			var imaging = new ImagingClient(binding, new EndpointAddress(new Uri(caps.Capabilities.Imaging.XAddr)));

			var time_shift = await GetDeviceTimeShift(device);
			imaging.ChannelFactory.Endpoint.EndpointBehaviors.Clear();
			imaging.ChannelFactory.Endpoint.EndpointBehaviors.Add(new SoapSecurityHeaderBehavior(username, password, time_shift));

			// Connectivity Test
			await imaging.OpenAsync();

			return imaging;
		}

		static async Task<TimeSpan> GetDeviceTimeShift(DeviceClient device)
		{
			var utc = (await device.GetSystemDateAndTimeAsync()).UTCDateTime;
			var dt = new System.DateTime(utc.Date.Year, utc.Date.Month, utc.Date.Day,
							  utc.Time.Hour, utc.Time.Minute, utc.Time.Second);
			return dt - System.DateTime.UtcNow;
		}
	}
}