using System;
using System.ComponentModel;
using System.Linq;
using System.Management;
using System.Reflection;
using System.Runtime.Serialization;
using System.Threading;
using System.Threading.Tasks;
using System.Xml;

namespace Vanara.Management
{
	/// <summary>Extension methods to work more easily with <see cref="System.Management"/>.</summary>
	public static class ManagementExtensions
	{
		internal enum JobState : ushort
		{
			New = 2,
			Starting = 3,
			Running = 4,
			Suspended = 5,
			ShuttingDown = 6,
			Completed = 7,
			Terminated = 8,
			Killed = 9,
			Exception = 10,
			Service = 11,
			QueryPending = 12,
			CompletedWithWarnings = 32768
		}

		/// <summary>Calls a service method that returns a Job asynchronously.</summary>
		/// <param name="scope">The scope.</param>
		/// <param name="cancellationToken">The cancellation token.</param>
		/// <param name="progress">The progress.</param>
		/// <param name="service">The service.</param>
		/// <param name="method">The method.</param>
		/// <param name="values">The values.</param>
		/// <returns>The resulting <see cref="ManagementBaseObject"/>.</returns>
		public static async Task<ManagementBaseObject> CallJobMethodAsync(this ManagementScope scope, CancellationToken cancellationToken, IProgress<int> progress, string service, string method, params (string, object)[] values) =>
			await Task.Factory.StartNew(() =>
			{
				if (!scope.IsConnected)
					scope.Connect();

				using ManagementObject imgMgmtSvc = scope.GetWMIService(service);
				using ManagementBaseObject inParams = imgMgmtSvc.GetMethodParameters(method);
				foreach ((string, object) kv in values)
					inParams[kv.Item1] = kv.Item2;

				ManagementBaseObject outputParameters = imgMgmtSvc.InvokeMethod(method, inParams, null);

				const int sleepDur = 500;

				if (outputParameters.IsAsync())
				{
					// The method invoked an asynchronous operation. Get the Job object and wait for it to complete. Then we can check its result.
					using ManagementObject job = new((string)outputParameters["Job"]) { Scope = scope };

					while (!job.GetProp<JobState>("JobState").IsJobComplete())
					{
						if (progress is not null)
						{
							try { progress.Report(job.GetProp<ushort>("PercentComplete")); }
							catch { }
						}

						Task.Delay(sleepDur);

						// ManagementObjects are offline objects. Call Get() on the object to have its current property state.
						job.Get();
					}

					switch (job.GetProp<JobState>("JobState"))
					{
						case JobState.Terminated:
						case JobState.Killed:
							throw new ThreadInterruptedException();
						case JobState.Exception:
							ManagementBaseObject errOut = job.InvokeMethod("GetError", null, null);
							var xml = new XmlDocument();
							xml.LoadXml(errOut.GetProp<string>("Error"));
							var errMsg = xml.DocumentElement.SelectSingleNode(@"//PROPERTY[@NAME='Message']/VALUE")?.InnerText;
							var ex = new InvalidOperationException(errMsg);
#if DEBUG
							foreach (var p in job.Properties.Cast<PropertyData>())
								ex.Data.Add(p.Name, p.Value);
#endif
							throw ex;
						case JobState.Completed:
						case JobState.CompletedWithWarnings:
							outputParameters.SetPropertyValue("ReturnValue", 0);
							break;

						default:
							break;
					}
				}
				progress?.Report(100);
				return outputParameters;
			}, cancellationToken);

		/// <summary>Gets the embedded instance string usable by WMI</summary>
		/// <typeparam name="T">The type of the instance.</typeparam>
		/// <param name="instance">The instance.</param>
		/// <param name="serverName">Name of the server.</param>
		/// <returns>Embedded instance string usable by WMI.</returns>
		/// <exception cref="System.InvalidOperationException">Generic type does not have a DataContract attribute.</exception>
		public static string GetInstanceText<T>(T instance, string serverName = ".")
		{
			DataContractAttribute attr = typeof(T).GetCustomAttributes<DataContractAttribute>(false).FirstOrDefault();
			if (attr is null)
				throw new InvalidOperationException("Generic type does not have a DataContract attribute.");
			var path = new ManagementPath() { Server = serverName, NamespacePath = attr.Namespace, ClassName = attr.Name };

			using var settingsClass = new ManagementClass(path);
			using ManagementObject settingsInstance = settingsClass.CreateInstance();

			foreach (PropertyInfo pi in typeof(T).GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
			{
				if (pi.GetCustomAttributes<IgnoreDataMemberAttribute>().Any() || !pi.CanRead)
					continue;
				DataMemberAttribute mattr = pi.GetCustomAttributes<DataMemberAttribute>(false).FirstOrDefault() ?? new DataMemberAttribute() { Name = pi.Name };
				var val = pi.PropertyType.IsEnum ? Convert.ChangeType(pi.GetValue(instance), pi.PropertyType.GetEnumUnderlyingType()) : pi.GetValue(instance);
				settingsInstance.SetPropertyValue(mattr.Name, val);
			}

			return settingsInstance.GetText(TextFormat.WmiDtd20);
		}

		/// <summary>Gets the specified property value of <paramref name="prop"/> from <paramref name="obj"/>.</summary>
		/// <typeparam name="T">The property type</typeparam>
		/// <param name="obj">The object.</param>
		/// <param name="prop">The property name.</param>
		/// <returns>The property value.</returns>
		public static T GetProp<T>(this ManagementBaseObject obj, string prop) => typeof(T).IsEnum ? (T)Enum.ToObject(typeof(T), obj[prop]) : (T)obj[prop];

		/// <summary>Gets the result from a return value or throws the appropriate exception.</summary>
		/// <param name="output">The method output object.</param>
		/// <param name="throwAll">if set to <see langword="true"/> throws all exceptions including those for 4096 and 32768.</param>
		/// <returns><see langword="true"/> on success; otherwise <see langword="false"/>.</returns>
		public static bool GetResultOrThrow(this ManagementBaseObject output, bool throwAll = false) => output.GetProp<uint>("ReturnValue") switch
		{
			0 => true,
			4096 => throwAll ? throw new SynchronizationLockException() : false,
			32768 => throwAll ? throw new Exception() : false,
			32769 => throw new UnauthorizedAccessException(),
			32770 => throw new NotSupportedException(),
			32773 => throw new ArgumentException(),
			32779 => throw new System.IO.FileNotFoundException(),
			32778 => throw new OutOfMemoryException(),
			32772 => throw new TimeoutException(),
			//Status is unknown(32771)
			//System is in use(32774)
			//Invalid state for this operation(32775)
			//Incorrect data type(32776)
			//System is not available(32777)
			_ => throw new Exception(),
		};

		/// <summary>Gets the specifid WMI service from a scope.</summary>
		/// <param name="scope">The scope.</param>
		/// <param name="path">The service path.</param>
		/// <returns>The service object.</returns>
		public static ManagementObject GetWMIService(this ManagementScope scope, string path)
		{
			using ManagementClass imageManagementServiceClass = new(path) { Scope = scope };
			return imageManagementServiceClass.GetInstances().Cast<ManagementObject>().FirstOrDefault();
		}

		/// <summary>
		/// Parses an embedded instance returned from the server and creates a new instance of <typeparamref name="T"/> with that information.
		/// </summary>
		/// <typeparam name="T">The type to fill with information from <paramref name="embeddedInstance"/>.</typeparam>
		/// <param name="embeddedInstance">The embedded instance.</param>
		/// <returns>An instance of <typeparamref name="T"/> with the data contained in the embedded instance.</returns>
		/// <exception cref="FormatException">If there was a problem parsing the embedded instance.</exception>
		/// <exception cref="ArgumentNullException">If either param is null.</exception>
		public static T Parse<T>(string embeddedInstance) where T : class, new()
		{
			var doc = new XmlDocument();
			doc.LoadXml(embeddedInstance);

			XmlNodeList nodelist = doc.SelectNodes(@"/INSTANCE/@CLASSNAME");
			var className = typeof(T).GetCustomAttributes<DataContractAttribute>(false).FirstOrDefault()?.Name ?? typeof(T).Name;
			if (nodelist.Count != 1 || nodelist[0].Value != className)
			{
				throw new FormatException();
			}

			var output = new T();
			foreach (PropertyInfo pi in typeof(T).GetProperties(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic))
			{
				if (pi.GetCustomAttributes<IgnoreDataMemberAttribute>().Any() || !pi.CanWrite)
					continue;
				DataMemberAttribute attr = pi.GetCustomAttributes<DataMemberAttribute>(false).FirstOrDefault() ?? new DataMemberAttribute() { Name = pi.Name };

				if (pi.PropertyType.IsArray)
				{
					if (doc.SelectSingleNode($@"//PROPERTY.ARRAY[@NAME = '{attr.Name}']") is not null)
					{
						var array = doc.SelectNodes($@"//PROPERTY.ARRAY[@NAME = '{attr.Name}']/VALUE.ARRAY/VALUE").Cast<XmlNode>().Select(n => n.InnerText).ToArray();
						var ret = Array.CreateInstance(pi.PropertyType.GetElementType(), array.Length);
						for (int i = 0; i < array.Length; i++)
							ret.SetValue(GetVal(pi.PropertyType.GetElementType(), array[i]), i);
						pi.SetValue(output, ret);
					}
					else if (attr.IsRequired)
						throw new FormatException();
				}
				else
				{
					nodelist = doc.SelectNodes($@"//PROPERTY[@NAME = '{attr.Name}']/VALUE/child::text()");
					if (attr.IsRequired && nodelist.Count != 1)
						throw new FormatException();
					if (nodelist.Count == 0)
						continue;
					pi.SetValue(output, GetVal(pi.PropertyType, nodelist[0].Value));
				}
			}
			return output;

			static object GetVal(Type type, string value)
			{
				if (type == typeof(string))
					return value;
				else if (type.IsEnum)
				{
					TypeConverter cv = TypeDescriptor.GetConverter(type.GetEnumUnderlyingType());
					var val = cv.ConvertFromInvariantString(value);
					if (!Enum.IsDefined(type, val))
						throw new FormatException();
					return Enum.ToObject(type, val);
				}
				else
				{
					TypeConverter cv = TypeDescriptor.GetConverter(type);
					return cv.ConvertFromInvariantString(value);
				}
			}
		}

		/// <summary>Converts a string in CIM_DATETIME format to a <see cref="DateTime"/>.</summary>
		/// <param name="cimdate">The CIM_DATETIME string in 'yyyymmddHHMMSS.mmmmmmsUUU' format.</param>
		/// <returns>A <see cref="DateTime"/> value in GMT equivalent to <paramref name="cimdate"/> or <see langword="null"/> if unable to process.</returns>
		public static DateTime? CimToDateTime(string cimdate)
		{
			if (cimdate is null || !(cimdate.Length is 14 or 21 or 25))
				return null;
			var dts = cimdate;
			if (dts.Length == 14)
				dts += ".000000";
			if (dts.Length == 21)
				dts += "+000";
			if (!short.TryParse(dts.Substring(21, 4), out var utcOffset))
				return null;
			dts = $"{dts.Substring(0, 21)}{(utcOffset < 0 ? '-' : '+')}{Math.Abs(utcOffset) / 60:D2}:{Math.Abs(utcOffset) % 60:D2}";
			if (!DateTime.TryParseExact(dts, "yyyyMMddHHmmss.FFFFFFFzzz", null, System.Globalization.DateTimeStyles.None, out var dt))
				return null;
			return dt;
		}

		/// <summary>Converts a <see cref="DateTime"/> value to CIM_DATETIME format.</summary>
		/// <param name="dt">The <see cref="DateTime"/> value.</param>
		/// <returns>A CIM_DATETIME string in 'yyyymmddHHMMSS.mmmmmmsUUU' format.</returns>
		public static string DateTimeToCim(this DateTime dt) => $"{dt.ToUniversalTime():yyyyMMddHHmmss.FFFFFFF}+000";

		/// <summary>Verifies whether a job is completed.</summary>
		/// <param name="jobStateObj">An object that represents the JobState of the job.</param>
		/// <returns>True if the job is completed, False otherwise.</returns>
		internal static bool IsJobComplete(this JobState jobStateObj) =>
			jobStateObj is JobState.Completed or JobState.CompletedWithWarnings or JobState.Terminated or JobState.Exception or JobState.Killed;

		/// <summary>Verifies whether a job succeeded.</summary>
		/// <param name="jobStateObj">An object representing the JobState of the job.</param>
		/// <returns><c>true</c> if the job succeeded; otherwise, <c>false</c>.</returns>
		internal static bool IsJobSuccessful(this JobState jobStateObj) => jobStateObj is JobState.Completed or JobState.CompletedWithWarnings;

		private static bool IsAsync(this ManagementBaseObject output) => output.GetProp<uint>("ReturnValue") == 4096;
	}
}