using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Threading;
using dnSpy.Contracts.Decompiler;
using dnSpy.Contracts.Documents.Tabs.DocViewer;
using dnSpy.Contracts.Documents.TreeView;
using dnSpy.Contracts.Images;
using dnSpy.Contracts.Text;
using dnSpy.Contracts.TreeView;

// This file contains classes that create new child nodes of IAssemblyFileNode and IModuleFileNode

namespace Example2.Extension {
	// This class adds a new child node to all assembly nodes
	[ExportTreeNodeDataProvider(Guid = DocumentTreeViewConstants.ASSEMBLY_NODE_GUID)]
	sealed class AssemblyTreeNodeDataProvider : ITreeNodeDataProvider {
		public IEnumerable<TreeNodeData> Create(TreeNodeDataProviderContext context) {
			yield return new AssemblyChildNode();
		}
	}

	// This class adds a new child node to all module nodes
	[ExportTreeNodeDataProvider(Guid = DocumentTreeViewConstants.MODULE_NODE_GUID)]
	sealed class ModuleTreeNodeDataProvider : ITreeNodeDataProvider {
		public IEnumerable<TreeNodeData> Create(TreeNodeDataProviderContext context) {
			yield return new ModuleChildNode();
		}
	}

	sealed class AssemblyChildNode : DocumentTreeNodeData { // All file tree nodes should implement DocumentTreeNodeData or derive from DocumentTreeNodeData
		//TODO: Use your own guid
		public static readonly Guid THE_GUID = new Guid("6CF91674-16CE-44EA-B9E8-80B68C327D30");

		public override Guid Guid => THE_GUID;
		public override NodePathName NodePathName => new NodePathName(Guid);

		// The image must be in an Images folder (in the resources) and have a .png extension
		protected override ImageReference GetIcon(IDotNetImageService dnImgMgr) => DsImages.EntryPoint;

		protected override void WriteCore(ITextColorWriter output, IDecompiler decompiler, DocumentNodeWriteOptions options) =>
			output.Write(BoxedTextColor.Text, "Assembly Child");

		// If you don't want the node to be appended to the children, override this
		public override ITreeNodeGroup? TreeNodeGroup => TreeNodeGroupImpl.Instance;

		sealed class TreeNodeGroupImpl : ITreeNodeGroup {
			public static readonly TreeNodeGroupImpl Instance = new TreeNodeGroupImpl(1);

			public TreeNodeGroupImpl(double order) => Order = order;

			public double Order { get; }

			public int Compare([AllowNull] TreeNodeData x, [AllowNull] TreeNodeData y) {
				if (x == y)
					return 0;
				var a = x as AssemblyChildNode;
				var b = y as AssemblyChildNode;
				if (a is null) return -1;
				if (b is null) return 1;
				// More checks can be added here...
				return 0;
			}
		}
	}

	// This class can decompile its own output and implements IDecompileSelf
	sealed class ModuleChildNode : DocumentTreeNodeData, IDecompileSelf { // All file tree nodes should implement DocumentTreeNodeData or derive from DocumentTreeNodeData
		//TODO: Use your own guid
		public static readonly Guid THE_GUID = new Guid("C8892F6C-6A49-4537-AAA0-D0DEF1E87277");

		public override Guid Guid => THE_GUID;
		public override NodePathName NodePathName => new NodePathName(Guid);

		// Initialize() is called after the constructor has been called, and after the TreeNode prop
		// has been initialized
		public override void Initialize() =>
			// Set LazyLoading if creating the children could take a while
			TreeNode.LazyLoading = true;

		// If TreeNode.LazyLoading is false, CreateChildren() is called after Initialize(), else it's
		// called when this node gets expanded.
		public override IEnumerable<TreeNodeData> CreateChildren() {
			// Add some children in random order. They will be sorted because SomeMessageNode
			// overrides the TreeNodeGroup prop.
			yield return new SomeMessageNode("ZZZZZZZZZZZZZ");
			yield return new SomeMessageNode("AAAAaaaaaAAAAAAA");
			yield return new SomeMessageNode("SAY");
		}

		// The image must be in an Images folder (in the resources) and have a .png extension
		protected override ImageReference GetIcon(IDotNetImageService dnImgMgr) => DsImages.String;

		protected override void WriteCore(ITextColorWriter output, IDecompiler decompiler, DocumentNodeWriteOptions options) => output.Write(BoxedTextColor.Text, "Module Child");

		// Gets called by dnSpy if there's only one node to decompile. This method gets called in a
		// worker thread. The output is also cached unless you call IDocumentViewerOutput.DisableCaching().
		public bool Decompile(IDecompileNodeContext context) {
			// Pretend we actually do something...
			Thread.Sleep(2000);

			// If you don't want the output to be cached, call DisableCaching()
			bool cacheOutput = true;
			if (!cacheOutput)
				(context.Output as IDocumentViewerOutput)?.DisableCaching();

			// Create the output and a few references that other code in this extension will use, eg.
			// to show a tooltip when hovering over the reference.
			context.ContentTypeString = ContentTypes.CSharp;
			context.Output.WriteLine("// Initialize it to the secret key", BoxedTextColor.Comment);
			context.Output.Write("int", new StringInfoReference("This is a reference added by the code"), DecompilerReferenceFlags.None, BoxedTextColor.Keyword);
			context.Output.Write(" ", BoxedTextColor.Text);
			context.Output.Write("secret", new StringInfoReference("The real secret is actually 42 not 1234"), DecompilerReferenceFlags.None, BoxedTextColor.Local);
			context.Output.Write(" ", BoxedTextColor.Text);
			context.Output.Write("=", BoxedTextColor.Operator);
			context.Output.Write(" ", BoxedTextColor.Text);
			context.Output.Write("1234", BoxedTextColor.Number);
			context.Output.Write(";", BoxedTextColor.Punctuation);
			context.Output.WriteLine();

			// We decompiled ourselves so return true
			return true;
		}

		// If you don't want the node to be appended to the children, override this
		public override ITreeNodeGroup? TreeNodeGroup => TreeNodeGroupImpl.Instance;

		sealed class TreeNodeGroupImpl : ITreeNodeGroup {
			// Make sure the order is unique. 0 is already used by the PE node, so use 1
			public static readonly TreeNodeGroupImpl Instance = new TreeNodeGroupImpl(1);

			public TreeNodeGroupImpl(double order) => Order = order;

			public double Order { get; }

			public int Compare([AllowNull] TreeNodeData x, [AllowNull] TreeNodeData y) {
				if (x == y)
					return 0;
				var a = x as ModuleChildNode;
				var b = y as ModuleChildNode;
				if (a is null) return -1;
				if (b is null) return 1;
				// More checks can be added here...
				return 0;
			}
		}
	}

	sealed class SomeMessageNode : DocumentTreeNodeData {
		//TODO: Use your own guid
		public static readonly Guid THE_GUID = new Guid("1751CD40-68CE-4F8A-84AF-99371B6FD843");

		public string Message { get; }

		public SomeMessageNode(string msg) => Message = msg;

		public override Guid Guid => THE_GUID;
		public override NodePathName NodePathName => new NodePathName(THE_GUID, Message);
		protected override ImageReference GetIcon(IDotNetImageService dnImgMgr) => DsImages.String;

		protected override void WriteCore(ITextColorWriter output, IDecompiler decompiler, DocumentNodeWriteOptions options) =>
			output.Write(BoxedTextColor.Comment, Message);

		public override ITreeNodeGroup? TreeNodeGroup => TreeNodeGroupImpl.Instance;

		sealed class TreeNodeGroupImpl : ITreeNodeGroup {
			public static readonly TreeNodeGroupImpl Instance = new TreeNodeGroupImpl(0);

			public TreeNodeGroupImpl(double order) => Order = order;

			public double Order { get; }

			public int Compare([AllowNull] TreeNodeData x, [AllowNull] TreeNodeData y) {
				if (x == y)
					return 0;
				var a = x as SomeMessageNode;
				var b = y as SomeMessageNode;
				if (a is null) return -1;
				if (b is null) return 1;
				return StringComparer.OrdinalIgnoreCase.Compare(a.Message, b.Message);
			}
		}
	}

	// SomeMessageNode doesn't implement IDecompileSelf, so we add a "decompiler" that can "decompile"
	// those nodes.
	[ExportDecompileNode]
	sealed class SomeMessageNodeDecompiler : IDecompileNode {
		public bool Decompile(IDecompileNodeContext context, DocumentTreeNodeData node) {
			var msgNode = node as SomeMessageNode;
			if (msgNode is null)
				return false;

			context.Decompiler.WriteCommentLine(context.Output, "The secret message has been decrypted.");
			context.Decompiler.WriteCommentLine(context.Output, $"The message is: {msgNode.Message}");
			context.ContentTypeString = ContentTypes.PlainText;
			return true;
		}
	}
}