//
// System.Reflection.Emit/AssemblyBuilder.cs
//
// Author:
//   Paolo Molaro (lupus@ximian.com)
//
// (C) 2001 Ximian, Inc.  http://www.ximian.com
//

using System;
using System.Reflection;
using System.Resources;
using System.IO;
using System.Security.Policy;
using System.Runtime.Serialization;
using System.Globalization;
using System.Runtime.CompilerServices;
using System.Collections;
using System.Runtime.InteropServices;

namespace System.Reflection.Emit {

	internal struct MonoResource {
		public byte[] data;
		public string name;
		public string filename;
		public ResourceAttributes attrs;
	}

	public sealed class AssemblyBuilder : Assembly {
		private IntPtr dynamic_assembly;
		private MethodInfo entry_point;
		private ModuleBuilder[] modules;
		private string name;
		private string dir;
		private CustomAttributeBuilder[] cattrs;
		private MonoResource[] resources;
		string keyfile;
		string version;
		string culture;
		uint algid;
		uint flags;
		PEFileKinds pekind = PEFileKinds.Dll;
		bool delay_sign;
		uint access;
		internal Type corlib_object_type = typeof (System.Object);
		internal Type corlib_value_type = typeof (System.ValueType);
		internal Type corlib_enum_type = typeof (System.Enum);
		internal Type corlib_void_type = typeof (void);
		private int[] table_indexes;
		Hashtable us_string_cache = new Hashtable ();
		ArrayList resource_writers = null;

		[MethodImplAttribute(MethodImplOptions.InternalCall)]
		private static extern void basic_init (AssemblyBuilder ab);
		
		internal AssemblyBuilder (AssemblyName n, string directory, AssemblyBuilderAccess access) {
			name = n.Name;
			dir = directory;
			this.access = (uint)access;
			basic_init (this);
		}

		internal int get_next_table_index (object obj, int table, bool inc) {
			if (table_indexes == null) {
				table_indexes = new int [64];
				for (int i=0; i < 64; ++i)
					table_indexes [i] = 1;
				/* allow room for .<Module> in TypeDef table */
				table_indexes [0x02] = 2;
			}
			// Console.WriteLine ("getindex for table "+table.ToString()+" got "+table_indexes [table].ToString());
			if (inc)
				return table_indexes [table]++;
			return table_indexes [table];
		}

		public override string CodeBase {
			get {
				throw not_supported ();
			}
		}
		
		public override MethodInfo EntryPoint {
			get {
				return entry_point;
			}
		}

		public override string Location {
			get {
				return null;
			}
		}

		public void AddResourceFile (string name, string fileName)
		{
			AddResourceFile (name, fileName, ResourceAttributes.Public);
		}

		public void AddResourceFile (string name, string fileName, ResourceAttributes attribute)
		{
			if (resources != null) {
				MonoResource[] new_r = new MonoResource [resources.Length + 1];
				System.Array.Copy(resources, new_r, resources.Length);
				resources = new_r;
			} else {
				resources = new MonoResource [1];
			}
			int p = resources.Length - 1;
			resources [p].name = name;
			resources [p].filename = fileName;
			resources [p].attrs = attribute;
		}

		public void EmbedResourceFile (string name, string fileName)
		{
			EmbedResourceFile (name, fileName, ResourceAttributes.Public);
		}

		public void EmbedResourceFile (string name, string fileName, ResourceAttributes attribute)
		{
			if (resources != null) {
				MonoResource[] new_r = new MonoResource [resources.Length + 1];
				System.Array.Copy(resources, new_r, resources.Length);
				resources = new_r;
			} else {
				resources = new MonoResource [1];
			}
			int p = resources.Length - 1;
			resources [p].name = name;
			resources [p].attrs = attribute;
			try {
				FileStream s = new FileStream (fileName, FileMode.Open, FileAccess.Read);
				long len = s.Length;
				resources [p].data = new byte [len];
				s.Read (resources [p].data, 0, (int)len);
				s.Close ();
			} catch {
				/* do something */
			}
		}

		internal void EmbedResource (string name, byte[] blob, ResourceAttributes attribute)
		{
			if (resources != null) {
				MonoResource[] new_r = new MonoResource [resources.Length + 1];
				System.Array.Copy(resources, new_r, resources.Length);
				resources = new_r;
			} else {
				resources = new MonoResource [1];
			}
			int p = resources.Length - 1;
			resources [p].name = name;
			resources [p].attrs = attribute;
			resources [p].data = blob;
		}

		public ModuleBuilder DefineDynamicModule (string name)
		{
			return DefineDynamicModule (name, name, false);
		}

		public ModuleBuilder DefineDynamicModule (string name, bool emitSymbolInfo)
		{
			return DefineDynamicModule (name, name, emitSymbolInfo);
		}

		public ModuleBuilder DefineDynamicModule(string name, string fileName)
		{
			return DefineDynamicModule (name, fileName, false);
		}

		public ModuleBuilder DefineDynamicModule (string name, string fileName,
							  bool emitSymbolInfo)
		{
			ModuleBuilder r = new ModuleBuilder (this, name, fileName, emitSymbolInfo, modules == null);

			if (modules != null) {
				ModuleBuilder[] new_modules = new ModuleBuilder [modules.Length + 1];
				System.Array.Copy(modules, new_modules, modules.Length);
				new_modules [modules.Length] = r;
				modules = new_modules;
			} else {
				modules = new ModuleBuilder [1];
				modules [0] = r;
			}
			return r;
		}

		public IResourceWriter DefineResource (string name, string description, string fileName)
		{
			return DefineResource (name, description, fileName, ResourceAttributes.Public);
		}

		public IResourceWriter DefineResource (string name, string description,
						       string fileName, ResourceAttributes attribute)
		{
			IResourceWriter writer;

			// description seems to be ignored
			AddResourceFile (name, fileName, attribute);
			writer = new ResourceWriter (fileName);
			if (resource_writers == null)
				resource_writers = new ArrayList ();
			resource_writers.Add (writer);
			return writer;
		}

		public void DefineUnmanagedResource (byte[] resource)
		{
		}

		public void DefineUnmanagedResource (string resourceFileName)
		{
		}

		public void DefineVersionInfoResource ()
		{
		}

		public void DefineVersionInfoResource (string product, string productVersion,
						       string company, string copyright, string trademark)
		{
		}

		public ModuleBuilder GetDynamicModule (string name)
		{
			if (name == null)
				throw new ArgumentNullException ("name");
			if (name == "")
				throw new ArgumentException ("Name can't be null");

			if (modules != null)
				for (int i = 0; i < modules.Length; ++i)
					if (modules [i].name == name)
						return modules [i];
			return null;
		}

		public override Type[] GetExportedTypes ()
		{
			throw not_supported ();
		}

		public override FileStream GetFile (string name)
		{
			throw not_supported ();
		}

		public override FileStream[] GetFiles() {
			throw not_supported ();
		}

		public override FileStream[] GetFiles(bool getResourceModules) {
			throw not_supported ();
		}

		public override ManifestResourceInfo GetManifestResourceInfo(string resourceName) {
			throw not_supported ();
		}

		public override string[] GetManifestResourceNames() {
			throw not_supported ();
		}

		public override Stream GetManifestResourceStream(string name) {
			throw not_supported ();
		}
		public override Stream GetManifestResourceStream(Type type, string name) {
			throw not_supported ();
		}

		[MethodImplAttribute(MethodImplOptions.InternalCall)]
		private static extern int getUSIndex (AssemblyBuilder ab, string str);

		[MethodImplAttribute(MethodImplOptions.InternalCall)]
		private static extern int getToken (AssemblyBuilder ab, object obj);

		internal int GetToken (string str) {
			if (us_string_cache.Contains (str))
				return (int)us_string_cache [str];
			int result = getUSIndex (this, str);
			us_string_cache [str] = result;
			return result;
		}
		
		internal int GetToken (MemberInfo member) {
			return getToken (this, member);
		}

		internal int GetToken (SignatureHelper helper) {
			return getToken (this, helper);
		}

		internal bool IsSave {
			get {
				return access != (uint)AssemblyBuilderAccess.Run;
			}
		}

		[MethodImplAttribute(MethodImplOptions.InternalCall)]
		private static extern int getDataChunk (AssemblyBuilder ab, byte[] buf, int offset);

		public void Save (string assemblyFileName)
		{
			byte[] buf = new byte [65536];
			FileStream file;
			int count, offset;

			if (resource_writers != null) {
				foreach (IResourceWriter writer in resource_writers) {
					writer.Generate ();
					writer.Close ();
				}
			}

			build_metadata (this);

			foreach (ModuleBuilder module in modules)
				module.Save ();

			if (dir != null) {
				assemblyFileName = String.Format ("{0}{1}{2}", dir, System.IO.Path.DirectorySeparatorChar, assemblyFileName);
			}

			file = new FileStream (assemblyFileName, FileMode.Create, FileAccess.Write);

			offset = 0;
			while ((count = getDataChunk (this, buf, offset)) != 0) {
				file.Write (buf, 0, count);
				offset += count;
			}
			file.Close ();

			//
			// The constant 0x80000000 is internal to Mono, it means `make executable'
			//
			File.SetAttributes (assemblyFileName, (FileAttributes) (unchecked ((int) 0x80000000)));
		}

		[MethodImplAttribute(MethodImplOptions.InternalCall)]
		private static extern void build_metadata (AssemblyBuilder ab);

		public void SetEntryPoint (MethodInfo entryMethod)
		{
			SetEntryPoint (entryMethod, PEFileKinds.ConsoleApplication);
		}

		public void SetEntryPoint (MethodInfo entryMethod, PEFileKinds fileKind)
		{
			if (entryMethod == null)
				throw new ArgumentNullException ("entryMethod");
			if (entryMethod.DeclaringType.Assembly != this)
				throw new InvalidOperationException ("Entry method is not defined in the same assembly.");

			entry_point = entryMethod;
			pekind = fileKind;
		}

		public void SetCustomAttribute( CustomAttributeBuilder customBuilder) {
			if (customBuilder == null)
				throw new ArgumentNullException ("customBuilder");

			string attrname = customBuilder.Ctor.ReflectedType.FullName;
			byte[] data;
			int len, pos;
			if (attrname == "System.Reflection.AssemblyVersionAttribute") {
				data = customBuilder.Data;
				pos = 2;
				len = CustomAttributeBuilder.decode_len (data, pos, out pos);
				version = CustomAttributeBuilder.string_from_bytes (data, pos, len);
				return;
			} else if (attrname == "System.Reflection.AssemblyKeyFileAttribute") {
				data = customBuilder.Data;
				pos = 2;
				len = CustomAttributeBuilder.decode_len (data, pos, out pos);
				keyfile = CustomAttributeBuilder.string_from_bytes (data, pos, len);
			} else if (attrname == "System.Reflection.AssemblyCultureAttribute") {
				data = customBuilder.Data;
				pos = 2;
				len = CustomAttributeBuilder.decode_len (data, pos, out pos);
				culture = CustomAttributeBuilder.string_from_bytes (data, pos, len);
			} else if (attrname == "System.Reflection.AssemblyAlgorithmIdAttribute") {
				data = customBuilder.Data;
				pos = 2;
				algid = (uint)data [pos];
				algid |= ((uint)data [pos + 1]) << 8;
				algid |= ((uint)data [pos + 2]) << 16;
				algid |= ((uint)data [pos + 3]) << 24;
			} else if (attrname == "System.Reflection.AssemblyFlagsAttribute") {
				data = customBuilder.Data;
				pos = 2;
				flags = (uint)data [pos];
				flags |= ((uint)data [pos + 1]) << 8;
				flags |= ((uint)data [pos + 2]) << 16;
				flags |= ((uint)data [pos + 3]) << 24;
				return;
			} else if (attrname == "System.Reflection.AssemblyDelaySignAttribute") {
				data = customBuilder.Data;
				pos = 2;
				delay_sign = data [2] != 0;
			}
			if (cattrs != null) {
				CustomAttributeBuilder[] new_array = new CustomAttributeBuilder [cattrs.Length + 1];
				cattrs.CopyTo (new_array, 0);
				new_array [cattrs.Length] = customBuilder;
				cattrs = new_array;
			} else {
				cattrs = new CustomAttributeBuilder [1];
				cattrs [0] = customBuilder;
			}
		}
		public void SetCustomAttribute( ConstructorInfo con, byte[] binaryAttribute) {
			if (con == null)
				throw new ArgumentNullException ("con");
			if (binaryAttribute == null)
				throw new ArgumentNullException ("binaryAttribute");

			SetCustomAttribute (new CustomAttributeBuilder (con, binaryAttribute));
		}

		public void SetCorlibTypeBuilders (Type corlib_object_type, Type corlib_value_type, Type corlib_enum_type) {
			this.corlib_object_type = corlib_object_type;
			this.corlib_value_type = corlib_value_type;
			this.corlib_enum_type = corlib_enum_type;
		}

		public void SetCorlibTypeBuilders (Type corlib_object_type, Type corlib_value_type, Type corlib_enum_type, Type corlib_void_type)
		{
			SetCorlibTypeBuilders (corlib_object_type, corlib_value_type, corlib_enum_type);
			this.corlib_void_type = corlib_void_type;
		}

		private Exception not_supported () {
			// Strange message but this is what MS.NET prints...
			return new NotSupportedException ("The invoked member is not supported in a dynamic module.");
		}
	}
}