//
// System.Resources.ResourceWriter.cs
//
// Authors:
//	Duncan Mak <duncan@ximian.com>
//	Dick Porter <dick@ximian.com>
//	Gert Driesen <drieseng@users.sourceforge.net>
//
// (C) 2001, 2002 Ximian, Inc. 	http://www.ximian.com
//

//
// Copyright (C) 2004 Novell, Inc (http://www.novell.com)
//
// 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.IO;
using System.Collections;
using System.Text;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Formatters.Binary;

namespace System.Resources
{
	[System.Runtime.InteropServices.ComVisible (true)]
	public sealed class ResourceWriter : IResourceWriter, IDisposable
	{
		class TypeByNameObject
		{
			public readonly string TypeName;
			public readonly byte [] Value;

			public TypeByNameObject (string typeName, byte [] value)
			{
				TypeName = typeName;
				Value = (byte []) value.Clone ();
			}
		}

#if NET_4_0
		class StreamWrapper
		{
			public readonly bool CloseAfterWrite;
			public readonly Stream Stream;

			public StreamWrapper (Stream stream, bool closeAfterWrite)
			{
				Stream = stream;
				CloseAfterWrite = closeAfterWrite;
			}
		}
#endif

		SortedList resources = new SortedList (StringComparer.OrdinalIgnoreCase);
		Stream stream;
		
		public ResourceWriter (Stream stream)
		{
			if (stream == null)
				throw new ArgumentNullException ("stream");
			if (!stream.CanWrite)
				throw new ArgumentException ("Stream was not writable.");

			this.stream = stream;
		}
		
		public ResourceWriter (String fileName)
		{
			if (fileName == null)
				throw new ArgumentNullException ("fileName");

			stream = new FileStream(fileName, FileMode.Create,
				FileAccess.Write);
		}
		
		public void AddResource (string name, byte[] value)
		{
			if (name == null)
				throw new ArgumentNullException ("name");
			if (resources == null)
				throw new InvalidOperationException ("The resource writer has already been closed and cannot be edited");
			if (resources [name] != null)
				throw new ArgumentException ("Resource already present: " + name);

			resources.Add(name, value);
		}
		
		public void AddResource (string name, object value)
		{
			if (name == null)
				throw new ArgumentNullException ("name");
			if (resources == null)
				throw new InvalidOperationException ("The resource writer has already been closed and cannot be edited");
			if (resources[name] != null)
				throw new ArgumentException ("Resource already present: " + name);
#if NET_4_0
			if (value is Stream) {
				Stream stream = value as Stream;
				if (!stream.CanSeek)
					throw new ArgumentException ("Stream does not support seeking.");

				if (!(value is MemoryStream)) // We already support MemoryStream
					value = new StreamWrapper (stream, false);
			}
#endif

			resources.Add(name, value);
		}
		
		public void AddResource (string name, string value)
		{
			if (name == null)
				throw new ArgumentNullException ("name");
			if (resources == null)
				throw new InvalidOperationException ("The resource writer has already been closed and cannot be edited");
			if (resources [name] != null)
				throw new ArgumentException ("Resource already present: " + name);

			resources.Add(name, value);
		}

#if NET_4_0
		public void AddResource (string name, Stream value)
		{
			// It seems .Net adds this overload just to make the api complete,
			// but AddResource (string name, object value) is already checking for Stream.
			AddResource (name, (object)value);
		}

		public void AddResource (string name, Stream value, bool closeAfterWrite)
		{
			if (name == null)
				throw new ArgumentNullException ("name");
			if (resources == null)
				throw new InvalidOperationException ("The resource writer has already been closed and cannot be edited");
			if (resources [name] != null)
				throw new ArgumentException ("Resource already present: " + name);

			if (stream == null) {
				resources.Add (name, null); // Odd.
				return;
			}
				
			if (!stream.CanSeek)
				throw new ArgumentException ("Stream does not support seeking.");

			resources.Add (name, new StreamWrapper (value, true));
		}
#endif

		public void Close ()
		{
			Dispose (true);
		}
		
		public void Dispose ()
		{
			Dispose (true);
		}

		private void Dispose (bool disposing)
		{
			if (disposing) {
				if (resources != null)
					Generate();
				if (stream != null)
					stream.Close();
				GC.SuppressFinalize (this);
			}
			resources = null;
			stream = null;
		}

		public void AddResourceData (string name, string typeName, byte [] serializedData)
		{
			if (name == null)
				throw new ArgumentNullException ("name");
			if (typeName == null)
				throw new ArgumentNullException ("typeName");
			if (serializedData == null)
				throw new ArgumentNullException ("serializedData");

			// shortcut
			AddResource (name, new TypeByNameObject (typeName, serializedData));
		}

		public void Generate ()
		{
			BinaryWriter writer;
			IFormatter formatter;

			if (resources == null)
				throw new InvalidOperationException ("The resource writer has already been closed and cannot be edited");

			writer = new BinaryWriter (stream, Encoding.UTF8);
			formatter = new BinaryFormatter (null, new StreamingContext (StreamingContextStates.File | StreamingContextStates.Persistence));

			/* The ResourceManager header */
			
			writer.Write (ResourceManager.MagicNumber);
			writer.Write (ResourceManager.HeaderVersionNumber);
			
			/* Build the rest of the ResourceManager
			 * header in memory, because we need to know
			 * how long it is in advance
			 */
			MemoryStream resman_stream = new MemoryStream ();
			BinaryWriter resman = new BinaryWriter (resman_stream,
							     Encoding.UTF8);

			resman.Write (typeof (ResourceReader).AssemblyQualifiedName);
			resman.Write (typeof (RuntimeResourceSet).FullName);

			/* Only space for 32 bits of header len in the
			 * resource file format
			 */
			int resman_len = (int) resman_stream.Length;
			writer.Write (resman_len);
			writer.Write (resman_stream.GetBuffer (), 0, resman_len);

			/* We need to build the ResourceReader name
			 * and data sections simultaneously
			 */
			MemoryStream res_name_stream = new MemoryStream ();
			BinaryWriter res_name = new BinaryWriter (res_name_stream, Encoding.Unicode);

			MemoryStream res_data_stream = new MemoryStream ();
			BinaryWriter res_data = new BinaryWriter (res_data_stream,
							       Encoding.UTF8);

			/* Not sure if this is the best collection to
			 * use, I just want an unordered list of
			 * objects with fast lookup, but without
			 * needing a key.  (I suppose a hashtable with
			 * key==value would work, but I need to find
			 * the index of each item later)
			 */
			ArrayList types = new ArrayList ();
			int [] hashes = new int [resources.Count];
			int [] name_offsets = new int [resources.Count];
			int count = 0;
			
			IDictionaryEnumerator res_enum = resources.GetEnumerator ();
			while (res_enum.MoveNext()) {
				/* Hash the name */
				hashes [count] = GetHash ((string) res_enum.Key);

				/* Record the offsets */
				name_offsets [count] = (int) res_name.BaseStream.Position;

				/* Write the name section */
				res_name.Write ((string) res_enum.Key);
				res_name.Write ((int) res_data.BaseStream.Position);

				if (res_enum.Value == null) {
					Write7BitEncodedInt (res_data, -1);
					count++;
					continue;
				}
				// implementation note: TypeByNameObject is
				// not used in 1.x profile.
				TypeByNameObject tbn = res_enum.Value as TypeByNameObject;
				Type type = tbn != null ? null : res_enum.Value.GetType();
				object typeObj = tbn != null ? (object) tbn.TypeName : type;

				/* Keep a list of unique types */
				// do not output predefined ones.
				switch ((type != null && !type.IsEnum) ? Type.GetTypeCode (type) : TypeCode.Empty) {
				case TypeCode.Decimal:
				case TypeCode.Single:
				case TypeCode.Double:
				case TypeCode.SByte:
				case TypeCode.Int16:
				case TypeCode.Int32:
				case TypeCode.Int64:
				case TypeCode.Byte:
				case TypeCode.UInt16:
				case TypeCode.UInt32:
				case TypeCode.UInt64:
				case TypeCode.DateTime:
				case TypeCode.String:
					break;
				default:
					if (type == typeof (TimeSpan))
						break;
					if (type == typeof (MemoryStream))
						break;
#if NET_4_0
					if (type == typeof (StreamWrapper))
						break;
#endif
					if (type==typeof(byte[]))
						break;

					if (!types.Contains (typeObj))
						types.Add (typeObj);
					/* Write the data section */
					Write7BitEncodedInt(res_data, (int) PredefinedResourceType.FistCustom + types.IndexOf(typeObj));
					break;
				}

				/* Strangely, Char is serialized
				 * rather than just written out
				 */
				if (tbn != null)
					res_data.Write((byte []) tbn.Value);
				else if (type == typeof (Byte)) {
					res_data.Write ((byte) PredefinedResourceType.Byte);
					res_data.Write ((Byte) res_enum.Value);
				} else if (type == typeof (Decimal)) {
					res_data.Write ((byte) PredefinedResourceType.Decimal);
					res_data.Write ((Decimal) res_enum.Value);
				} else if (type == typeof (DateTime)) {
					res_data.Write ((byte) PredefinedResourceType.DateTime);
					res_data.Write (((DateTime) res_enum.Value).Ticks);
				} else if (type == typeof (Double)) {
					res_data.Write ((byte) PredefinedResourceType.Double);
					res_data.Write ((Double) res_enum.Value);
				} else if (type == typeof (Int16)) {
					res_data.Write ((byte) PredefinedResourceType.Int16);
					res_data.Write ((Int16) res_enum.Value);
				} else if (type == typeof (Int32)) {
					res_data.Write ((byte) PredefinedResourceType.Int32);
					res_data.Write ((Int32) res_enum.Value);
				} else if (type == typeof (Int64)) {
					res_data.Write ((byte) PredefinedResourceType.Int64);
					res_data.Write ((Int64) res_enum.Value);
				} else if (type == typeof (SByte)) {
					res_data.Write ((byte) PredefinedResourceType.SByte);
					res_data.Write ((SByte) res_enum.Value);
				} else if (type == typeof (Single)) {
					res_data.Write ((byte) PredefinedResourceType.Single);
					res_data.Write ((Single) res_enum.Value);
				} else if (type == typeof (String)) {
					res_data.Write ((byte) PredefinedResourceType.String);
					res_data.Write ((String) res_enum.Value);
				} else if (type == typeof (TimeSpan)) {
					res_data.Write ((byte) PredefinedResourceType.TimeSpan);
					res_data.Write (((TimeSpan) res_enum.Value).Ticks);
				} else if (type == typeof (UInt16)) {
					res_data.Write ((byte) PredefinedResourceType.UInt16);
					res_data.Write ((UInt16) res_enum.Value);
				} else if (type == typeof (UInt32)) {
					res_data.Write ((byte) PredefinedResourceType.UInt32);
					res_data.Write ((UInt32) res_enum.Value);
				} else if (type == typeof (UInt64)) {
					res_data.Write ((byte) PredefinedResourceType.UInt64);
					res_data.Write ((UInt64) res_enum.Value);
				} else if (type == typeof (byte[])) {
					res_data.Write ((byte) PredefinedResourceType.ByteArray);
					byte [] data = (byte[]) res_enum.Value;
					res_data.Write ((uint) data.Length);
					res_data.Write (data, 0, data.Length);
				} else if (type == typeof (MemoryStream)) {
					res_data.Write ((byte) PredefinedResourceType.Stream);
					byte [] data = ((MemoryStream) res_enum.Value).ToArray ();
					res_data.Write ((uint) data.Length);
					res_data.Write (data, 0, data.Length);
#if NET_4_0
				} else if (type == typeof (StreamWrapper)) {
					StreamWrapper sw = (StreamWrapper) res_enum.Value;
					sw.Stream.Position = 0;

					res_data.Write ((byte) PredefinedResourceType.Stream);
					byte [] data = ReadStream (sw.Stream);
					res_data.Write ((uint) data.Length);
					res_data.Write (data, 0, data.Length);

					if (sw.CloseAfterWrite)
						sw.Stream.Close ();
#endif
				} else {
					/* non-intrinsic types are
					 * serialized
					 */
					formatter.Serialize (res_data.BaseStream, res_enum.Value);
				}
				count++;
			}

			/* Sort the hashes, keep the name offsets
			 * matching up
			 */
			Array.Sort (hashes, name_offsets);
			
			/* now do the ResourceReader header */

			writer.Write (2);
			writer.Write (resources.Count);
			writer.Write (types.Count);

			/* Write all of the unique types */
			foreach (object type in types) {
				if (type is Type)
					writer.Write(((Type) type).AssemblyQualifiedName);
				else
					writer.Write((string) type);
			}

			/* Pad the next fields (hash values) on an 8
			 * byte boundary, using the letters "PAD"
			 */
			int pad_align = (int) (writer.BaseStream.Position & 7);
			int pad_chars = 0;

			if (pad_align != 0)
				pad_chars = 8 - pad_align;

			for (int i = 0; i < pad_chars; i++)
				writer.Write ((byte) "PAD" [i % 3]);

			/* Write the hashes */
			for (int i = 0; i < resources.Count; i++)
				writer.Write (hashes[i]);

			/* and the name offsets */
			for (int i = 0; i < resources.Count; i++)
				writer.Write (name_offsets [i]);

			/* Write the data section offset */
			int data_offset= (int) writer.BaseStream.Position +
				(int) res_name_stream.Length + 4;
			writer.Write (data_offset);

			/* The name section goes next */
			writer.Write (res_name_stream.GetBuffer(), 0,
				     (int) res_name_stream.Length);
			/* The data section is last */
			writer.Write (res_data_stream.GetBuffer(), 0,
				     (int) res_data_stream.Length);

			res_name.Close ();
			res_data.Close ();

			/* Don't close writer, according to the spec */
			writer.Flush ();

			// ResourceWriter is no longer editable
			resources = null;
		}

#if NET_4_0
		byte [] ReadStream (Stream stream)
		{
			byte [] buff = new byte [stream.Length];
			int pos = 0;

			// Read Stream.Length bytes at most, and stop
			// immediately if Read returns 0.
			do {
				int n = stream.Read (buff, pos, buff.Length - pos);
				if (n == 0)
					break;

				pos += n;

			} while (pos < stream.Length);

			return buff;
		}
#endif

		// looks like it is (similar to) DJB hash
		int GetHash (string name)
		{
			uint hash = 5381;

			for (int i=0; i<name.Length; i++)
				hash = ((hash << 5) + hash) ^ name [i];
			
			return ((int) hash);
		}

		/* Cut and pasted from BinaryWriter, because it's
		 * 'protected' there.
		 */
		void Write7BitEncodedInt (BinaryWriter writer, int value)
		{
			do {
				int high = (value >> 7) & 0x01ffffff;
				byte b = (byte) (value & 0x7f);

				if (high != 0)
					b = (byte) (b | 0x80);

				writer.Write (b);
				value = high;
			} while (value != 0);
		}

		internal Stream Stream {
			get {
				return stream;
			}
		}
	}
}