//
// System.Diagnostics.SymbolStore/MonoSymbolTableWriter.cs
//
// Author:
//   Martin Baulig (martin@gnome.org)
//
// (C) 2002 Ximian, Inc.  http://www.ximian.com
//

using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Collections;
using System.Text;
using System.IO;
	
namespace Mono.CSharp.Debugger
{
	internal class MonoSymbolTableWriter : IDisposable
	{
		BinaryWriter bw;
		Hashtable type_hash;
		int last_type_index;

		public MonoSymbolTableWriter (string output_filename)
		{
			FileStream stream = new FileStream (output_filename, FileMode.Create);
			bw = new BinaryWriter (stream);
			type_hash = new Hashtable ();
		}

		int GetTypeIndex (Type type)
		{
			if (type_hash.Contains (type))
				return (int) type_hash [type];

			int index = ++last_type_index;
			type_hash.Add (type, index);
			return index;
		}

		public void WriteSymbolTable (MonoSymbolWriter symwriter)
		{
			// Magic number and file version.
			bw.Write (OffsetTable.Magic);
			bw.Write (OffsetTable.Version);

			OffsetTable ot = new OffsetTable ();

			//
			// Offsets of file sections; we must write this after we're done
			// writing the whole file, so we just reserve the space for it here.
			//
			long offset_table_offset = bw.BaseStream.Position;
			ot.Write (bw);

			//
			// Write source file table.
			//
			Hashtable sources = new Hashtable ();

			ot.source_table_offset = (int) bw.BaseStream.Position;
			foreach (SourceFile source in symwriter.Sources) {
				if (sources.ContainsKey (source))
					continue;

				sources.Add (source, (int) bw.BaseStream.Position);
				byte[] file_name = Encoding.UTF8.GetBytes (source.FileName);
				bw.Write ((int) file_name.Length);
				bw.Write (file_name);
			}
			ot.source_table_size = (int) bw.BaseStream.Position - ot.source_table_offset;

			Hashtable source_table = new Hashtable ();

			//
			// Write line number table
			//
			ArrayList methods = new ArrayList ();

			int num_methods = 0;

			ot.line_number_table_offset = (int) bw.BaseStream.Position;
			foreach (SourceMethod method in symwriter.Methods) {
				if (method.Start == null || method.Start.Row == 0)
					continue;

				int count = method.Lines.Length;
				LineNumberEntry[] lines = new LineNumberEntry [count];

				int pos = (int) bw.BaseStream.Position;

				int num_params = method.Parameters.Length;
				int[] param_type_indices = new int [num_params];
				for (int i = 0; i < num_params; i++) {
					Type type = method.Parameters [i].ParameterType;
					param_type_indices [i] = GetTypeIndex (type);
				}

				int num_locals = method.Locals.Length;
				int[] local_type_indices = new int [num_locals];
				for (int i = 0; i < num_locals; i++)
					local_type_indices [i] = ++last_type_index;

				int type_index_table_offset = ot.type_index_table_size;
				ot.type_index_table_size += 4 * (num_params + num_locals);

				int this_type_index = 0;
				if (!method.MethodBase.IsStatic)
					this_type_index = GetTypeIndex (method.MethodBase.ReflectedType);

				for (int i = 0; i < count; i++) {
					lines [i] = new LineNumberEntry (method.Lines [i]);
					lines [i].Write (bw);
				}

				MethodEntry entry = new MethodEntry (
					(int) method.Token, (int) sources [method.SourceFile],
					method.SourceFile.FileName, this_type_index,
					param_type_indices, local_type_indices, method.Locals, lines, pos,
					(int) method.Start.Row, (int) method.End.Row);

				methods.Add (entry);
			}
			ot.line_number_table_size = (int) bw.BaseStream.Position -
				ot.line_number_table_offset;

			//
			// Write type index table.
			//

			ot.type_index_table_offset = (int) bw.BaseStream.Position;
			for (int i = 0; i < methods.Count; i++) {
				MethodEntry entry = (MethodEntry) methods [i];

				entry.TypeIndexTableOffset = (int) bw.BaseStream.Position;

				for (int j = 0; j < entry.NumParameters; j++)
					bw.Write (entry.ParamTypeIndices [j]);
				for (int j = 0; j < entry.NumLocals; j++)
					bw.Write (entry.LocalTypeIndices [j]);
			}
			ot.type_index_table_size = (int) bw.BaseStream.Position -
				ot.type_index_table_offset;

			//
			// Write local variable table.
			//

			ot.local_variable_table_offset = (int) bw.BaseStream.Position;
			for (int i = 0; i < methods.Count; i++) {
				MethodEntry entry = (MethodEntry) methods [i];

				entry.LocalVariableTableOffset = (int) bw.BaseStream.Position;

				for (int j = 0; j < entry.NumLocals; j++)
					entry.Locals [j].Write (bw);
			}
			ot.local_variable_table_size = (int) bw.BaseStream.Position -
				ot.local_variable_table_offset;

			//
			// Write method table
			//
			ot.method_count = methods.Count;
			ot.method_table_offset = (int) bw.BaseStream.Position;
			for (int i = 0; i < methods.Count; i++) {
				MethodEntry entry = (MethodEntry) methods [i];
				SourceFileEntry source = (SourceFileEntry) source_table [entry.SourceFileOffset];
				if (source == null) {
					source = new SourceFileEntry (entry.SourceFile);
					source_table.Add (entry.SourceFileOffset, source);
				}

				source.AddMethod (new MethodSourceEntry (
					i, (int) bw.BaseStream.Position, entry.StartRow, entry.EndRow));

				entry.Write (bw);
			}
			ot.method_table_size = (int) bw.BaseStream.Position -  ot.method_table_offset;

			//
			// Write source file table.
			//
			ot.source_file_count = source_table.Count;
			ot.source_file_table_offset = (int) bw.BaseStream.Position;
			foreach (SourceFileEntry source in source_table.Values)
				source.Write (bw);
			ot.source_file_table_size = (int) bw.BaseStream.Position - ot.source_file_table_offset;

			//
			// Write offset table
			//
			ot.type_count = last_type_index;
			ot.total_file_size = (int) bw.BaseStream.Position;
			bw.Seek ((int) offset_table_offset, SeekOrigin.Begin);
			ot.Write (bw);
			bw.Seek (0, SeekOrigin.End);
		}

		void IDisposable.Dispose() {
			Dispose (true);
		}

		protected virtual void Dispose (bool disposing)
		{
			if (disposing)
			{
				bw.Close ();
			}
		}
	}
}