using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;
using C = Mono.Cecil;
using Mono.Cecil.Metadata;

namespace Mono.Debugger.Soft
{
	public class MethodMirror : Mirror
	{
		string name;
		MethodInfo info;
		TypeMirror declaring_type;
		DebugInfo debug_info;
		C.MethodDefinition meta;
		ParameterInfoMirror[] param_info;
		ParameterInfoMirror ret_param;
		LocalVariable[] locals;
		IList<Location> locations;
		MethodBodyMirror body;

		internal MethodMirror (VirtualMachine vm, long id) : base (vm, id) {
		}

		public string Name {
			get {
				if (name == null)
					name = vm.conn.Method_GetName (id);
				return name;
			}
	    }

		public TypeMirror DeclaringType {
			get {
				if (declaring_type == null)
					declaring_type = vm.GetType (vm.conn.Method_GetDeclaringType (id));
				return declaring_type;
			}
	    }

		public TypeMirror ReturnType {
			get {
				return ReturnParameter.ParameterType;
			}
		}

		// FIXME:
		public string FullName {
			get {
				string type_namespace = DeclaringType.Namespace;
				string type_name = DeclaringType.Name;
				StringBuilder sb = new StringBuilder ();
				sb.Append (ReturnType.Name);
				sb.Append (' ');
				if (type_namespace == String.Empty)
					sb.Append (type_name + ":" + Name + " ()");
				else
					sb.Append (type_namespace + "." + type_name + ":" + Name + " ()");
				return sb.ToString ();
			}
	    }

		void GetInfo () {
			if (info == null)
				info = vm.conn.Method_GetInfo (id);
		}

		public int MetadataToken {
			get {
				GetInfo ();
				return info.token;
			}
		}

		public MethodAttributes Attributes {
			get {
				GetInfo ();
				return (MethodAttributes)info.attributes;
			}
		}

		public bool IsPublic { 
			get {
				return (Attributes & MethodAttributes.MemberAccessMask) == MethodAttributes.Public;
			}
		}
		public bool IsPrivate {
			get {
				return (Attributes & MethodAttributes.MemberAccessMask) == MethodAttributes.Private;
			}
		}
		public bool IsFamily {
			get {
				return (Attributes & MethodAttributes.MemberAccessMask) == MethodAttributes.Family;
			}
		}
		public bool IsAssembly {
			get {
				return (Attributes & MethodAttributes.MemberAccessMask) == MethodAttributes.Assembly;
			}
		}
		public bool IsFamilyAndAssembly {
			get {
				return (Attributes & MethodAttributes.MemberAccessMask) == MethodAttributes.FamANDAssem;
			}
		}
		public bool IsFamilyOrAssembly {
			get {
				return (Attributes & MethodAttributes.MemberAccessMask) == MethodAttributes.FamORAssem;
			}
		}
		public bool IsStatic {
			get {
				return (Attributes & MethodAttributes.Static) != 0;
			}
		}
		public bool IsFinal {
			get {
				return (Attributes & MethodAttributes.Final) != 0;
			}
		}
		public bool IsVirtual {
			get {
				return (Attributes & MethodAttributes.Virtual) != 0;
			}
		}
		public bool IsHideBySig {
			get {
				return (Attributes & MethodAttributes.HideBySig) != 0;
			}
		}
		public bool IsAbstract {
			get {
				return (Attributes & MethodAttributes.Abstract) != 0;
			}
		}
		public bool IsSpecialName {
			get {
				return (Attributes & MethodAttributes.SpecialName) != 0;
			}
		}

		public bool IsConstructor {
			get {
				int attr = (int)Attributes;
				return ((attr & (int)MethodAttributes.RTSpecialName) != 0
					&& (Name == ".ctor"));
			}
		}

	    public ParameterInfoMirror[] GetParameters () {
			if (param_info == null) {
				var pi = vm.conn.Method_GetParamInfo (id);
				param_info = new ParameterInfoMirror [pi.param_count];
				// Return
				ret_param = new ParameterInfoMirror (this, -1, vm.GetType (pi.ret_type), null, ParameterAttributes.Retval);
				// FIXME: this
				// FIXME: Attributes
				for (int i = 0; i < pi.param_count; ++i) {
					param_info [i] = new ParameterInfoMirror (this, i, vm.GetType (pi.param_types [i]), pi.param_names [i], 0);
				}
			}

			return param_info;
		}

	    public ParameterInfoMirror ReturnParameter {
			get {
				if (ret_param == null)
					GetParameters ();
				return ret_param;
			}
		}

		public LocalVariable[] GetLocals () {
			if (locals == null) {
				var li = vm.conn.Method_GetLocalsInfo (id);
				// Add the arguments as well
				var pi = vm.conn.Method_GetParamInfo (id);

				locals = new LocalVariable [pi.param_count + li.names.Length];

				for (int i = 0; i < pi.param_count; ++i)
					locals [i] = new LocalVariable (vm, this, i, pi.param_types [i], pi.param_names [i], -1, -1, true);

				for (int i = 0; i < li.names.Length; ++i)
					locals [i + pi.param_count] = new LocalVariable (vm, this, i, li.types [i], li.names [i], li.live_range_start [i], li.live_range_end [i], false);
			}
			return locals;
		}

		public LocalVariable GetLocal (string name) {
			if (name == null)
				throw new ArgumentNullException ("name");

			GetLocals ();

			LocalVariable res = null;
			for (int i = 0; i < locals.Length; ++i) {
				if (locals [i].Name == name) {
					if (res != null)
						throw new AmbiguousMatchException ("More that one local has the name '" + name + "'.");
					res = locals [i];
				}
			}

			return res;
		}

		public MethodBodyMirror GetMethodBody () {
			if (body == null) {
				MethodBodyInfo info = vm.conn.Method_GetBody (id);

				body = new MethodBodyMirror (vm, this, info.il);
			}
			return body;
		}

		public IList<int> ILOffsets {
			get {
				if (debug_info == null)
					debug_info = vm.conn.Method_GetDebugInfo (id);
				return Array.AsReadOnly (debug_info.il_offsets);
			}
	    }

		public IList<int> LineNumbers {
			get {
				if (debug_info == null)
					debug_info = vm.conn.Method_GetDebugInfo (id);
				return Array.AsReadOnly (debug_info.line_numbers);
			}
	    }

		public string SourceFile {
			get {
				if (debug_info == null)
					debug_info = vm.conn.Method_GetDebugInfo (id);
				return debug_info.filename;
			}
	    }

		public IList<Location> Locations {
			get {
				if (locations == null) {
					var il_offsets = ILOffsets;
					var line_numbers = LineNumbers;
					IList<Location> res = new Location [ILOffsets.Count];
					for (int i = 0; i < il_offsets.Count; ++i)
						res [i] = new Location (vm, this, -1, il_offsets [i], SourceFile, line_numbers [i], 0);
					locations = res;
				}
				return locations;
			}
		}				

		internal int il_offset_to_line_number (int il_offset) {
			if (debug_info == null)
				debug_info = vm.conn.Method_GetDebugInfo (id);

			// FIXME: Optimize this
			for (int i = debug_info.il_offsets.Length - 1; i >= 0; --i) {
				if (debug_info.il_offsets [i] <= il_offset)
					return debug_info.line_numbers [i];
			}
			return -1;
	    }

		public Location LocationAtILOffset (int il_offset) {
			IList<Location> locs = Locations;

			// FIXME: Optimize this
			for (int i = locs.Count - 1; i >= 0; --i) {
				if (locs [i].ILOffset <= il_offset)
					return locs [i];
			}

			return null;
		}

		public C.MethodDefinition Metadata {
			get {
				if (meta == null)
					meta = (C.MethodDefinition)DeclaringType.Assembly.Metadata.MainModule.LookupByToken (new MetadataToken (MetadataToken));
				return meta;
			}
		}
    }
}