//
// Mono.ILASM.CodeGen.cs
//
// Author(s):
//  Sergey Chaban (serge@wildwestsoftware.com)
//  Jackson Harper (Jackson@LatitudeGeo.com)
//
// (C) Sergey Chaban
// (C) 2003 Jackson Harper, All rights reserved
//

using PEAPI;
using System;
using System.IO;
using System.Collections;
using System.Reflection;
using System.Reflection.Emit;
using System.Text;
using System.Security;

using SSPermissionSet = System.Security.PermissionSet;
using MIPermissionSet = Mono.ILASM.PermissionSet;

using MIAssembly = Mono.ILASM.Assembly;

namespace Mono.ILASM {

        public class CodeGen {

                private PEFile pefile;
                private ExternAssembly current_assemblyref;
                private ExternModule current_moduleref;
                private string current_namespace;
                private TypeDef current_typedef;
                private MethodDef current_methoddef;
                private ArrayList typedef_stack;
		private int typedef_stack_top;
		private SymbolWriter symwriter;
                private ICustomAttrTarget current_customattrtarget;
                private IDeclSecurityTarget current_declsectarget;
                private PEAPI.NativeType current_field_native_type;

                private MIAssembly this_assembly;
                        
                private TypeManager type_manager;
                private ExternTable extern_table;
                private Hashtable global_field_table;
                private Hashtable global_method_table;
                private Hashtable global_methodref_table;
                private Hashtable global_fieldref_table;
                private Hashtable data_table;
                private FileRef file_ref;
                private ArrayList manifestResources;
                private Hashtable typeref_table;
                
                private ArrayList defcont_list;

                private int sub_system;
                private int cor_flags;
                private long image_base;
                private long stack_reserve;

                private string output_file;
		private string debug_file;
                private bool is_dll;
                private bool entry_point;

                private Module this_module;

                public CodeGen (string output_file, bool is_dll, bool debugging_info)
                {
                        this.output_file = output_file;
                        this.is_dll = is_dll;

			if (debugging_info)
				symwriter = new SymbolWriter (CreateDebugFile (output_file));

                        type_manager = new TypeManager (this);
                        extern_table = new ExternTable ();
                        typedef_stack = new ArrayList ();
			typedef_stack_top = 0;
                        global_field_table = new Hashtable ();
                        global_method_table = new Hashtable ();

                        data_table = new Hashtable ();

                        defcont_list = new ArrayList ();

                        sub_system = -1;
                        cor_flags = -1;
                        image_base = -1;
                        stack_reserve = -1;
                        entry_point = false;
                        this_module = null;
                }

		private string CreateDebugFile (string output_file)
		{
			int ext_index = output_file.LastIndexOf ('.');

			if (ext_index == -1)
				ext_index = output_file.Length;

			return String.Format ("{0}.{1}", output_file.Substring (0, ext_index),
					      "mdb");
		}

                public PEFile PEFile {
                        get { return pefile; }
                }

		public SymbolWriter SymbolWriter {
			get { return symwriter; }
		}

                public string CurrentNameSpace {
                        get { return current_namespace; }
                        set { current_namespace = value; }
                }

                public TypeDef CurrentTypeDef {
                        get { return current_typedef; }
                }

                public MethodDef CurrentMethodDef {
                        get { return current_methoddef; }
                }

                public ExternAssembly CurrentAssemblyRef {
                        get { return current_assemblyref; }
                }

                public ExternModule CurrentModuleRef {
                        get { return current_moduleref; }
                }

                public ICustomAttrTarget CurrentCustomAttrTarget {
                        get { return current_customattrtarget; }
                        set { current_customattrtarget = value; }
                }

                public IDeclSecurityTarget CurrentDeclSecurityTarget {
                        get { return current_declsectarget; }
                        set { current_declsectarget = value; }
                }

                public ExternTable ExternTable {
                        get { return extern_table; }
                }

                public TypeManager TypeManager {
                        get { return type_manager; }
                }

                public bool HasEntryPoint {
                        get { return entry_point; }
                        set { 
                                /* if (!value) error: unsetting entrypoint ? */
                                if (entry_point)
                                        Report.Error ("Multiple .entrypoint declarations.");
                                entry_point = value;
                        }                
                }

                public TypeRef GetTypeRef (string name)
                {
                        TypeRef tr = null;

                        if (typeref_table == null) 
                                typeref_table = new Hashtable ();
                        else 
                                tr = typeref_table [name] as TypeRef;

                        if (tr == null) {
                                tr = new TypeRef (name, false, null);
                                typeref_table [name] = tr;
                        }

                        return tr;
                }

                public GlobalMethodRef GetGlobalMethodRef (BaseTypeRef ret_type, PEAPI.CallConv call_conv,
                                string name, BaseTypeRef[] param, int gen_param_count)
                {
                        string key = MethodDef.CreateSignature (ret_type, name, param, gen_param_count);

                        GlobalMethodRef methref = null;

                        if (global_methodref_table == null)
                                global_methodref_table = new Hashtable ();
                        else
                                methref = (GlobalMethodRef) global_methodref_table [key];

                        if (methref == null) {
                                methref = new GlobalMethodRef (ret_type, call_conv, name, param, gen_param_count);
                                global_methodref_table [key] = methref;
                        }
                        
                        return methref;
                }

                public GlobalFieldRef GetGlobalFieldRef (BaseTypeRef ret_type, string name)
                {
                        string key = ret_type.FullName + name;

                        GlobalFieldRef fieldref = null;

                        if (global_fieldref_table == null)
                                global_fieldref_table = new Hashtable ();
                        else
                                fieldref = (GlobalFieldRef) global_fieldref_table [key];

                        if (fieldref == null) {
                                fieldref = new GlobalFieldRef (ret_type, name);
                                global_fieldref_table [key] = fieldref;
                        }
                        
                        return fieldref;
                }

                public void SetSubSystem (int sub_system)
                {
                        this.sub_system = sub_system;
                }

                public void SetCorFlags (int cor_flags)
                {
                        this.cor_flags = cor_flags;
                }

                public void SetImageBase (long image_base)
                {
                        this.image_base = image_base;
                }

                public void SetStackReserve (long stack_reserve)
                {
                        this.stack_reserve = stack_reserve;
                }

                public void SetThisAssembly (string name, PEAPI.AssemAttr attr)
                {
                        if (this_assembly != null && this_assembly.Name != name)
                                Report.Error ("Multiple assembly declarations");

                        this_assembly = new Assembly (name);
                        this_assembly.SetAssemblyAttr (attr);
                        if (name != "mscorlib")
                                ExternTable.AddCorlib ();
                }

                public void SetModuleName (string module_name)
                {
                        this_module = new Module (module_name);
                        CurrentCustomAttrTarget = this_module;
                }

                public void SetFileRef (FileRef file_ref)
                {
                        this.file_ref = file_ref;
                }

                public MIAssembly ThisAssembly {
                        get { return this_assembly; }
                }

                public bool IsThisAssembly (string name)
                {
                        return (this_assembly != null && name == this_assembly.Name);
                }

                public Module ThisModule {
                        get { return this_module; }
                }
                
                public bool IsThisModule (string name)
                {
                        return (this_module != null && name == this_module.Name);
                }

		public void BeginSourceFile (string name)
		{
			if (symwriter != null)
				symwriter.BeginSourceFile (name);
		}

		public void EndSourceFile ()
		{
			if (symwriter != null)
				symwriter.EndSourceFile ();
		}

                public void BeginTypeDef (TypeAttr attr, string name, BaseClassRef parent,
                                ArrayList impl_list, Location location, GenericParameters gen_params)
                {
                        TypeDef outer = null;
                        string cache_name = CacheName (name);
                        if (typedef_stack_top > 0) {
				StringBuilder sb = new StringBuilder ();

				for (int i = 0; i < typedef_stack_top; i++){
					outer = (TypeDef) typedef_stack [i];
					if (i == 0)
						/* Use FullName for outermost class to get the
						   namespace also */
						sb.Append (outer.FullName);
					else
						sb.Append (outer.Name);
					sb.Append ("/");
				}
				sb.Append (name);
				cache_name = sb.ToString ();
                        }

                        TypeDef typedef = type_manager[cache_name];

                        if (typedef != null) {
                                // Class head is allready defined, we are just reopening the class
                                current_customattrtarget = current_typedef = typedef;
                                current_declsectarget = typedef;
                                typedef_stack.Add (current_typedef);
				typedef_stack_top++;
                                return;
                        }

                        typedef = new TypeDef (attr, current_namespace,
                                        name, parent, impl_list, location, gen_params, outer);

                        type_manager[cache_name] = typedef;
                        current_customattrtarget = current_typedef = typedef;
                        current_declsectarget = typedef;
			typedef_stack.Add (typedef);
			typedef_stack_top++;
                }

                public void AddFieldMarshalInfo (PEAPI.NativeType native_type)
                {
                        current_field_native_type = native_type;
                }

                public void AddFieldDef (FieldDef fielddef)
                {
                        if (current_field_native_type != null) {
                                fielddef.AddMarshalInfo (current_field_native_type);
                                current_field_native_type = null;
                        }

                        if (current_typedef != null) {
                                current_typedef.AddFieldDef (fielddef);
                        } else {
                                global_field_table.Add (
                                        new DictionaryEntry (fielddef.Name, fielddef.Type.FullName),
                                        fielddef);
                        }
                }

                public void AddDataDef (DataDef datadef)
                {
                        if (data_table [datadef.Name] != null)
                                Report.Error ("Duplicate global label '" + datadef.Name + "'");
                        data_table [datadef.Name] = datadef;
                }

		public void AddManifestResource (ManifestResource mr)
		{
			if (manifestResources == null)
				manifestResources = new ArrayList ();
			manifestResources.Add (mr);
		}

                public PEAPI.DataConstant GetDataConst (string name)
                {
                        DataDef def = (DataDef) data_table [name];
                        if (def == null)
                                return null;

                        return (DataConstant) def.PeapiConstant;
                }

                public void BeginMethodDef (MethodDef methoddef)
                {
                        if (current_typedef != null) {
                                current_typedef.AddMethodDef (methoddef);
                        } else {
                                global_method_table.Add (methoddef.Signature,
                                                methoddef);
                        }

                        current_customattrtarget = current_methoddef = methoddef;
                        current_declsectarget = methoddef;
                }

                public void EndMethodDef (Location location)
                {
			if (symwriter != null)
				symwriter.EndMethod (location);

                        current_methoddef = null;
                }

                public void EndTypeDef ()
                {
			typedef_stack_top--;
			typedef_stack.RemoveAt (typedef_stack_top);

                        if (typedef_stack_top > 0)
                                current_typedef = (TypeDef) typedef_stack [typedef_stack_top-1];
                        else
                                current_typedef = null;

                }

                public void BeginAssemblyRef (string name, AssemblyName asmb_name, PEAPI.AssemAttr attr)
                {
                        current_customattrtarget = current_assemblyref = ExternTable.AddAssembly (name, asmb_name, attr);
                        current_declsectarget = current_assemblyref;
                }

                public void EndAssemblyRef ()
                {
                        current_assemblyref = null;
                        current_customattrtarget = null;
                        current_declsectarget = null;
                }

                public void AddToDefineContentsList (TypeDef typedef)
                {
                        defcont_list.Add (typedef);
                }

                public void AddPermission (PEAPI.SecurityAction sec_action, object perm)
                {
                        if (CurrentDeclSecurityTarget == null)
                                return;

                        AddPermission (sec_action, perm, CurrentDeclSecurityTarget.DeclSecurity);
                }

                private void AddPermission (PEAPI.SecurityAction sec_action, object perm, DeclSecurity decl_sec)
                {
                        SSPermissionSet ps = perm as SSPermissionSet;
                        if (ps != null) {
                                decl_sec.AddPermissionSet (sec_action, ps);
                                return;
                        }

                        IPermission iper = perm as IPermission;
                        if (iper != null) {
                                decl_sec.AddPermission (sec_action, iper);
                                return;
                        }

                        MIPermissionSet ps20 = perm as MIPermissionSet;
                        if (ps20 != null) {
                                decl_sec.AddPermissionSet (sec_action, ps20);
                                return;
                        }
                }

                public void Write ()
                {
                        FileStream out_stream = null;

                        try {
                                if (ThisModule == null)
                                        this_module = new Module (Path.GetFileName (output_file));

                                out_stream = new FileStream (output_file, FileMode.Create, FileAccess.Write);
                                pefile = new PEFile (ThisAssembly != null ? ThisAssembly.Name : null, ThisModule.Name, is_dll, ThisAssembly != null, null, out_stream);
                                PEAPI.Assembly asmb = pefile.GetThisAssembly ();

                                ThisModule.PeapiModule = pefile.GetThisModule ();

                                if (file_ref != null)
                                        file_ref.Resolve (this);

                                extern_table.Resolve (this);
                                type_manager.DefineAll ();

				if (manifestResources != null) {
					foreach (ManifestResource mr in manifestResources)
						pefile.AddManifestResource (mr);
				}

                                foreach (FieldDef fielddef in global_field_table.Values) {
                                        fielddef.Define (this);
                                }

                                foreach (MethodDef methoddef in global_method_table.Values) {
                                        methoddef.Define (this);
                                }

                                foreach (TypeDef typedef in defcont_list) {
                                        typedef.DefineContents (this);
                                }

                                if (ThisAssembly != null)
                                        ThisAssembly.Resolve (this, pefile.GetThisAssembly ());
                                ThisModule.Resolve (this, pefile.GetThisModule ());

                                if (sub_system != -1)
                                        pefile.SetSubSystem ((PEAPI.SubSystem) sub_system);
                                if (cor_flags != -1)
                                        pefile.SetCorFlags (cor_flags);
                                if (stack_reserve != -1)
                                        pefile.SetStackReserve (stack_reserve);

                                pefile.WritePEFile ();

				if (symwriter != null) {
					Guid guid = pefile.GetThisModule ().Guid;
					symwriter.Write (guid);
				}
                        } finally {
                                if (out_stream != null)
                                        out_stream.Close ();
                        }
                }

                public PEAPI.Method ResolveMethod (string signature)
                {
                        MethodDef methoddef = (MethodDef) global_method_table[signature];
                        if (methoddef == null)
                                Report.Error ("Unable to resolve global method : " + signature);

                        return methoddef.Resolve (this);
                }

                public PEAPI.Method ResolveVarargMethod (string signature,
                                CodeGen code_gen, PEAPI.Type[] opt)
                {
                        MethodDef methoddef = (MethodDef) global_method_table[signature];
                        methoddef.Resolve (code_gen);

                        return methoddef.GetVarargSig (opt);
                }

                public PEAPI.Field ResolveField (string name, string type_name)
                {
                        FieldDef fielddef = (FieldDef) global_field_table[new DictionaryEntry (name, type_name)]; 
                        if (fielddef == null)
                                Report.Error (String.Format ("Unable to resolve global field : {0} {1}", type_name, name));

                        return fielddef.Resolve (this);
                }

                private string CacheName (string name)
                {
                        if (current_namespace == null ||
                                        current_namespace == String.Empty)
                                return name;

                        return current_namespace + "." + name;
                }
        }

}