#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2012 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;

namespace HeuristicLab.Persistence {
  [Transformer("78556C88-0FEE-4602-95C7-A469B2DDB468", 100)]
  [StorableType("3a578289-43ca-40f8-9f1e-2bdd255cb8fb")]
  internal sealed class StorableClassBoxTransformer : BoxTransformer<object> {
    public override bool CanTransformType(Type type) {
      return StorableTypeAttribute.IsStorableType(type) && !type.IsValueType && !type.IsEnum || // don't transform structs or enums
        type.BaseType != null && CanTransformType(type.BaseType);
    }

    protected override void Populate(Box.Builder box, object value, Mapper mapper) {
      var b = StorableClassBox.CreateBuilder();
      var type = value.GetType();
      var typeInfo = Mapper.StaticCache.GetTypeInfo(type);

      var emptyArgs = new object[0];
      foreach (var hook in typeInfo.BeforeSerializationHooks) {
        hook.Invoke(value, emptyArgs);
      }

      var components = new Dictionary<uint, uint>();
      foreach (var componentInfo in typeInfo.Fields) {
        var field = (FieldInfo)componentInfo.MemberInfo;
        var component = mapper.GetBoxId(field.GetValue(value));
        components.Add(mapper.GetStringId(componentInfo.Name), component);
      }

      foreach (var componentInfo in typeInfo.Properties.Where(x => x.Readable)) {
        var property = (PropertyInfo)componentInfo.MemberInfo;
        var component = mapper.GetBoxId(property.GetValue(value, null));
        components.Add(mapper.GetStringId(componentInfo.Name), component);
      }

      b.AddRangeKeyIds(components.Keys);
      b.AddRangeValueIds(components.Values);

      box.SetExtension(StorableClassBox.StorableClass, b.Build());
    }

    protected override object Extract(Box box, Type type, Mapper mapper) {
      return mapper.CreateInstance(type);
    }
    public override void FillFromBox(object obj, Box box, Mapper mapper) {
      var data = box.GetExtension(StorableClassBox.StorableClass);
      var type = obj.GetType();
      var typeInfo = Mapper.StaticCache.GetTypeInfo(type);
      var typeBox = mapper.GetBox(box.TypeId).GetExtension(TypeBox.Type);
      var version = typeBox.HasVersion ? typeBox.Version : 1;
      var typeGuid = typeInfo.StorableTypeAttribute.Guid;

      var components = new Dictionary<uint, uint>();
      for (int i = 0; i < data.KeyIdsList.Count; i++) {
        components.Add(data.KeyIdsList[i], data.ValueIdsList[i]);
      }

      var conversionMethods =
        type.Assembly.GetTypes().SelectMany(t =>
          t.GetMethods(BindingFlags.NonPublic | BindingFlags.Static)
          .Where(StorableConversionAttribute.IsStorableConversionMethod)
          .Where(mi => StorableConversionAttribute.GetGuid(mi) == typeGuid &&
                       StorableConversionAttribute.GetVersion(mi) >= version))
          .OrderBy(StorableConversionAttribute.GetVersion)
          .ToArray();

      // put all objects into dictionary for conversion 
      var dict = new Dictionary<string, object>();
      foreach (var component in components) {
        dict.Add(mapper.GetString(component.Key), mapper.GetObject(component.Value));
      }

      Dictionary<string, object> lastDict = new Dictionary<string, object>();
      foreach (var convMeth in conversionMethods) {
        if (StorableConversionAttribute.GetVersion(convMeth) != version)
          throw new PersistenceException(string.Format("No conversion method defined for type {0} version {1}", typeGuid, version));
        lastDict = (Dictionary<string, object>)convMeth.Invoke(null, new object[] { dict });
        foreach (var kvp in lastDict) {
          dict[kvp.Key] = kvp.Value;
        }
        version++;
      }
      if (version != typeInfo.StorableTypeAttribute.Version)
        throw new PersistenceException(string.Format("Missing one or more conversion methods for type {0} version {1}",
          typeGuid, typeInfo.StorableTypeAttribute.Version));

      // set default values for all fields and properties
      foreach (var componentInfo in typeInfo.Fields) {
        var field = (FieldInfo)componentInfo.MemberInfo;
        if (componentInfo.StorableAttribute != null && componentInfo.StorableAttribute.DefaultValue != null)
          field.SetValue(obj, componentInfo.StorableAttribute.DefaultValue);
      }
      foreach (var componentInfo in typeInfo.Properties.Where(x => x.Writeable)) {
        var property = (PropertyInfo)componentInfo.MemberInfo;
        if (componentInfo.StorableAttribute != null && componentInfo.StorableAttribute.DefaultValue != null)
          property.SetValue(obj, componentInfo.StorableAttribute.DefaultValue, null);
      }

      // set all members as generated by conversion method chain
      foreach (var kvp in dict) {
        var key = kvp.Key;
        var val = kvp.Value;
        var fieldInfo = typeInfo.Fields.FirstOrDefault(fi => fi.Name == key);
        if (fieldInfo != null) {
          var field = (FieldInfo)fieldInfo.MemberInfo;
          field.SetValue(obj, val);
          lastDict.Remove(fieldInfo.Name); // only for consistency check
          continue;
        }
        var propInfo = typeInfo.Properties.Where(x => x.Writeable).FirstOrDefault(pi => pi.Name == key);
        if (propInfo != null) {
          var prop = (PropertyInfo)propInfo.MemberInfo;
          prop.SetValue(obj, val, null);
          lastDict.Remove(propInfo.Name);    // only for consistency check
          continue;
        }
      }

      if (lastDict.Any())
        throw new PersistenceException(string.Format("Invalid conversion method. The following members are undefined in type {0} version {1}: {2}",
          typeGuid, typeInfo.StorableTypeAttribute.Version,
          string.Join(", ", lastDict.Keys)));

      var emptyArgs = new object[0];
      foreach (var hook in typeInfo.AfterDeserializationHooks) {
        hook.Invoke(obj, emptyArgs);
      }
    }
  }
}