/*
 * Copyright 2019 by its authors. See AUTHORS.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#ifndef EOLIAN_MONO_FUNCTION_DEFINITION_HH
#define EOLIAN_MONO_FUNCTION_DEFINITION_HH

#include <Eina.hh>

#include "grammar/generator.hpp"
#include "grammar/klass_def.hpp"

#include "grammar/kleene.hpp"
#include "grammar/indentation.hpp"
#include "grammar/list.hpp"
#include "grammar/alternative.hpp"
#include "grammar/attribute_reorder.hpp"
#include "grammar/counter.hpp"
#include "logging.hh"
#include "type.hh"
#include "name_helpers.hh"
#include "helpers.hh"
#include "function_helpers.hh"
#include "marshall_type.hh"
#include "parameter.hh"
#include "documentation.hh"
#include "using_decl.hh"
#include "generation_contexts.hh"
#include "blacklist.hh"

namespace eolian_mono {

struct native_function_definition_generator
{
  attributes::klass_def const* klass;
  
  template <typename OutputIterator, typename Context>
  bool generate(OutputIterator sink, attributes::function_def const& f, Context const& context) const
  {
    EINA_CXX_DOM_LOG_DBG(eolian_mono::domain) << "native_function_definition_generator: " << f.c_name << std::endl;
    if(blacklist::is_function_blacklisted(f, context))
      return true;

    auto const& indent = current_indentation(context);

    // Delegate for the C# method we will export to EO as a method implementation.
    if(!as_generator
       (
        indent << eolian_mono::marshall_annotation(true) << "\n"
        << indent << "private delegate "
        << eolian_mono::marshall_type(true)
        << " "
        << string
        << "_delegate(" << (f.is_static ? "" : "System.IntPtr obj, System.IntPtr pd")
        << ((!f.is_static && f.parameters.size() > 0) ? ", " : "")
        << (grammar::attribute_reorder<-1, -1>
        (
         (marshall_annotation << " " << marshall_parameter)
        ) % ", ")
        << ");\n\n")
       .generate(sink, std::make_tuple(f.return_type, f.return_type, f.c_name, f.parameters), context))
      return false;

    // API delegate is the wrapper for the Eo methods exported from C that we will use from C#.
    if(!as_generator
       (
        indent << eolian_mono::marshall_annotation(true) << "\n"
        << indent << "public delegate "
        << eolian_mono::marshall_type(true)
        << " "
        << string << "_api_delegate(" << (f.is_static ? "" : "System.IntPtr obj")
        << ((!f.is_static && f.parameters.size() > 0) ? ", " : "")
        << (grammar::attribute_reorder<-1, -1>
        (
         (marshall_annotation << " " << marshall_parameter)
        ) % ", ")
        << ");\n\n")
       .generate(sink, std::make_tuple(f.return_type, f.return_type, f.c_name, f.parameters), context))
      return false;

    // Delegate holder (so it can't be collected).
    if(!as_generator
       (indent << "public static readonly Efl.Eo.FunctionWrapper<" << string << "_api_delegate> " << string << "_ptr = new Efl.Eo.FunctionWrapper<"
          << string << "_api_delegate>(Module, \"" << string << "\");\n\n")
       .generate(sink, std::make_tuple(f.c_name, f.c_name, f.c_name, f.c_name), context))
      return false;

    // We do not generate the wrapper to be called from C for non public interface member directly.
    if (blacklist::is_non_public_interface_member(f, *klass))
      return true;

    // Do not generate static method in interface
    if (((klass->type == attributes::class_type::interface_) ||
        (klass->type == attributes::class_type::mixin)) && f.is_static)
      return true;

    // Actual method implementation to be called from C.
    std::string return_type;
    if(!as_generator(eolian_mono::type(true)).generate(std::back_inserter(return_type), f.return_type, context))
      return false;

    std::string klass_cast_name;
    if ((klass->type == attributes::class_type::interface_) ||
        ((klass->type == attributes::class_type::mixin) && !f.is_static))
      klass_cast_name = name_helpers::klass_interface_name(*klass);
    else
      klass_cast_name = name_helpers::klass_inherit_name(*klass);

    std::string self = "Efl.Eo.Globals.Super(obj, Efl.Eo.Globals.GetClass(obj))";

    if (f.is_static)
      self = "";

    if(!as_generator
       (indent << "private static "
        << eolian_mono::marshall_type(true) << " "
        << string
        << "(System.IntPtr obj, System.IntPtr pd"
        << *(", " << marshall_parameter)
        << ")\n"
        << indent << "{\n"
        << indent << scope_tab << "Eina.Log.Debug(\"function " << string << " was called\");\n"
        << indent << scope_tab << "var ws = Efl.Eo.Globals.GetWrapperSupervisor(obj);\n"
        << indent << scope_tab << "if (ws != null)\n"
        << indent << scope_tab << "{\n"
        << indent << scope_tab << scope_tab << eolian_mono::native_function_definition_preamble() << "\n"
        << indent << scope_tab << scope_tab << "try\n"
        << indent << scope_tab << scope_tab << "{\n"
        << indent << scope_tab << scope_tab << scope_tab << (return_type != "void" ? "_ret_var = " : "")
        << (f.is_static ? "" : "((") << klass_cast_name << (f.is_static ? "." : ")ws.Target).") << string
        << "(" << (native_argument_invocation % ", ") << ");\n"
        << indent << scope_tab << scope_tab << "}\n"
        << indent << scope_tab << scope_tab << "catch (Exception e)\n"
        << indent << scope_tab << scope_tab << "{\n"
        << indent << scope_tab << scope_tab << scope_tab << "Eina.Log.Warning($\"Callback error: {e.ToString()}\");\n"
        << indent << scope_tab << scope_tab << scope_tab << "Eina.Error.Set(Eina.Error.UNHANDLED_EXCEPTION);\n"
        << indent << scope_tab << scope_tab << "}\n\n"
        << indent << eolian_mono::native_function_definition_epilogue(*klass) << "\n"
        << indent << scope_tab << "}\n"
        << indent << scope_tab << "else\n"
        << indent << scope_tab << "{\n"
        << indent << scope_tab << scope_tab << (return_type != "void" ? "return " : "") << string
        << "_ptr.Value.Delegate(" << self << ((!f.is_static && f.parameters.size() > 0) ? ", " : "") << (argument % ", ") << ");\n"
        << indent << scope_tab << "}\n"
        << indent << "}\n\n"
       )
       .generate(sink, std::make_tuple(f.return_type, escape_keyword(f.name), f.parameters
                                       , /***/f.c_name/***/
                                       , f
                                       , name_helpers::managed_method_name(f)
                                       , f.parameters
                                       , f
                                       , f.c_name
                                       , f.parameters
                                      )
                 , context))
      return false;

    // Static functions do not need to be called from C
    if (f.is_static)
      return true;

    // This is the delegate that will be passed to Eo to be called from C.
    if(!as_generator(
            indent << "private static " << f.c_name << "_delegate " << f.c_name << "_static_delegate;\n\n"
        ).generate(sink, attributes::unused, context))
      return false;

    return true;
  }
};
  
struct function_definition_generator
{
  function_definition_generator(bool do_super = false)
    : do_super(do_super)
  {}

  template <typename OutputIterator, typename Context>
  bool generate(OutputIterator sink, attributes::function_def const& f, Context const& context) const
  {
    EINA_CXX_DOM_LOG_DBG(eolian_mono::domain) << "function_definition_generator: " << f.c_name << std::endl;

    bool is_concrete = context_find_tag<class_context>(context).current_wrapper_kind == class_context::concrete;
    if(blacklist::is_function_blacklisted(f, context))
      return true;

    // Do not generate static function for concrete class
    if (is_concrete && f.is_static)
      return true;

    std::string return_type;
    if(!as_generator(eolian_mono::type(true)).generate(std::back_inserter(return_type), f.return_type, context))
      return false;

    if(!as_generator
       (documentation(1)).generate(sink, f, context))
      return false;

    std::string self = "this.NativeHandle";

    // IsGeneratedBindingClass is set in the constructor, true if this
    // instance is from a pure C# class (not generated).
    if (do_super && !f.is_static)
      self = "(IsGeneratedBindingClass ? " + self + " : Efl.Eo.Globals.Super(" + self + ", this.NativeClass))";
    else if (f.is_static)
      self = "";

    if(!as_generator
       (scope_tab << eolian_mono::function_scope_get(f) << ((do_super && !f.is_static) ? "virtual " : "") << (f.is_static ? "static " : "") << return_type << " " << string << "(" << (parameter % ", ")
        << ") {\n"
        << scope_tab(2) << eolian_mono::function_definition_preamble()
        << klass_full_native_inherit_name(f.klass) << "." << string << "_ptr.Value.Delegate("
        << self
        << ((!f.is_static && (f.parameters.size() > 0)) ? "," : "")
        << (argument_invocation % ", ") << ");\n"
        << scope_tab(2) << eolian_mono::function_definition_epilogue()
        << scope_tab(1) << "}\n\n")
       .generate(sink, std::make_tuple(name_helpers::managed_method_name(f), f.parameters, f, f.c_name, f.parameters, f), context))
      return false;

    return true;
  }

  bool do_super;
};

struct function_definition_parameterized
{
  function_definition_generator operator()(bool do_super) const
  {
    return {do_super};
  }
} const function_definition;
function_definition_generator as_generator(function_definition_parameterized)
{
  return {};
}
struct native_function_definition_parameterized
{
  native_function_definition_generator operator()(attributes::klass_def const& klass) const
  {
    return {&klass};
  }
} const native_function_definition;

struct property_extension_method_definition_generator
{
   template<typename OutputIterator, typename Context>
   bool generate(OutputIterator sink, attributes::property_def const& property, Context context) const
   {
      if (blacklist::is_property_blacklisted(property, context))
        return true;

      auto options = efl::eolian::grammar::context_find_tag<options_context>(context);

      if (!options.want_beta)
        return true; // Bindable is a beta feature for now.

      auto get_params = property.getter.is_engaged() ? property.getter->parameters.size() : 0;
      auto set_params = property.setter.is_engaged() ? property.setter->parameters.size() : 0;

      std::string managed_name = name_helpers::property_managed_name(property);

      if (get_params > 0 || set_params > 1)
        return true;

      std::string dir_mod;
      if (property.setter.is_engaged())
        dir_mod = direction_modifier(property.setter->parameters[0]);

      if (property.setter.is_engaged())
        {
          attributes::type_def prop_type = property.setter->parameters[0].type;
          if (!as_generator(scope_tab << "public static Efl.BindableProperty<" << type(true) << "> " << managed_name << "<T>(this Efl.Ui.ItemFactory<T> fac, Efl.Csharp.ExtensionTag<"
                            << name_helpers::klass_full_concrete_or_interface_name(cls)
                            << ", T>magic = null) where T : " << name_helpers::klass_full_concrete_or_interface_name(cls) <<  " {\n"
                            << scope_tab << scope_tab << "return new Efl.BindableProperty<" << type(true) << ">(\"" << property.name << "\", fac);\n"
                            << scope_tab << "}\n\n"
                            ).generate(sink, std::make_tuple(prop_type, prop_type), context))
            return false;
        }

      // Do we need BindablePart extensions for this class?
      // IContent parts are handled directly through BindableFactoryParts
      if (!helpers::inherits_from(cls, "Efl.Ui.LayoutPart") || helpers::inherits_from(cls, "Efl.IContent"))
        return true;

      if (property.setter.is_engaged())
        {
          attributes::type_def prop_type = property.setter->parameters[0].type;
          if (!as_generator(scope_tab << "public static Efl.BindableProperty<" << type(true) << "> " << managed_name << "<T>(this Efl.BindablePart<T> part, Efl.Csharp.ExtensionTag<"
                            << name_helpers::klass_full_concrete_or_interface_name(cls)
                            << ", T>magic = null) where T : " << name_helpers::klass_full_concrete_or_interface_name(cls) <<  " {\n"
                            << scope_tab << scope_tab << "return new Efl.BindableProperty<" << type(true) << ">(part.PartName, \"" << property.name << "\", part.Binder);\n"
                            << scope_tab << "}\n\n"
                            ).generate(sink, std::make_tuple(prop_type, prop_type), context))
            return false;
        }

      return true;
   }

   grammar::attributes::klass_def const& cls;
};

property_extension_method_definition_generator property_extension_method_definition (grammar::attributes::klass_def const& cls)
{
  return {cls};
}

struct property_wrapper_definition_generator
{
   template<typename OutputIterator, typename Context>
   bool generate(OutputIterator sink, attributes::property_def const& property, Context const& context) const
   {
      using efl::eolian::grammar::attribute_reorder;
      using efl::eolian::grammar::counter;
      using efl::eolian::grammar::attributes::parameter_direction;
      using efl::eolian::grammar::attributes::parameter_def;

      if (blacklist::is_property_blacklisted(property, *implementing_klass, context))
        return true;

      bool is_interface = context_find_tag<class_context>(context).current_wrapper_kind == class_context::interface;
      bool is_static = (property.getter.is_engaged() && property.getter->is_static)
                       || (property.setter.is_engaged() && property.setter->is_static);
      bool is_concrete = context_find_tag<class_context>(context).current_wrapper_kind == class_context::concrete;


      if ((is_concrete || is_interface) && is_static)
        return true;

      auto get_params = property.getter.is_engaged() ? property.getter->parameters.size() : 0;
      //auto set_params = property.setter.is_engaged() ? property.setter->parameters.size() : 0;

      // C# properties must have a single value.
      //
      // Single values in getters are automatically converted to return_type,
      // meaning they should have 0 parameters.
      //
      // For setters, we ignore the return type - usually boolean.
      // if (get_params > 0 || set_params > 1)
      //   return true;

      if (property.getter
          && std::find_if (property.getter->parameters.begin()
                           , property.getter->parameters.end()
                           , [] (parameter_def const& p)
                           {
                             return p.direction != parameter_direction::out;
                           }) != property.getter->parameters.end())
        return true;
      if (property.setter
          && std::find_if (property.setter->parameters.begin()
                           , property.setter->parameters.end()
                           , [] (parameter_def const& p)
                           {
                             return p.direction != parameter_direction::in;
                           }) != property.setter->parameters.end())
        return true;

      if (property.getter && property.setter)
      {
        if (get_params != 0 && property.setter->parameters.size() != property.getter->parameters.size())
          return true;
      }

      std::vector<attributes::parameter_def> parameters;

      if (property.setter.is_engaged())
      {
        std::transform (property.setter->parameters.begin(), property.setter->parameters.end()
                        , std::back_inserter(parameters)
                        , [] (parameter_def p) -> parameter_def
                        {
                          //p.direction = efl::eolian::attributes::parameter_direction::in;
                          return p;
                        });
      }
      else if (property.getter.is_engaged())
      {
        // if getter has parameters, then we ignore return type, otherwise
        // we use the return type.
        if (get_params == 0)
          parameters.push_back({parameter_direction::in
                , property.getter->return_type, "propertyResult", {}
                , property.getter->unit});
        else
          std::transform (property.getter->parameters.begin(), property.getter->parameters.end()
                          , std::back_inserter(parameters)
                          , [] (parameter_def p) -> parameter_def
                          {
                            p.direction = parameter_direction::in;
                            return p;
                          });
      }
        else
        {
           EINA_CXX_DOM_LOG_ERR(eolian_mono::domain) << "Property must have either a getter or a setter." << std::endl;
           return false;
        }

      std::string dir_mod;
      if (property.setter.is_engaged())
        dir_mod = direction_modifier(property.setter->parameters[0]);

      std::string managed_name = name_helpers::property_managed_name(property);

      std::string scope = "public ";
      std::string get_scope = property.getter.is_engaged() ? eolian_mono::function_scope_get(*property.getter) : "";
      bool is_get_public = get_scope == "public ";
      std::string set_scope = property.setter.is_engaged() ? eolian_mono::function_scope_get(*property.setter) : "";
      bool is_set_public = set_scope == "public ";

      // No need to generate this wrapper as no accessor is public.
      if (is_interface && (!is_get_public && !is_set_public))
          return true;

      // C# interface members are declared automatically as public
      if (is_interface)
        {
           scope = "";
           get_scope = "";
           set_scope = "";
        }
      else if ((get_scope != "") && (get_scope == set_scope))
        {
           scope = get_scope;
           get_scope = "";
           set_scope = "";
        }
      else if (!property.setter.is_engaged() || (get_scope == scope))
        {
           scope = get_scope;
           get_scope = "";
        }
      else if (!property.getter.is_engaged() || (set_scope == scope))
        {
           scope = set_scope;
           set_scope = "";
        }

      if (parameters.size() == 1)
      {
        if (!as_generator(
                    documentation(1)
                    << scope_tab << scope << (is_static ? "static " : "") << type(true) << " " << managed_name << " {\n"
              ).generate(sink, std::make_tuple(property, parameters[0].type), context))
          return false;
      }
      else
      {
        if (!as_generator
            (
             documentation(1)
             << scope_tab << scope << (is_static ? "static (" : "(")
             << (attribute_reorder<1, -1>(type(true) /*<< " " << argument*/) % ", ") << ") "
             << managed_name << " {\n"
            ).generate(sink, std::make_tuple(property, parameters), context))
          return false;
      }

      if (property.getter.is_engaged() && is_interface)
      {
        if (is_get_public)
          if (!as_generator(scope_tab << scope_tab << set_scope <<  "get;\n"
                            ).generate(sink, attributes::unused, context))
            return false;
      }
      else if (property.getter.is_engaged() && get_params == 0/*parameters.size() == 1 && property.getter.is_engaged()*/)
      {
        if (!as_generator
            (scope_tab << scope_tab << get_scope
             << "get " << "{ return " + name_helpers::managed_method_name(*property.getter) + "(); }\n"
            ).generate(sink, attributes::unused, context))
          return false;
      }
      else if (parameters.size() >= 1 && property.getter)
      {
        if (!as_generator
                 (scope_tab << scope_tab << get_scope << "get "
                  << "{\n"
                  << *attribute_reorder<1, -1, 1>
                    (scope_tab(3) << type(true) << " _out_"
                     << argument(false) << " = default(" << type(true) << ");\n"
                    )
                  << scope_tab(3) << name_helpers::managed_method_name(*property.getter)
                  << "(" << (("out _out_" << argument(false)) % ",") << ");\n"
                  << scope_tab(3) << "return (" << (("_out_"<< argument(false)) % ",") << ");\n"
                  << scope_tab(2) << "}" << "\n"
                 ).generate(sink, std::make_tuple(parameters, parameters, parameters), context))
          return false;
      }
      // else if (parameters.size() == 1)
      // {
      //   if (!as_generator
      //            (scope_tab << scope_tab << get_scope << "get "
      //             << "{\n"
      //             << *attribute_reorder<1, -1, 1>(scope_tab(3) << type(true) << " _out_" << argument(false) << " = default(" << type(true) << ");\n")
      //             << scope_tab(3) << name_helpers::managed_method_name(*property.getter)
      //             << "(" << (("out _out_" << argument(false)) % ",") << ");\n"
      //             << scope_tab(3) << "return " << (("_out_"<< argument(false)) % ",") << ";\n"
      //             << scope_tab(2) << "}" << "\n"
      //            ).generate(sink, std::make_tuple(parameters, parameters, parameters), context))
      //     return false;
      // }

      if (property.setter.is_engaged() && is_interface)
      {
        if (is_set_public)
          if (!as_generator(scope_tab << scope_tab << set_scope <<  "set;\n"
                            ).generate(sink, attributes::unused, context))
            return false;
      }
      else if (parameters.size() == 1 && property.setter.is_engaged())
      {
        if (!as_generator(scope_tab << scope_tab << set_scope <<  "set " << "{ " + name_helpers::managed_method_name(*property.setter) + "(" + dir_mod + "value); }\n"
            ).generate(sink, attributes::unused, context))
          return false;
      }
      else if (parameters.size() > 1 && property.setter.is_engaged())
      {
        if (!as_generator(scope_tab << scope_tab << set_scope <<  "set " << ("{ " + name_helpers::managed_method_name(*property.setter) + "(" + dir_mod) << ((" value.Item" << counter(1)) % ", ") << "); }" << "\n"
           ).generate(sink, parameters, context))
          return false;
      }

      if (!as_generator(scope_tab << "}\n\n").generate(sink, attributes::unused, context))
        return false;

      return true;
   }
   attributes::klass_def const* implementing_klass;
};
struct property_wrapper_definition_parameterized
{
  property_wrapper_definition_generator operator()(attributes::klass_def const& klass) const
  {
     return {&klass};
  }
} const property_wrapper_definition;
property_wrapper_definition_generator as_generator(property_wrapper_definition_parameterized)
{
   return {};
}

}

namespace efl { namespace eolian { namespace grammar {

template <>
struct is_eager_generator< ::eolian_mono::function_definition_generator> : std::true_type {};
template <>
struct is_eager_generator< ::eolian_mono::native_function_definition_generator> : std::true_type {};
template <>
struct is_eager_generator< ::eolian_mono::property_extension_method_definition_generator> : std::true_type {};
template <>
struct is_eager_generator< ::eolian_mono::property_wrapper_definition_generator> : std::true_type {};
template <>
struct is_eager_generator< ::eolian_mono::property_wrapper_definition_parameterized> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::function_definition_generator> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::native_function_definition_generator> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::function_definition_parameterized> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::property_extension_method_definition_generator> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::property_wrapper_definition_generator> : std::true_type {};
template <>
struct is_generator< ::eolian_mono::property_wrapper_definition_parameterized> : std::true_type {};

namespace type_traits {
template <>
struct attributes_needed< ::eolian_mono::function_definition_generator> : std::integral_constant<int, 1> {};

template <>
struct attributes_needed< ::eolian_mono::function_definition_parameterized> : std::integral_constant<int, 1> {};

template <>
struct attributes_needed< ::eolian_mono::native_function_definition_generator> : std::integral_constant<int, 1> {};

template <>
struct attributes_needed< ::eolian_mono::property_extension_method_definition_generator> : std::integral_constant<int, 1> {};

template <>
struct attributes_needed< ::eolian_mono::property_wrapper_definition_generator> : std::integral_constant<int, 1> {};
template <>
struct attributes_needed< ::eolian_mono::property_wrapper_definition_parameterized> : std::integral_constant<int, 1> {};
}
      
} } }

#endif