$$ This is a pump file for generating file templates.  Pump is a python
$$ script that is part of the Google Test suite of utilities.  Description
$$ can be found here:
$$
$$ http://code.google.com/p/googletest/wiki/PumpManual
$$

$$ Maximum number of different member types in a union.
$var MAX_MEMBERS = 4
/*
 * Copyright 2016 Google Inc. All Rights Reserved.
 *
 * 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 COBALT_SCRIPT_MOZJS_UNION_TYPE_CONVERSION_IMPL_H_
#define COBALT_SCRIPT_MOZJS_UNION_TYPE_CONVERSION_IMPL_H_

#include "cobalt/base/type_id.h"
#include "cobalt/script/mozjs/mozjs_exception_state.h"
#include "cobalt/script/mozjs/mozjs_global_environment.h"
#include "cobalt/script/mozjs/mozjs_object_handle.h"
#include "cobalt/script/mozjs/mozjs_user_object_holder.h"
#include "cobalt/script/mozjs/type_traits.h"
#include "cobalt/script/union_type.h"

// Conversion to/from JS::Value for IDL union types.

namespace cobalt {
namespace script {
namespace mozjs {

$range NUM_MEMBERS 2..MAX_MEMBERS
$for NUM_MEMBERS [[

$range TYPE 1..NUM_MEMBERS

template <$for TYPE , [[typename T$(TYPE)]]>
void ToJSValue(
    JSContext* context,
    const script::UnionType$(NUM_MEMBERS)<$for TYPE , [[T$(TYPE)]]>& in_union,
    JS::MutableHandleValue out_value) {
$for TYPE [[

  if (in_union.template IsType<T$(TYPE)>()) {
    ToJSValue(context, in_union.template AsType<T$(TYPE)>(), out_value);
    return;
  }
]]

  NOTREACHED();
  out_value.setUndefined();
}

template <$for TYPE , [[typename T$(TYPE)]]>
void FromJSValue(JSContext* context, JS::HandleValue value,
                 int conversion_flags, ExceptionState* exception_state,
                 script::UnionType$(NUM_MEMBERS)<$for TYPE , [[T$(TYPE)]]>* out_union) {
  DCHECK_EQ(0, conversion_flags);
  // JS -> IDL type conversion procedure described here:
  // http://heycam.github.io/webidl/#es-union

  // TODO: Support Date, RegExp, DOMException, Error, ArrayBuffer, DataView,
  //       TypedArrayName, callback functions, dictionary.

  // 1. If the union type includes a nullable type and |V| is null or undefined,
  // then return the IDL value null.
  if (value.isNull() || value.isUndefined()) {
    // Since the nullability should have been detected by the conversion for
    // base::optional, we should throw, because if we get here it means the
    // union does not include a nullable type, but have been passed a null
    // value.
    exception_state->SetSimpleException(kNotUnionType);
    return;
  }

  // Typedef for readability.

$for TYPE [[
  typedef ::cobalt::script::internal::UnionTypeTraits<T$(TYPE)> UnionTypeTraitsT$(TYPE);

]]

  // 2. Let |types| be the flattened member types of the union type.
  // Forward declare all potential types

$for TYPE [[
  T$(TYPE) t$(TYPE);

]]

  // 4. If |V| is a platform object, then:
  //   1. If |types| includes an interface type that V implements, then return
  //      the IDL value that is a reference to the object |V|.
  //   2. If |types| includes object, then return the IDL value that is a
  //      reference to the object |V|.
  if (value.isObject()) {
    // The specification doesn't dictate what should happen if V implements
    // more than one of the interfaces. For example, if V implements interface
    // B and interface B inherits from interface A, what happens if both A and
    // B are union members? Blink doesn't seem to do anything special for this
    // case. Just choose the first interface in the flattened members that
    // matches.

    JS::RootedObject rooted_object(context);
    bool success = JS_ValueToObject(context, value, rooted_object.address());
    DCHECK(success);

    MozjsGlobalEnvironment* global_environment =
        static_cast<MozjsGlobalEnvironment*>(JS_GetContextPrivate(context));
    const WrapperFactory* wrapper_factory =
        global_environment->wrapper_factory();

$for TYPE [[

    if (UnionTypeTraitsT$(TYPE)::is_interface_type &&
        wrapper_factory->DoesObjectImplementInterface(
            rooted_object, UnionTypeTraitsT$(TYPE)::GetTypeID())) {
      FromJSValue(context, value, conversion_flags, exception_state, &t$(TYPE));
      *out_union = script::UnionType$(NUM_MEMBERS)<$for TYPE , [[T$(TYPE)]]>(t$(TYPE));
      return;
    }

]]
  }

  // 11. If |Type(V)| is Object, then:
  //   1. If |types| includes a sequence type, then
  //     1. Let |method| be the result of GetMethod(V, @@iterator)
  //     2. ReturnIfAbrupt(method)
  //     3. If method is not undefined, return the result of creating a sequence
  //        of that type from |V| and |method|.
  if (value.isObject()) {
$for TYPE [[

    if (UnionTypeTraitsT$(TYPE)::is_sequence_type) {
      FromJSValue(context, value, conversion_flags, exception_state, &t$(TYPE));
      *out_union = script::UnionType$(NUM_MEMBERS)<$for TYPE , [[T$(TYPE)]]>(t$(TYPE));
      return;
    }

]]
  }

  // 12. If |Type(V)| is Boolean, then:
  //   1. If |types| includes a boolean, then return the result of converting |V|
  //      to boolean.
  if (value.isBoolean()) {
$for TYPE [[

    if (UnionTypeTraitsT$(TYPE)::is_boolean_type) {
      FromJSValue(context, value, conversion_flags, exception_state, &t$(TYPE));
      *out_union = script::UnionType$(NUM_MEMBERS)<$for TYPE , [[T$(TYPE)]]>(t$(TYPE));
      return;
    }

]]
  }

  // 13. If |Type(V)| is a Number, then:
  //   1. If |types| includes a numeric type, then return the result of
  //      converting |V| to that numeric type.
  if (value.isNumber()) {
$for TYPE [[

    if (UnionTypeTraitsT$(TYPE)::is_numeric_type) {
      FromJSValue(context, value, conversion_flags, exception_state, &t$(TYPE));
      *out_union = script::UnionType$(NUM_MEMBERS)<$for TYPE , [[T$(TYPE)]]>(t$(TYPE));
      return;
    }

]]
  }

  // 14. If |types| includes a string type, then return the result of converting
  //     |V| to that type.
  if (value.isString()) {
$for TYPE [[

    if (UnionTypeTraitsT$(TYPE)::is_string_type) {
      FromJSValue(context, value, conversion_flags, exception_state, &t$(TYPE));
      *out_union = script::UnionType$(NUM_MEMBERS)<$for TYPE , [[T$(TYPE)]]>(t$(TYPE));
      return;
    }

]]
  }

  // 15. If |types| includes a numeric type, then return the result of
  //     converting |V| to that numeric type.
$for TYPE [[

  if (UnionTypeTraitsT$(TYPE)::is_numeric_type) {
    FromJSValue(context, value, conversion_flags, exception_state, &t$(TYPE));
    *out_union = script::UnionType$(NUM_MEMBERS)<$for TYPE , [[T$(TYPE)]]>(t$(TYPE));
    return;
  }

]]

  // 16. If |types| includes a boolean, then return the result of converting |V|
  //     to boolean.
$for TYPE [[

  if (UnionTypeTraitsT$(TYPE)::is_boolean_type) {
    FromJSValue(context, value, conversion_flags, exception_state, &t$(TYPE));
    *out_union = script::UnionType$(NUM_MEMBERS)<$for TYPE , [[T$(TYPE)]]>(t$(TYPE));
    return;
  }

]]

  // 17. Throw a TypeError.
  exception_state->SetSimpleException(kNotUnionType);
}

]]  $$ for NUM_MEMBERS

}  // namespace mozjs
}  // namespace script
}  // namespace cobalt

#endif  // COBALT_SCRIPT_MOZJS_UNION_TYPE_CONVERSION_IMPL_H_