/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsImportModule_h
#define nsImportModule_h

#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"

#include "nsCOMPtr.h"
#include "mozilla/RefPtr.h"

namespace mozilla {
namespace loader {

nsresult ImportESModule(const char* aURI, const char* aExportName,
                        const nsIID& aIID, void** aResult, bool aInfallible);

}  // namespace loader
}  // namespace mozilla

class MOZ_STACK_CLASS nsImportESModule final : public nsCOMPtr_helper {
 public:
  nsImportESModule(const char* aURI, const char* aExportName,
                   nsresult* aErrorPtr, bool aInfallible)
      : mURI(aURI),
        mExportName(aExportName),
        mErrorPtr(aErrorPtr),
        mInfallible(aInfallible) {
    MOZ_ASSERT_IF(mErrorPtr, !mInfallible);
  }

  virtual nsresult NS_FASTCALL operator()(const nsIID& aIID,
                                          void** aResult) const override {
    nsresult rv = ::mozilla::loader::ImportESModule(mURI, mExportName, aIID,
                                                    aResult, mInfallible);
    if (mErrorPtr) {
      *mErrorPtr = rv;
    }
    return rv;
  }

 private:
  const char* mURI;
  const char* mExportName;
  nsresult* mErrorPtr;
  bool mInfallible;
};

/**
 * Usage with exported name:
 *
 * Foo.sys.mjs:
 *
 *   export function foo(bar) {
 *     return bar.toString();
 *   }
 *
 * mozIFoo.idl:
 *
 *   interface mozIFoo : nsISupports {
 *     AString foo(double meh);
 *   }
 *
 * Thing.cpp:
 *
 *   nsCOMPtr<mozIFoo> foo = do_ImportESModule(
 *     "resource://meh/Foo.sys.mjs");
 *
 *   MOZ_TRY(foo->Foo(42));
 *
 * Usage with a single named object:
 *
 * Foo.sys.mjs:
 *
 *   export var Foo = {
 *     function foo(bar) {
 *       return bar.toString();
 *     }
 *   };
 *
 * Thing.cpp:
 *
 *   nsCOMPtr<mozIFoo> foo = do_ImportESModule(
 *       "resource:://meh/Foo.sys.mjs", "Foo");
 */

template <size_t N>
inline nsImportESModule do_ImportESModule(const char (&aURI)[N]) {
  return {aURI, nullptr, nullptr, /* infallible */ true};
}

template <size_t N>
inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
                                          const mozilla::fallible_t&) {
  return {aURI, nullptr, nullptr, /* infallible */ false};
}

template <size_t N>
inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
                                          nsresult* aRv) {
  return {aURI, nullptr, aRv, /* infallible */ false};
}

template <size_t N, size_t N2>
inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
                                          const char (&aExportName)[N2]) {
  return {aURI, aExportName, nullptr, /* infallible */ true};
}

template <size_t N, size_t N2>
inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
                                          const char (&aExportName)[N2],
                                          const mozilla::fallible_t&) {
  return {aURI, aExportName, nullptr, /* infallible */ false};
}

template <size_t N, size_t N2>
inline nsImportESModule do_ImportESModule(const char (&aURI)[N],
                                          const char (&aExportName)[N2],
                                          nsresult* aRv) {
  return {aURI, aExportName, aRv, /* infallible */ false};
}

#endif  // defined nsImportModule_h