// Copyright (c) 2020, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
//
// SharedObjects=ffi_test_functions
// VMOptions=
// VMOptions=--use_slow_path

import 'dart:ffi';

import 'package:expect/expect.dart';

import 'dylib_utils.dart';

void main() {
  testHandle();
  testHandleInReturn();
  testHandleWithInteger();
  testReadField();
  testTrueHandle();
  testClosureCallback();
  testReturnHandleInCallback();
  testPropagateError();
  testCallbackReturnException();
  testDeepException();
  testDeepException2();
  testNull();
  testDeepRecursive();
  testNoHandlePropagateError();
  testThrowOnReturnOfError();
}

void testHandle() {
  print("testHandle");
  final s = SomeClass(123);
  print("passObjectToC($s)");
  final result = passObjectToC(s);
  print("result = $result");
  Expect.isTrue(identical(s, result));
}

void testHandleInReturn() {
  final string = 'foo';
  Expect.identical(string, stringFromString(string));
  Expect.identical(string, stringFromObject(string));
  Expect.identical(42, intFromInt(42));
  Expect.identical(42, intFromObject(42));
  // TODO(https://dartbug.com/49518): Uncomment the lines below when the
  // runtime checks are added.
  //
  // Expect.throws(() => stringFromObject(Object()));
  // Expect.throws(() => stringFromObject(42));
  // Expect.throws(() => intFromObject(Object()));
  // Expect.throws(() => intFromObject(string));
}

void testHandleWithInteger() {
  print("testHandleWithInteger");
  final s = 1337;
  print("passObjectToC($s)");
  final result = passObjectToC(s);
  print("result = $result");
  Expect.isTrue(identical(s, result));
}

void testReadField() {
  final s = SomeClass(123);
  final result = handleReadFieldValue(s);
  Expect.equals(s.a, result);
}

void testTrueHandle() {
  final result = trueHandle();
  Expect.isTrue(result);
}

int globalCounter = 0;

void increaseCounter() {
  print("increaseCounter");
  globalCounter++;
}

void doClosureCallback(Object callback) {
  print("doClosureCallback");
  print(callback.runtimeType);
  print(callback);
  final callback_as_function = callback as void Function();
  callback_as_function();
}

final closureCallbackPointer = Pointer.fromFunction<Void Function(Handle)>(
  doClosureCallback,
);

void testClosureCallback() {
  print("testClosureCallback $closureCallbackPointer");
  Expect.equals(0, globalCounter);
  closureCallbackThroughHandle(closureCallbackPointer, increaseCounter);
  Expect.equals(1, globalCounter);
  closureCallbackThroughHandle(closureCallbackPointer, increaseCounter);
  Expect.equals(2, globalCounter);
}

final someObject = SomeClass(12356789);

Object returnHandleCallback() {
  print("returnHandleCallback returning $someObject");
  return someObject;
}

final returnHandleCallbackPointer = Pointer.fromFunction<Handle Function()>(
  returnHandleCallback,
);

void testReturnHandleInCallback() {
  print("testReturnHandleInCallback");
  final result = returnHandleInCallback(returnHandleCallbackPointer);
  Expect.isTrue(identical(someObject, result));
}

class SomeClass {
  // We use this getter in the native api, don't tree shake it.
  @pragma("vm:entry-point")
  final int a;
  SomeClass(this.a);
}

void testPropagateError() {
  final s = SomeOtherClass(123);
  Expect.throws(() => handleReadFieldValue(s));
}

class SomeOtherClass {
  final int notA;
  SomeOtherClass(this.notA);
}

final someException = Exception("exceptionHandleCallback exception");

Object exceptionHandleCallback() {
  print("exceptionHandleCallback throwing ($someException)");
  throw someException;
}

final exceptionHandleCallbackPointer = Pointer.fromFunction<Handle Function()>(
  exceptionHandleCallback,
);

void testCallbackReturnException() {
  print("testCallbackReturnException");
  bool throws = false;
  try {
    final result = returnHandleInCallback(exceptionHandleCallbackPointer);
    print(result);
  } catch (e) {
    throws = true;
    print("caught ($e)");
    Expect.isTrue(identical(someException, e));
  }
  Expect.isTrue(throws);
}

Object callCAgainFromCallback() {
  print("callCAgainFromCallback");
  final s = SomeOtherClass(123);
  Expect.throws(() => handleReadFieldValue(s));
  return someObject;
}

final callCAgainFromCallbackPointer = Pointer.fromFunction<Handle Function()>(
  callCAgainFromCallback,
);

void testDeepException() {
  print("testDeepException");
  final result = returnHandleInCallback(callCAgainFromCallbackPointer);
  Expect.isTrue(identical(someObject, result));
}

Object callCAgainFromCallback2() {
  print("callCAgainFromCallback2");
  final s = SomeOtherClass(123);
  handleReadFieldValue(s); // throws.
  return someObject;
}

final callCAgainFromCallbackPointer2 = Pointer.fromFunction<Handle Function()>(
  callCAgainFromCallback2,
);

void testDeepException2() {
  print("testDeepException2");
  Expect.throws(() => returnHandleInCallback(callCAgainFromCallbackPointer2));
}

Object? returnNullHandleCallback() {
  print("returnHandleCallback returning null");
  return null;
}

final returnNullHandleCallbackPointer = Pointer.fromFunction<Handle Function()>(
  returnNullHandleCallback,
);

void testNull() {
  print("testNull");
  final result = passObjectToC(null);
  Expect.isNull(result);

  final result2 = returnHandleInCallback(returnNullHandleCallbackPointer);
  Expect.isNull(result2);
}

Object recurseAbove0(int i) {
  print("recurseAbove0($i)");
  if (i == 0) {
    print("throwing");
    throw someException;
  }
  if (i < 0) {
    print("returning");
    return someObject;
  }
  final result = handleRecursion(
    SomeClassWithMethod(),
    recurseAbove0Pointer,
    i - 1,
  );
  print("return $i");
  return result;
}

final recurseAbove0Pointer = Pointer.fromFunction<Handle Function(Int64)>(
  recurseAbove0,
);

class SomeClassWithMethod {
  // We use this method in the native api, don't tree shake it.
  @pragma("vm:entry-point")
  Object a(int i) => recurseAbove0(i);
}

void testDeepRecursive() {
  // works on arm.
  Expect.throws(() {
    handleRecursion(123, recurseAbove0Pointer, 1);
  });

  Expect.throws(() {
    handleRecursion(SomeClassWithMethod(), recurseAbove0Pointer, 1);
  });

  Expect.throws(() {
    recurseAbove0(100);
  });

  final result = recurseAbove0(101);
  Expect.isTrue(identical(someObject, result));
}

void testNoHandlePropagateError() {
  bool throws = false;
  try {
    final result = propagateErrorWithoutHandle(exceptionHandleCallbackPointer);
    print(result.runtimeType);
    print(result);
  } catch (e) {
    throws = true;
    print("caught ($e, ${e.runtimeType})");
    Expect.isTrue(identical(someException, e));
  }
  Expect.isTrue(throws);
}

void testThrowOnReturnOfError() {
  bool throws = false;
  try {
    final result = autoPropagateErrorInHandle(exceptionHandleCallbackPointer);
    print(result.runtimeType);
    print(result);
  } catch (e) {
    throws = true;
    print("caught ($e)");
    Expect.isTrue(identical(someException, e));
  }
  Expect.isTrue(throws);
}

final testLibrary = dlopenPlatformSpecific("ffi_test_functions");

final passObjectToC = testLibrary
    .lookupFunction<Handle Function(Handle), Object? Function(Object?)>(
      "PassObjectToC",
    );

final stringFromString = testLibrary
    .lookupFunction<Handle Function(Handle), String Function(String)>(
      "PassObjectToC",
    );
final stringFromObject = testLibrary
    .lookupFunction<Handle Function(Handle), String Function(Object)>(
      "PassObjectToC",
    );
final intFromInt = testLibrary
    .lookupFunction<Handle Function(Handle), int Function(int)>(
      "PassObjectToC",
    );
final intFromObject = testLibrary
    .lookupFunction<Handle Function(Handle), int Function(Object)>(
      "PassObjectToC",
    );

final handleReadFieldValue = testLibrary
    .lookupFunction<Int64 Function(Handle), int Function(Object)>(
      "HandleReadFieldValue",
    );

final trueHandle = testLibrary
    .lookupFunction<Handle Function(), Object Function()>("TrueHandle");

final closureCallbackThroughHandle = testLibrary
    .lookupFunction<
      Void Function(Pointer<NativeFunction<Void Function(Handle)>>, Handle),
      void Function(Pointer<NativeFunction<Void Function(Handle)>>, Object)
    >("ClosureCallbackThroughHandle");

final returnHandleInCallback = testLibrary
    .lookupFunction<
      Handle Function(Pointer<NativeFunction<Handle Function()>>),
      Object Function(Pointer<NativeFunction<Handle Function()>>)
    >("ReturnHandleInCallback");

final handleRecursion = testLibrary
    .lookupFunction<
      Handle Function(
        Handle,
        Pointer<NativeFunction<Handle Function(Int64)>>,
        Int64,
      ),
      Object Function(
        Object,
        Pointer<NativeFunction<Handle Function(Int64)>>,
        int,
      )
    >("HandleRecursion");

final propagateErrorWithoutHandle = testLibrary
    .lookupFunction<
      Int64 Function(Pointer<NativeFunction<Handle Function()>>),
      int Function(Pointer<NativeFunction<Handle Function()>>)
    >("PropagateErrorWithoutHandle");

final autoPropagateErrorInHandle = testLibrary
    .lookupFunction<
      Handle Function(Pointer<NativeFunction<Handle Function()>>),
      Object Function(Pointer<NativeFunction<Handle Function()>>)
    >("ThrowOnReturnOfError");