// Copyright 2022 Alibaba Group Holding Limited.
//
// 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.

#include "Pemja.h"
#include "java_class/JavaClass.h"
#include "python_class/PythonClass.h"
#include "structmember.h"

static int pyjconstructor_init(JNIEnv *env, PyJMethodObject *self) {
  jobjectArray parameters;

  if ((*env)->PushLocalFrame(env, 16) != 0) {
    return -1;
  }

  self->md_id = (*env)->FromReflectedMethod(env, self->md);
  parameters = JavaConstructor_getParameterTypes(env, self->md);

  if (!parameters) {
    goto EXIT_ERROR;
  }

  self->md_params = (*env)->NewGlobalRef(env, parameters);
  self->md_params_num = (*env)->GetArrayLength(env, parameters);
  self->md_return_id = JOBJECT_ID;
  self->md_is_static = 1;

  (*env)->PopLocalFrame(env, NULL);
  return 0;

EXIT_ERROR:
  (*env)->PopLocalFrame(env, NULL);
  return -1;
}

static PyObject *pyjconstructor_call(PyJMethodObject *self, PyObject *args,
                                     PyObject *kwargs) {
  PyObject *arg, *pyobject;
  PyJClassObject *clazz;

  JNIEnv *env;
  jvalue *jargs;
  jobject object;

  if (kwargs != NULL) {
    PyErr_Format(PyExc_RuntimeError,
                 "Keywords are not supported in constructing Object.");
  }

  // `JClass` Object as the first argument.
  if (self->md_params_num != PyTuple_GET_SIZE(args) - 1) {
    PyErr_Format(PyExc_RuntimeError,
                 "Invalid number of arguments: %i, expected %i for constructor",
                 (int)PyTuple_GET_SIZE(args) - 1, self->md_params_num);
    return NULL;
  }

  arg = PyTuple_GetItem(args, 0);
  if (!PyJClass_Check(arg)) {
    PyErr_Format(PyExc_RuntimeError,
                 "The first argument type must be a Java Class Type");
  }

  clazz = (PyJClassObject *)arg;

  env = JcpThreadEnv_Get();
  if ((*env)->PushLocalFrame(env, 16 + self->md_params_num) != 0) {
    return NULL;
  }

  jargs = (jvalue *)PyMem_Malloc(sizeof(jvalue) * self->md_params_num);

  for (int i = 0; i < self->md_params_num; i++) {
    arg = PyTuple_GetItem(args, i + 1);
    jclass paramType =
        (jclass)(*env)->GetObjectArrayElement(env, self->md_params, i);
    if (JcpJavaErr_Throw(env)) {
      goto EXIT_ERROR;
    }
    jargs[i] = JcpPyObject_AsJValue(env, arg, paramType);
    (*env)->DeleteLocalRef(env, paramType);
    if (JcpJavaErr_Throw(env) || PyErr_Occurred()) {
      goto EXIT_ERROR;
    }
  }

  object = (*env)->NewObjectA(env, clazz->clazz, self->md_id, jargs);
  if (!object || JcpJavaErr_Throw(env)) {
    // failed to construct the object.
    goto EXIT_ERROR;
  }

  pyobject = JcpPyObject_FromJObject(env, object);
  if (!pyobject) {
    goto EXIT_ERROR;
  }

  PyMem_Free(jargs);
  (*env)->PopLocalFrame(env, NULL);
  return pyobject;

EXIT_ERROR:
  PyMem_Free(jargs);
  (*env)->PopLocalFrame(env, NULL);
  return NULL;
}

/* Creates a new PyJConstructor with a Java Object. */

PyObject *JcpPyJConstructor_New(JNIEnv *env, jobject constructor) {
  PyJMethodObject *self;

  if (PyType_Ready(&PyJMethod_Type) < 0) {
    return NULL;
  }

  if (!PyJConstructor_Type.tp_base) {
    PyJConstructor_Type.tp_base = &PyJMethod_Type;
    if (PyType_Ready(&PyJConstructor_Type) < 0) {
      return NULL;
    }
  }

  self = PyObject_NEW(PyJMethodObject, &PyJConstructor_Type);
  self->md = (*env)->NewGlobalRef(env, constructor);
  self->md_name = PyUnicode_FromString("<init>");

  if (pyjconstructor_init(env, self) < 0 || JcpJavaErr_Throw(env)) {
    Py_DECREF(self);
    return NULL;
  }

  return (PyObject *)self;
}

PyTypeObject PyJConstructor_Type = {
    PyVarObject_HEAD_INIT(NULL, 0) "pemja.PyJConstructor", /* tp_name */
    sizeof(PyJMethodObject),                               /* tp_basicsize */
    0,                                                     /* tp_itemsize */
    0,                                                     /* tp_dealloc */
    0,                                                     /* tp_print */
    0,                                                     /* tp_getattr */
    0,                                                     /* tp_setattr */
    0,                                                     /* tp_reserved */
    0,                                                     /* tp_repr */
    0,                                                     /* tp_as_number */
    0,                                                     /* tp_as_sequence */
    0,                                                     /* tp_as_mapping */
    0,                                                     /* tp_hash */
    (ternaryfunc)pyjconstructor_call,                      /* tp_call */
    0,                                                     /* tp_str */
    0,                                                     /* tp_getattro */
    0,                                                     /* tp_setattro */
    0,                                                     /* tp_as_buffer */
    Py_TPFLAGS_DEFAULT,                                    /* tp_flags */
    "Java Constructor Object s",                           /* tp_doc */
    0,                                                     /* tp_traverse */
    0,                                                     /* tp_clear */
    0,                                                     /* tp_richcompare */
    0, /* tp_weaklistoffset */
    0, /* tp_iter */
    0, /* tp_iternext */
    0, /* tp_methods */
    0, /* tp_members */
    0, /* tp_getset */
    0, /* tp_base */
    0, /* tp_dict */
    0, /* tp_descr_get */
    0, /* tp_descr_set */
    0, /* tp_dictoffset */
    0, /* tp_init */
    0, /* tp_alloc */
    0, /* tp_new */
};
