# -*- coding: utf-8 -*-
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# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you 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.

import contextlib
import ctypes
import gc

import pyarrow as pa
try:
    from pyarrow.cffi import ffi
except ImportError:
    ffi = None

import pytest

try:
    import pandas as pd
    import pandas.testing as tm
except ImportError:
    pd = tm = None


needs_cffi = pytest.mark.skipif(ffi is None,
                                reason="test needs cffi package installed")

assert_schema_released = pytest.raises(
    ValueError, match="Cannot import released ArrowSchema")

assert_array_released = pytest.raises(
    ValueError, match="Cannot import released ArrowArray")

assert_stream_released = pytest.raises(
    ValueError, match="Cannot import released ArrowArrayStream")


def PyCapsule_IsValid(capsule, name):
    return ctypes.pythonapi.PyCapsule_IsValid(ctypes.py_object(capsule), name) == 1


@contextlib.contextmanager
def registered_extension_type(ext_type):
    pa.register_extension_type(ext_type)
    try:
        yield
    finally:
        pa.unregister_extension_type(ext_type.extension_name)


class ParamExtType(pa.ExtensionType):

    def __init__(self, width):
        self._width = width
        super().__init__(pa.binary(width),
                         "pyarrow.tests.test_cffi.ParamExtType")

    @property
    def width(self):
        return self._width

    def __arrow_ext_serialize__(self):
        return str(self.width).encode()

    @classmethod
    def __arrow_ext_deserialize__(cls, storage_type, serialized):
        width = int(serialized.decode())
        return cls(width)


def make_schema():
    return pa.schema([('ints', pa.list_(pa.int32()))],
                     metadata={b'key1': b'value1'})


def make_extension_schema():
    return pa.schema([('ext', ParamExtType(3))],
                     metadata={b'key1': b'value1'})


def make_extension_storage_schema():
    # Should be kept in sync with make_extension_schema
    return pa.schema([('ext', ParamExtType(3).storage_type)],
                     metadata={b'key1': b'value1'})


def make_batch():
    return pa.record_batch([[[1], [2, 42]]], make_schema())


def make_extension_batch():
    schema = make_extension_schema()
    ext_col = schema[0].type.wrap_array(pa.array([b"foo", b"bar"],
                                                 type=pa.binary(3)))
    return pa.record_batch([ext_col], schema)


def make_batches():
    schema = make_schema()
    return [
        pa.record_batch([[[1], [2, 42]]], schema),
        pa.record_batch([[None, [], [5, 6]]], schema),
    ]


def make_serialized(schema, batches):
    with pa.BufferOutputStream() as sink:
        with pa.ipc.new_stream(sink, schema) as out:
            for batch in batches:
                out.write(batch)
        return sink.getvalue()


@needs_cffi
def test_export_import_type():
    c_schema = ffi.new("struct ArrowSchema*")
    ptr_schema = int(ffi.cast("uintptr_t", c_schema))

    gc.collect()  # Make sure no Arrow data dangles in a ref cycle
    old_allocated = pa.total_allocated_bytes()

    typ = pa.list_(pa.int32())
    typ._export_to_c(ptr_schema)
    assert pa.total_allocated_bytes() > old_allocated
    # Delete and recreate C++ object from exported pointer
    del typ
    assert pa.total_allocated_bytes() > old_allocated
    typ_new = pa.DataType._import_from_c(ptr_schema)
    assert typ_new == pa.list_(pa.int32())
    assert pa.total_allocated_bytes() == old_allocated
    # Now released
    with assert_schema_released:
        pa.DataType._import_from_c(ptr_schema)

    # Invalid format string
    pa.int32()._export_to_c(ptr_schema)
    bad_format = ffi.new("char[]", b"zzz")
    c_schema.format = bad_format
    with pytest.raises(ValueError,
                       match="Invalid or unsupported format string"):
        pa.DataType._import_from_c(ptr_schema)
    # Now released
    with assert_schema_released:
        pa.DataType._import_from_c(ptr_schema)


@needs_cffi
def test_export_import_field():
    c_schema = ffi.new("struct ArrowSchema*")
    ptr_schema = int(ffi.cast("uintptr_t", c_schema))

    gc.collect()  # Make sure no Arrow data dangles in a ref cycle
    old_allocated = pa.total_allocated_bytes()

    field = pa.field("test", pa.list_(pa.int32()), nullable=True)
    field._export_to_c(ptr_schema)
    assert pa.total_allocated_bytes() > old_allocated
    # Delete and recreate C++ object from exported pointer
    del field
    assert pa.total_allocated_bytes() > old_allocated

    field_new = pa.Field._import_from_c(ptr_schema)
    assert field_new == pa.field("test", pa.list_(pa.int32()), nullable=True)
    assert pa.total_allocated_bytes() == old_allocated

    # Now released
    with assert_schema_released:
        pa.Field._import_from_c(ptr_schema)


def check_export_import_array(array_type, exporter, importer):
    c_schema = ffi.new("struct ArrowSchema*")
    ptr_schema = int(ffi.cast("uintptr_t", c_schema))
    c_array = ffi.new(f"struct {array_type}*")
    ptr_array = int(ffi.cast("uintptr_t", c_array))

    gc.collect()  # Make sure no Arrow data dangles in a ref cycle
    old_allocated = pa.total_allocated_bytes()

    # Type is known up front
    typ = pa.list_(pa.int32())
    arr = pa.array([[1], [2, 42]], type=typ)
    py_value = arr.to_pylist()
    exporter(arr, ptr_array)
    assert pa.total_allocated_bytes() > old_allocated
    # Delete recreate C++ object from exported pointer
    del arr
    arr_new = importer(ptr_array, typ)
    assert arr_new.to_pylist() == py_value
    assert arr_new.type == pa.list_(pa.int32())
    assert pa.total_allocated_bytes() > old_allocated
    del arr_new, typ
    assert pa.total_allocated_bytes() == old_allocated
    # Now released
    with assert_array_released:
        importer(ptr_array, pa.list_(pa.int32()))

    # Type is exported and imported at the same time
    arr = pa.array([[1], [2, 42]], type=pa.list_(pa.int32()))
    py_value = arr.to_pylist()
    exporter(arr, ptr_array, ptr_schema)
    # Delete and recreate C++ objects from exported pointers
    del arr
    arr_new = importer(ptr_array, ptr_schema)
    assert arr_new.to_pylist() == py_value
    assert arr_new.type == pa.list_(pa.int32())
    assert pa.total_allocated_bytes() > old_allocated
    del arr_new
    assert pa.total_allocated_bytes() == old_allocated
    # Now released
    with assert_schema_released:
        importer(ptr_array, ptr_schema)


@needs_cffi
def test_export_import_array():
    check_export_import_array(
        "ArrowArray",
        pa.Array._export_to_c,
        pa.Array._import_from_c,
    )


@needs_cffi
def test_export_import_device_array():
    check_export_import_array(
        "ArrowDeviceArray",
        pa.Array._export_to_c_device,
        pa.Array._import_from_c_device,
    )

    # verify exported struct
    c_array = ffi.new("struct ArrowDeviceArray*")
    ptr_array = int(ffi.cast("uintptr_t", c_array))
    arr = pa.array([[1], [2, 42]], type=pa.list_(pa.int32()))
    arr._export_to_c_device(ptr_array)

    assert c_array.device_type == 1  # ARROW_DEVICE_CPU 1
    assert c_array.device_id == -1
    assert c_array.array.length == 2


def check_export_import_schema(schema_factory, expected_schema_factory=None):
    if expected_schema_factory is None:
        expected_schema_factory = schema_factory

    c_schema = ffi.new("struct ArrowSchema*")
    ptr_schema = int(ffi.cast("uintptr_t", c_schema))

    gc.collect()  # Make sure no Arrow data dangles in a ref cycle
    old_allocated = pa.total_allocated_bytes()

    schema_factory()._export_to_c(ptr_schema)
    assert pa.total_allocated_bytes() > old_allocated
    # Delete and recreate C++ object from exported pointer
    schema_new = pa.Schema._import_from_c(ptr_schema)
    assert schema_new == expected_schema_factory()
    assert pa.total_allocated_bytes() == old_allocated
    del schema_new
    assert pa.total_allocated_bytes() == old_allocated
    # Now released
    with assert_schema_released:
        pa.Schema._import_from_c(ptr_schema)

    # Not a struct type
    pa.int32()._export_to_c(ptr_schema)
    with pytest.raises(ValueError,
                       match="ArrowSchema describes non-struct type"):
        pa.Schema._import_from_c(ptr_schema)
    # Now released
    with assert_schema_released:
        pa.Schema._import_from_c(ptr_schema)


@needs_cffi
def test_export_import_schema():
    check_export_import_schema(make_schema)


@needs_cffi
def test_export_import_schema_with_extension():
    # Extension type is unregistered => the storage type is imported
    check_export_import_schema(make_extension_schema,
                               make_extension_storage_schema)

    # Extension type is registered => the extension type is imported
    with registered_extension_type(ParamExtType(1)):
        check_export_import_schema(make_extension_schema)


@needs_cffi
def test_export_import_schema_float_pointer():
    # Previous versions of the R Arrow library used to pass pointer
    # values as a double.
    c_schema = ffi.new("struct ArrowSchema*")
    ptr_schema = int(ffi.cast("uintptr_t", c_schema))

    match = "Passing a pointer value as a float is unsafe"
    with pytest.warns(UserWarning, match=match):
        make_schema()._export_to_c(float(ptr_schema))
    with pytest.warns(UserWarning, match=match):
        schema_new = pa.Schema._import_from_c(float(ptr_schema))
    assert schema_new == make_schema()


def check_export_import_batch(array_type, exporter, importer, batch_factory):
    c_schema = ffi.new("struct ArrowSchema*")
    ptr_schema = int(ffi.cast("uintptr_t", c_schema))
    c_array = ffi.new(f"struct {array_type}*")
    ptr_array = int(ffi.cast("uintptr_t", c_array))

    gc.collect()  # Make sure no Arrow data dangles in a ref cycle
    old_allocated = pa.total_allocated_bytes()

    # Schema is known up front
    batch = batch_factory()
    schema = batch.schema
    py_value = batch.to_pydict()
    exporter(batch, ptr_array)
    assert pa.total_allocated_bytes() > old_allocated
    # Delete and recreate C++ object from exported pointer
    del batch
    batch_new = importer(ptr_array, schema)
    assert batch_new.to_pydict() == py_value
    assert batch_new.schema == schema
    assert pa.total_allocated_bytes() > old_allocated
    del batch_new, schema
    assert pa.total_allocated_bytes() == old_allocated
    # Now released
    with assert_array_released:
        importer(ptr_array, make_schema())