# Copyright (c) ONNX Project Contributors

# SPDX-License-Identifier: Apache-2.0

from __future__ import annotations

import typing

import numpy as np

import onnx
from onnx import TensorProto
from onnx.backend.test.case.base import Base
from onnx.backend.test.case.model import expect


def SequenceEmptyImpl() -> list[np.ndarray | None]:
    return []


def SequenceConstructImpl(*tensors: np.ndarray) -> list[np.ndarray]:
    return list(tensors)


def SequenceInsertImpl(
    sequence: list[np.ndarray], tensor: np.ndarray, position: int | None = None
) -> list[np.ndarray]:
    if position is None:
        position = len(sequence)
    sequence.insert(position, tensor)
    return sequence


def SequenceAtImpl(sequence: list[np.ndarray], position: int) -> np.ndarray:
    return sequence[position]


def SequenceEraseImpl(
    sequence: list[np.ndarray], position: int | None = None
) -> list[np.ndarray | None]:
    if position is None:
        position = -1
    del sequence[position]
    return sequence


def SequenceLengthImpl(sequence: list[np.ndarray]) -> np.int64:
    return np.int64(len(sequence))


def SplitToSequenceImpl(
    tensor: np.ndarray,
    split: int | list[int] | None = None,
    axis: int = 0,
    keepdims: int = 1,
) -> list[np.ndarray]:
    dim_size = tensor.shape[axis]
    if split is None:
        split = 1
        split_indices = [
            i * split + 1 for i in range(dim_size) if i * split + 1 < dim_size
        ]
        if not keepdims:
            results = np.array_split(tensor, split_indices, axis)
            return [np.squeeze(res, axis) for res in results]
    if np.isscalar(split):
        split_indices = [
            i * split + 1 for i in range(dim_size) if i * split + 1 < dim_size
        ]  # type: ignore
    else:
        split_indices = np.cumsum(split) + 1
    return np.array_split(tensor, split_indices, axis)  # type: ignore


def ConcatFromSequenceImpl(
    sequence: list[np.ndarray], axis: int, new_axis: int | None = 0
) -> np.ndarray:
    if not new_axis:
        return np.concatenate(sequence, axis)
    return np.stack(sequence, axis)


class Sequence(Base):
    @staticmethod
    def export() -> None:
        def make_graph(
            nodes: list[onnx.helper.NodeProto],
            input_shapes: list[typing.Sequence[str | int] | None],
            output_shapes: list[typing.Sequence[str | int] | None],
            input_names: list[str],
            output_names: list[str],
            input_types: list[TensorProto.DataType],
            output_types: list[TensorProto.DataType],
            initializers: list[TensorProto] | None = None,
        ) -> onnx.helper.GraphProto:
            graph = onnx.helper.make_graph(
                nodes=nodes,
                name="Sequence",
                inputs=[
                    onnx.helper.make_tensor_value_info(name, input_type, input_shape)
                    for name, input_type, input_shape in zip(
                        input_names, input_types, input_shapes
                    )
                ],
                outputs=[
                    onnx.helper.make_tensor_value_info(name, output_type, output_shape)
                    for name, output_type, output_shape in zip(
                        output_names, output_types, output_shapes
                    )
                ],
                initializer=initializers,
            )
            return graph

        # 1st testcase - insert and at.
        # 1. SequenceEmpty:         -> []
        # 2. SequenceInsert(x):     -> [x]
        # 3. SequenceInsert(y):     -> [x, y]
        # 4. SequenceInsert(z, 1):  -> [x, z, y]
        # 5. SequenceAt(2):         -> y
        seq_empty_node = onnx.helper.make_node("SequenceEmpty", [], ["Seq_empty"])
        seq_insert_node = onnx.helper.make_node(
            "SequenceInsert", ["Seq_empty", "X"], ["Seq_1"]
        )
        seq_insert_node2 = onnx.helper.make_node(
            "SequenceInsert", ["Seq_1", "Y"], ["Seq_2"]
        )
        seq_insert_node3 = onnx.helper.make_node(
            "SequenceInsert", ["Seq_2", "Z", "pos"], ["Seq_3"]
        )
        seq_at_node = onnx.helper.make_node("SequenceAt", ["Seq_3", "pos_at"], ["out"])

        x_shape = [2, 3, 4]
        y_shape = [1, 3, 4]
        z_shape = [3, 3, 4]
        out_shape = [None, 3, 4]

        x = np.ones(x_shape, dtype=np.float32)
        y = np.zeros(y_shape, dtype=np.float32)
        z = np.ones(z_shape, dtype=np.float32) * 2
        pos_val = 1
        pos_at_val = 2

        out = SequenceEmptyImpl()
        out = SequenceInsertImpl(out, x)
        out = SequenceInsertImpl(out, y)
        out = SequenceInsertImpl(out, z, pos_val)
        out = SequenceAtImpl(out, pos_at_val)
        assert np.array_equal(out, y)

        pos = onnx.helper.make_tensor("pos", TensorProto.INT64, (), (pos_val,))
        pos_at = onnx.helper.make_tensor("pos_at", TensorProto.INT64, (), (pos_at_val,))

        graph = make_graph(
            [
                seq_empty_node,
                seq_insert_node,
                seq_insert_node2,
                seq_insert_node3,
                seq_at_node,
            ],
            [x_shape, y_shape, z_shape, [], []],  # type: ignore
            [out_shape],  # type: ignore
            ["X", "Y", "Z", "pos", "pos_at"],
            ["out"],
            [onnx.TensorProto.FLOAT] * 3 + [onnx.TensorProto.INT64] * 2,  # type: ignore
            [onnx.TensorProto.FLOAT],
            [pos, pos_at],
        )
        model = onnx.helper.make_model_gen_version(
            graph,
            producer_name="backend-test",
            opset_imports=[onnx.helper.make_opsetid("", 12)],
        )
        expect(model, inputs=[x, y, z], outputs=[out], name="test_sequence_model1")

        # 2nd testcase - erase and at.
        # 1. SequenceConstruct(x, y, z):    -> [x, y, z]
        # 2. SequenceErase(1):              -> [x, z]
        # 3. SequenceAt(1):                 -> z
        seq_construct_node = onnx.helper.make_node(
            "SequenceConstruct", ["X", "Y", "Z"], ["seq_1"]
        )
        seq_erase_node = onnx.helper.make_node(
            "SequenceErase", ["seq_1", "pos_erase"], ["seq_2"]
        )
        seq_at_node = onnx.helper.make_node("SequenceAt", ["seq_2", "pos_at"], ["out"])

        tensor_shape = [2, 3, 4]

        x = np.ones(tensor_shape, dtype=np.float32)
        y = np.zeros(tensor_shape, dtype=np.float32)
        z = np.ones(tensor_shape, dtype=np.float32) * 2
        pos_erase_val = 1
        pos_at_val = 1

        out = SequenceConstructImpl(x, y, z)
        out = SequenceEraseImpl(out, pos_erase_val)
        out = SequenceAtImpl(out, pos_at_val)
        assert np.array_equal(out, z)

        pos_erase = onnx.helper.make_tensor(
            "pos_erase", TensorProto.INT64, (), (pos_erase_val,)
        )
        pos_at = onnx.helper.make_tensor("pos_at", TensorProto.INT64, (), (pos_at_val,))

        graph = make_graph(
            [seq_construct_node, seq_erase_node, seq_at_node],
            [tensor_shape, tensor_shape, tensor_shape, [], []],  # type: ignore
            [tensor_shape],  # type: ignore
            ["X", "Y", "Z", "pos_erase", "pos_at"],
            ["out"],
            [onnx.TensorProto.FLOAT] * 3 + [onnx.TensorProto.INT64] * 2,  # type: ignore
            [onnx.TensorProto.FLOAT],
            [pos_erase, pos_at],
        )
        model = onnx.helper.make_model_gen_version(
            graph,
            producer_name="backend-test",
            opset_imports=[onnx.helper.make_opsetid("", 12)],
        )
        expect(model, inputs=[x, y, z], outputs=[out], name="test_sequence_model2")

        # 3rd testcase - erase, insert and at, with negative index value.
        # 1. SequenceConstruct(x, y, z):    -> [x, y, z]
        # 2. SequenceErase(-3):             -> [y, z]
        # 3. SequenceInsert(x, -1):         -> [y, x, z]
        # 4. SequenceAt(-1):                -> z
        seq_construct_node = onnx.helper.make_node(
            "SequenceConstruct", ["X", "Y", "Z"], ["seq_1"]
        )
        seq_erase_node = onnx.helper.make_node(
            "SequenceErase", ["seq_1", "pos_erase"], ["seq_2"]
        )
        seq_insert_node = onnx.helper.make_node(
            "SequenceInsert", ["seq_2", "X", "pos_insert"], ["seq_3"]
        )
        seq_at_node = onnx.helper.make_node("SequenceAt", ["seq_3", "pos_at"], ["out"])

        tensor_shape = [2, 3, 4]

        x = np.ones(tensor_shape, dtype=np.float32)
        y = np.zeros(tensor_shape, dtype=np.float32)
        z = np.ones(tensor_shape, dtype=np.float32) * 2
        pos_erase_val = -3
        pos_insert_val = -1
        pos_at_val = -1
        out = SequenceConstructImpl(x, y, z)
        out = SequenceEraseImpl(out, pos_erase_val)
        out = SequenceInsertImpl(out, x, pos_insert_val)
        out = SequenceAtImpl(out, pos_at_val)
        assert np.array_equal(out, z)

        pos_erase = onnx.helper.make_tensor(
            "pos_erase", TensorProto.INT64, (), (pos_erase_val,)
        )
        pos_insert = onnx.helper.make_tensor(
            "pos_insert", TensorProto.INT64, (), (pos_insert_val,)
        )
        pos_at = onnx.helper.make_tensor("pos_at", TensorProto.INT64, (), (pos_at_val,))

        graph = make_graph(
            [seq_construct_node, seq_erase_node, seq_insert_node, seq_at_node],
            [tensor_shape, tensor_shape, tensor_shape, [], [], []],  # type: ignore
            [tensor_shape],  # type: ignore
            ["X", "Y", "Z", "pos_erase", "pos_insert", "pos_at"],
            ["out"],
            [onnx.TensorProto.FLOAT] * 3 + [onnx.TensorProto.INT64] * 3,  # type: ignore
            [onnx.TensorProto.FLOAT],
            [pos_erase, pos_insert, pos_at],
        )
        model = onnx.helper.make_model_gen_version(
            graph,
            producer_name="backend-test",
            opset_imports=[onnx.helper.make_opsetid("", 12)],
        )
        expect(model, inputs=[x, y, z], outputs=[out], name="test_sequence_model3")

        # 4th testcase - concat
        seq_construct_node = onnx.helper.make_node(
            "SequenceConstruct", ["X", "Y", "Z"], ["seq_1"]
        )
        seq_concat_node = onnx.helper.make_node(
            "ConcatFromSequence", ["seq_1"], ["out"], axis=1
        )

        tensor_shape = [2, 3, 4]
        concat_out_shape = [2, None, 4]

        x = np.ones(tensor_shape, dtype=np.float32)
        y = np.zeros(tensor_shape, dtype=np.float32)
        z = np.ones(tensor_shape, dtype=np.float32) * 2
        out = SequenceConstructImpl(x, y, z)
        concat_out = ConcatFromSequenceImpl(out, 1)

        graph = make_graph(
            [seq_construct_node, seq_concat_node],
            [tensor_shape] * 3,  # type: ignore
            [concat_out_shape],  # type: ignore
            ["X", "Y", "Z"],
            ["out"],
            [onnx.TensorProto.FLOAT] * 3,  # type: ignore
            [onnx.TensorProto.FLOAT],
        )
        model = onnx.helper.make_model_gen_version(
            graph,
            producer_name="backend-test",
            opset_imports=[onnx.helper.make_opsetid("", 12)],
        )
        expect(
            model, inputs=[x, y, z], outputs=[concat_out], name="test_sequence_model4"
        )

        # 5th testcase - concat with new_axis = 1
        seq_construct_node = onnx.helper.make_node(
            "SequenceConstruct", ["X", "Y", "Z"], ["seq_1"]
        )
        seq_concat_node = onnx.helper.make_node(
            "ConcatFromSequence", ["seq_1"], ["out"], axis=-1, new_axis=1
        )

        tensor_shape = [2, 3, 4]
        concat_out_shape = [2, 3, 4, 3]

        x = np.ones(tensor_shape, dtype=np.float32)
        y = np.zeros(tensor_shape, dtype=np.float32)
        z = np.ones(tensor_shape, dtype=np.float32) * 2
        out = SequenceConstructImpl(x, y, z)
        concat_out = ConcatFromSequenceImpl(out, -1, 1)

        graph = make_graph(
            [seq_construct_node, seq_concat_node],
            [tensor_shape] * 3,  # type: ignore
            [concat_out_shape],  # type: ignore
            ["X", "Y", "Z"],
            ["out"],
            [onnx.TensorProto.FLOAT] * 3,  # type: ignore
            [onnx.TensorProto.FLOAT],
        )
        model = onnx.helper.make_model_gen_version(
            graph,
            producer_name="backend-test",
            opset_imports=[onnx.helper.make_opsetid("", 12)],
        )
        expect(
            model, inputs=[x, y, z], outputs=[concat_out], name="test_sequence_model5"
        )

        # 6th testcase - split and len
        seq_split_node = onnx.helper.make_node(
            "SplitToSequence", ["X"], ["seq_1"], axis=-1
        )
        seq_len_node = onnx.helper.make_node("SequenceLength", ["seq_1"], ["len"])

        tensor_shape = [2, 3, 4]
        len_shape = []  # type: ignore

        x = np.ones(tensor_shape, dtype=np.float32)
        out = SplitToSequenceImpl(x, axis=-1)
        out = SequenceLengthImpl(out)
        assert np.array_equal(out, np.int64(4))

        graph = onnx.helper.make_graph(
            nodes=[seq_split_node, seq_len_node],
            name="Sequence",
            inputs=[
                onnx.helper.make_tensor_value_info(
                    "X", onnx.TensorProto.FLOAT, tensor_shape
                )
            ],
            outputs=[
                onnx.helper.make_tensor_value_info(
                    "len", onnx.TensorProto.INT64, len_shape
                )
            ],
        )  # type: ignore

        model = onnx.helper.make_model_gen_version(
            graph,
            producer_name="backend-test",
            opset_imports=[onnx.helper.make_opsetid("", 12)],
        )
        expect(model, inputs=[x], outputs=[out], name="test_sequence_model6")

        # 7th testcase - split with keepdims=0, and SequenceAt
        seq_split_node = onnx.helper.make_node(
            "SplitToSequence", ["X"], ["seq_1"], axis=0, keepdims=0
        )
        seq_at_node = onnx.helper.make_node("SequenceAt", ["seq_1", "pos_at"], ["out"])

        tensor_shape = [2, 3, 4]
        out_shape = [3, 4]

        x = np.random.rand(*tensor_shape)
        pos_at_val = 1
        out = SplitToSequenceImpl(x, axis=0, keepdims=0)
        out = SequenceAtImpl(out, pos_at_val)
        assert np.array_equal(out, x[pos_at_val])

        pos_at = onnx.helper.make_tensor("pos_at", TensorProto.INT64, (), (pos_at_val,))

        graph = make_graph(
            [seq_split_node, seq_at_node],
            [tensor_shape, []],  # type: ignore
            [out_shape],  # type: ignore
            ["X", "pos_at"],
            ["out"],
            [onnx.TensorProto.DOUBLE, onnx.TensorProto.INT64],
            [onnx.TensorProto.DOUBLE],
            [pos_at],
        )
        model = onnx.helper.make_model_gen_version(
            graph,
            producer_name="backend-test",
            opset_imports=[onnx.helper.make_opsetid("", 12)],
        )
        expect(model, inputs=[x], outputs=[out], name="test_sequence_model7")

        # 8th testcase - split zero length
        seq_split_node = onnx.helper.make_node(
            "SplitToSequence", ["X", "Splits"], ["seq_1"]
        )
        seq_len_node = onnx.helper.make_node("SequenceLength", ["seq_1"], ["len"])

        tensor_shape = ["n"]  # type: ignore
        splits_shape = [3]  # type: ignore

        x = np.array([]).astype(np.float32)
        splits = np.array([0, 0, 0]).astype(np.int64)
        out_len = np.int64(3)

        graph = onnx.helper.make_graph(
            nodes=[seq_split_node, seq_len_node],
            name="Sequence",
            inputs=[
                onnx.helper.make_tensor_value_info(
                    "X", onnx.TensorProto.FLOAT, tensor_shape
                ),  # type: ignore
                onnx.helper.make_tensor_value_info(
                    "Splits", onnx.TensorProto.INT64, splits_shape
                ),
            ],  # type: ignore
            outputs=[
                onnx.helper.make_tensor_value_info(
                    "len", onnx.TensorProto.INT64, len_shape
                )
            ],
        )  # type: ignore

        model = onnx.helper.make_model_gen_version(
            graph,
            producer_name="backend-test",
            opset_imports=[onnx.helper.make_opsetid("", 12)],
        )
        expect(
            model, inputs=[x, splits], outputs=[out_len], name="test_sequence_model8"
        )
