# Copyright 2025 Arm Limited and/or its affiliates.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree.

# pyre-unsafe

from typing import Any, List

import torch
import torch.fx

from executorch.backends.arm.operators.node_visitor import (
    NodeVisitor,
    register_node_visitor,
)
from executorch.backends.arm.operators.operator_validation_utils import (
    validate_num_inputs,
    validate_same_dtype,
)
from executorch.backends.arm.tosa_mapping import TosaArg


def identity_operator_factory_v0_80(identity_target: str):
    """
    Creates and registers NodeVisitors for operators that map directly
    to a TOSA IDENTITY op.
    """

    class IdentityOperatorVisitor(NodeVisitor):
        target = identity_target

        tosa_specs = NodeVisitor.tosa_specs_0_80

        def define_node(
            self,
            node: torch.fx.Node,
            tosa_graph: Any,
            inputs: List[TosaArg],
            output: TosaArg,
        ) -> None:
            import tosa_tools.v0_80.serializer.tosa_serializer as ts

            validate_num_inputs(self.target, inputs, 1)
            validate_same_dtype(self.target, [*inputs, output])

            # Simply add an identityOp
            tosa_graph.addOperator(
                ts.TosaOp.Op().IDENTITY, [inputs[0].name], [output.name]
            )

    register_node_visitor(IdentityOperatorVisitor)


identity_operator_factory_v0_80("getitem")
identity_operator_factory_v0_80("aten.alias_copy.default")


def identity_operator_factory(identity_target: str):
    """
    Creates and registers NodeVisitors for operators that map directly
    to a TOSA IDENTITY op.
    """

    class IdentityOperatorVisitor(NodeVisitor):
        target = identity_target

        tosa_specs = NodeVisitor.tosa_specs_1_00

        def define_node(
            self,
            node: torch.fx.Node,
            tosa_graph: Any,
            inputs: List[TosaArg],
            output: TosaArg,
        ) -> None:
            import serializer.tosa_serializer as ts

            validate_num_inputs(self.target, inputs, 1)
            validate_same_dtype(self.target, [*inputs, output])

            # Simply add an identityOp
            tosa_graph.addOperator(
                ts.TosaOp.Op().IDENTITY, [inputs[0].name], [output.name]
            )

    register_node_visitor(IdentityOperatorVisitor)


identity_operator_factory("getitem")
identity_operator_factory("aten.alias_copy.default")