//===----------------------------------------------------------------------===//
//
// This file is licensed under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// Also available under a BSD-style license. See LICENSE.
//
//===----------------------------------------------------------------------===//

#include "torch-mlir/Dialect/Torch/Utils/Utils.h"
#include "torch-mlir/Dialect/Torch/IR/TorchOps.h"

using namespace mlir;
using namespace mlir::torch;
using namespace mlir::torch::Torch;

int64_t Torch::toPositiveDim(int64_t dim, int64_t inputRank) {
  return dim >= 0 ? dim : dim + inputRank;
}

bool Torch::isValidDim(int64_t dim, int64_t inputRank) {
  return dim >= 0 && dim < inputRank;
}

bool Torch::getListConstructElements(Value v, SmallVectorImpl<Value> &elems) {
  auto listConstruct = v.getDefiningOp<PrimListConstructOp>();
  if (!listConstruct)
    return false;
  elems = llvm::to_vector<4>(listConstruct.elements());
  return true;
}

torch_upstream::ScalarType Torch::getScalarTypeForType(Type type) {
  if (type.isa<Float32Type>())
    return torch_upstream::ScalarType::Float;
  if (type.isa<Float64Type>())
    return torch_upstream::ScalarType::Double;
  if (type.isSignedInteger(64))
    return torch_upstream::ScalarType::Long;
  if (type.isSignedInteger(32))
    return torch_upstream::ScalarType::Int;
  if (type.isUnsignedInteger(1))
    return torch_upstream::ScalarType::Bool;
  llvm::report_fatal_error("unhandled type for getScalarTypeForType");
}

static Value getDtypeIntValueForType(PatternRewriter &rewriter, Location loc,
                                     Type dtype) {
  int intType = (int)getScalarTypeForType(dtype);
  return rewriter.create<ConstantIntOp>(loc,
                                        rewriter.getI64IntegerAttr(intType));
}

// Helper to convert a tensor to a specific scalar type.
Value Torch::convertTensorToDtype(PatternRewriter &rewriter, Location loc,
                                  Value input, Type dtype) {
  BaseTensorType origType = input.getType().cast<BaseTensorType>();
  Type newType = origType.getWithSizesAndDtype(origType.getSizes(), dtype);
  // `convertIntVal` contains the corresponding integer for the dtype which is
  // used by the aten.to.dtype op.
  Value convertIntVal = getDtypeIntValueForType(rewriter, loc, dtype);
  Value falseVal = rewriter.create<ConstantBoolOp>(loc, false);
  Value noneVal = rewriter.create<ConstantNoneOp>(loc);
  Value converted = rewriter.create<AtenToDtypeOp>(
      loc, newType, input, convertIntVal, falseVal, falseVal, noneVal);
  return converted;
}