//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, 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.
//
//===----------------------------------------------------------------------===//
#ifdef TORCH_MLIR_ENABLE_MHLO
#include "PassDetail.h"

#include "mhlo/IR/hlo_ops.h"
#include "mlir/Dialect/Arith/IR/Arith.h"
#include "mlir/Dialect/Func/IR/FuncOps.h"
#include "mlir/Dialect/Shape/IR/Shape.h"
#include "mlir/Dialect/Tensor/IR/Tensor.h"
#include "mlir/IR/BuiltinOps.h"
#include "mlir/IR/OpDefinition.h"
#include "mlir/Transforms/DialectConversion.h"
#include "stablehlo/dialect/ChloOps.h"
#include "torch-mlir/Dialect/TorchConversion/Transforms/Passes.h"

using namespace mlir;
using namespace mlir::torch;
using namespace mlir::torch::TorchConversion;

namespace {
class VerifyMhloBackendContractPass
    : public VerifyMhloBackendContractBase<VerifyMhloBackendContractPass> {
  void runOnOperation() override {
    MLIRContext *context = &getContext();
    auto module = getOperation();
    TypeConverter converter;
    converter.addConversion([](Type type) -> Type {
      auto elemTy = type;
      if (isa<TensorType>(type)) {
        elemTy = type.cast<TensorType>().getElementType();
      }
      if (BaseMemRefType::isValidElementType(elemTy))
        return type;
      return nullptr;
    });

    auto opHasLegalTypes = [&](Operation *op) { return converter.isLegal(op); };

    ConversionTarget target(*context);

    // Structural operations.
    target.addDynamicallyLegalOp<ModuleOp, func::FuncOp, func::ReturnOp>(opHasLegalTypes);
    // Shape operations.
    target.addDynamicallyLegalOp<shape::ShapeOfOp>(opHasLegalTypes);

    target.addLegalDialect<mhlo::MhloDialect>();
    target.addLegalDialect<chlo::ChloDialect>();
    target.addLegalDialect<tensor::TensorDialect>();
    target.addLegalDialect<arith::ArithDialect>();

    RewritePatternSet patterns(context);
    if (failed(applyFullConversion(module, target, std::move(patterns)))) {
      // We avoid `module.emitError()` so that mlir-print-op-on-diagnostics
      // doesn't unnecessarily spew out the entire module.
      emitError(module.getLoc())
          << "Module does not conform to the MHLO backend contract. "
             "See dialect conversion legality information above.";
      return signalPassFailure();
    }
  }
};
} // namespace

std::unique_ptr<OperationPass<ModuleOp>>
mlir::torch::TorchConversion::createVerifyMhloBackendContractPass() {
  return std::make_unique<VerifyMhloBackendContractPass>();
}
#endif // TORCH_MLIR_ENABLE_MHLO