// Copyright 2021 The IREE Authors
//
// 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

#include "./SPIRVToWGSL.h"

#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "tint/tint.h"

namespace mlir::iree_compiler::IREE::HAL {

std::optional<std::string>
compileSPIRVToWGSL(llvm::ArrayRef<uint32_t> spvBinary) {
  // TODO(scotttodd): reroute to MLIR diagnostics?
  auto diagPrinter = tint::diag::Printer::create(stderr, true);
  tint::diag::Formatter diagFormatter;

  // TODO(scotttodd): remove this copy (API for std::span or [uint8_t*, size]?)
  std::vector<uint32_t> binaryVector(spvBinary.size());
  std::memcpy(binaryVector.data(), spvBinary.data(),
              spvBinary.size() * sizeof(uint32_t));

  auto program =
      std::make_unique<tint::Program>(tint::reader::spirv::Parse(binaryVector));
  if (!program) {
    llvm::errs() << "Tint failed to parse SPIR-V program\n";
    return std::nullopt;
  }

  if (program->Diagnostics().contains_errors()) {
    llvm::errs() << "Tint reported " << program->Diagnostics().error_count()
                 << " error(s) for a SPIR-V program, see diagnostics:\n";
    diagFormatter.format(program->Diagnostics(), diagPrinter.get());
    return std::nullopt;
  }

  if (!program->IsValid()) {
    llvm::errs() << "Tint parsed an invalid SPIR-V program\n";
    return std::nullopt;
  }

  tint::writer::wgsl::Options genOptions;
  auto result = tint::writer::wgsl::Generate(program.get(), genOptions);
  if (!result.success) {
    llvm::errs() << "Tint failed to generate WGSL: " << result.error << "\n";
    return std::nullopt;
  }

  return result.wgsl;
}

} // namespace mlir::iree_compiler::IREE::HAL