// SPDX-License-Identifier: GPL-3.0-or-later

#include "TableGenBackends.h"

#include <cstdint>
#include <ostream>
#include <ranges>
#include <span>
#include <sstream>
#include <string>
#include <string_view>
#include <unordered_set>

namespace rcc::targetgen {
namespace {

void emitRegisterIDList(std::ostream &Output, const NormalizedTargetModel &Model,
                        std::span<const std::uint32_t> IDs) {
  for (const std::uint32_t ID : IDs)
    Output << "PhysicalRegisterID::" << findRegister(Model, ID).Symbol << ", ";
}

} // namespace

[[nodiscard]] std::string emitRegisterHeader(const NormalizedTargetModel &Model,
                                             std::string_view SourceName) {
  const std::string Guard = "RCC_TARGET_" + upperIdentifier(Model.Target.Namespace) + "_" +
                            upperIdentifier(Model.Target.Name) + "REGISTERS_H";
  std::ostringstream Output;
  Output << "// SPDX-License-Identifier: GPL-3.0-or-later\n\n";
  Output << "// This file is generated by rcc-tblgen from ";
  appendQuoted(Output, SourceName);
  Output << ". Do not edit it manually.\n\n";
  Output << "#ifndef " << Guard << "\n#define " << Guard << "\n\n";
  Output << "#include <cstdint>\n#include <string_view>\n\n";
  Output << "namespace rcc::" << Model.Target.Namespace << " {\n\n";
  Output << "inline constexpr std::string_view TargetName = ";
  appendQuoted(Output, Model.Target.Name);
  Output << ";\ninline constexpr std::string_view TargetTriple = ";
  appendQuoted(Output, Model.Target.Triple);
  Output << ";\ninline constexpr std::string_view TargetCPU = ";
  appendQuoted(Output, Model.Target.CPU);
  Output << ";\ninline constexpr std::string_view TargetABI = ";
  appendQuoted(Output, Model.Target.ABI);
  Output << ";\ninline constexpr std::string_view TargetDataLayout = ";
  appendQuoted(Output, Model.Target.DataLayout);
  Output << ";\n\ninline constexpr std::string_view TargetFeatures[] = {\n";
  for (const std::string &Feature : Model.Target.Features) {
    Output << "    ";
    appendQuoted(Output, Feature);
    Output << ",\n";
  }
  Output << "};\n\n";

  Output << "enum class PhysicalRegisterID : std::uint32_t {\n  NoRegister = 0,\n";
  for (const NormalizedRegister &Register : Model.Registers)
    Output << "  " << Register.Symbol << " = " << Register.ID << ",\n";
  Output << "};\n\n";
  Output << "enum class RegisterUnit : std::uint32_t {\n";
  for (const SourceRegisterUnit &Unit : Model.RegisterUnits)
    Output << "  " << Unit.Symbol << " = " << Unit.ID << ",\n";
  Output << "};\n\n";
  Output << "enum class RegisterBank : std::uint32_t {\n";
  for (const NormalizedRegisterBank &Bank : Model.RegisterBanks)
    Output << "  " << Bank.Symbol << " = " << Bank.ID << ",\n";
  Output << "};\n\n";
  Output << "enum class RegisterClass : std::uint32_t {\n";
  for (const NormalizedRegisterClass &Class : Model.RegisterClasses)
    Output << "  " << Class.Symbol << " = " << Class.ID << ",\n";
  Output << "};\n\n";
  Output << "} // namespace rcc::" << Model.Target.Namespace << "\n\n";
  Output << "#endif // " << Guard << "\n";
  return Output.str();
}

std::string emitRegisterInfo(const NormalizedTargetModel &Model, std::string_view SourceName) {
  std::ostringstream Output;
  Output << "// SPDX-License-Identifier: GPL-3.0-or-later\n\n";
  Output << "// This file is generated by rcc-tblgen from ";
  appendQuoted(Output, SourceName);
  Output << ". Do not edit it manually.\n\n";
  Output << "void appendGeneratedRegisterInfo(TargetRegisterInfoDesc &Description) {\n";
  Output << "  Description.RegisterUnits = {\n";
  for (const SourceRegisterUnit &Unit : Model.RegisterUnits) {
    Output << "      {RegisterUnitID::fromValue(" << Unit.ID << "), ";
    appendQuoted(Output, Unit.Name);
    Output << "},\n";
  }
  Output << "  };\n\n  Description.PhysicalRegisters = {\n";
  for (const NormalizedRegister &Register : Model.Registers) {
    Output << "      {physical(PhysicalRegisterID::" << Register.Symbol << "), ";
    appendQuoted(Output, Register.Name);
    Output << ", " << Register.Encoding << ", {";
    for (const NormalizedRegisterUnitLane &Unit : Register.Units) {
      Output << "unitLane(RegisterUnit::" << findRegisterUnit(Model, Unit.UnitID).Symbol << ", "
             << Unit.Lanes << "), ";
    }
    Output << "}, " << (Register.IsConstant ? "true" : "false") << ", "
           << (Register.IsArtificial ? "true" : "false") << ", "
           << (Register.IsReserved ? "true" : "false") << ", {";
    for (const std::string &Alias : Register.AlternativeNames) {
      appendQuoted(Output, Alias);
      Output << ", ";
    }
    Output << "}},\n";
  }
  Output << "  };\n\n  Description.RegisterBanks = {\n";
  Output << emitRegisterBanks(Model);
  Output << "  };\n\n  Description.RegisterClasses = {\n";
  for (const NormalizedRegisterClass &Class : Model.RegisterClasses) {
    Output << "      registerClass(RegisterClass::" << Class.Symbol << ", ";
    appendQuoted(Output, Class.Name);
    Output << ", {";
    emitRegisterIDList(Output, Model, Class.Registers);
    Output << "}, {";
    emitRegisterIDList(Output, Model, Class.AllocationOrder);
    Output << "}, RegisterBank::" << findRegisterBank(Model, Class.BankID).Symbol << ", "
           << Class.SizeInBits << ", " << Class.SpillSizeInBits << ", "
           << Class.SpillAlignmentInBits << ", " << Class.Lanes << ", "
           << (Class.Allocatable ? "true" : "false") << ", " << Class.CopyCost << "),\n";
  }
  Output << "  };\n}\n\n";
  Output << "void appendGeneratedMIRTextInfo(TargetMIRTextInfoDesc &Description) {\n";
  Output << "  Description.DirectOperandFlagMask = " << Model.MIROperandFlags.DirectMask
         << ";\n  Description.DirectOperandFlags = {\n";
  for (const SourceMIROperandFlag &Flag : Model.MIROperandFlags.Direct) {
    Output << "      {";
    appendQuoted(Output, Flag.Name);
    Output << ", " << Flag.Value << "},\n";
  }
  Output << "  };\n  Description.BitmaskOperandFlags = {\n";
  for (const SourceMIROperandFlag &Flag : Model.MIROperandFlags.Bitmask) {
    Output << "      {";
    appendQuoted(Output, Flag.Name);
    Output << ", " << Flag.Value << "},\n";
  }
  Output << "  };\n";
  Output << "  Description.RegisterMasks = {\n";
  for (const NormalizedRegisterMask &Mask : Model.RegisterMasks) {
    Output << "      {";
    appendQuoted(Output, Mask.Name);
    Output << ", makePreservedMask({";
    emitRegisterIDList(Output, Model, Mask.PreservedRegisters);
    Output << "})},\n";
  }
  Output << "  };\n  Description.CFIRegisters = {\n";
  std::unordered_set<std::uint32_t> CanonicalDwarfRegisters;
  for (const NormalizedRegister &Register : Model.Registers) {
    const bool IsCanonical = CanonicalDwarfRegisters.insert(Register.DwarfRegister).second;
    Output << "      {physical(PhysicalRegisterID::" << Register.Symbol << "), "
           << Register.DwarfRegister << ", " << (IsCanonical ? "true" : "false") << "},\n";
  }
  Output << "  };\n}\n\n";

  return Output.str();
}

} // namespace rcc::targetgen