// SPDX-License-Identifier: Apache-2.0

// SPDX-FileCopyrightText: Copyright The WasmEdge Authors

#include "ast/module.h"

#include "common/configure.h"

#include "common/filesystem.h"

#include "common/spdlog.h"

#include "driver/tool.h"

#include "loader/loader.h"

#include <cstdlib>

#include <map>

#include <string>

#include <string_view>

using namespace std::literals;

namespace WasmEdge {

namespace Driver {

namespace {

struct NameSection {

  std::map<uint32_t, std::string> FuncNames;

  std::map<uint32_t, std::string> GlobalNames;

};

uint32_t decodeLEB128U32(Span<const Byte> Data, uint32_t &Offset) {

  uint32_t Result = 0;

  uint32_t Shift = 0;

  while (Offset < Data.size()) {

    uint8_t B = static_cast<uint8_t>(Data[Offset++]);

    Result |= static_cast<uint32_t>(B & 0x7F) << Shift;

    if ((B & 0x80) == 0)

      break;

    Shift += 7;

  }

  return Result;

}

std::string decodeName(Span<const Byte> Data, uint32_t &Offset) {

  uint32_t Len = decodeLEB128U32(Data, Offset);

  if (Offset + Len > Data.size())

    return {};

  std::string Name(reinterpret_cast<const char *>(&Data[Offset]), Len);

  Offset += Len;

  return Name;

}

std::map<uint32_t, std::string> decodeNameMap(Span<const Byte> Data,

                                              uint32_t &Offset) {

  std::map<uint32_t, std::string> Map;

  uint32_t Count = decodeLEB128U32(Data, Offset);

  for (uint32_t I = 0; I < Count && Offset < Data.size(); I++) {

    uint32_t Idx = decodeLEB128U32(Data, Offset);

    std::string Name = decodeName(Data, Offset);

    Map[Idx] = std::move(Name);

  }

  return Map;

}

NameSection parseNameSection(Span<const Byte> Data) {

  NameSection NS;

  uint32_t Offset = 0;

  while (Offset < Data.size()) {

    uint8_t SubId = static_cast<uint8_t>(Data[Offset++]);

    uint32_t SubSize = decodeLEB128U32(Data, Offset);

    uint32_t SubEnd = Offset + SubSize;

    if (SubEnd > Data.size())

      break;

    if (SubId == 1) {

      NS.FuncNames = decodeNameMap(Data, Offset);

    } else if (SubId == 7) {

      NS.GlobalNames = decodeNameMap(Data, Offset);

    }

    Offset = SubEnd;

  }

  return NS;

}

std::string getInitExprStr(const AST::Expression &Expr) {

  const auto Instrs = Expr.getInstrs();

  if (Instrs.empty())

    return {};

  const auto &Instr = Instrs[0];

  switch (Instr.getOpCode()) {

  case OpCode::I32__const:

    return fmt::format("i32={}"sv, Instr.getNum().get<int32_t>());

  case OpCode::I64__const:

    return fmt::format("i64={}"sv, Instr.getNum().get<int64_t>());

  case OpCode::F32__const:

    return fmt::format("f32={}"sv, Instr.getNum().get<float>());

  case OpCode::F64__const:

    return fmt::format("f64={}"sv, Instr.getNum().get<double>());

  case OpCode::Global__get:

    return fmt::format("global.get {}"sv, Instr.getTargetIndex());

  case OpCode::Ref__func:

    return fmt::format("ref.func {}"sv, Instr.getTargetIndex());

  case OpCode::Ref__null:

    return fmt::format("ref.null {}"sv, Instr.getValType());

  default:

    return {};

  }

}

// Renders a single element segment entry, i.e. one of the init expressions

// in an element segment's `getInitExprs()` list.

std::string getElemEntryStr(const AST::Expression &Expr) {

  const auto Instrs = Expr.getInstrs();

  if (Instrs.empty())

    return "ref.null";

  const auto &Instr = Instrs[0];

  switch (Instr.getOpCode()) {

  case OpCode::Ref__func:

    return fmt::format("func[{}]"sv, Instr.getTargetIndex());

  case OpCode::Ref__null:

    return "ref.null";

  default:

    return getInitExprStr(Expr);

  }

}

} // namespace

int ParseTool(struct DriverToolOptions &Opt) noexcept {

  std::ios::sync_with_stdio(false);

  Configure Conf = createConfigure(Opt);

  const auto InputPath = std::filesystem::absolute(u8path(Opt.SoName.value()));

  Loader::Loader Loader(Conf);

  auto Res = Loader.parseModule(InputPath);

  if (!Res) {

    spdlog::error("Failed to parse WASM module."sv);

    return EXIT_FAILURE;

  }

  const auto &Mod = **Res;

  const auto &Customs = Mod.getCustomSections();

  NameSection NS;

  for (const auto &Custom : Customs) {

    if (Custom.getName() == "name") {

      NS = parseNameSection(Custom.getContent());

      break;

    }

  }

  const auto &Imports = Mod.getImportSection().getContent();

  uint32_t ImportedFuncCount = 0;

  uint32_t ImportedGlobalCount = 0;

  uint32_t ImportedTableCount = 0;

  uint32_t ImportedMemCount = 0;

  uint32_t ImportedTagCount = 0;

  for (const auto &Imp : Imports) {

    if (Imp.getExternalType() == ExternalType::Function)

      ImportedFuncCount++;

    else if (Imp.getExternalType() == ExternalType::Global)

      ImportedGlobalCount++;

    else if (Imp.getExternalType() == ExternalType::Table)

      ImportedTableCount++;

    else if (Imp.getExternalType() == ExternalType::Memory)

      ImportedMemCount++;

    else if (Imp.getExternalType() == ExternalType::Tag)

      ImportedTagCount++;

  }

  auto FuncName = [&](uint32_t Idx) -> std::string {

    auto It = NS.FuncNames.find(Idx);

    if (It != NS.FuncNames.end())

      return fmt::format(" <{}>"sv, It->second);

    return {};

  };

  auto GlobalName = [&](uint32_t Idx) -> std::string {

    auto It = NS.GlobalNames.find(Idx);

    if (It != NS.GlobalNames.end())

      return fmt::format(" <{}>"sv, It->second);

    return {};

  };

  fmt::print("{}:  file format wasm 0x1\n\n", InputPath.filename().string());

  fmt::print("Section Details:\n\n");

  // Type Section

  const auto &Types = Mod.getTypeSection().getContent();

  if (!Types.empty()) {

    fmt::print("Type[{}]:\n", Types.size());

    for (uint32_t I = 0; I < Types.size(); I++) {

      const auto &FuncType = Types[I].getCompositeType().getFuncType();

      fmt::print(" - type[{}] (", I);

      const auto &Params = FuncType.getParamTypes();

      for (uint32_t J = 0; J < Params.size(); J++) {

        if (J > 0)

          fmt::print(", ");

        fmt::print("{}", Params[J]);

      }

      fmt::print(") -> ");

      const auto &Returns = FuncType.getReturnTypes();

      if (Returns.empty()) {

        fmt::print("nil");

      } else {

        for (uint32_t J = 0; J < Returns.size(); J++) {

          if (J > 0)

            fmt::print(", ");

          fmt::print("{}", Returns[J]);

        }

      }

      fmt::print("\n");

    }

  }

  // Import Section

  if (!Imports.empty()) {

    fmt::print("Import[{}]:\n", Imports.size());

    uint32_t ImpFuncIdx = 0;

    uint32_t ImpGlobalIdx = 0;

    uint32_t ImpMemIdx = 0;

    uint32_t ImpTableIdx = 0;

    uint32_t ImpTagIdx = 0;

    for (const auto &Imp : Imports) {

      switch (Imp.getExternalType()) {

      case ExternalType::Function:

        fmt::print(" - func[{}] sig={}{} <- {}.{}\n", ImpFuncIdx,

                   Imp.getExternalFuncTypeIdx(), FuncName(ImpFuncIdx),

                   Imp.getModuleName(), Imp.getExternalName());

        ImpFuncIdx++;

        break;

      case ExternalType::Memory: {

        const auto &Limit = Imp.getExternalMemoryType().getLimit();

        fmt::print(" - memory[{}] pages: initial={}", ImpMemIdx,

                   Limit.getMin());

        if (Limit.hasMax())

          fmt::print(" max={}", Limit.getMax());

        fmt::print(" <- {}.{}\n", Imp.getModuleName(), Imp.getExternalName());

        ImpMemIdx++;

        break;

      }

      case ExternalType::Table:

        fmt::print(" - table[{}] <- {}.{}\n", ImpTableIdx, Imp.getModuleName(),

                   Imp.getExternalName());

        ImpTableIdx++;

        break;

      case ExternalType::Global: {

        const auto &GT = Imp.getExternalGlobalType();

        fmt::print(" - global[{}] {} mutable={}{} <- {}.{}\n", ImpGlobalIdx,

                   GT.getValType(), GT.getValMut() == ValMut::Var ? 1 : 0,

                   GlobalName(ImpGlobalIdx), Imp.getModuleName(),

                   Imp.getExternalName());

        ImpGlobalIdx++;

        break;

      }

      case ExternalType::Tag:

        fmt::print(" - tag[{}] sig={} <- {}.{}\n", ImpTagIdx,

                   Imp.getExternalTagType().getTypeIdx(), Imp.getModuleName(),

                   Imp.getExternalName());

        ImpTagIdx++;

        break;

      default:

        break;

      }

    }

  }

  // Function Section

  const auto &Funcs = Mod.getFunctionSection().getContent();

  if (!Funcs.empty()) {

    fmt::print("Function[{}]:\n", Funcs.size());

    for (uint32_t I = 0; I < Funcs.size(); I++) {

      uint32_t Idx = I + ImportedFuncCount;

      fmt::print(" - func[{}] sig={}{}\n", Idx, Funcs[I], FuncName(Idx));

    }

  }

  // Table Section

  const auto &Tables = Mod.getTableSection().getContent();

  if (!Tables.empty()) {

    fmt::print("Table[{}]:\n", Tables.size());

    for (uint32_t I = 0; I < Tables.size(); I++) {

      uint32_t Idx = I + ImportedTableCount;

      const auto &TT = Tables[I].getTableType();

      const auto &Lim = TT.getLimit();

      fmt::print(" - table[{}] type={} initial={}", Idx, TT.getRefType(),

                 Lim.getMin());

      if (Lim.hasMax())

        fmt::print(" max={}", Lim.getMax());

      fmt::print("\n");

    }

  }

  // Memory Section

  const auto &Mems = Mod.getMemorySection().getContent();

  if (!Mems.empty()) {

    fmt::print("Memory[{}]:\n", Mems.size());

    for (uint32_t I = 0; I < Mems.size(); I++) {

      uint32_t Idx = I + ImportedMemCount;

      const auto &Lim = Mems[I].getLimit();

      fmt::print(" - memory[{}] pages: initial={}", Idx, Lim.getMin());

      if (Lim.hasMax())

        fmt::print(" max={}", Lim.getMax());

      fmt::print("\n");

    }

  }

  // Tag Section

  const auto &Tags = Mod.getTagSection().getContent();

  if (!Tags.empty()) {

    fmt::print("Tag[{}]:\n", Tags.size());

    for (uint32_t I = 0; I < Tags.size(); I++) {

      uint32_t Idx = I + ImportedTagCount;

      fmt::print(" - tag[{}] sig={}\n", Idx, Tags[I].getTypeIdx());

    }

  }

  // Global Section

  const auto &Globals = Mod.getGlobalSection().getContent();

  if (!Globals.empty()) {

    fmt::print("Global[{}]:\n", Globals.size());

    for (uint32_t I = 0; I < Globals.size(); I++) {

      uint32_t Idx = I + ImportedGlobalCount;

      const auto &GT = Globals[I].getGlobalType();

      std::string InitStr = getInitExprStr(Globals[I].getExpr());

      fmt::print(" - global[{}] {} mutable={}{}", Idx, GT.getValType(),

                 GT.getValMut() == ValMut::Var ? 1 : 0, GlobalName(Idx));

      if (!InitStr.empty())

        fmt::print(" - init {}", InitStr);

      fmt::print("\n");

    }

  }

  // Export Section

  const auto &Exports = Mod.getExportSection().getContent();

  if (!Exports.empty()) {

    fmt::print("Export[{}]:\n", Exports.size());

    for (const auto &Exp : Exports) {

      uint32_t Idx = Exp.getExternalIndex();

      switch (Exp.getExternalType()) {

      case ExternalType::Function:

        fmt::print(" - func[{}]{} -> \"{}\"\n", Idx, FuncName(Idx),

                   Exp.getExternalName());

        break;

      case ExternalType::Global:

        fmt::print(" - global[{}] -> \"{}\"\n", Idx, Exp.getExternalName());

        break;

      case ExternalType::Memory:

        fmt::print(" - memory[{}] -> \"{}\"\n", Idx, Exp.getExternalName());

        break;

      case ExternalType::Table:

        fmt::print(" - table[{}] -> \"{}\"\n", Idx, Exp.getExternalName());

        break;

      default:

        break;

      }

    }

  }

  // Start Section

  if (auto StartIdx = Mod.getStartSection().getContent()) {

    fmt::print("Start:\n");

    fmt::print(" - func[{}]{}\n", *StartIdx, FuncName(*StartIdx));

  }

  // Element Section

  const auto &Elems = Mod.getElementSection().getContent();

  if (!Elems.empty()) {

    fmt::print("Element[{}]:\n", Elems.size());

    for (uint32_t I = 0; I < Elems.size(); I++) {

      const auto &Elem = Elems[I];

      const auto &Entries = Elem.getInitExprs();

      switch (Elem.getMode()) {

      case AST::ElementSegment::ElemMode::Active: {

        fmt::print(" - segment[{}] flags=0 table={} type={} count={}", I,

                   Elem.getIdx(), Elem.getRefType(), Entries.size());

        std::string OffsetStr = getInitExprStr(Elem.getExpr());

        if (!OffsetStr.empty())

          fmt::print(" - init {}", OffsetStr);

        fmt::print("\n");

        break;

      }

      case AST::ElementSegment::ElemMode::Passive:

        fmt::print(" - segment[{}] flags=1 passive type={} count={}\n", I,

                   Elem.getRefType(), Entries.size());

        break;

      case AST::ElementSegment::ElemMode::Declarative:

        fmt::print(" - segment[{}] flags=3 declarative type={} count={}\n", I,

                   Elem.getRefType(), Entries.size());

        break;

      }

      for (uint32_t J = 0; J < Entries.size(); J++) {

        fmt::print("  - elem[{}] = {}\n", J, getElemEntryStr(Entries[J]));

      }

    }

  }

  // DataCount Section

  if (auto Count = Mod.getDataCountSection().getContent()) {

    fmt::print("DataCount section: {}\n", *Count);

  }

  // Code Section

  const auto &Codes = Mod.getCodeSection().getContent();

  if (!Codes.empty()) {

    fmt::print("Code[{}]:\n", Codes.size());

    for (uint32_t I = 0; I < Codes.size(); I++) {

      uint32_t Idx = I + ImportedFuncCount;

      fmt::print(" - func[{}] size={}{}\n", Idx, Codes[I].getSegSize(),

                 FuncName(Idx));

    }

  }

  // Data Section

  const auto &Datas = Mod.getDataSection().getContent();

  if (!Datas.empty()) {

    fmt::print("Data[{}]:\n", Datas.size());

    for (uint32_t I = 0; I < Datas.size(); I++) {

      const auto &Data = Datas[I];

      switch (Data.getMode()) {

      case AST::DataSegment::DataMode::Active: {

        fmt::print(" - segment[{}] memory={} size={}", I, Data.getIdx(),

                   Data.getData().size());

        std::string OffsetStr = getInitExprStr(Data.getExpr());

        if (!OffsetStr.empty())

          fmt::print(" - init {}", OffsetStr);

        fmt::print("\n");

        break;

      }

      case AST::DataSegment::DataMode::Passive:

        fmt::print(" - segment[{}] passive size={}\n", I,

                   Data.getData().size());

        break;

      }

    }

  }

  // Custom Sections

  for (const auto &Custom : Customs) {

    fmt::print("Custom:\n");

    fmt::print(" - name: \"{}\"\n", Custom.getName());

    if (Custom.getName() == "name") {

      for (const auto &[Idx, Name] : NS.FuncNames) {

        fmt::print(" - func[{}] <{}>\n", Idx, Name);

      }

      for (const auto &[Idx, Name] : NS.GlobalNames) {

        fmt::print(" - global[{}] <{}>\n", Idx, Name);

      }

    }

  }

  return EXIT_SUCCESS;

}

} // namespace Driver

} // namespace WasmEdge