//===--- SymbolYAML.cpp ------------------------------------------*- C++-*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "SymbolYAML.h"
#include "Index.h"
#include "llvm/ADT/Optional.h"
#include "llvm/Support/Errc.h"
#include "llvm/Support/MemoryBuffer.h"
#include "llvm/Support/raw_ostream.h"

LLVM_YAML_IS_DOCUMENT_LIST_VECTOR(clang::clangd::Symbol)

namespace llvm {
namespace yaml {

using clang::clangd::Symbol;
using clang::clangd::SymbolID;
using clang::clangd::SymbolLocation;
using clang::index::SymbolInfo;
using clang::index::SymbolLanguage;
using clang::index::SymbolKind;

// Helper to (de)serialize the SymbolID. We serialize it as a hex string.
struct NormalizedSymbolID {
  NormalizedSymbolID(IO &) {}
  NormalizedSymbolID(IO &, const SymbolID& ID) {
    llvm::raw_string_ostream OS(HexString);
    OS << ID;
  }

  SymbolID denormalize(IO&) {
    SymbolID ID;
    HexString >> ID;
    return ID;
  }

  std::string HexString;
};

template <> struct MappingTraits<SymbolLocation::Position> {
  static void mapping(IO &IO, SymbolLocation::Position &Value) {
    IO.mapRequired("Line", Value.Line);
    IO.mapRequired("Column", Value.Column);
  }
};

template <> struct MappingTraits<SymbolLocation> {
  static void mapping(IO &IO, SymbolLocation &Value) {
    IO.mapRequired("FileURI", Value.FileURI);
    IO.mapRequired("Start", Value.Start);
    IO.mapRequired("End", Value.End);
  }
};

template <> struct MappingTraits<SymbolInfo> {
  static void mapping(IO &io, SymbolInfo &SymInfo) {
    // FIXME: expose other fields?
    io.mapRequired("Kind", SymInfo.Kind);
    io.mapRequired("Lang", SymInfo.Lang);
  }
};

template <> struct MappingTraits<Symbol::Details> {
  static void mapping(IO &io, Symbol::Details &Detail) {
    io.mapOptional("Documentation", Detail.Documentation);
    io.mapOptional("CompletionDetail", Detail.CompletionDetail);
    io.mapOptional("IncludeHeader", Detail.IncludeHeader);
  }
};

// A YamlIO normalizer for fields of type "const T*" allocated on an arena.
// Normalizes to Optional<T>, so traits should be provided for T.
template <typename T> struct ArenaPtr {
  ArenaPtr(IO &) {}
  ArenaPtr(IO &, const T *D) {
    if (D)
      Opt = *D;
  }

  const T *denormalize(IO &IO) {
    assert(IO.getContext() && "Expecting an arena (as context) to allocate "
                              "data for read symbols.");
    if (!Opt)
      return nullptr;
    return new (*static_cast<llvm::BumpPtrAllocator *>(IO.getContext()))
        T(std::move(*Opt)); // Allocate a copy of Opt on the arena.
  }

  llvm::Optional<T> Opt;
};

template <> struct MappingTraits<Symbol> {
  static void mapping(IO &IO, Symbol &Sym) {
    MappingNormalization<NormalizedSymbolID, SymbolID> NSymbolID(IO, Sym.ID);
    MappingNormalization<ArenaPtr<Symbol::Details>, const Symbol::Details *>
        NDetail(IO, Sym.Detail);
    IO.mapRequired("ID", NSymbolID->HexString);
    IO.mapRequired("Name", Sym.Name);
    IO.mapRequired("Scope", Sym.Scope);
    IO.mapRequired("SymInfo", Sym.SymInfo);
    IO.mapOptional("CanonicalDeclaration", Sym.CanonicalDeclaration,
                   SymbolLocation());
    IO.mapOptional("Definition", Sym.Definition, SymbolLocation());
    IO.mapOptional("References", Sym.References, 0u);
    IO.mapOptional("IsIndexedForCodeCompletion", Sym.IsIndexedForCodeCompletion,
                   false);
    IO.mapRequired("CompletionLabel", Sym.CompletionLabel);
    IO.mapRequired("CompletionFilterText", Sym.CompletionFilterText);
    IO.mapRequired("CompletionPlainInsertText", Sym.CompletionPlainInsertText);

    IO.mapOptional("CompletionSnippetInsertText",
                   Sym.CompletionSnippetInsertText);
    IO.mapOptional("Detail", NDetail->Opt);
  }
};

template <> struct ScalarEnumerationTraits<SymbolLanguage> {
  static void enumeration(IO &IO, SymbolLanguage &Value) {
    IO.enumCase(Value, "C", SymbolLanguage::C);
    IO.enumCase(Value, "Cpp", SymbolLanguage::CXX);
    IO.enumCase(Value, "ObjC", SymbolLanguage::ObjC);
    IO.enumCase(Value, "Swift", SymbolLanguage::Swift);
  }
};

template <> struct ScalarEnumerationTraits<SymbolKind> {
  static void enumeration(IO &IO, SymbolKind &Value) {
#define DEFINE_ENUM(name) IO.enumCase(Value, #name, SymbolKind::name)

    DEFINE_ENUM(Unknown);
    DEFINE_ENUM(Function);
    DEFINE_ENUM(Module);
    DEFINE_ENUM(Namespace);
    DEFINE_ENUM(NamespaceAlias);
    DEFINE_ENUM(Macro);
    DEFINE_ENUM(Enum);
    DEFINE_ENUM(Struct);
    DEFINE_ENUM(Class);
    DEFINE_ENUM(Protocol);
    DEFINE_ENUM(Extension);
    DEFINE_ENUM(Union);
    DEFINE_ENUM(TypeAlias);
    DEFINE_ENUM(Function);
    DEFINE_ENUM(Variable);
    DEFINE_ENUM(Field);
    DEFINE_ENUM(EnumConstant);
    DEFINE_ENUM(InstanceMethod);
    DEFINE_ENUM(ClassMethod);
    DEFINE_ENUM(StaticMethod);
    DEFINE_ENUM(InstanceProperty);
    DEFINE_ENUM(ClassProperty);
    DEFINE_ENUM(StaticProperty);
    DEFINE_ENUM(Constructor);
    DEFINE_ENUM(Destructor);
    DEFINE_ENUM(ConversionFunction);
    DEFINE_ENUM(Parameter);
    DEFINE_ENUM(Using);

#undef DEFINE_ENUM
  }
};

} // namespace yaml
} // namespace llvm

namespace clang {
namespace clangd {

SymbolSlab SymbolsFromYAML(llvm::StringRef YAMLContent) {
  // Store data of pointer fields (excl. `StringRef`) like `Detail`.
  llvm::BumpPtrAllocator Arena;
  llvm::yaml::Input Yin(YAMLContent, &Arena);
  std::vector<Symbol> S;
  Yin >> S;

  SymbolSlab::Builder Syms;
  for (auto &Sym : S)
    Syms.insert(Sym);
  return std::move(Syms).build();
}

Symbol SymbolFromYAML(llvm::yaml::Input &Input, llvm::BumpPtrAllocator &Arena) {
  // We could grab Arena out of Input, but it'd be a huge hazard for callers.
  assert(Input.getContext() == &Arena);
  Symbol S;
  Input >> S;
  return S;
}

void SymbolsToYAML(const SymbolSlab& Symbols, llvm::raw_ostream &OS) {
  llvm::yaml::Output Yout(OS);
  for (Symbol S : Symbols) // copy: Yout<< requires mutability.
    Yout << S;
}

std::string SymbolToYAML(Symbol Sym) {
  std::string Str;
  llvm::raw_string_ostream OS(Str);
  llvm::yaml::Output Yout(OS);
  Yout << Sym;
  return OS.str();
}

} // namespace clangd
} // namespace clang