// Copyright 2017-2018 ccls Authors
// SPDX-License-Identifier: Apache-2.0

#pragma once

#include "clang_utils.h"
#include "language.h"
#include "lsp.h"
#include "lsp_diagnostic.h"
#include "maybe.h"
#include "position.h"
#include "serializer.h"
#include "symbol.h"
#include "utils.h"

#include <clang/Basic/Specifiers.h>
#include <llvm/ADT/CachedHashString.h>
#include <llvm/ADT/DenseMap.h>

#include <algorithm>
#include <optional>
#include <stdint.h>
#include <string_view>
#include <unordered_map>
#include <vector>

using Usr = uint64_t;

struct SymbolIdx {
  Usr usr;
  SymbolKind kind;

  bool operator==(const SymbolIdx &o) const {
    return usr == o.usr && kind == o.kind;
  }
  bool operator<(const SymbolIdx &o) const {
    return usr != o.usr ? usr < o.usr : kind < o.kind;
  }
};
MAKE_REFLECT_STRUCT(SymbolIdx, usr, kind);

struct Reference {
  Range range;
  Usr usr;
  SymbolKind kind;
  Role role;

  bool Valid() const { return range.Valid(); }
  operator SymbolIdx() const { return {usr, kind}; }
  std::tuple<Range, Usr, SymbolKind, Role> ToTuple() const {
    return std::make_tuple(range, usr, kind, role);
  }
  bool operator==(const Reference &o) const { return ToTuple() == o.ToTuple(); }
  bool operator<(const Reference &o) const { return ToTuple() < o.ToTuple(); }
};

// |id,kind| refer to the referenced entity.
struct SymbolRef : Reference {};
MAKE_HASHABLE(SymbolRef, t.range, t.usr, t.kind, t.role);

// Represents an occurrence of a variable/type, |usr,kind| refer to the lexical
// parent.
struct Use : Reference {
  // |file| is used in Query* but not in Index*
  int file_id = -1;
  bool operator==(const Use &o) const {
    // lexical container info is ignored.
    return range == o.range && file_id == o.file_id;
  }
};
MAKE_HASHABLE(Use, t.range, t.file_id)

struct DeclRef : Use {
  Range extent;
};
MAKE_HASHABLE(DeclRef, t.range, t.file_id)

void Reflect(Reader &visitor, Reference &value);
void Reflect(Writer &visitor, Reference &value);
void Reflect(Reader &visitor, Use &value);
void Reflect(Writer &visitor, Use &value);
void Reflect(Reader &visitor, DeclRef &value);
void Reflect(Writer &visitor, DeclRef &value);

template <typename D> struct NameMixin {
  std::string_view Name(bool qualified) const {
    auto self = static_cast<const D *>(this);
    return qualified
               ? std::string_view(self->detailed_name + self->qual_name_offset,
                                  self->short_name_offset -
                                      self->qual_name_offset +
                                      self->short_name_size)
               : std::string_view(self->detailed_name + self->short_name_offset,
                                  self->short_name_size);
  }
};

struct FuncDef : NameMixin<FuncDef> {
  // General metadata.
  const char *detailed_name = "";
  const char *hover = "";
  const char *comments = "";
  Maybe<Use> spell;
  Maybe<Use> extent;

  // Method this method overrides.
  std::vector<Usr> bases;

  // Local variables or parameters.
  std::vector<Usr> vars;

  // Functions that this function calls.
  std::vector<SymbolRef> callees;

  int file_id = -1;
  int16_t qual_name_offset = 0;
  int16_t short_name_offset = 0;
  int16_t short_name_size = 0;
  lsSymbolKind kind = lsSymbolKind::Unknown;
  uint8_t storage = clang::SC_None;

  std::vector<Usr> GetBases() const { return bases; }
};
MAKE_REFLECT_STRUCT(FuncDef, detailed_name, qual_name_offset, short_name_offset,
                    short_name_size, kind, storage, hover, comments, spell,
                    extent, bases, vars, callees);

struct IndexFunc : NameMixin<IndexFunc> {
  using Def = FuncDef;
  Usr usr;
  Def def;
  std::vector<DeclRef> declarations;
  std::vector<Use> uses;
  std::vector<Usr> derived;
};

struct TypeDef : NameMixin<TypeDef> {
  const char *detailed_name = "";
  const char *hover = "";
  const char *comments = "";

  Maybe<Use> spell;
  Maybe<Use> extent;

  std::vector<Usr> bases;

  // Types, functions, and variables defined in this type.
  std::vector<Usr> types;
  std::vector<Usr> funcs;
  std::vector<std::pair<Usr, int64_t>> vars;

  // If set, then this is the same underlying type as the given value (ie, this
  // type comes from a using or typedef statement).
  Usr alias_of = 0;

  int file_id = -1;
  int16_t qual_name_offset = 0;
  int16_t short_name_offset = 0;
  int16_t short_name_size = 0;
  lsSymbolKind kind = lsSymbolKind::Unknown;

  std::vector<Usr> GetBases() const { return bases; }
};
MAKE_REFLECT_STRUCT(TypeDef, detailed_name, qual_name_offset, short_name_offset,
                    short_name_size, kind, hover, comments, spell, extent,
                    alias_of, bases, types, funcs, vars);

struct IndexType {
  using Def = TypeDef;
  Usr usr;
  Def def;
  std::vector<DeclRef> declarations;
  std::vector<Use> uses;
  std::vector<Usr> derived;
  std::vector<Usr> instances;
};

struct VarDef : NameMixin<VarDef> {
  // General metadata.
  const char *detailed_name = "";
  const char *hover = "";
  const char *comments = "";
  Maybe<Use> spell;
  Maybe<Use> extent;

  // Type of the variable.
  Usr type = 0;

  int file_id = -1;
  int16_t qual_name_offset = 0;
  int16_t short_name_offset = 0;
  int16_t short_name_size = 0;

  lsSymbolKind kind = lsSymbolKind::Unknown;
  // Note a variable may have instances of both |None| and |Extern|
  // (declaration).
  uint8_t storage = clang::SC_None;

  bool is_local() const {
    return spell && spell->kind == SymbolKind::Func &&
           storage == clang::SC_None;
  }

  std::vector<Usr> GetBases() const { return {}; }
};
MAKE_REFLECT_STRUCT(VarDef, detailed_name, qual_name_offset, short_name_offset,
                    short_name_size, hover, comments, spell, extent, type, kind,
                    storage);

struct IndexVar {
  using Def = VarDef;
  Usr usr;
  Def def;
  std::vector<DeclRef> declarations;
  std::vector<Use> uses;
};

struct IndexInclude {
  // Line that has the include directive. We don't have complete range
  // information - a line is good enough for clicking.
  int line = 0;
  // Absolute path to the index.
  const char *resolved_path;
};

namespace std {
template <> struct hash<llvm::sys::fs::UniqueID> {
  std::size_t operator()(llvm::sys::fs::UniqueID ID) const {
    size_t ret = ID.getDevice();
    hash_combine(ret, ID.getFile());
    return ret;
  }
};
} // namespace std

struct IndexFile {
  // For both JSON and MessagePack cache files.
  static const int kMajorVersion;
  // For MessagePack cache files.
  // JSON has good forward compatibility because field addition/deletion do not
  // harm but currently no efforts have been made to make old MessagePack cache
  // files accepted by newer ccls.
  static const int kMinorVersion;

  llvm::sys::fs::UniqueID UniqueID;
  std::string path;
  std::vector<const char *> args;
  // This is unfortunately time_t as used by clang::FileEntry
  int64_t mtime = 0;
  LanguageId language = LanguageId::C;

  // uid2lid_and_path is used to generate lid2path, but not serialized.
  std::unordered_map<llvm::sys::fs::UniqueID, std::pair<int, std::string>>
      uid2lid_and_path;
  std::vector<std::pair<int, std::string>> lid2path;

  // The path to the translation unit cc file which caused the creation of this
  // IndexFile. When parsing a translation unit we generate many IndexFile
  // instances (ie, each header has a separate one). When the user edits a
  // header we need to lookup the original translation unit and reindex that.
  std::string import_file;

  // Source ranges that were not processed.
  std::vector<Range> skipped_ranges;

  std::vector<IndexInclude> includes;
  llvm::DenseMap<llvm::CachedHashStringRef, int64_t> dependencies;
  std::unordered_map<Usr, IndexFunc> usr2func;
  std::unordered_map<Usr, IndexType> usr2type;
  std::unordered_map<Usr, IndexVar> usr2var;

  // File contents at the time of index. Not serialized.
  std::string file_contents;

  IndexFile(llvm::sys::fs::UniqueID UniqueID, const std::string &path,
            const std::string &contents);

  IndexFunc &ToFunc(Usr usr);
  IndexType &ToType(Usr usr);
  IndexVar &ToVar(Usr usr);

  std::string ToString();
};

struct CompletionManager;
struct WorkingFiles;
struct VFS;

namespace ccls::idx {
void Init();
std::vector<std::unique_ptr<IndexFile>>
Index(CompletionManager *complete, WorkingFiles *wfiles, VFS *vfs,
      const std::string &opt_wdir, const std::string &file,
      const std::vector<const char *> &args,
      const std::vector<std::pair<std::string, std::string>> &remapped,
      bool &ok);
} // namespace ccls::idx