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

#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANGD_CLANGDLSPSERVER_H
#define LLVM_CLANG_TOOLS_EXTRA_CLANGD_CLANGDLSPSERVER_H

#include "ClangdServer.h"
#include "DraftStore.h"
#include "FindSymbols.h"
#include "GlobalCompilationDatabase.h"
#include "Path.h"
#include "Protocol.h"
#include "ProtocolHandlers.h"
#include "clang/Tooling/Core/Replacement.h"
#include "llvm/ADT/Optional.h"
#include <memory>

namespace clang {
namespace clangd {

class JSONOutput;
class SymbolIndex;

/// This class exposes ClangdServer's capabilities via Language Server Protocol.
///
/// JSONRPCDispatcher binds the implemented ProtocolCallbacks methods
/// (e.g. onInitialize) to corresponding JSON-RPC methods ("initialize").
/// The server also supports $/cancelRequest (JSONRPCDispatcher provides this).
class ClangdLSPServer : private DiagnosticsConsumer, private ProtocolCallbacks {
public:
  /// If \p CompileCommandsDir has a value, compile_commands.json will be
  /// loaded only from \p CompileCommandsDir. Otherwise, clangd will look
  /// for compile_commands.json in all parent directories of each file.
  ClangdLSPServer(JSONOutput &Out, const clangd::CodeCompleteOptions &CCOpts,
                  llvm::Optional<Path> CompileCommandsDir,
                  bool ShouldUseInMemoryCDB, const ClangdServer::Options &Opts);

  /// Run LSP server loop, receiving input for it from \p In. \p In must be
  /// opened in binary mode. Output will be written using Out variable passed to
  /// class constructor. This method must not be executed more than once for
  /// each instance of ClangdLSPServer.
  ///
  /// \return Whether we received a 'shutdown' request before an 'exit' request.
  bool run(std::FILE *In,
           JSONStreamStyle InputStyle = JSONStreamStyle::Standard);

private:
  // Implement DiagnosticsConsumer.
  void onDiagnosticsReady(PathRef File, std::vector<Diag> Diagnostics) override;

  // Implement ProtocolCallbacks.
  void onInitialize(InitializeParams &Params) override;
  void onShutdown(ShutdownParams &Params) override;
  void onExit(ExitParams &Params) override;
  void onDocumentDidOpen(DidOpenTextDocumentParams &Params) override;
  void onDocumentDidChange(DidChangeTextDocumentParams &Params) override;
  void onDocumentDidClose(DidCloseTextDocumentParams &Params) override;
  void
  onDocumentOnTypeFormatting(DocumentOnTypeFormattingParams &Params) override;
  void
  onDocumentRangeFormatting(DocumentRangeFormattingParams &Params) override;
  void onDocumentFormatting(DocumentFormattingParams &Params) override;
  void onDocumentSymbol(DocumentSymbolParams &Params) override;
  void onCodeAction(CodeActionParams &Params) override;
  void onCompletion(TextDocumentPositionParams &Params) override;
  void onSignatureHelp(TextDocumentPositionParams &Params) override;
  void onGoToDefinition(TextDocumentPositionParams &Params) override;
  void onReference(ReferenceParams &Params) override;
  void onSwitchSourceHeader(TextDocumentIdentifier &Params) override;
  void onDocumentHighlight(TextDocumentPositionParams &Params) override;
  void onFileEvent(DidChangeWatchedFilesParams &Params) override;
  void onCommand(ExecuteCommandParams &Params) override;
  void onWorkspaceSymbol(WorkspaceSymbolParams &Params) override;
  void onRename(RenameParams &Parames) override;
  void onHover(TextDocumentPositionParams &Params) override;
  void onChangeConfiguration(DidChangeConfigurationParams &Params) override;

  std::vector<Fix> getFixes(StringRef File, const clangd::Diagnostic &D);

  /// Forces a reparse of all currently opened files.  As a result, this method
  /// may be very expensive.  This method is normally called when the
  /// compilation database is changed.
  void reparseOpenedFiles();
  void applyConfiguration(const ClangdConfigurationParamsChange &Settings);

  JSONOutput &Out;
  /// Used to indicate that the 'shutdown' request was received from the
  /// Language Server client.
  bool ShutdownRequestReceived = false;

  /// Used to indicate that the 'exit' notification was received from the
  /// Language Server client.
  /// It's used to break out of the LSP parsing loop.
  bool IsDone = false;

  std::mutex FixItsMutex;
  typedef std::map<clangd::Diagnostic, std::vector<Fix>, LSPDiagnosticCompare>
      DiagnosticToReplacementMap;
  /// Caches FixIts per file and diagnostics
  llvm::StringMap<DiagnosticToReplacementMap> FixItsMap;

  /// Encapsulates the directory-based or the in-memory compilation database
  /// that's used by the LSP server.
  class CompilationDB {
  public:
    static CompilationDB makeInMemory();
    static CompilationDB
    makeDirectoryBased(llvm::Optional<Path> CompileCommandsDir);

    void invalidate(PathRef File);

    /// Sets the compilation command for a particular file.
    /// Only valid for in-memory CDB, no-op and error log on DirectoryBasedCDB.
    ///
    /// \returns True if the File had no compilation command before.
    bool
    setCompilationCommandForFile(PathRef File,
                                 tooling::CompileCommand CompilationCommand);

    /// Adds extra compilation flags to the compilation command for a particular
    /// file. Only valid for directory-based CDB, no-op and error log on
    /// InMemoryCDB;
    void setExtraFlagsForFile(PathRef File,
                              std::vector<std::string> ExtraFlags);

    /// Set the compile commands directory to \p P.
    /// Only valid for directory-based CDB, no-op and error log on InMemoryCDB;
    void setCompileCommandsDir(Path P);

    /// Returns a CDB that should be used to get compile commands for the
    /// current instance of ClangdLSPServer.
    GlobalCompilationDatabase &getCDB();

  private:
    CompilationDB(std::unique_ptr<GlobalCompilationDatabase> CDB,
                  std::unique_ptr<CachingCompilationDb> CachingCDB,
                  bool IsDirectoryBased)
        : CDB(std::move(CDB)), CachingCDB(std::move(CachingCDB)),
          IsDirectoryBased(IsDirectoryBased) {}

    // if IsDirectoryBased is true, an instance of InMemoryCDB.
    // If IsDirectoryBased is false, an instance of DirectoryBasedCDB.
    // unique_ptr<GlobalCompilationDatabase> CDB;
    std::unique_ptr<GlobalCompilationDatabase> CDB;
    // Non-null only for directory-based CDB
    std::unique_ptr<CachingCompilationDb> CachingCDB;
    bool IsDirectoryBased;
  };

  // Various ClangdServer parameters go here. It's important they're created
  // before ClangdServer.
  CompilationDB CDB;

  RealFileSystemProvider FSProvider;
  /// Options used for code completion
  clangd::CodeCompleteOptions CCOpts;
  /// Options used for diagnostics.
  ClangdDiagnosticOptions DiagOpts;
  /// The supported kinds of the client.
  SymbolKindBitset SupportedSymbolKinds;
  /// The supported completion item kinds of the client.
  CompletionItemKindBitset SupportedCompletionItemKinds;

  // Store of the current versions of the open documents.
  DraftStore DraftMgr;

  // Server must be the last member of the class to allow its destructor to exit
  // the worker thread that may otherwise run an async callback on partially
  // destructed instance of ClangdLSPServer.
  // Set in construtor and destroyed when run() finishes. To ensure all worker
  // threads exit before run() returns.
  std::unique_ptr<ClangdServer> Server;
};
} // namespace clangd
} // namespace clang

#endif // LLVM_CLANG_TOOLS_EXTRA_CLANGD_CLANGDLSPSERVER_H