//===-- REPL.h --------------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef LLDB_EXPRESSION_REPL_H
#define LLDB_EXPRESSION_REPL_H

#include <string>

#include "lldb/Core/IOHandler.h"
#include "lldb/Interpreter/OptionGroupFormat.h"
#include "lldb/Interpreter/OptionGroupValueObjectDisplay.h"
#include "lldb/Target/Target.h"
#include "llvm/Support/ExtensibleRTTI.h"

namespace lldb_private {

class REPL : public IOHandlerDelegate,
             public llvm::RTTIExtends<REPL, llvm::RTTIRoot> {
public:
  /// LLVM RTTI support
  static char ID;

  REPL(Target &target);

  ~REPL() override;

  /// Get a REPL with an existing target (or, failing that, a debugger to use),
  /// and (optional) extra arguments for the compiler.
  ///
  /// \param[out] Status
  ///     If this language is supported but the REPL couldn't be created, this
  ///     error is populated with the reason.
  ///
  /// \param[in] language
  ///     The language to create a REPL for.
  ///
  /// \param[in] debugger
  ///     If provided, and target is nullptr, the debugger to use when setting
  ///     up a top-level REPL.
  ///
  /// \param[in] target
  ///     If provided, the target to put the REPL inside.
  ///
  /// \param[in] repl_options
  ///     If provided, additional options for the compiler when parsing REPL
  ///     expressions.
  ///
  /// \return
  ///     The range of the containing object in the target process.
  static lldb::REPLSP Create(Status &Status, lldb::LanguageType language,
                             Debugger *debugger, Target *target,
                             const char *repl_options);

  void SetFormatOptions(const OptionGroupFormat &options) {
    m_format_options = options;
  }

  void
  SetValueObjectDisplayOptions(const OptionGroupValueObjectDisplay &options) {
    m_varobj_options = options;
  }

  void SetEvaluateOptions(const EvaluateExpressionOptions &options) {
    m_expr_options = options;
  }

  void SetCompilerOptions(const char *options) {
    if (options)
      m_compiler_options = options;
  }

  lldb::IOHandlerSP GetIOHandler();

  Status RunLoop();

  // IOHandler::Delegate functions
  void IOHandlerActivated(IOHandler &io_handler, bool interactive) override;

  bool IOHandlerInterrupt(IOHandler &io_handler) override;

  void IOHandlerInputInterrupted(IOHandler &io_handler,
                                 std::string &line) override;

  const char *IOHandlerGetFixIndentationCharacters() override;

  llvm::StringRef IOHandlerGetControlSequence(char ch) override;

  const char *IOHandlerGetCommandPrefix() override;

  const char *IOHandlerGetHelpPrologue() override;

  bool IOHandlerIsInputComplete(IOHandler &io_handler,
                                StringList &lines) override;

  int IOHandlerFixIndentation(IOHandler &io_handler, const StringList &lines,
                              int cursor_position) override;

  void IOHandlerInputComplete(IOHandler &io_handler,
                              std::string &line) override;

  void IOHandlerComplete(IOHandler &io_handler,
                         CompletionRequest &request) override;

protected:
  /// Method that can be optionally overriden by subclasses to get notified
  /// whenever an expression has been evaluated. The params of this method
  /// include the inputs and outputs of the expression evaluation.
  ///
  /// Note: meta commands that start with : are not covered by this method.
  ///
  /// \return
  ///   An \a Error object that, if it is a failure, aborts the regular
  ///   REPL expression result handling.
  virtual llvm::Error
  OnExpressionEvaluated(const ExecutionContext &exe_ctx, llvm::StringRef code,
                        const EvaluateExpressionOptions &expr_options,
                        lldb::ExpressionResults execution_results,
                        const lldb::ValueObjectSP &result_valobj_sp,
                        const Status &error) {
    return llvm::Error::success();
  }

  static int CalculateActualIndentation(const StringList &lines);

  // Subclasses should override these functions to implement a functional REPL.

  virtual Status DoInitialization() = 0;

  virtual llvm::StringRef GetSourceFileBasename() = 0;

  virtual const char *GetAutoIndentCharacters() = 0;

  virtual bool SourceIsComplete(const std::string &source) = 0;

  virtual lldb::offset_t GetDesiredIndentation(
      const StringList &lines, int cursor_position,
      int tab_size) = 0; // LLDB_INVALID_OFFSET means no change

  virtual lldb::LanguageType GetLanguage() = 0;

  virtual bool PrintOneVariable(Debugger &debugger,
                                lldb::StreamFileSP &output_sp,
                                lldb::ValueObjectSP &valobj_sp,
                                ExpressionVariable *var = nullptr) = 0;

  virtual void CompleteCode(const std::string &current_code,
                            CompletionRequest &request) = 0;

  OptionGroupFormat m_format_options = OptionGroupFormat(lldb::eFormatDefault);
  OptionGroupValueObjectDisplay m_varobj_options;
  EvaluateExpressionOptions m_expr_options;
  std::string m_compiler_options;

  bool m_enable_auto_indent = true;
  std::string m_indent_str; // Use this string for each level of indentation
  std::string m_current_indent_str;
  uint32_t m_current_indent_level = 0;

  std::string m_repl_source_path;
  bool m_dedicated_repl_mode = false;

  StringList m_code; // All accumulated REPL statements are saved here

  Target &m_target;
  lldb::IOHandlerSP m_io_handler_sp;

private:
  std::string GetSourcePath();
};

} // namespace lldb_private

#endif // LLDB_EXPRESSION_REPL_H