// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef TOOLS_GN_SCOPE_PER_FILE_PROVIDER_H_
#define TOOLS_GN_SCOPE_PER_FILE_PROVIDER_H_

#include <memory>
#include <string_view>

#include "gn/scope.h"

// ProgrammaticProvider for a scope to provide it with per-file built-in
// variable support.
class ScopePerFileProvider : public Scope::ProgrammaticProvider {
 public:
  // allow_target_vars allows the target-related variables to get resolved.
  // When allow_target_vars is unset, the target-related values will be
  // undefined to GN script. When dotfile_scope is set, only the values
  // safe to reference in a dotfile will be resolved. At the moment that
  // is gn_version, host_cpu, and host_os.
  ScopePerFileProvider(Scope* scope,
                       bool allow_target_vars,
                       bool dotfile_scope = false);
  ~ScopePerFileProvider() override;

  // ProgrammaticProvider implementation.
  const Value* GetProgrammaticValue(std::string_view ident) override;

 private:
  const Value* GetCurrentToolchain();
  const Value* GetDefaultToolchain();
  const Value* GetGnVersion();
  const Value* GetHostCpu();
  const Value* GetHostOs();
  const Value* GetPythonPath();
  const Value* GetRootBuildDir();
  const Value* GetRootGenDir();
  const Value* GetRootOutDir();
  const Value* GetTargetGenDir();
  const Value* GetTargetOutDir();

  bool allow_target_vars_;
  bool dotfile_scope_;

  // All values are lazily created.
  std::unique_ptr<Value> current_toolchain_;
  std::unique_ptr<Value> default_toolchain_;
  std::unique_ptr<Value> gn_version_;
  std::unique_ptr<Value> host_cpu_;
  std::unique_ptr<Value> host_os_;
  std::unique_ptr<Value> python_path_;
  std::unique_ptr<Value> root_build_dir_;
  std::unique_ptr<Value> root_gen_dir_;
  std::unique_ptr<Value> root_out_dir_;
  std::unique_ptr<Value> target_gen_dir_;
  std::unique_ptr<Value> target_out_dir_;

  ScopePerFileProvider(const ScopePerFileProvider&) = delete;
  ScopePerFileProvider& operator=(const ScopePerFileProvider&) = delete;
};

#endif  // TOOLS_GN_SCOPE_PER_FILE_PROVIDER_H_