// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_WEBUI_WEB_UI_DATA_SOURCE_IMPL_H_
#define CONTENT_BROWSER_WEBUI_WEB_UI_DATA_SOURCE_IMPL_H_

#include <stdint.h>

#include <map>
#include <string>
#include <string_view>

#include "base/containers/flat_map.h"
#include "base/functional/callback.h"
#include "base/values.h"
#include "content/browser/webui/url_data_source_impl.h"
#include "content/common/content_export.h"
#include "content/public/browser/url_data_source.h"
#include "content/public/browser/web_ui_data_source.h"
#include "content/public/common/buildflags.h"
#include "ui/base/template_expressions.h"
#include "url/origin.h"

namespace content {

// A data source that can help with implementing the common operations
// needed by the chrome WEBUI settings/history/downloads pages.
class CONTENT_EXPORT WebUIDataSourceImpl : public URLDataSourceImpl,
                                           public WebUIDataSource {
 public:
  static constexpr int kNonExistentResource = -1;

  WebUIDataSourceImpl(const WebUIDataSourceImpl&) = delete;
  WebUIDataSourceImpl& operator=(const WebUIDataSourceImpl&) = delete;

  // WebUIDataSource:
  void AddString(std::string_view name, std::u16string_view value) override;
  void AddString(std::string_view name, std::string_view value) override;
  void AddLocalizedString(std::string_view name, int ids) override;
  void AddLocalizedStrings(
      base::span<const webui::LocalizedString> strings) override;
  void AddLocalizedStrings(const base::DictValue& localized_strings) override;
  void AddBoolean(std::string_view name, bool value) override;
  void AddInteger(std::string_view name, int32_t value) override;
  void AddDouble(std::string_view name, double value) override;
  void UseStringsJs() override;
  void AddResourcePath(std::string_view path, int resource_id) override;
  void AddResourcePaths(base::span<const webui::ResourcePath> paths) override;
  void SetDefaultResource(int resource_id) override;
  void SetResourcePathToResponse(std::string_view path,
                                 std::string_view content) override;
  void PopulateWebUIResources(
      base::flat_map<std::string, std::string>& map) const override;
  void SetRequestFilter(const WebUIDataSource::ShouldHandleRequestCallback&
                            should_handle_request_callback,
                        const WebUIDataSource::HandleRequestCallback&
                            handle_request_callback) override;
  void OverrideContentSecurityPolicy(network::mojom::CSPDirectiveName directive,
                                     const std::string& value) override;
  void OverrideCrossOriginOpenerPolicy(const std::string& value) override;
  void OverrideCrossOriginEmbedderPolicy(const std::string& value) override;
  void OverrideCrossOriginResourcePolicy(const std::string& value) override;
  void DisableTrustedTypesCSP() override;
  void DisableDenyXFrameOptions() override;
  void EnableReplaceI18nInJS() override;
  std::string GetSource() override;
  url::Origin GetOrigin() override;
  void SetSupportedScheme(std::string_view scheme) override;

  // URLDataSourceImpl:
  const ui::TemplateReplacements* GetReplacements() const override;

  // Add the locale to the load time data defaults. May be called repeatedly.
  void EnsureLoadTimeDataDefaultsAdded();

  bool IsWebUIDataSourceImpl() const override;
  void AddFrameAncestor(const GURL& frame_ancestor) override;

  // URL path to resource ID (Grit IDR) map.
  const base::flat_map<std::string, int>& path_to_idr_map() const {
    return path_to_idr_map_;
  }

  const std::map<std::string, std::string>& path_to_response_map() const {
    return path_to_response_map_;
  }

 protected:
  explicit WebUIDataSourceImpl(const std::string& source_name);
  ~WebUIDataSourceImpl() override;

  // Completes a request by sending our dictionary of localized strings.
  void SendLocalizedStringsAsJSON(URLDataSource::GotDataCallback callback,
                                  bool from_js_module);

  // Protected for testing.
  const base::DictValue& GetLocalizedStringsForTesting() const;

  // Protected for testing.
  int URLToIdrOrDefault(const GURL& url) const;

 private:
  class InternalDataSource;
  friend class InternalDataSource;
  friend class URLDataManagerBackend;
  friend class URLDataManagerBackendTest;
  friend class WebUIDataSource;
  friend class WebUIDataSourceTest;
  friend class WebUIImplTestBase;

  // Methods that match URLDataSource which are called by
  // InternalDataSource.
  std::string_view GetMimeType(const GURL& url) const;
  void StartDataRequest(const GURL& url,
                        const WebContents::Getter& wc_getter,
                        URLDataSource::GotDataCallback callback);

  // Note: this must be called before StartDataRequest() to have an effect.
  void disable_load_time_data_defaults_for_testing() {
    add_load_time_data_defaults_ = false;
  }

  bool ShouldReplaceI18nInJS() const;

  // The name of this source.
  // E.g., for favicons, this could be "favicon", which results in paths for
  // specific resources like "favicon/34" getting sent to this source.
  std::string source_name_;
  bool use_strings_js_ = false;
  base::flat_map<std::string, int> path_to_idr_map_;
  std::map<std::string, std::string> path_to_response_map_;
#if BUILDFLAG(LOAD_WEBUI_FROM_DISK)
  std::map<int, std::string> idr_to_file_map_;
  bool load_from_disk_ = false;
#endif

  // The replacements are initialized in the main thread and then used in the
  // IO thread. The map is safe to read from multiple threads as long as no
  // futher changes are made to it after initialization.
  ui::TemplateReplacements replacements_;
  // The |replacements_| is intended to replace |localized_strings_|.
  // TODO(dschuyler): phase out |localized_strings_| in Q1 2017. (Or rename
  // to |load_time_flags_| if the usage is reduced to storing flags only).
  base::DictValue localized_strings_;
  WebUIDataSource::HandleRequestCallback filter_callback_;
  WebUIDataSource::ShouldHandleRequestCallback should_handle_request_callback_;

  base::flat_map<network::mojom::CSPDirectiveName, std::string> csp_overrides_;
  std::string coop_value_;
  std::string coep_value_;
  std::string corp_value_;
  bool deny_xframe_options_ = true;
  bool add_load_time_data_defaults_ = true;
  bool should_replace_i18n_in_js_ = false;
  std::set<GURL> frame_ancestors_;

  // Supported scheme if not one of the default supported schemes.
  std::optional<std::string> supported_scheme_;

  mutable bool resources_frozen_ = false;
};

}  // namespace content

#endif  // CONTENT_BROWSER_WEBUI_WEB_UI_DATA_SOURCE_IMPL_H_