text: // Copyright (c) 2012 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-CHROMIUM file.
  
  #include "shell/browser/ui/devtools_ui.h"
  
  #include <memory>
  #include <string>
  
  #include "base/memory/ref_counted_memory.h"
  #include "base/strings/string_util.h"
  #include "base/strings/stringprintf.h"
  #include "content/public/browser/devtools_frontend_host.h"
  #include "content/public/browser/url_data_source.h"
  #include "content/public/browser/web_contents.h"
  #include "content/public/browser/web_ui.h"
  
  namespace electron {
  
  namespace {
  
  const char kChromeUIDevToolsHost[] = "devtools";
  const char kChromeUIDevToolsBundledPath[] = "bundled";
  
  std::string PathWithoutParams(const std::string& path) {
    return GURL(std::string("devtools://devtools/") + path).path().substr(1);
  }
  
  std::string GetMimeTypeForPath(const std::string& path) {
    std::string filename = PathWithoutParams(path);
    if (base::EndsWith(filename, ".html", base::CompareCase::INSENSITIVE_ASCII)) {
      return "text/html";
    } else if (base::EndsWith(filename, ".css",
                              base::CompareCase::INSENSITIVE_ASCII)) {
      return "text/css";
    } else if (base::EndsWith(filename, ".js",
                              base::CompareCase::INSENSITIVE_ASCII)) {
      return "application/javascript";
    } else if (base::EndsWith(filename, ".png",
                              base::CompareCase::INSENSITIVE_ASCII)) {
      return "image/png";
    } else if (base::EndsWith(filename, ".gif",
                              base::CompareCase::INSENSITIVE_ASCII)) {
      return "image/gif";
    } else if (base::EndsWith(filename, ".svg",
                              base::CompareCase::INSENSITIVE_ASCII)) {
      return "image/svg+xml";
    } else if (base::EndsWith(filename, ".manifest",
                              base::CompareCase::INSENSITIVE_ASCII)) {
      return "text/cache-manifest";
    }
    return "text/html";
  }
  
  class BundledDataSource : public content::URLDataSource {
   public:
    BundledDataSource() = default;
    ~BundledDataSource() override = default;
  
    // content::URLDataSource implementation.
    std::string GetSource() override { return kChromeUIDevToolsHost; }
  
    void StartDataRequest(const std::string& path,
                          const content::WebContents::Getter& wc_getter,
                          const GotDataCallback& callback) override {
      // Serve request from local bundle.
      std::string bundled_path_prefix(kChromeUIDevToolsBundledPath);
      bundled_path_prefix += "/";
      if (base::StartsWith(path, bundled_path_prefix,
                           base::CompareCase::INSENSITIVE_ASCII)) {
        StartBundledDataRequest(path.substr(bundled_path_prefix.length()),
                                callback);
        return;
      }
  
      // We do not handle remote and custom requests.
      callback.Run(nullptr);
    }
  
    std::string GetMimeType(const std::string& path) override {
      return GetMimeTypeForPath(path);
    }
  
    bool ShouldAddContentSecurityPolicy() override { return false; }
  
    bool ShouldDenyXFrameOptions() override { return false; }
  
    bool ShouldServeMimeTypeAsContentTypeHeader() override { return true; }
  
    void StartBundledDataRequest(const std::string& path,
                                 const GotDataCallback& callback) {
      std::string filename = PathWithoutParams(path);
      base::StringPiece resource =
          content::DevToolsFrontendHost::GetFrontendResource(filename);
  
      DLOG_IF(WARNING, resource.empty())
          << "Unable to find dev tool resource: " << filename
          << ". If you compiled with debug_devtools=1, try running with "
             "--debug-devtools.";
      scoped_refptr<base::RefCountedStaticMemory> bytes(
          new base::RefCountedStaticMemory(resource.data(), resource.length()));
      callback.Run(bytes.get());
    }
  
   private:
    DISALLOW_COPY_AND_ASSIGN(BundledDataSource);
  };
  
  }  // namespace
  
  DevToolsUI::DevToolsUI(content::BrowserContext* browser_context,
                         content::WebUI* web_ui)
      : WebUIController(web_ui) {
    web_ui->SetBindings(0);
    content::URLDataSource::Add(browser_context,
                                std::make_unique<BundledDataSource>());
  }
  
  }  // namespace electron
  