// Copyright 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.

#include "libcef/browser/devtools/devtools_frontend.h"

#include <stddef.h>

#include <iomanip>
#include <utility>

#include "libcef/browser/browser_context.h"
#include "libcef/browser/devtools/devtools_manager_delegate.h"
#include "libcef/browser/net/devtools_scheme_handler.h"
#include "libcef/common/cef_switches.h"
#include "libcef/common/task_runner_manager.h"

#include "base/base64.h"
#include "base/command_line.h"
#include "base/files/file_util.h"
#include "base/guid.h"
#include "base/json/json_reader.h"
#include "base/json/json_writer.h"
#include "base/json/string_escape.h"
#include "base/macros.h"
#include "base/memory/ptr_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "base/task/post_task.h"
#include "base/values.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/common/pref_names.h"
#include "components/prefs/scoped_user_pref_update.h"
#include "content/public/browser/browser_context.h"
#include "content/public/browser/browser_task_traits.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/file_url_loader.h"
#include "content/public/browser/navigation_handle.h"
#include "content/public/browser/render_frame_host.h"
#include "content/public/browser/render_view_host.h"
#include "content/public/browser/shared_cors_origin_access_list.h"
#include "content/public/browser/storage_partition.h"
#include "content/public/browser/web_contents.h"
#include "content/public/common/content_client.h"
#include "content/public/common/url_constants.h"
#include "content/public/common/url_utils.h"
#include "ipc/ipc_channel.h"
#include "net/base/completion_once_callback.h"
#include "net/base/io_buffer.h"
#include "net/base/net_errors.h"
#include "net/http/http_response_headers.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
#include "services/network/public/cpp/simple_url_loader.h"
#include "services/network/public/cpp/simple_url_loader_stream_consumer.h"
#include "services/network/public/cpp/wrapper_shared_url_loader_factory.h"
#include "services/network/public/mojom/url_response_head.mojom.h"
#include "storage/browser/file_system/native_file_util.h"

#if defined(OS_WIN)
#include <windows.h>
#elif defined(OS_POSIX)
#include <time.h>
#endif

namespace {

// This constant should be in sync with the constant in
// chrome/browser/devtools/devtools_ui_bindings.cc.
constexpr size_t kMaxMessageChunkSize = IPC::Channel::kMaximumMessageSize / 4;

constexpr int kMaxLogLineLength = 1024;

static std::string GetFrontendURL() {
  return base::StringPrintf("%s://%s/devtools_app.html",
                            content::kChromeDevToolsScheme,
                            scheme::kChromeDevToolsHost);
}

base::DictionaryValue BuildObjectForResponse(const net::HttpResponseHeaders* rh,
                                             bool success,
                                             int net_error) {
  base::DictionaryValue response;
  int responseCode = 200;
  if (rh) {
    responseCode = rh->response_code();
  } else if (!success) {
    // In case of no headers, assume file:// URL and failed to load
    responseCode = 404;
  }
  response.SetInteger("statusCode", responseCode);
  response.SetInteger("netError", net_error);
  response.SetString("netErrorName", net::ErrorToString(net_error));

  auto headers = std::make_unique<base::DictionaryValue>();
  size_t iterator = 0;
  std::string name;
  std::string value;
  // TODO(caseq): this probably needs to handle duplicate header names
  // correctly by folding them.
  while (rh && rh->EnumerateHeaderLines(&iterator, &name, &value))
    headers->SetString(name, value);

  response.Set("headers", std::move(headers));
  return response;
}

void WriteTimestamp(std::stringstream& stream) {
#if defined(OS_WIN)
  SYSTEMTIME local_time;
  GetLocalTime(&local_time);
  stream << std::setfill('0') << std::setw(2) << local_time.wMonth
         << std::setw(2) << local_time.wDay << '/' << std::setw(2)
         << local_time.wHour << std::setw(2) << local_time.wMinute
         << std::setw(2) << local_time.wSecond << '.' << std::setw(3)
         << local_time.wMilliseconds;
#elif defined(OS_POSIX)
  timeval tv;
  gettimeofday(&tv, nullptr);
  time_t t = tv.tv_sec;
  struct tm local_time;
  localtime_r(&t, &local_time);
  struct tm* tm_time = &local_time;
  stream << std::setfill('0') << std::setw(2) << 1 + tm_time->tm_mon
         << std::setw(2) << tm_time->tm_mday << '/' << std::setw(2)
         << tm_time->tm_hour << std::setw(2) << tm_time->tm_min << std::setw(2)
         << tm_time->tm_sec << '.' << std::setw(6) << tv.tv_usec;
#else
#error Unsupported platform
#endif
}

void LogProtocolMessage(const base::FilePath& log_file,
                        ProtocolMessageType type,
                        std::string to_log) {
  // Track if logging has failed, in which case we don't keep trying.
  static bool log_error = false;
  if (log_error)
    return;

  if (storage::NativeFileUtil::EnsureFileExists(log_file, nullptr) !=
      base::File::FILE_OK) {
    LOG(ERROR) << "Failed to create file " << log_file.value();
    log_error = true;
    return;
  }

  std::string type_label;
  switch (type) {
    case ProtocolMessageType::METHOD:
      type_label = "METHOD";
      break;
    case ProtocolMessageType::RESULT:
      type_label = "RESULT";
      break;
    case ProtocolMessageType::EVENT:
      type_label = "EVENT";
      break;
  }

  std::stringstream stream;
  WriteTimestamp(stream);
  stream << ": " << type_label << ": " << to_log << "\n";
  const std::string& str = stream.str();
  if (!base::AppendToFile(log_file, base::StringPiece(str))) {
    LOG(ERROR) << "Failed to write file " << log_file.value();
    log_error = true;
  }
}

}  // namespace

class CefDevToolsFrontend::NetworkResourceLoader
    : public network::SimpleURLLoaderStreamConsumer {
 public:
  NetworkResourceLoader(int stream_id,
                        CefDevToolsFrontend* bindings,
                        std::unique_ptr<network::SimpleURLLoader> loader,
                        network::mojom::URLLoaderFactory* url_loader_factory,
                        int request_id)
      : stream_id_(stream_id),
        bindings_(bindings),
        loader_(std::move(loader)),
        request_id_(request_id) {
    loader_->SetOnResponseStartedCallback(base::BindOnce(
        &NetworkResourceLoader::OnResponseStarted, base::Unretained(this)));
    loader_->DownloadAsStream(url_loader_factory, this);
  }

 private:
  void OnResponseStarted(const GURL& final_url,
                         const network::mojom::URLResponseHead& response_head) {
    response_headers_ = response_head.headers;
  }

  void OnDataReceived(base::StringPiece chunk,
                      base::OnceClosure resume) override {
    base::Value chunkValue;

    bool encoded = !base::IsStringUTF8(chunk);
    if (encoded) {
      std::string encoded_string;
      base::Base64Encode(chunk, &encoded_string);
      chunkValue = base::Value(std::move(encoded_string));
    } else {
      chunkValue = base::Value(chunk);
    }
    base::Value id(stream_id_);
    base::Value encodedValue(encoded);

    bindings_->CallClientFunction("DevToolsAPI", "streamWrite", std::move(id),
                                  std::move(chunkValue),
                                  std::move(encodedValue));
    std::move(resume).Run();
  }

  void OnComplete(bool success) override {
    auto response = BuildObjectForResponse(response_headers_.get(), success,
                                           loader_->NetError());
    bindings_->SendMessageAck(request_id_, std::move(response));

    bindings_->loaders_.erase(bindings_->loaders_.find(this));
  }

  void OnRetry(base::OnceClosure start_retry) override { NOTREACHED(); }

  const int stream_id_;
  CefDevToolsFrontend* const bindings_;
  std::unique_ptr<network::SimpleURLLoader> loader_;
  int request_id_;
  scoped_refptr<net::HttpResponseHeaders> response_headers_;

  DISALLOW_COPY_AND_ASSIGN(NetworkResourceLoader);
};

// static
CefDevToolsFrontend* CefDevToolsFrontend::Show(
    AlloyBrowserHostImpl* inspected_browser,
    const CefWindowInfo& windowInfo,
    CefRefPtr<CefClient> client,
    const CefBrowserSettings& settings,
    const CefPoint& inspect_element_at,
    base::OnceClosure frontend_destroyed_callback) {
  CefBrowserSettings new_settings = settings;
  if (!windowInfo.windowless_rendering_enabled &&
      CefColorGetA(new_settings.background_color) != SK_AlphaOPAQUE) {
    // Use white as the default background color for windowed DevTools instead
    // of the CefSettings.background_color value.
    new_settings.background_color = SK_ColorWHITE;
  }

  CefBrowserCreateParams create_params;
  if (!inspected_browser->is_views_hosted())
    create_params.window_info.reset(new CefWindowInfo(windowInfo));
  create_params.client = client;
  create_params.settings = new_settings;
  create_params.devtools_opener = inspected_browser;
  create_params.request_context = inspected_browser->GetRequestContext();
  create_params.extra_info = inspected_browser->browser_info()->extra_info();

  CefRefPtr<AlloyBrowserHostImpl> frontend_browser =
      AlloyBrowserHostImpl::Create(create_params);

  content::WebContents* inspected_contents = inspected_browser->web_contents();

  // CefDevToolsFrontend will delete itself when the frontend WebContents is
  // destroyed.
  CefDevToolsFrontend* devtools_frontend = new CefDevToolsFrontend(
      static_cast<AlloyBrowserHostImpl*>(frontend_browser.get()),
      inspected_contents, inspect_element_at,
      std::move(frontend_destroyed_callback));

  // Need to load the URL after creating the DevTools objects.
  frontend_browser->GetMainFrame()->LoadURL(GetFrontendURL());

  return devtools_frontend;
}

void CefDevToolsFrontend::Activate() {
  frontend_browser_->ActivateContents(web_contents());
}

void CefDevToolsFrontend::Focus() {
  frontend_browser_->SetFocus(true);
}

void CefDevToolsFrontend::InspectElementAt(int x, int y) {
  if (inspect_element_at_.x != x || inspect_element_at_.y != y)
    inspect_element_at_.Set(x, y);
  if (agent_host_)
    agent_host_->InspectElement(inspected_contents_->GetFocusedFrame(), x, y);
}

void CefDevToolsFrontend::Close() {
  base::PostTask(FROM_HERE, {content::BrowserThread::UI},
                 base::BindOnce(&AlloyBrowserHostImpl::CloseBrowser,
                                frontend_browser_.get(), true));
}

CefDevToolsFrontend::CefDevToolsFrontend(
    AlloyBrowserHostImpl* frontend_browser,
    content::WebContents* inspected_contents,
    const CefPoint& inspect_element_at,
    base::OnceClosure frontend_destroyed_callback)
    : content::WebContentsObserver(frontend_browser->web_contents()),
      frontend_browser_(frontend_browser),
      inspected_contents_(inspected_contents),
      inspect_element_at_(inspect_element_at),
      frontend_destroyed_callback_(std::move(frontend_destroyed_callback)),
      file_manager_(frontend_browser, GetPrefs()),
      protocol_log_file_(
          base::CommandLine::ForCurrentProcess()->GetSwitchValuePath(
              switches::kDevToolsProtocolLogFile)),
      weak_factory_(this) {
  DCHECK(!frontend_destroyed_callback_.is_null());
}

CefDevToolsFrontend::~CefDevToolsFrontend() {}

void CefDevToolsFrontend::ReadyToCommitNavigation(
    content::NavigationHandle* navigation_handle) {
  content::RenderFrameHost* frame = navigation_handle->GetRenderFrameHost();
  if (navigation_handle->IsInMainFrame()) {
    frontend_host_ = content::DevToolsFrontendHost::Create(
        frame, base::BindRepeating(
                   &CefDevToolsFrontend::HandleMessageFromDevToolsFrontend,
                   base::Unretained(this)));
    return;
  }

  std::string origin = navigation_handle->GetURL().GetOrigin().spec();
  auto it = extensions_api_.find(origin);
  if (it == extensions_api_.end())
    return;
  std::string script = base::StringPrintf("%s(\"%s\")", it->second.c_str(),
                                          base::GenerateGUID().c_str());
  content::DevToolsFrontendHost::SetupExtensionsAPI(frame, script);
}

void CefDevToolsFrontend::DocumentAvailableInMainFrame(
    content::RenderFrameHost* render_frame_host) {
  // Don't call AttachClient multiple times for the same DevToolsAgentHost.
  // Otherwise it will call AgentHostClosed which closes the DevTools window.
  // This may happen in cases where the DevTools content fails to load.
  scoped_refptr<content::DevToolsAgentHost> agent_host =
      content::DevToolsAgentHost::GetOrCreateFor(inspected_contents_);
  if (agent_host != agent_host_) {
    if (agent_host_)
      agent_host_->DetachClient(this);
    agent_host_ = agent_host;
    agent_host_->AttachClient(this);
    if (!inspect_element_at_.IsEmpty()) {
      agent_host_->InspectElement(inspected_contents_->GetFocusedFrame(),
                                  inspect_element_at_.x, inspect_element_at_.y);
    }
  }
}

void CefDevToolsFrontend::WebContentsDestroyed() {
  if (agent_host_) {
    agent_host_->DetachClient(this);
    agent_host_ = nullptr;
  }
  std::move(frontend_destroyed_callback_).Run();
  delete this;
}

void CefDevToolsFrontend::HandleMessageFromDevToolsFrontend(
    base::Value message) {
  if (!message.is_dict())
    return;
  const std::string* method = message.FindStringKey("method");
  if (!method)
    return;

  int request_id = message.FindIntKey("id").value_or(0);
  base::Value* params_value = message.FindListKey("params");

  // Since we've received message by value, we can take the list.
  base::Value::ListStorage params;
  if (params_value) {
    params = std::move(*params_value).TakeList();
  }

  if (*method == "dispatchProtocolMessage") {
    if (params.size() < 1)
      return;
    const std::string* protocol_message = params[0].GetIfString();
    if (!agent_host_ || !protocol_message)
      return;
    if (ProtocolLoggingEnabled()) {
      LogProtocolMessage(ProtocolMessageType::METHOD, *protocol_message);
    }
    agent_host_->DispatchProtocolMessage(
        this, base::as_bytes(base::make_span(*protocol_message)));
  } else if (*method == "loadCompleted") {
    web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(
        u"DevToolsAPI.setUseSoftMenu(true);", base::NullCallback());
  } else if (*method == "loadNetworkResource") {
    if (params.size() < 3)
      return;

    // TODO(pfeldman): handle some of the embedder messages in content.
    const std::string* url = params[0].GetIfString();
    const std::string* headers = params[1].GetIfString();
    absl::optional<const int> stream_id = params[2].GetIfInt();
    if (!url || !headers || !stream_id.has_value()) {
      return;
    }

    GURL gurl(*url);
    if (!gurl.is_valid()) {
      base::DictionaryValue response;
      response.SetInteger("statusCode", 404);
      response.SetBoolean("urlValid", false);
      SendMessageAck(request_id, std::move(response));
      return;
    }

    net::NetworkTrafficAnnotationTag traffic_annotation =
        net::DefineNetworkTrafficAnnotation(
            "devtools_handle_front_end_messages", R"(
            semantics {
              sender: "Developer Tools"
              description:
                "When user opens Developer Tools, the browser may fetch "
                "additional resources from the network to enrich the debugging "
                "experience (e.g. source map resources)."
              trigger: "User opens Developer Tools to debug a web page."
              data: "Any resources requested by Developer Tools."
              destination: OTHER
            }
            policy {
              cookies_allowed: YES
              cookies_store: "user"
              setting:
                "It's not possible to disable this feature from settings."
              chrome_policy {
                DeveloperToolsAvailability {
                  policy_options {mode: MANDATORY}
                  DeveloperToolsAvailability: 2
                }
              }
            })");

    // Based on DevToolsUIBindings::LoadNetworkResource.
    auto resource_request = std::make_unique<network::ResourceRequest>();
    resource_request->url = gurl;
    // TODO(caseq): this preserves behavior of URLFetcher-based
    // implementation. We really need to pass proper first party origin from
    // the front-end.
    resource_request->site_for_cookies = net::SiteForCookies::FromUrl(gurl);
    resource_request->headers.AddHeadersFromString(*headers);

    scoped_refptr<network::SharedURLLoaderFactory> url_loader_factory;
    if (gurl.SchemeIsFile()) {
      mojo::PendingRemote<network::mojom::URLLoaderFactory> pending_remote =
          content::CreateFileURLLoaderFactory(
              base::FilePath() /* profile_path */,
              nullptr /* shared_cors_origin_access_list */);
      url_loader_factory = network::SharedURLLoaderFactory::Create(
          std::make_unique<network::WrapperPendingSharedURLLoaderFactory>(
              std::move(pending_remote)));
    } else if (content::HasWebUIScheme(gurl)) {
      base::DictionaryValue response;
      response.SetInteger("statusCode", 403);
      SendMessageAck(request_id, std::move(response));
      return;
    } else {
      auto* partition =
          web_contents()->GetBrowserContext()->GetStoragePartitionForUrl(gurl);
      url_loader_factory = partition->GetURLLoaderFactoryForBrowserProcess();
    }

    auto simple_url_loader = network::SimpleURLLoader::Create(
        std::move(resource_request), traffic_annotation);
    auto resource_loader = std::make_unique<NetworkResourceLoader>(
        *stream_id, this, std::move(simple_url_loader),
        url_loader_factory.get(), request_id);
    loaders_.insert(std::move(resource_loader));
    return;
  } else if (*method == "getPreferences") {
    SendMessageAck(
        request_id,
        GetPrefs()->GetDictionary(prefs::kDevToolsPreferences)->Clone());
    return;
  } else if (*method == "setPreference") {
    if (params.size() < 2)
      return;
    const std::string* name = params[0].GetIfString();

    // We're just setting params[1] as a value anyways, so just make sure it's
    // the type we want, but don't worry about getting it.
    if (!name || !params[1].is_string())
      return;

    DictionaryPrefUpdate update(GetPrefs(), prefs::kDevToolsPreferences);
    update.Get()->SetKey(*name, std::move(params[1]));
  } else if (*method == "removePreference") {
    const std::string* name = params[0].GetIfString();
    if (!name)
      return;
    DictionaryPrefUpdate update(GetPrefs(), prefs::kDevToolsPreferences);
    update.Get()->RemoveKey(*name);
  } else if (*method == "requestFileSystems") {
    web_contents()->GetMainFrame()->ExecuteJavaScriptForTests(
        u"DevToolsAPI.fileSystemsLoaded([]);", base::NullCallback());
  } else if (*method == "reattach") {
    if (!agent_host_)
      return;
    agent_host_->DetachClient(this);
    agent_host_->AttachClient(this);
  } else if (*method == "registerExtensionsAPI") {
    if (params.size() < 2)
      return;
    const std::string* origin = params[0].GetIfString();
    const std::string* script = params[1].GetIfString();
    if (!origin || !script)
      return;
    extensions_api_[*origin + "/"] = *script;
  } else if (*method == "save") {
    if (params.size() < 3)
      return;
    const std::string* url = params[0].GetIfString();
    const std::string* content = params[1].GetIfString();
    absl::optional<bool> save_as = params[2].GetIfBool();
    if (!url || !content || !save_as.has_value())
      return;
    file_manager_.SaveToFile(*url, *content, *save_as);
  } else if (*method == "append") {
    if (params.size() < 2)
      return;
    const std::string* url = params[0].GetIfString();
    const std::string* content = params[1].GetIfString();
    if (!url || !content)
      return file_manager_.AppendToFile(*url, *content);
  } else {
    return;
  }

  if (request_id)
    SendMessageAck(request_id, base::Value());
}

void CefDevToolsFrontend::DispatchProtocolMessage(
    content::DevToolsAgentHost* agent_host,
    base::span<const uint8_t> message) {
  if (!frontend_browser_->GetWebContents() ||
      frontend_browser_->GetWebContents()->IsBeingDestroyed()) {
    return;
  }

  base::StringPiece str_message(reinterpret_cast<const char*>(message.data()),
                                message.size());
  if (ProtocolLoggingEnabled()) {
    // Quick check to avoid parsing the JSON object. Events begin with a
    // "method" value whereas method results begin with an "id" value.
    LogProtocolMessage(base::StartsWith(str_message, "{\"method\":")
                           ? ProtocolMessageType::EVENT
                           : ProtocolMessageType::RESULT,
                       str_message);
  }

  if (str_message.length() < kMaxMessageChunkSize) {
    CallClientFunction("DevToolsAPI", "dispatchMessage",
                       base::Value(std::string(str_message)));
  } else {
    size_t total_size = str_message.length();
    for (size_t pos = 0; pos < str_message.length();
         pos += kMaxMessageChunkSize) {
      base::StringPiece str_message_chunk =
          str_message.substr(pos, kMaxMessageChunkSize);

      CallClientFunction(
          "DevToolsAPI", "dispatchMessageChunk",
          base::Value(std::string(str_message_chunk)),
          base::Value(base::NumberToString(pos ? 0 : total_size)));
    }
  }
}

void CefDevToolsFrontend::CallClientFunction(
    const std::string& object_name,
    const std::string& method_name,
    base::Value arg1,
    base::Value arg2,
    base::Value arg3,
    base::OnceCallback<void(base::Value)> cb) {
  std::string javascript;

  web_contents()->GetMainFrame()->AllowInjectingJavaScript();

  base::Value arguments(base::Value::Type::LIST);
  if (!arg1.is_none()) {
    arguments.Append(std::move(arg1));
    if (!arg2.is_none()) {
      arguments.Append(std::move(arg2));
      if (!arg3.is_none()) {
        arguments.Append(std::move(arg3));
      }
    }
  }
  web_contents()->GetMainFrame()->ExecuteJavaScriptMethod(
      base::ASCIIToUTF16(object_name), base::ASCIIToUTF16(method_name),
      std::move(arguments), std::move(cb));
}

void CefDevToolsFrontend::SendMessageAck(int request_id, base::Value arg) {
  CallClientFunction("DevToolsAPI", "embedderMessageAck",
                     base::Value(request_id), std::move(arg));
}

bool CefDevToolsFrontend::ProtocolLoggingEnabled() const {
  return !protocol_log_file_.empty();
}

void CefDevToolsFrontend::LogProtocolMessage(ProtocolMessageType type,
                                             const base::StringPiece& message) {
  DCHECK(ProtocolLoggingEnabled());

  std::string to_log(message.substr(0, kMaxLogLineLength));

  // Execute in an ordered context that allows blocking.
  auto task_runner = CefTaskRunnerManager::Get()->GetBackgroundTaskRunner();
  task_runner->PostTask(
      FROM_HERE, base::BindOnce(::LogProtocolMessage, protocol_log_file_, type,
                                std::move(to_log)));
}

void CefDevToolsFrontend::AgentHostClosed(
    content::DevToolsAgentHost* agent_host) {
  DCHECK(agent_host == agent_host_.get());
  agent_host_ = nullptr;
  Close();
}

PrefService* CefDevToolsFrontend::GetPrefs() const {
  return CefBrowserContext::FromBrowserContext(
             frontend_browser_->web_contents()->GetBrowserContext())
      ->AsProfile()
      ->GetPrefs();
}