// Copyright (c) 2011 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 "build/build_config.h"

#include "chrome/browser/download/save_file_manager.h"

#include "base/file_util.h"
#include "base/logging.h"
#include "base/stl_util-inl.h"
#include "base/string_util.h"
#include "base/task.h"
#include "base/threading/thread.h"
#include "chrome/browser/download/save_file.h"
#include "chrome/browser/download/save_package.h"
#include "chrome/browser/platform_util.h"
#include "chrome/browser/tab_contents/tab_util.h"
#include "chrome/browser/ui/download/download_tab_helper.h"
#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
#include "chrome/common/chrome_paths.h"
#include "content/browser/browser_thread.h"
#include "content/browser/renderer_host/resource_dispatcher_host.h"
#include "content/browser/tab_contents/tab_contents.h"
#include "googleurl/src/gurl.h"
#include "net/base/net_util.h"
#include "net/base/io_buffer.h"
#include "net/url_request/url_request_context.h"
#include "net/url_request/url_request_context_getter.h"

SaveFileManager::SaveFileManager(ResourceDispatcherHost* rdh)
    : next_id_(0),
      resource_dispatcher_host_(rdh) {
  DCHECK(resource_dispatcher_host_);
}

SaveFileManager::~SaveFileManager() {
  // Check for clean shutdown.
  DCHECK(save_file_map_.empty());
}

// Called during the browser shutdown process to clean up any state (open files,
// timers) that live on the saving thread (file thread).
void SaveFileManager::Shutdown() {
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      NewRunnableMethod(this, &SaveFileManager::OnShutdown));
}

// Stop file thread operations.
void SaveFileManager::OnShutdown() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  STLDeleteValues(&save_file_map_);
}

SaveFile* SaveFileManager::LookupSaveFile(int save_id) {
  SaveFileMap::iterator it = save_file_map_.find(save_id);
  return it == save_file_map_.end() ? NULL : it->second;
}

// Called on the IO thread when
// a) The ResourceDispatcherHost has decided that a request is savable.
// b) The resource does not come from the network, but we still need a
// save ID for for managing the status of the saving operation. So we
// file a request from the file thread to the IO thread to generate a
// unique save ID.
int SaveFileManager::GetNextId() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  return next_id_++;
}

void SaveFileManager::RegisterStartingRequest(const GURL& save_url,
                                              SavePackage* save_package) {
  // Make sure it runs in the UI thread.
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  int tab_id = save_package->tab_id();

  // Register this starting request.
  StartingRequestsMap& starting_requests = tab_starting_requests_[tab_id];
  bool never_present = starting_requests.insert(
      StartingRequestsMap::value_type(save_url.spec(), save_package)).second;
  DCHECK(never_present);
}

SavePackage* SaveFileManager::UnregisterStartingRequest(
    const GURL& save_url, int tab_id) {
  // Make sure it runs in UI thread.
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  TabToStartingRequestsMap::iterator it = tab_starting_requests_.find(tab_id);
  if (it != tab_starting_requests_.end()) {
    StartingRequestsMap& requests = it->second;
    StartingRequestsMap::iterator sit = requests.find(save_url.spec());
    if (sit == requests.end())
      return NULL;

    // Found, erase it from starting list and return SavePackage.
    SavePackage* save_package = sit->second;
    requests.erase(sit);
    // If there is no element in requests, remove it
    if (requests.empty())
      tab_starting_requests_.erase(it);
    return save_package;
  }

  return NULL;
}

// Look up a SavePackage according to a save id.
SavePackage* SaveFileManager::LookupPackage(int save_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackageMap::iterator it = packages_.find(save_id);
  if (it != packages_.end())
    return it->second;
  return NULL;
}

// Call from SavePackage for starting a saving job
void SaveFileManager::SaveURL(
    const GURL& url,
    const GURL& referrer,
    int render_process_host_id,
    int render_view_id,
    SaveFileCreateInfo::SaveFileSource save_source,
    const FilePath& file_full_path,
    net::URLRequestContextGetter* request_context_getter,
    SavePackage* save_package) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  // Register a saving job.
  RegisterStartingRequest(url, save_package);
  if (save_source == SaveFileCreateInfo::SAVE_FILE_FROM_NET) {
    DCHECK(url.is_valid());

    BrowserThread::PostTask(
        BrowserThread::IO, FROM_HERE,
        NewRunnableMethod(this,
                          &SaveFileManager::OnSaveURL,
                          url,
                          referrer,
                          render_process_host_id,
                          render_view_id,
                          make_scoped_refptr(request_context_getter)));
  } else {
    // We manually start the save job.
    SaveFileCreateInfo* info = new SaveFileCreateInfo(file_full_path,
         url,
         save_source,
         -1);
    info->render_process_id = render_process_host_id;
    info->render_view_id = render_view_id;

    // Since the data will come from render process, so we need to start
    // this kind of save job by ourself.
    BrowserThread::PostTask(
        BrowserThread::IO, FROM_HERE,
        NewRunnableMethod(
            this, &SaveFileManager::OnRequireSaveJobFromOtherSource, info));
  }
}

// Utility function for look up table maintenance, called on the UI thread.
// A manager may have multiple save page job (SavePackage) in progress,
// so we just look up the save id and remove it from the tracking table.
// If the save id is -1, it means we just send a request to save, but the
// saving action has still not happened, need to call UnregisterStartingRequest
// to remove it from the tracking map.
void SaveFileManager::RemoveSaveFile(int save_id, const GURL& save_url,
                                     SavePackage* package) {
  DCHECK(package);
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  // A save page job (SavePackage) can only have one manager,
  // so remove it if it exists.
  if (save_id == -1) {
    SavePackage* old_package = UnregisterStartingRequest(save_url,
                                                         package->tab_id());
    DCHECK_EQ(old_package, package);
  } else {
    SavePackageMap::iterator it = packages_.find(save_id);
    if (it != packages_.end())
      packages_.erase(it);
  }
}

// Static
// Utility function for converting request IDs to a TabContents. Must be called
// only on the UI thread.
SavePackage* SaveFileManager::GetSavePackageFromRenderIds(
    int render_process_id, int render_view_id) {
  TabContents* contents = tab_util::GetTabContentsByID(render_process_id,
                                                       render_view_id);
  if (contents) {
    TabContentsWrapper* wrapper =
        TabContentsWrapper::GetCurrentWrapperForContents(contents);
    return wrapper->download_tab_helper()->save_package();
  }

  return NULL;
}

// Utility function for deleting specified file.
void SaveFileManager::DeleteDirectoryOrFile(const FilePath& full_path,
                                            bool is_dir) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      NewRunnableMethod(
          this, &SaveFileManager::OnDeleteDirectoryOrFile, full_path, is_dir));
}

void SaveFileManager::SendCancelRequest(int save_id) {
  // Cancel the request which has specific save id.
  DCHECK_GT(save_id, -1);
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      NewRunnableMethod(this, &SaveFileManager::CancelSave, save_id));
}

// Notifications sent from the IO thread and run on the file thread:

// The IO thread created |info|, but the file thread (this method) uses it
// to create a SaveFile which will hold and finally destroy |info|. It will
// then passes |info| to the UI thread for reporting saving status.
void SaveFileManager::StartSave(SaveFileCreateInfo* info) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  DCHECK(info);
  SaveFile* save_file = new SaveFile(info);

  // TODO(phajdan.jr): We should check the return value and handle errors here.
  save_file->Initialize(false);  // No need to calculate hash.

  DCHECK(!LookupSaveFile(info->save_id));
  save_file_map_[info->save_id] = save_file;
  info->path = save_file->full_path();

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      NewRunnableMethod(this, &SaveFileManager::OnStartSave, info));
}

// We do forward an update to the UI thread here, since we do not use timer to
// update the UI. If the user has canceled the saving action (in the UI
// thread). We may receive a few more updates before the IO thread gets the
// cancel message. We just delete the data since the SaveFile has been deleted.
void SaveFileManager::UpdateSaveProgress(int save_id,
                                         net::IOBuffer* data,
                                         int data_len) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  SaveFile* save_file = LookupSaveFile(save_id);
  if (save_file) {
    bool write_success = save_file->AppendDataToFile(data->data(), data_len);
    BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
        NewRunnableMethod(
            this, &SaveFileManager::OnUpdateSaveProgress, save_file->save_id(),
            save_file->bytes_so_far(), write_success));
  }
}

// The IO thread will call this when saving is completed or it got error when
// fetching data. In the former case, we forward the message to OnSaveFinished
// in UI thread. In the latter case, the save ID will be -1, which means the
// saving action did not even start, so we need to call OnErrorFinished in UI
// thread, which will use the save URL to find corresponding request record and
// delete it.
void SaveFileManager::SaveFinished(int save_id,
                                   const GURL& save_url,
                                   int render_process_id,
                                   bool is_success) {
  VLOG(20) << " " << __FUNCTION__ << "()"
           << " save_id = " << save_id
           << " save_url = \"" << save_url.spec() << "\""
           << " is_success = " << is_success;
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  SaveFileMap::iterator it = save_file_map_.find(save_id);
  if (it != save_file_map_.end()) {
    SaveFile* save_file = it->second;
  VLOG(20) << " " << __FUNCTION__ << "()"
           << " save_file = " << save_file->DebugString();
    BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
        NewRunnableMethod(
            this, &SaveFileManager::OnSaveFinished, save_id,
            save_file->bytes_so_far(), is_success));

    save_file->Finish();
    save_file->Detach();
  } else if (save_id == -1) {
    // Before saving started, we got error. We still call finish process.
    DCHECK(!save_url.is_empty());
    BrowserThread::PostTask(
        BrowserThread::UI, FROM_HERE,
        NewRunnableMethod(
            this, &SaveFileManager::OnErrorFinished, save_url,
            render_process_id));
  }
}

// Notifications sent from the file thread and run on the UI thread.

void SaveFileManager::OnStartSave(const SaveFileCreateInfo* info) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackage* save_package =
      GetSavePackageFromRenderIds(info->render_process_id,
                                  info->render_view_id);
  if (!save_package) {
    // Cancel this request.
    SendCancelRequest(info->save_id);
    return;
  }

  // Insert started saving job to tracking list.
  SavePackageMap::iterator sit = packages_.find(info->save_id);
  if (sit == packages_.end()) {
    // Find the registered request. If we can not find, it means we have
    // canceled the job before.
    SavePackage* old_save_package = UnregisterStartingRequest(info->url,
        info->render_process_id);
    if (!old_save_package) {
      // Cancel this request.
      SendCancelRequest(info->save_id);
      return;
    }
    DCHECK_EQ(old_save_package, save_package);
    packages_[info->save_id] = save_package;
  } else {
    NOTREACHED();
  }

  // Forward this message to SavePackage.
  save_package->StartSave(info);
}

void SaveFileManager::OnUpdateSaveProgress(int save_id, int64 bytes_so_far,
                                           bool write_success) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackage* package = LookupPackage(save_id);
  if (package)
    package->UpdateSaveProgress(save_id, bytes_so_far, write_success);
  else
    SendCancelRequest(save_id);
}

void SaveFileManager::OnSaveFinished(int save_id,
                                     int64 bytes_so_far,
                                     bool is_success) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackage* package = LookupPackage(save_id);
  if (package)
    package->SaveFinished(save_id, bytes_so_far, is_success);
}

void SaveFileManager::OnErrorFinished(const GURL& save_url, int tab_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  SavePackage* save_package = UnregisterStartingRequest(save_url, tab_id);
  if (save_package)
    save_package->SaveFailed(save_url);
}

// Notifications sent from the UI thread and run on the IO thread.

void SaveFileManager::OnSaveURL(
    const GURL& url,
    const GURL& referrer,
    int render_process_host_id,
    int render_view_id,
    net::URLRequestContextGetter* request_context_getter) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  net::URLRequestContext* context =
      request_context_getter->GetURLRequestContext();
  resource_dispatcher_host_->BeginSaveFile(url,
                                           referrer,
                                           render_process_host_id,
                                           render_view_id,
                                           context);
}

void SaveFileManager::OnRequireSaveJobFromOtherSource(
    SaveFileCreateInfo* info) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  DCHECK_EQ(info->save_id, -1);
  // Generate a unique save id.
  info->save_id = GetNextId();
  // Start real saving action.
  BrowserThread::PostTask(
      BrowserThread::FILE, FROM_HERE,
      NewRunnableMethod(this, &SaveFileManager::StartSave, info));
}

void SaveFileManager::ExecuteCancelSaveRequest(int render_process_id,
                                               int request_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  resource_dispatcher_host_->CancelRequest(render_process_id,
                                           request_id,
                                           false);
}

// Notifications sent from the UI thread and run on the file thread.

// This method will be sent via a user action, or shutdown on the UI thread,
// and run on the file thread. We don't post a message back for cancels,
// but we do forward the cancel to the IO thread. Since this message has been
// sent from the UI thread, the saving job may have already completed and
// won't exist in our map.
void SaveFileManager::CancelSave(int save_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  SaveFileMap::iterator it = save_file_map_.find(save_id);
  if (it != save_file_map_.end()) {
    SaveFile* save_file = it->second;

    // If the data comes from the net IO thread, then forward the cancel
    // message to IO thread. If the data comes from other sources, just
    // ignore the cancel message.
    if (save_file->save_source() == SaveFileCreateInfo::SAVE_FILE_FROM_NET) {
      BrowserThread::PostTask(
          BrowserThread::IO, FROM_HERE,
          NewRunnableMethod(
              this, &SaveFileManager::ExecuteCancelSaveRequest,
              save_file->render_process_id(), save_file->request_id()));

      // UI thread will notify the render process to stop sending data,
      // so in here, we need not to do anything, just close the save file.
      save_file->Cancel();
    } else {
      // If we did not find SaveFile in map, the saving job should either get
      // data from other sources or have finished.
      DCHECK(save_file->save_source() !=
             SaveFileCreateInfo::SAVE_FILE_FROM_NET ||
             !save_file->in_progress());
    }
    // Whatever the save file is renamed or not, just delete it.
    save_file_map_.erase(it);
    delete save_file;
  }
}

// It is possible that SaveItem which has specified save_id has been canceled
// before this function runs. So if we can not find corresponding SaveFile by
// using specified save_id, just return.
void SaveFileManager::SaveLocalFile(const GURL& original_file_url,
                                    int save_id,
                                    int render_process_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  SaveFile* save_file = LookupSaveFile(save_id);
  if (!save_file)
    return;
  // If it has finished, just return.
  if (!save_file->in_progress())
    return;

  // Close the save file before the copy operation.
  save_file->Finish();
  save_file->Detach();

  DCHECK(original_file_url.SchemeIsFile());
  FilePath file_path;
  net::FileURLToFilePath(original_file_url, &file_path);
  // If we can not get valid file path from original URL, treat it as
  // disk error.
  if (file_path.empty())
    SaveFinished(save_id, original_file_url, render_process_id, false);

  // Copy the local file to the temporary file. It will be renamed to its
  // final name later.
  bool success = file_util::CopyFile(file_path, save_file->full_path());
  if (!success)
    file_util::Delete(save_file->full_path(), false);
  SaveFinished(save_id, original_file_url, render_process_id, success);
}

void SaveFileManager::OnDeleteDirectoryOrFile(const FilePath& full_path,
                                              bool is_dir) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  DCHECK(!full_path.empty());

  file_util::Delete(full_path, is_dir);
}

// Open a saved page package, show it in a Windows Explorer window.
// We run on this thread to avoid blocking the UI with slow Shell operations.
#if !defined(OS_MACOSX)
void SaveFileManager::OnShowSavedFileInShell(const FilePath full_path) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
  platform_util::ShowItemInFolder(full_path);
}
#endif

void SaveFileManager::RenameAllFiles(
    const FinalNameList& final_names,
    const FilePath& resource_dir,
    int render_process_id,
    int render_view_id,
    int save_package_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));

  if (!resource_dir.empty() && !file_util::PathExists(resource_dir))
    file_util::CreateDirectory(resource_dir);

  for (FinalNameList::const_iterator i = final_names.begin();
      i != final_names.end(); ++i) {
    SaveFileMap::iterator it = save_file_map_.find(i->first);
    if (it != save_file_map_.end()) {
      SaveFile* save_file = it->second;
      DCHECK(!save_file->in_progress());
      save_file->Rename(i->second);
      delete save_file;
      save_file_map_.erase(it);
    }
  }

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      NewRunnableMethod(
          this, &SaveFileManager::OnFinishSavePageJob, render_process_id,
          render_view_id, save_package_id));
}

void SaveFileManager::OnFinishSavePageJob(int render_process_id,
                                          int render_view_id,
                                          int save_package_id) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

  SavePackage* save_package =
      GetSavePackageFromRenderIds(render_process_id, render_view_id);

  if (save_package && save_package->id() == save_package_id)
    save_package->Finish();
}

void SaveFileManager::RemoveSavedFileFromFileMap(
    const SaveIDList& save_ids) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));

  for (SaveIDList::const_iterator i = save_ids.begin();
      i != save_ids.end(); ++i) {
    SaveFileMap::iterator it = save_file_map_.find(*i);
    if (it != save_file_map_.end()) {
      SaveFile* save_file = it->second;
      DCHECK(!save_file->in_progress());
      file_util::Delete(save_file->full_path(), false);
      delete save_file;
      save_file_map_.erase(it);
    }
  }
}