// 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 "chrome/browser/browsing_data_indexed_db_helper.h"

#include "base/callback_old.h"
#include "base/file_util.h"
#include "base/memory/scoped_ptr.h"
#include "base/message_loop.h"
#include "base/string_util.h"
#include "base/utf_string_conversions.h"
#include "chrome/browser/profiles/profile.h"
#include "content/browser/browser_thread.h"
#include "content/browser/in_process_webkit/webkit_context.h"
#include "webkit/database/database_util.h"
#include "webkit/glue/webkit_glue.h"

using webkit_database::DatabaseUtil;

namespace {

class BrowsingDataIndexedDBHelperImpl : public BrowsingDataIndexedDBHelper {
 public:
  explicit BrowsingDataIndexedDBHelperImpl(Profile* profile);

  virtual void StartFetching(
      Callback1<const std::list<IndexedDBInfo>& >::Type* callback);
  virtual void CancelNotification();
  virtual void DeleteIndexedDB(const GURL& origin);

 private:
  virtual ~BrowsingDataIndexedDBHelperImpl();

  // Enumerates all indexed database files in the WEBKIT thread.
  void FetchIndexedDBInfoInWebKitThread();
  // Notifies the completion callback in the UI thread.
  void NotifyInUIThread();
  // Delete a single indexed database in the WEBKIT thread.
  void DeleteIndexedDBInWebKitThread(const GURL& origin);

  scoped_refptr<IndexedDBContext> indexed_db_context_;

  // This only mutates in the WEBKIT thread.
  std::list<IndexedDBInfo> indexed_db_info_;

  // This only mutates on the UI thread.
  scoped_ptr<Callback1<const std::list<IndexedDBInfo>& >::Type >
      completion_callback_;
  // Indicates whether or not we're currently fetching information:
  // it's true when StartFetching() is called in the UI thread, and it's reset
  // after we notified the callback in the UI thread.
  // This only mutates on the UI thread.
  bool is_fetching_;

  DISALLOW_COPY_AND_ASSIGN(BrowsingDataIndexedDBHelperImpl);
};

BrowsingDataIndexedDBHelperImpl::BrowsingDataIndexedDBHelperImpl(
    Profile* profile)
    : indexed_db_context_(profile->GetWebKitContext()->indexed_db_context()),
      completion_callback_(NULL),
      is_fetching_(false) {
  DCHECK(indexed_db_context_.get());
}

BrowsingDataIndexedDBHelperImpl::~BrowsingDataIndexedDBHelperImpl() {
}

void BrowsingDataIndexedDBHelperImpl::StartFetching(
    Callback1<const std::list<IndexedDBInfo>& >::Type* callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!is_fetching_);
  DCHECK(callback);
  is_fetching_ = true;
  completion_callback_.reset(callback);
  BrowserThread::PostTask(
      BrowserThread::WEBKIT, FROM_HERE,
      NewRunnableMethod(
          this,
          &BrowsingDataIndexedDBHelperImpl::FetchIndexedDBInfoInWebKitThread));
}

void BrowsingDataIndexedDBHelperImpl::CancelNotification() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  completion_callback_.reset();
}

void BrowsingDataIndexedDBHelperImpl::DeleteIndexedDB(
    const GURL& origin) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  BrowserThread::PostTask(
      BrowserThread::WEBKIT, FROM_HERE,
       NewRunnableMethod(
           this,
           &BrowsingDataIndexedDBHelperImpl::
              DeleteIndexedDBInWebKitThread,
           origin));
}

void BrowsingDataIndexedDBHelperImpl::FetchIndexedDBInfoInWebKitThread() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT));
  std::vector<GURL> origins;
  indexed_db_context_->GetAllOrigins(&origins);
  for (std::vector<GURL>::const_iterator iter = origins.begin();
       iter != origins.end(); ++iter) {
    const GURL& origin = *iter;
    if (origin.SchemeIs(chrome::kExtensionScheme))
      continue;  // Extension state is not considered browsing data.
    indexed_db_info_.push_back(IndexedDBInfo(
        origin,
        indexed_db_context_->GetOriginDiskUsage(origin),
        indexed_db_context_->GetOriginLastModified(origin)));
  }

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      NewRunnableMethod(
          this, &BrowsingDataIndexedDBHelperImpl::NotifyInUIThread));
}

void BrowsingDataIndexedDBHelperImpl::NotifyInUIThread() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(is_fetching_);
  // Note: completion_callback_ mutates only in the UI thread, so it's safe to
  // test it here.
  if (completion_callback_ != NULL) {
    completion_callback_->Run(indexed_db_info_);
    completion_callback_.reset();
  }
  is_fetching_ = false;
}

void BrowsingDataIndexedDBHelperImpl::DeleteIndexedDBInWebKitThread(
    const GURL& origin) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::WEBKIT));
  indexed_db_context_->DeleteIndexedDBForOrigin(origin);
}

}  // namespace

BrowsingDataIndexedDBHelper::IndexedDBInfo::IndexedDBInfo(
    const GURL& origin,
    int64 size,
    base::Time last_modified)
    : origin(origin),
      size(size),
      last_modified(last_modified) {
}

BrowsingDataIndexedDBHelper::IndexedDBInfo::~IndexedDBInfo() {}

// static
BrowsingDataIndexedDBHelper* BrowsingDataIndexedDBHelper::Create(
    Profile* profile) {
  return new BrowsingDataIndexedDBHelperImpl(profile);
}

CannedBrowsingDataIndexedDBHelper::
PendingIndexedDBInfo::PendingIndexedDBInfo() {
}

CannedBrowsingDataIndexedDBHelper::
PendingIndexedDBInfo::PendingIndexedDBInfo(const GURL& origin,
                                           const string16& description)
    : origin(origin),
      description(description) {
}

CannedBrowsingDataIndexedDBHelper::
PendingIndexedDBInfo::~PendingIndexedDBInfo() {
}

CannedBrowsingDataIndexedDBHelper::CannedBrowsingDataIndexedDBHelper()
    : completion_callback_(NULL),
      is_fetching_(false) {
}

CannedBrowsingDataIndexedDBHelper* CannedBrowsingDataIndexedDBHelper::Clone() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  CannedBrowsingDataIndexedDBHelper* clone =
      new CannedBrowsingDataIndexedDBHelper();

  base::AutoLock auto_lock(lock_);
  clone->pending_indexed_db_info_ = pending_indexed_db_info_;
  clone->indexed_db_info_ = indexed_db_info_;
  return clone;
}

void CannedBrowsingDataIndexedDBHelper::AddIndexedDB(
    const GURL& origin, const string16& description) {
  base::AutoLock auto_lock(lock_);
  pending_indexed_db_info_.push_back(PendingIndexedDBInfo(origin, description));
}

void CannedBrowsingDataIndexedDBHelper::Reset() {
  base::AutoLock auto_lock(lock_);
  indexed_db_info_.clear();
  pending_indexed_db_info_.clear();
}

bool CannedBrowsingDataIndexedDBHelper::empty() const {
  base::AutoLock auto_lock(lock_);
  return indexed_db_info_.empty() && pending_indexed_db_info_.empty();
}

void CannedBrowsingDataIndexedDBHelper::StartFetching(
    Callback1<const std::list<IndexedDBInfo>& >::Type* callback) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(!is_fetching_);
  DCHECK(callback);
  is_fetching_ = true;
  completion_callback_.reset(callback);
  BrowserThread::PostTask(BrowserThread::WEBKIT, FROM_HERE, NewRunnableMethod(
      this,
      &CannedBrowsingDataIndexedDBHelper::ConvertPendingInfoInWebKitThread));
}

CannedBrowsingDataIndexedDBHelper::~CannedBrowsingDataIndexedDBHelper() {}

void CannedBrowsingDataIndexedDBHelper::ConvertPendingInfoInWebKitThread() {
  base::AutoLock auto_lock(lock_);
  for (std::list<PendingIndexedDBInfo>::const_iterator
       info = pending_indexed_db_info_.begin();
       info != pending_indexed_db_info_.end(); ++info) {
    bool duplicate = false;
    for (std::list<IndexedDBInfo>::iterator
         indexed_db = indexed_db_info_.begin();
         indexed_db != indexed_db_info_.end(); ++indexed_db) {
      if (indexed_db->origin == info->origin) {
        duplicate = true;
        break;
      }
    }
    if (duplicate)
      continue;

    indexed_db_info_.push_back(IndexedDBInfo(
        info->origin,
        0,
        base::Time()));
  }
  pending_indexed_db_info_.clear();

  BrowserThread::PostTask(
      BrowserThread::UI, FROM_HERE,
      NewRunnableMethod(
          this, &CannedBrowsingDataIndexedDBHelper::NotifyInUIThread));
}

void CannedBrowsingDataIndexedDBHelper::NotifyInUIThread() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  DCHECK(is_fetching_);
  // Note: completion_callback_ mutates only in the UI thread, so it's safe to
  // test it here.
  if (completion_callback_ != NULL) {
    completion_callback_->Run(indexed_db_info_);
    completion_callback_.reset();
  }
  is_fetching_ = false;
}

void CannedBrowsingDataIndexedDBHelper::CancelNotification() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  completion_callback_.reset();
}