// 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 "chrome/browser/android/foreign_session_helper.h"

#include <jni.h>
#include <stddef.h>

#include "base/android/jni_string.h"
#include "chrome/browser/android/tab_android.h"
#include "chrome/browser/chrome_notification_types.h"
#include "chrome/browser/profiles/profile_android.h"
#include "chrome/browser/sessions/session_restore.h"
#include "chrome/browser/sync/profile_sync_service_factory.h"
#include "chrome/browser/sync/session_sync_service_factory.h"
#include "chrome/browser/ui/android/tab_model/tab_model.h"
#include "chrome/browser/ui/android/tab_model/tab_model_list.h"
#include "chrome/common/pref_names.h"
#include "chrome/common/url_constants.h"
#include "components/browser_sync/profile_sync_service.h"
#include "components/prefs/pref_service.h"
#include "components/prefs/scoped_user_pref_update.h"
#include "components/sync_sessions/open_tabs_ui_delegate.h"
#include "components/sync_sessions/session_sync_service.h"
#include "content/public/browser/notification_details.h"
#include "content/public/browser/notification_service.h"
#include "content/public/browser/notification_source.h"
#include "content/public/browser/web_contents.h"
#include "jni/ForeignSessionHelper_jni.h"

using base::android::JavaParamRef;
using base::android::ScopedJavaGlobalRef;
using base::android::ScopedJavaLocalRef;
using base::android::AttachCurrentThread;
using base::android::ConvertUTF16ToJavaString;
using base::android::ConvertUTF8ToJavaString;
using base::android::ConvertJavaStringToUTF8;
using sync_sessions::OpenTabsUIDelegate;
using sync_sessions::SyncedSession;

namespace {

OpenTabsUIDelegate* GetOpenTabsUIDelegate(Profile* profile) {
  sync_sessions::SessionSyncService* service =
      SessionSyncServiceFactory::GetInstance()->GetForProfile(profile);

  // Only return the delegate if it exists.
  if (!service)
    return NULL;

  return service->GetOpenTabsUIDelegate();
}

bool ShouldSkipTab(const sessions::SessionTab& session_tab) {
    if (session_tab.navigations.empty())
      return true;

    int selected_index = session_tab.normalized_navigation_index();
    const sessions::SerializedNavigationEntry& current_navigation =
        session_tab.navigations.at(selected_index);

    if (current_navigation.virtual_url().is_empty())
      return true;

    return false;
}

bool ShouldSkipWindow(const sessions::SessionWindow& window) {
  for (const auto& tab_ptr : window.tabs) {
    const sessions::SessionTab& session_tab = *(tab_ptr.get());
    if (!ShouldSkipTab(session_tab))
      return false;
  }
  return true;
}

bool ShouldSkipSession(const SyncedSession& session) {
  for (const auto& window_pair : session.windows) {
    const sessions::SessionWindow& window = window_pair.second->wrapped_window;
    if (!ShouldSkipWindow(window))
      return false;
  }
  return true;
}

void JNI_ForeignSessionHelper_CopyTabToJava(
    JNIEnv* env,
    const sessions::SessionTab& tab,
    ScopedJavaLocalRef<jobject>& j_window) {
  int selected_index = tab.normalized_navigation_index();
  DCHECK_GE(selected_index, 0);
  DCHECK_LT(selected_index, static_cast<int>(tab.navigations.size()));

  const sessions::SerializedNavigationEntry& current_navigation =
      tab.navigations.at(selected_index);

  GURL tab_url = current_navigation.virtual_url();

  Java_ForeignSessionHelper_pushTab(
      env, j_window, ConvertUTF8ToJavaString(env, tab_url.spec()),
      ConvertUTF16ToJavaString(env, current_navigation.title()),
      tab.timestamp.ToJavaTime(), tab.tab_id.id());
}

void JNI_ForeignSessionHelper_CopyWindowToJava(
    JNIEnv* env,
    const sessions::SessionWindow& window,
    ScopedJavaLocalRef<jobject>& j_window) {
  for (const auto& tab_ptr : window.tabs) {
    const sessions::SessionTab& session_tab = *(tab_ptr.get());

    if (ShouldSkipTab(session_tab))
      return;

    JNI_ForeignSessionHelper_CopyTabToJava(env, session_tab, j_window);
  }
}

void JNI_ForeignSessionHelper_CopySessionToJava(
    JNIEnv* env,
    const SyncedSession& session,
    ScopedJavaLocalRef<jobject>& j_session) {
  for (const auto& window_pair : session.windows) {
    const sessions::SessionWindow& window = window_pair.second->wrapped_window;

    if (ShouldSkipWindow(window))
      continue;

    ScopedJavaLocalRef<jobject> last_pushed_window;
    last_pushed_window.Reset(Java_ForeignSessionHelper_pushWindow(
        env, j_session, window.timestamp.ToJavaTime(), window.window_id.id()));

    JNI_ForeignSessionHelper_CopyWindowToJava(env, window, last_pushed_window);
  }
}

}  // namespace

static jlong JNI_ForeignSessionHelper_Init(
    JNIEnv* env,
    const JavaParamRef<jobject>& profile) {
  ForeignSessionHelper* foreign_session_helper = new ForeignSessionHelper(
      ProfileAndroid::FromProfileAndroid(profile));
  return reinterpret_cast<intptr_t>(foreign_session_helper);
}

ForeignSessionHelper::ForeignSessionHelper(Profile* profile)
    : profile_(profile) {
  sync_sessions::SessionSyncService* service =
      SessionSyncServiceFactory::GetInstance()->GetForProfile(profile);

  // NOTE: The SessionSyncService can be null in tests.
  if (service) {
    // base::Unretained() is safe below because the subscription itself is a
    // class member field and handles destruction well.
    foreign_session_updated_subscription_ =
        service->SubscribeToForeignSessionsChanged(base::BindRepeating(
            &ForeignSessionHelper::FireForeignSessionCallback,
            base::Unretained(this)));
  }
}

ForeignSessionHelper::~ForeignSessionHelper() {
}

void ForeignSessionHelper::Destroy(JNIEnv* env,
                                   const JavaParamRef<jobject>& obj) {
  delete this;
}

jboolean ForeignSessionHelper::IsTabSyncEnabled(
    JNIEnv* env,
    const JavaParamRef<jobject>& obj) {
  sync_sessions::SessionSyncService* service =
      SessionSyncServiceFactory::GetInstance()->GetForProfile(profile_);
  return service && service->GetOpenTabsUIDelegate();
}

void ForeignSessionHelper::TriggerSessionSync(
    JNIEnv* env,
    const JavaParamRef<jobject>& obj) {
  browser_sync::ProfileSyncService* service =
      ProfileSyncServiceFactory::GetInstance()->GetForProfile(profile_);
  if (!service)
    return;

  const syncer::ModelTypeSet types(syncer::SESSIONS);
  service->TriggerRefresh(types);
}

void ForeignSessionHelper::SetOnForeignSessionCallback(
    JNIEnv* env,
    const JavaParamRef<jobject>& obj,
    const JavaParamRef<jobject>& callback) {
  callback_.Reset(env, callback);
}

void ForeignSessionHelper::FireForeignSessionCallback() {
  if (callback_.is_null())
    return;

  JNIEnv* env = AttachCurrentThread();
  Java_ForeignSessionCallback_onUpdated(env, callback_);
}

jboolean ForeignSessionHelper::GetForeignSessions(
    JNIEnv* env,
    const JavaParamRef<jobject>& obj,
    const JavaParamRef<jobject>& result) {
  OpenTabsUIDelegate* open_tabs = GetOpenTabsUIDelegate(profile_);
  if (!open_tabs)
    return false;

  std::vector<const SyncedSession*> sessions;
  if (!open_tabs->GetAllForeignSessions(&sessions))
    return false;

  // Use a pref to keep track of sessions that were collapsed by the user.
  // To prevent the pref from accumulating stale sessions, clear it each time
  // and only add back sessions that are still current.
  DictionaryPrefUpdate pref_update(profile_->GetPrefs(),
                                   prefs::kNtpCollapsedForeignSessions);
  base::DictionaryValue* pref_collapsed_sessions = pref_update.Get();
  std::unique_ptr<base::DictionaryValue> collapsed_sessions(
      pref_collapsed_sessions->DeepCopy());
  pref_collapsed_sessions->Clear();

  ScopedJavaLocalRef<jobject> last_pushed_session;

  // Note: we don't own the SyncedSessions themselves.
  for (size_t i = 0; i < sessions.size(); ++i) {
    const SyncedSession& session = *(sessions[i]);
    if (ShouldSkipSession(session))
      continue;

    const bool is_collapsed = collapsed_sessions->HasKey(session.session_tag);

    if (is_collapsed)
      pref_collapsed_sessions->SetBoolean(session.session_tag, true);

    last_pushed_session.Reset(Java_ForeignSessionHelper_pushSession(
        env, result, ConvertUTF8ToJavaString(env, session.session_tag),
        ConvertUTF8ToJavaString(env, session.session_name), session.device_type,
        session.modified_time.ToJavaTime()));

    // Push the full session, with tabs ordered by visual position.
    JNI_ForeignSessionHelper_CopySessionToJava(env, session,
                                               last_pushed_session);
  }

  return true;
}

jboolean ForeignSessionHelper::OpenForeignSessionTab(
    JNIEnv* env,
    const JavaParamRef<jobject>& obj,
    const JavaParamRef<jobject>& j_tab,
    const JavaParamRef<jstring>& session_tag,
    jint session_tab_id,
    jint j_disposition) {
  OpenTabsUIDelegate* open_tabs = GetOpenTabsUIDelegate(profile_);
  if (!open_tabs) {
    LOG(ERROR) << "Null OpenTabsUIDelegate returned.";
    return false;
  }

  const sessions::SessionTab* session_tab;

  if (!open_tabs->GetForeignTab(ConvertJavaStringToUTF8(env, session_tag),
                                SessionID::FromSerializedValue(session_tab_id),
                                &session_tab)) {
    LOG(ERROR) << "Failed to load foreign tab.";
    return false;
  }

  if (session_tab->navigations.empty()) {
    LOG(ERROR) << "Foreign tab no longer has valid navigations.";
    return false;
  }

  TabAndroid* tab_android = TabAndroid::GetNativeTab(env, j_tab);
  if (!tab_android)
    return false;
  content::WebContents* web_contents = tab_android->web_contents();
  if (!web_contents)
    return false;

  WindowOpenDisposition disposition =
      static_cast<WindowOpenDisposition>(j_disposition);
  SessionRestore::RestoreForeignSessionTab(web_contents,
                                           *session_tab,
                                           disposition);

  return true;
}

void ForeignSessionHelper::DeleteForeignSession(
    JNIEnv* env,
    const JavaParamRef<jobject>& obj,
    const JavaParamRef<jstring>& session_tag) {
  OpenTabsUIDelegate* open_tabs = GetOpenTabsUIDelegate(profile_);
  if (open_tabs)
    open_tabs->DeleteForeignSession(ConvertJavaStringToUTF8(env, session_tag));
}

void ForeignSessionHelper::SetInvalidationsForSessionsEnabled(
    JNIEnv* env,
    const JavaParamRef<jobject>& obj,
    jboolean enabled) {
  browser_sync::ProfileSyncService* service =
      ProfileSyncServiceFactory::GetInstance()->GetForProfile(profile_);
  if (!service)
    return;

  service->SetInvalidationsForSessionsEnabled(enabled);
}