/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License
 */

package com.android.server.wm;

import static android.app.ActivityManagerInternal.APP_TRANSITION_RECENTS_ANIM;
import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;
import static android.app.WindowConfiguration.WINDOWING_MODE_SPLIT_SCREEN_PRIMARY;
import static android.app.WindowConfiguration.WINDOWING_MODE_UNDEFINED;
import static android.view.RemoteAnimationTarget.MODE_CLOSING;
import static android.view.WindowManager.INPUT_CONSUMER_RECENTS_ANIMATION;
import static com.android.server.policy.WindowManagerPolicy.FINISH_LAYOUT_REDO_WALLPAPER;
import static com.android.server.wm.AnimationAdapterProto.REMOTE;
import static com.android.server.wm.RemoteAnimationAdapterWrapperProto.TARGET;
import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_RECENTS_ANIMATIONS;
import static com.android.server.wm.WindowManagerService.H.NOTIFY_APP_TRANSITION_STARTING;

import android.annotation.IntDef;
import android.app.ActivityManager.TaskSnapshot;
import android.app.WindowConfiguration;
import android.graphics.Point;
import android.graphics.Rect;
import android.os.Binder;
import android.os.IBinder.DeathRecipient;
import android.os.RemoteException;
import android.os.SystemClock;
import android.util.ArraySet;
import android.util.Slog;
import android.util.SparseBooleanArray;
import android.util.SparseIntArray;
import android.util.proto.ProtoOutputStream;
import android.view.IRecentsAnimationController;
import android.view.IRecentsAnimationRunner;
import android.view.RemoteAnimationTarget;
import android.view.SurfaceControl;
import android.view.SurfaceControl.Transaction;
import com.android.internal.annotations.VisibleForTesting;
import com.android.server.wm.SurfaceAnimator.OnAnimationFinishedCallback;
import com.android.server.wm.utils.InsetUtils;
import com.google.android.collect.Sets;
import java.io.PrintWriter;
import java.util.ArrayList;

/**
 * Controls a single instance of the remote driven recents animation. In particular, this allows
 * the calling SystemUI to animate the visible task windows as a part of the transition. The remote
 * runner is provided an animation controller which allows it to take screenshots and to notify
 * window manager when the animation is completed. In addition, window manager may also notify the
 * app if it requires the animation to be canceled at any time (ie. due to timeout, etc.)
 */
public class RecentsAnimationController implements DeathRecipient {
    private static final String TAG = RecentsAnimationController.class.getSimpleName();
    private static final long FAILSAFE_DELAY = 1000;

    public static final int REORDER_KEEP_IN_PLACE = 0;
    public static final int REORDER_MOVE_TO_TOP = 1;
    public static final int REORDER_MOVE_TO_ORIGINAL_POSITION = 2;

    @IntDef(prefix = { "REORDER_MODE_" }, value = {
            REORDER_KEEP_IN_PLACE,
            REORDER_MOVE_TO_TOP,
            REORDER_MOVE_TO_ORIGINAL_POSITION
    })
    public @interface ReorderMode {}

    private final WindowManagerService mService;
    private final IRecentsAnimationRunner mRunner;
    private final RecentsAnimationCallbacks mCallbacks;
    private final ArrayList<TaskAnimationAdapter> mPendingAnimations = new ArrayList<>();
    private final int mDisplayId;
    private final Runnable mFailsafeRunnable = () -> {
        cancelAnimation(REORDER_MOVE_TO_ORIGINAL_POSITION, "failSafeRunnable");
    };

    // The recents component app token that is shown behind the visibile tasks
    private AppWindowToken mTargetAppToken;
    private Rect mMinimizedHomeBounds = new Rect();

    // We start the RecentsAnimationController in a pending-start state since we need to wait for
    // the wallpaper/activity to draw before we can give control to the handler to start animating
    // the visible task surfaces
    private boolean mPendingStart = true;

    // Set when the animation has been canceled
    private boolean mCanceled;

    // Whether or not the input consumer is enabled. The input consumer must be both registered and
    // enabled for it to start intercepting touch events.
    private boolean mInputConsumerEnabled;

    // Whether or not the recents animation should cause the primary split-screen stack to be
    // minimized
    private boolean mSplitScreenMinimized;

    private final Rect mTmpRect = new Rect();

    private boolean mLinkedToDeathOfRunner;

    public interface RecentsAnimationCallbacks {
        void onAnimationFinished(@ReorderMode int reorderMode);
    }

    private final IRecentsAnimationController mController =
            new IRecentsAnimationController.Stub() {

        @Override
        public TaskSnapshot screenshotTask(int taskId) {
            if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "screenshotTask(" + taskId + "):"
                    + " mCanceled=" + mCanceled);
            final long token = Binder.clearCallingIdentity();
            try {
                synchronized (mService.getWindowManagerLock()) {
                    if (mCanceled) {
                        return null;
                    }
                    for (int i = mPendingAnimations.size() - 1; i >= 0; i--) {
                        final TaskAnimationAdapter adapter = mPendingAnimations.get(i);
                        final Task task = adapter.mTask;
                        if (task.mTaskId == taskId) {
                            final TaskSnapshotController snapshotController =
                                    mService.mTaskSnapshotController;
                            final ArraySet<Task> tasks = Sets.newArraySet(task);
                            snapshotController.snapshotTasks(tasks);
                            snapshotController.addSkipClosingAppSnapshotTasks(tasks);
                            return snapshotController.getSnapshot(taskId, 0 /* userId */,
                                    false /* restoreFromDisk */, false /* reducedResolution */);
                        }
                    }
                    return null;
                }
            } finally {
                Binder.restoreCallingIdentity(token);
            }
        }

        @Override
        public void finish(boolean moveHomeToTop) {
            if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "finish(" + moveHomeToTop + "):"
                    + " mCanceled=" + mCanceled);
            final long token = Binder.clearCallingIdentity();
            try {
                synchronized (mService.getWindowManagerLock()) {
                    if (mCanceled) {
                        return;
                    }
                }

                // Note, the callback will handle its own synchronization, do not lock on WM lock
                // prior to calling the callback
                mCallbacks.onAnimationFinished(moveHomeToTop
                        ? REORDER_MOVE_TO_TOP
                        : REORDER_MOVE_TO_ORIGINAL_POSITION);
            } finally {
                Binder.restoreCallingIdentity(token);
            }
        }

        @Override
        public void setAnimationTargetsBehindSystemBars(boolean behindSystemBars)
                throws RemoteException {
            final long token = Binder.clearCallingIdentity();
            try {
                synchronized (mService.getWindowManagerLock()) {
                    for (int i = mPendingAnimations.size() - 1; i >= 0; i--) {
                        mPendingAnimations.get(i).mTask.setCanAffectSystemUiFlags(behindSystemBars);
                    }
                    mService.mWindowPlacerLocked.requestTraversal();
                }
            } finally {
                Binder.restoreCallingIdentity(token);
            }
        }

        @Override
        public void setInputConsumerEnabled(boolean enabled) {
            if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "setInputConsumerEnabled(" + enabled + "):"
                    + " mCanceled=" + mCanceled);
            final long token = Binder.clearCallingIdentity();
            try {
                synchronized (mService.getWindowManagerLock()) {
                    if (mCanceled) {
                        return;
                    }

                    mInputConsumerEnabled = enabled;
                    mService.mInputMonitor.updateInputWindowsLw(true /*force*/);
                    mService.scheduleAnimationLocked();
                }
            } finally {
                Binder.restoreCallingIdentity(token);
            }
        }

        @Override
        public void setSplitScreenMinimized(boolean minimized) {
            final long token = Binder.clearCallingIdentity();
            try {
                synchronized (mService.getWindowManagerLock()) {
                    if (mCanceled) {
                        return;
                    }

                    mSplitScreenMinimized = minimized;
                    mService.checkSplitScreenMinimizedChanged(true /* animate */);
                }
            } finally {
                Binder.restoreCallingIdentity(token);
            }
        }
    };

    /**
     * @param remoteAnimationRunner The remote runner which should be notified when the animation is
     *                              ready to start or has been canceled
     * @param callbacks Callbacks to be made when the animation finishes
     */
    RecentsAnimationController(WindowManagerService service,
            IRecentsAnimationRunner remoteAnimationRunner, RecentsAnimationCallbacks callbacks,
            int displayId) {
        mService = service;
        mRunner = remoteAnimationRunner;
        mCallbacks = callbacks;
        mDisplayId = displayId;
    }

    /**
     * Initializes the recents animation controller. This is a separate call from the constructor
     * because it may call cancelAnimation() which needs to properly clean up the controller
     * in the window manager.
     */
    public void initialize(int targetActivityType, SparseBooleanArray recentTaskIds) {
        // Make leashes for each of the visible tasks and add it to the recents animation to be
        // started
        final DisplayContent dc = mService.mRoot.getDisplayContent(mDisplayId);
        final ArrayList<Task> visibleTasks = dc.getVisibleTasks();
        final int taskCount = visibleTasks.size();
        for (int i = 0; i < taskCount; i++) {
            final Task task = visibleTasks.get(i);
            final WindowConfiguration config = task.getWindowConfiguration();
            if (config.tasksAreFloating()
                    || config.getWindowingMode() == WINDOWING_MODE_SPLIT_SCREEN_PRIMARY
                    || config.getActivityType() == targetActivityType) {
                continue;
            }
            addAnimation(task, !recentTaskIds.get(task.mTaskId));
        }

        // Skip the animation if there is nothing to animate
        if (mPendingAnimations.isEmpty()) {
            cancelAnimation(REORDER_MOVE_TO_ORIGINAL_POSITION, "initialize-noVisibleTasks");
            return;
        }

        try {
            linkToDeathOfRunner();
        } catch (RemoteException e) {
            cancelAnimation(REORDER_MOVE_TO_ORIGINAL_POSITION, "initialize-failedToLinkToDeath");
            return;
        }

        // Adjust the wallpaper visibility for the showing target activity
        final AppWindowToken recentsComponentAppToken = dc.getStack(WINDOWING_MODE_UNDEFINED,
                targetActivityType).getTopChild().getTopFullscreenAppToken();
        if (recentsComponentAppToken != null) {
            if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "setHomeApp("
                    + recentsComponentAppToken.getName() + ")");
            mTargetAppToken = recentsComponentAppToken;
            if (recentsComponentAppToken.windowsCanBeWallpaperTarget()) {
                dc.pendingLayoutChanges |= FINISH_LAYOUT_REDO_WALLPAPER;
                dc.setLayoutNeeded();
            }
        }

        // Save the minimized home height
        dc.getDockedDividerController().getHomeStackBoundsInDockedMode(mMinimizedHomeBounds);

        mService.mWindowPlacerLocked.performSurfacePlacement();
    }

    @VisibleForTesting
    AnimationAdapter addAnimation(Task task, boolean isRecentTaskInvisible) {
        if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "addAnimation(" + task.getName() + ")");
        // TODO: Refactor this to use the task's animator
        final SurfaceAnimator anim = new SurfaceAnimator(task, null /* animationFinishedCallback */,
                mService);
        final TaskAnimationAdapter taskAdapter = new TaskAnimationAdapter(task,
                isRecentTaskInvisible);
        anim.startAnimation(task.getPendingTransaction(), taskAdapter, false /* hidden */);
        task.commitPendingTransaction();
        mPendingAnimations.add(taskAdapter);
        return taskAdapter;
    }

    @VisibleForTesting
    void removeAnimation(TaskAnimationAdapter taskAdapter) {
        if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "removeAnimation("
                + taskAdapter.mTask.mTaskId + ")");
        taskAdapter.mTask.setCanAffectSystemUiFlags(true);
        taskAdapter.mCapturedFinishCallback.onAnimationFinished(taskAdapter);
        mPendingAnimations.remove(taskAdapter);
    }

    void startAnimation() {
        if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "startAnimation(): mPendingStart=" + mPendingStart
                + " mCanceled=" + mCanceled);
        if (!mPendingStart || mCanceled) {
            // Skip starting if we've already started or canceled the animation
            return;
        }
        try {
            final ArrayList<RemoteAnimationTarget> appAnimations = new ArrayList<>();
            for (int i = mPendingAnimations.size() - 1; i >= 0; i--) {
                final TaskAnimationAdapter taskAdapter = mPendingAnimations.get(i);
                final RemoteAnimationTarget target = taskAdapter.createRemoteAnimationApp();
                if (target != null) {
                    appAnimations.add(target);
                } else {
                    removeAnimation(taskAdapter);
                }
            }

            // Skip the animation if there is nothing to animate
            if (appAnimations.isEmpty()) {
                cancelAnimation(REORDER_MOVE_TO_ORIGINAL_POSITION, "startAnimation-noAppWindows");
                return;
            }

            final RemoteAnimationTarget[] appTargets = appAnimations.toArray(
                    new RemoteAnimationTarget[appAnimations.size()]);
            mPendingStart = false;

            final Rect minimizedHomeBounds = mTargetAppToken != null
                    && mTargetAppToken.inSplitScreenSecondaryWindowingMode()
                            ? mMinimizedHomeBounds
                            : null;
            final Rect contentInsets = mTargetAppToken != null
                    && mTargetAppToken.findMainWindow() != null
                            ? mTargetAppToken.findMainWindow().mContentInsets
                            : null;
            mRunner.onAnimationStart_New(mController, appTargets, contentInsets,
                    minimizedHomeBounds);
            if (DEBUG_RECENTS_ANIMATIONS) {
                Slog.d(TAG, "startAnimation(): Notify animation start:");
                for (int i = 0; i < mPendingAnimations.size(); i++) {
                    final Task task = mPendingAnimations.get(i).mTask;
                    Slog.d(TAG, "\t" + task.mTaskId);
                }
            }
        } catch (RemoteException e) {
            Slog.e(TAG, "Failed to start recents animation", e);
        }
        final SparseIntArray reasons = new SparseIntArray();
        reasons.put(WINDOWING_MODE_FULLSCREEN, APP_TRANSITION_RECENTS_ANIM);
        mService.mH.obtainMessage(NOTIFY_APP_TRANSITION_STARTING,
                reasons).sendToTarget();
    }

    void cancelAnimation(@ReorderMode int reorderMode, String reason) {
        if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG, "cancelAnimation()");
        synchronized (mService.getWindowManagerLock()) {
            if (mCanceled) {
                // We've already canceled the animation
                return;
            }
            mService.mH.removeCallbacks(mFailsafeRunnable);
            mCanceled = true;
            try {
                mRunner.onAnimationCanceled();
            } catch (RemoteException e) {
                Slog.e(TAG, "Failed to cancel recents animation", e);
            }
        }

        // Clean up and return to the previous app
        // Don't hold the WM lock here as it calls back to AM/RecentsAnimation
        mCallbacks.onAnimationFinished(reorderMode);
    }

    void cleanupAnimation(@ReorderMode int reorderMode) {
        if (DEBUG_RECENTS_ANIMATIONS) Slog.d(TAG,
                "cleanupAnimation(): Notify animation finished mPendingAnimations="
                        + mPendingAnimations.size() + " reorderMode=" + reorderMode);
        for (int i = mPendingAnimations.size() - 1; i >= 0; i--) {
            final TaskAnimationAdapter taskAdapter = mPendingAnimations.get(i);
            if (reorderMode == REORDER_MOVE_TO_TOP || reorderMode == REORDER_KEEP_IN_PLACE) {
                taskAdapter.mTask.dontAnimateDimExit();
            }
            removeAnimation(taskAdapter);
        }

        unlinkToDeathOfRunner();
        // Clear associated input consumers
        mService.mInputMonitor.updateInputWindowsLw(true /*force*/);
        mService.destroyInputConsumer(INPUT_CONSUMER_RECENTS_ANIMATION);
    }

    void scheduleFailsafe() {
        mService.mH.postDelayed(mFailsafeRunnable, FAILSAFE_DELAY);
    }

    private void linkToDeathOfRunner() throws RemoteException {
        if (!mLinkedToDeathOfRunner) {
            mRunner.asBinder().linkToDeath(this, 0);
            mLinkedToDeathOfRunner = true;
        }
    }

    private void unlinkToDeathOfRunner() {
        if (mLinkedToDeathOfRunner) {
            mRunner.asBinder().unlinkToDeath(this, 0);
            mLinkedToDeathOfRunner = false;
        }
    }

    @Override
    public void binderDied() {
        cancelAnimation(REORDER_MOVE_TO_ORIGINAL_POSITION, "binderDied");
    }

    void checkAnimationReady(WallpaperController wallpaperController) {
        if (mPendingStart) {
            final boolean wallpaperReady = !isTargetOverWallpaper()
                    || (wallpaperController.getWallpaperTarget() != null
                            && wallpaperController.wallpaperTransitionReady());
            if (wallpaperReady) {
                mService.getRecentsAnimationController().startAnimation();
            }
        }
    }

    boolean isSplitScreenMinimized() {
        return mSplitScreenMinimized;
    }

    boolean isWallpaperVisible(WindowState w) {
        return w != null && w.mAppToken != null && mTargetAppToken == w.mAppToken
                && isTargetOverWallpaper();
    }

    boolean hasInputConsumerForApp(AppWindowToken appToken) {
        return mInputConsumerEnabled && isAnimatingApp(appToken);
    }

    boolean updateInputConsumerForApp(InputConsumerImpl recentsAnimationInputConsumer,
            boolean hasFocus) {
        // Update the input consumer touchable region to match the target app main window
        final WindowState targetAppMainWindow = mTargetAppToken != null
                ? mTargetAppToken.findMainWindow()
                : null;
        if (targetAppMainWindow != null) {
            targetAppMainWindow.getBounds(mTmpRect);
            recentsAnimationInputConsumer.mWindowHandle.hasFocus = hasFocus;
            recentsAnimationInputConsumer.mWindowHandle.touchableRegion.set(mTmpRect);
            return true;
        }
        return false;
    }

    private boolean isTargetOverWallpaper() {
        if (mTargetAppToken == null) {
            return false;
        }
        return mTargetAppToken.windowsCanBeWallpaperTarget();
    }

    boolean isAnimatingTask(Task task) {
        for (int i = mPendingAnimations.size() - 1; i >= 0; i--) {
            if (task == mPendingAnimations.get(i).mTask) {
                return true;
            }
        }
        return false;
    }

    private boolean isAnimatingApp(AppWindowToken appToken) {
        for (int i = mPendingAnimations.size() - 1; i >= 0; i--) {
            final Task task = mPendingAnimations.get(i).mTask;
            for (int j = task.getChildCount() - 1; j >= 0; j--) {
                final AppWindowToken app = task.getChildAt(j);
                if (app == appToken) {
                    return true;
                }
            }
        }
        return false;
    }

    @VisibleForTesting
    class TaskAnimationAdapter implements AnimationAdapter {

        private final Task mTask;
        private SurfaceControl mCapturedLeash;
        private OnAnimationFinishedCallback mCapturedFinishCallback;
        private final boolean mIsRecentTaskInvisible;
        private RemoteAnimationTarget mTarget;
        private final Point mPosition = new Point();
        private final Rect mBounds = new Rect();

        TaskAnimationAdapter(Task task, boolean isRecentTaskInvisible) {
            mTask = task;
            mIsRecentTaskInvisible = isRecentTaskInvisible;
            final WindowContainer container = mTask.getParent();
            container.getRelativePosition(mPosition);
            container.getBounds(mBounds);
        }

        RemoteAnimationTarget createRemoteAnimationApp() {
            final WindowState mainWindow = mTask.getTopVisibleAppMainWindow();
            if (mainWindow == null) {
                return null;
            }
            final Rect insets = new Rect(mainWindow.mContentInsets);
            InsetUtils.addInsets(insets, mainWindow.mAppToken.getLetterboxInsets());
            mTarget = new RemoteAnimationTarget(mTask.mTaskId, MODE_CLOSING, mCapturedLeash,
                    !mTask.fillsParent(), mainWindow.mWinAnimator.mLastClipRect,
                    insets, mTask.getPrefixOrderIndex(), mPosition, mBounds,
                    mTask.getWindowConfiguration(), mIsRecentTaskInvisible);
            return mTarget;
        }

        @Override
        public boolean getDetachWallpaper() {
            return false;
        }

        @Override
        public boolean getShowWallpaper() {
            return false;
        }

        @Override
        public int getBackgroundColor() {
            return 0;
        }

        @Override
        public void startAnimation(SurfaceControl animationLeash, Transaction t,
                OnAnimationFinishedCallback finishCallback) {
            t.setPosition(animationLeash, mPosition.x, mPosition.y);
            mCapturedLeash = animationLeash;
            mCapturedFinishCallback = finishCallback;
        }

        @Override
        public void onAnimationCancelled(SurfaceControl animationLeash) {
            cancelAnimation(REORDER_MOVE_TO_ORIGINAL_POSITION, "taskAnimationAdapterCanceled");
        }

        @Override
        public long getDurationHint() {
            return 0;
        }

        @Override
        public long getStatusBarTransitionsStartTime() {
            return SystemClock.uptimeMillis();
        }

        @Override
        public void dump(PrintWriter pw, String prefix) {
            pw.print(prefix); pw.println("task=" + mTask);
            if (mTarget != null) {
                pw.print(prefix); pw.println("Target:");
                mTarget.dump(pw, prefix + "  ");
            } else {
                pw.print(prefix); pw.println("Target: null");
            }
            pw.println("mIsRecentTaskInvisible=" + mIsRecentTaskInvisible);
            pw.println("mPosition=" + mPosition);
            pw.println("mBounds=" + mBounds);
            pw.println("mIsRecentTaskInvisible=" + mIsRecentTaskInvisible);
        }

        @Override
        public void writeToProto(ProtoOutputStream proto) {
            final long token = proto.start(REMOTE);
            if (mTarget != null) {
                mTarget.writeToProto(proto, TARGET);
            }
            proto.end(token);
        }
    }

    public void dump(PrintWriter pw, String prefix) {
        final String innerPrefix = prefix + "  ";
        pw.print(prefix); pw.println(RecentsAnimationController.class.getSimpleName() + ":");
        pw.print(innerPrefix); pw.println("mPendingStart=" + mPendingStart);
        pw.print(innerPrefix); pw.println("mCanceled=" + mCanceled);
        pw.print(innerPrefix); pw.println("mInputConsumerEnabled=" + mInputConsumerEnabled);
        pw.print(innerPrefix); pw.println("mSplitScreenMinimized=" + mSplitScreenMinimized);
        pw.print(innerPrefix); pw.println("mTargetAppToken=" + mTargetAppToken);
        pw.print(innerPrefix); pw.println("isTargetOverWallpaper=" + isTargetOverWallpaper());
    }
}