/*
 * Copyright (C) 2019 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 android.view;

import static android.view.WindowCallbacks.RESIZE_MODE_INVALID;

import android.annotation.Nullable;
import android.content.res.Configuration;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.Region;
import android.os.Binder;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteCallback;
import android.os.RemoteException;
import android.util.Log;
import android.util.MergedConfiguration;
import android.window.ClientWindowFrames;
import android.window.OnBackInvokedCallbackInfo;

import java.util.HashMap;
import java.util.List;
import java.util.Objects;

/**
* A simplistic implementation of IWindowSession. Rather than managing Surfaces
* as children of the display, it manages Surfaces as children of a given root.
*
* By parcelling the root surface, the app can offer another app content for embedding.
* @hide
*/
public class WindowlessWindowManager implements IWindowSession {
    private final static String TAG = "WindowlessWindowManager";

    private class State {
        SurfaceControl mSurfaceControl;
        WindowManager.LayoutParams mParams = new WindowManager.LayoutParams();
        int mDisplayId;
        IBinder mInputChannelToken;
        Region mInputRegion;
        IWindow mClient;
        State(SurfaceControl sc, WindowManager.LayoutParams p, int displayId,
              IBinder inputChannelToken, IWindow client) {
            mSurfaceControl = sc;
            mParams.copyFrom(p);
            mDisplayId = displayId;
            mInputChannelToken = inputChannelToken;
            mClient = client;
        }
    };

    /**
     * Used to store SurfaceControl we've built for clients to
     * reconfigure them if relayout is called.
     */
    final HashMap<IBinder, State> mStateForWindow = new HashMap<IBinder, State>();

    public interface ResizeCompleteCallback {
        public void finished(SurfaceControl.Transaction completion);
    }

    final HashMap<IBinder, ResizeCompleteCallback> mResizeCompletionForWindow =
        new HashMap<IBinder, ResizeCompleteCallback>();

    private final SurfaceSession mSurfaceSession = new SurfaceSession();
    protected final SurfaceControl mRootSurface;
    private final Configuration mConfiguration;
    private final IWindowSession mRealWm;
    private final IBinder mHostInputToken;
    private final IBinder mFocusGrantToken = new Binder();
    private InsetsState mInsetsState;
    private final ClientWindowFrames mTmpFrames = new ClientWindowFrames();
    private final MergedConfiguration mTmpConfig = new MergedConfiguration();

    public WindowlessWindowManager(Configuration c, SurfaceControl rootSurface,
            IBinder hostInputToken) {
        mRootSurface = rootSurface;
        mConfiguration = new Configuration(c);
        mRealWm = WindowManagerGlobal.getWindowSession();
        mHostInputToken = hostInputToken;
    }

    public void setConfiguration(Configuration configuration) {
        mConfiguration.setTo(configuration);
    }

    IBinder getFocusGrantToken() {
        return mFocusGrantToken;
    }

    /**
     * Utility API.
     */
    void setCompletionCallback(IBinder window, ResizeCompleteCallback callback) {
        if (mResizeCompletionForWindow.get(window) != null) {
            Log.w(TAG, "Unsupported overlapping resizes");
        }
        mResizeCompletionForWindow.put(window, callback);
    }

    protected void setTouchRegion(IBinder window, @Nullable Region region) {
        State state;
        synchronized (this) {
            // Do everything while locked so that we synchronize with relayout. This should be a
            // very infrequent operation.
            state = mStateForWindow.get(window);
            if (state == null) {
                return;
            }
            if (Objects.equals(region, state.mInputRegion)) {
                return;
            }
            state.mInputRegion = region != null ? new Region(region) : null;
            if (state.mInputChannelToken != null) {
                try {
                    mRealWm.updateInputChannel(state.mInputChannelToken, state.mDisplayId,
                            state.mSurfaceControl, state.mParams.flags, state.mParams.privateFlags,
                            state.mInputRegion);
                } catch (RemoteException e) {
                    Log.e(TAG, "Failed to update surface input channel: ", e);
                }
            }
        }
    }

    protected void attachToParentSurface(IWindow window, SurfaceControl.Builder b) {
        b.setParent(mRootSurface);
    }

    /**
     * IWindowSession implementation.
     */
    @Override
    public int addToDisplay(IWindow window, WindowManager.LayoutParams attrs,
            int viewVisibility, int displayId, InsetsVisibilities requestedVisibilities,
            InputChannel outInputChannel, InsetsState outInsetsState,
            InsetsSourceControl[] outActiveControls) {
        final SurfaceControl.Builder b = new SurfaceControl.Builder(mSurfaceSession)
                .setFormat(attrs.format)
                .setBLASTLayer()
                .setName(attrs.getTitle().toString())
                .setCallsite("WindowlessWindowManager.addToDisplay");
        attachToParentSurface(window, b);
        final SurfaceControl sc = b.build();

        if (((attrs.inputFeatures &
                WindowManager.LayoutParams.INPUT_FEATURE_NO_INPUT_CHANNEL) == 0)) {
            try {
                if (mRealWm instanceof IWindowSession.Stub) {
                    mRealWm.grantInputChannel(displayId,
                            new SurfaceControl(sc, "WindowlessWindowManager.addToDisplay"),
                            window, mHostInputToken, attrs.flags, attrs.privateFlags, attrs.type,
                            mFocusGrantToken, attrs.getTitle().toString(), outInputChannel);
                } else {
                    mRealWm.grantInputChannel(displayId, sc, window, mHostInputToken, attrs.flags,
                            attrs.privateFlags, attrs.type, mFocusGrantToken,
                            attrs.getTitle().toString(), outInputChannel);
                }
            } catch (RemoteException e) {
                Log.e(TAG, "Failed to grant input to surface: ", e);
            }
        }

        final State state = new State(sc, attrs, displayId,
            outInputChannel != null ? outInputChannel.getToken() : null, window);
        synchronized (this) {
            mStateForWindow.put(window.asBinder(), state);
        }

        final int res = WindowManagerGlobal.ADD_OKAY | WindowManagerGlobal.ADD_FLAG_APP_VISIBLE |
                        WindowManagerGlobal.ADD_FLAG_USE_BLAST;

        // Include whether the window is in touch mode.
        return isInTouchMode() ? res | WindowManagerGlobal.ADD_FLAG_IN_TOUCH_MODE : res;
    }

    /**
     * IWindowSession implementation. Currently this class doesn't need to support for multi-user.
     */
    @Override
    public int addToDisplayAsUser(IWindow window, WindowManager.LayoutParams attrs,
            int viewVisibility, int displayId, int userId, InsetsVisibilities requestedVisibilities,
            InputChannel outInputChannel, InsetsState outInsetsState,
            InsetsSourceControl[] outActiveControls) {
        return addToDisplay(window, attrs, viewVisibility, displayId, requestedVisibilities,
                outInputChannel, outInsetsState, outActiveControls);
    }

    @Override
    public int addToDisplayWithoutInputChannel(android.view.IWindow window,
            android.view.WindowManager.LayoutParams attrs, int viewVisibility, int layerStackId,
            android.view.InsetsState insetsState) {
        return 0;
    }

    @Override
    public void remove(android.view.IWindow window) throws RemoteException {
        mRealWm.remove(window);
        State state;
        synchronized (this) {
            state = mStateForWindow.remove(window.asBinder());
        }
        if (state == null) {
            throw new IllegalArgumentException(
                    "Invalid window token (never added or removed already)");
        }
        removeSurface(state.mSurfaceControl);
    }

    /** Separate from {@link #remove} so that subclasses can put removal on a sync transaction. */
    protected void removeSurface(SurfaceControl sc) {
        try (SurfaceControl.Transaction t = new SurfaceControl.Transaction()) {
            t.remove(sc).apply();
        }
    }

    private boolean isOpaque(WindowManager.LayoutParams attrs) {
        if (attrs.surfaceInsets != null && attrs.surfaceInsets.left != 0 ||
                attrs.surfaceInsets.top != 0 || attrs.surfaceInsets.right != 0 ||
                attrs.surfaceInsets.bottom != 0) {
            return false;
        }
        return !PixelFormat.formatHasAlpha(attrs.format);
    }

    private boolean isInTouchMode() {
        try {
            return WindowManagerGlobal.getWindowSession().getInTouchMode();
        } catch (RemoteException e) {
            Log.e(TAG, "Unable to check if the window is in touch mode", e);
        }
        return false;
    }

    /** Access to package members for SystemWindow leashing
     * @hide
     */
    protected IBinder getWindowBinder(View rootView) {
        final ViewRootImpl root = rootView.getViewRootImpl();
        if (root == null) {
            return null;
        }
        return root.mWindow.asBinder();
    }

    /** @hide */
    @Nullable
    protected SurfaceControl getSurfaceControl(View rootView) {
        final ViewRootImpl root = rootView.getViewRootImpl();
        if (root == null) {
            return null;
        }
        return getSurfaceControl(root.mWindow);
    }

    /** @hide */
    @Nullable
    protected SurfaceControl getSurfaceControl(IWindow window) {
        final State s = mStateForWindow.get(window.asBinder());
        if (s == null) {
            return null;
        }
        return s.mSurfaceControl;
    }

    @Override
    public int relayout(IWindow window, WindowManager.LayoutParams inAttrs,
            int requestedWidth, int requestedHeight, int viewFlags, int flags,
            ClientWindowFrames outFrames, MergedConfiguration mergedConfiguration,
            SurfaceControl outSurfaceControl, InsetsState outInsetsState,
            InsetsSourceControl[] outActiveControls, Bundle outSyncSeqIdBundle) {
        final State state;
        synchronized (this) {
            state = mStateForWindow.get(window.asBinder());
        }
        if (state == null) {
            throw new IllegalArgumentException(
                    "Invalid window token (never added or removed already)");
        }
        SurfaceControl sc = state.mSurfaceControl;
        SurfaceControl.Transaction t = new SurfaceControl.Transaction();

        int attrChanges = 0;
        if (inAttrs != null) {
            attrChanges = state.mParams.copyFrom(inAttrs);
        }
        WindowManager.LayoutParams attrs = state.mParams;

        if (viewFlags == View.VISIBLE) {
            t.setOpaque(sc, isOpaque(attrs)).show(sc).apply();
            outSurfaceControl.copyFrom(sc, "WindowlessWindowManager.relayout");
        } else {
            t.hide(sc).apply();
            outSurfaceControl.release();
        }
        outFrames.frame.set(0, 0, attrs.width, attrs.height);
        outFrames.displayFrame.set(outFrames.frame);

        mergedConfiguration.setConfiguration(mConfiguration, mConfiguration);

        if ((attrChanges & WindowManager.LayoutParams.FLAGS_CHANGED) != 0
                && state.mInputChannelToken != null) {
            try {
                if(mRealWm instanceof IWindowSession.Stub) {
                    mRealWm.updateInputChannel(state.mInputChannelToken, state.mDisplayId,
                            new SurfaceControl(sc, "WindowlessWindowManager.relayout"),
                            attrs.flags, attrs.privateFlags, state.mInputRegion);
                } else {
                    mRealWm.updateInputChannel(state.mInputChannelToken, state.mDisplayId, sc,
                            attrs.flags, attrs.privateFlags, state.mInputRegion);
                }
            } catch (RemoteException e) {
                Log.e(TAG, "Failed to update surface input channel: ", e);
            }
        }

        if (mInsetsState != null) {
            outInsetsState.set(mInsetsState);
        }

        return 0;
    }

    @Override
    public int updateVisibility(IWindow window, WindowManager.LayoutParams inAttrs,
            int viewVisibility, MergedConfiguration outMergedConfiguration,
            SurfaceControl outSurfaceControl, InsetsState outInsetsState,
            InsetsSourceControl[] outActiveControls) {
        // TODO(b/161810301): Finish the implementation.
        return 0;
    }

    @Override
    public void updateLayout(IWindow window, WindowManager.LayoutParams inAttrs, int flags,
            ClientWindowFrames clientWindowFrames, int requestedWidth, int requestedHeight) {
        // TODO(b/161810301): Finish the implementation.
    }

    @Override
    public void prepareToReplaceWindows(android.os.IBinder appToken, boolean childrenOnly) {
    }

    @Override
    public boolean outOfMemory(android.view.IWindow window) {
        return false;
    }

    @Override
    public void setInsets(android.view.IWindow window, int touchableInsets,
            android.graphics.Rect contentInsets, android.graphics.Rect visibleInsets,
            android.graphics.Region touchableRegion) {
        setTouchRegion(window.asBinder(), touchableRegion);
    }

    @Override
    public void clearTouchableRegion(android.view.IWindow window) {
        setTouchRegion(window.asBinder(), null);
    }

    @Override
    public void finishDrawing(android.view.IWindow window,
            android.view.SurfaceControl.Transaction postDrawTransaction, int seqId) {
        synchronized (this) {
            final ResizeCompleteCallback c =
                mResizeCompletionForWindow.get(window.asBinder());
            if (c == null) {
                // No one wanted the callback, but it wasn't necessarily unexpected.
                postDrawTransaction.apply();
                return;
            }
            c.finished(postDrawTransaction);
            mResizeCompletionForWindow.remove(window.asBinder());
        }
    }

    @Override
    public void setInTouchMode(boolean showFocus) {
    }

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

    @Override
    public boolean performHapticFeedback(int effectId, boolean always) {
        return false;
    }

    @Override
    public android.os.IBinder performDrag(android.view.IWindow window, int flags,
            android.view.SurfaceControl surface, int touchSource, float touchX, float touchY,
            float thumbCenterX, float thumbCenterY, android.content.ClipData data) {
        return null;
    }

    @Override
    public void reportDropResult(android.view.IWindow window, boolean consumed) {
    }

    @Override
    public void cancelDragAndDrop(android.os.IBinder dragToken, boolean skipAnimation) {
    }

    @Override
    public void dragRecipientEntered(android.view.IWindow window) {
    }

    @Override
    public void dragRecipientExited(android.view.IWindow window) {
    }

    @Override
    public void setWallpaperPosition(android.os.IBinder windowToken, float x, float y,
            float xstep, float ystep) {
    }

    @Override
    public void setWallpaperZoomOut(android.os.IBinder windowToken, float zoom) {
    }

    @Override
    public void setShouldZoomOutWallpaper(android.os.IBinder windowToken, boolean shouldZoom) {
    }

    @Override
    public void wallpaperOffsetsComplete(android.os.IBinder window) {
    }

    @Override
    public void setWallpaperDisplayOffset(android.os.IBinder windowToken, int x, int y) {
    }

    @Override
    public android.os.Bundle sendWallpaperCommand(android.os.IBinder window,
            java.lang.String action, int x, int y, int z, android.os.Bundle extras, boolean sync) {
        return null;
    }

    @Override
    public void wallpaperCommandComplete(android.os.IBinder window, android.os.Bundle result) {
    }

    @Override
    public void onRectangleOnScreenRequested(android.os.IBinder token,
            android.graphics.Rect rectangle) {
    }

    @Override
    public android.view.IWindowId getWindowId(android.os.IBinder window) {
        return null;
    }

    @Override
    public void pokeDrawLock(android.os.IBinder window) {
    }

    @Override
    public boolean startMovingTask(android.view.IWindow window, float startX, float startY) {
        return false;
    }

    @Override
    public void finishMovingTask(android.view.IWindow window) {
    }

    @Override
    public void updatePointerIcon(android.view.IWindow window) {
    }

    @Override
    public void updateTapExcludeRegion(android.view.IWindow window,
            android.graphics.Region region) {
    }

    @Override
    public void updateRequestedVisibilities(IWindow window, InsetsVisibilities visibilities)  {
    }

    @Override
    public void reportSystemGestureExclusionChanged(android.view.IWindow window,
            List<Rect> exclusionRects) {
    }

    @Override
    public void reportKeepClearAreasChanged(android.view.IWindow window, List<Rect> restrictedRects,
            List<Rect> unrestrictedRects) {
    }

    @Override
    public void grantInputChannel(int displayId, SurfaceControl surface, IWindow window,
            IBinder hostInputToken, int flags, int privateFlags, int type, IBinder focusGrantToken,
            String inputHandleName, InputChannel outInputChannel) {
    }

    @Override
    public void updateInputChannel(IBinder channelToken, int displayId, SurfaceControl surface,
            int flags, int privateFlags, Region region) {
    }

    @Override
    public android.os.IBinder asBinder() {
        return null;
    }

    @Override
    public void grantEmbeddedWindowFocus(IWindow callingWindow, IBinder targetInputToken,
                                         boolean grantFocus) {
    }

    @Override
    public void generateDisplayHash(IWindow window, Rect boundsInWindow, String hashAlgorithm,
            RemoteCallback callback) {
    }

    @Override
    public void setOnBackInvokedCallbackInfo(IWindow iWindow,
            OnBackInvokedCallbackInfo callbackInfo) throws RemoteException { }

    @Override
    public boolean dropForAccessibility(IWindow window, int x, int y) {
        return false;
    }

    public void setInsetsState(InsetsState state) {
        mInsetsState = state;
        for (State s : mStateForWindow.values()) {
            try {
                mTmpFrames.frame.set(0, 0, s.mParams.width, s.mParams.height);
                mTmpFrames.displayFrame.set(mTmpFrames.frame);
                mTmpConfig.setConfiguration(mConfiguration, mConfiguration);
                s.mClient.resized(mTmpFrames, false /* reportDraw */, mTmpConfig, state,
                        false /* forceLayout */, false /* alwaysConsumeSystemBars */, s.mDisplayId,
                        Integer.MAX_VALUE, RESIZE_MODE_INVALID);
            } catch (RemoteException e) {
                // Too bad
            }
        }
    }

    @Override
    public boolean cancelDraw(IWindow window) {
        return false;
    }
}