/*
 * Copyright (C) 2020 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.WindowConfiguration.WINDOWING_MODE_FREEFORM;
import static android.view.Display.DEFAULT_DISPLAY;

import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_INPUT;
import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;
import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
import static com.android.server.wm.WindowManagerService.H.ON_POINTER_DOWN_OUTSIDE_FOCUS;

import android.annotation.NonNull;
import android.annotation.Nullable;
import android.graphics.PointF;
import android.os.Debug;
import android.os.IBinder;
import android.util.Slog;
import android.view.Display;
import android.view.InputApplicationHandle;
import android.view.KeyEvent;
import android.view.SurfaceControl;
import android.view.WindowManager;
import android.view.WindowManagerPolicyConstants;

import com.android.internal.util.function.pooled.PooledLambda;
import com.android.server.input.InputManagerService;

import java.io.PrintWriter;
import java.util.OptionalInt;

final class InputManagerCallback implements InputManagerService.WindowManagerCallbacks {
    private static final String TAG = TAG_WITH_CLASS_NAME ? "InputManagerCallback" : TAG_WM;

    private final WindowManagerService mService;

    // Set to true when the first input device configuration change notification
    // is received to indicate that the input devices are ready.
    private final Object mInputDevicesReadyMonitor = new Object();
    private boolean mInputDevicesReady;

    // When true, prevents input dispatch from proceeding until set to false again.
    private boolean mInputDispatchFrozen;

    // The reason the input is currently frozen or null if the input isn't frozen.
    private String mInputFreezeReason = null;

    // When true, input dispatch proceeds normally.  Otherwise all events are dropped.
    // Initially false, so that input does not get dispatched until boot is finished at
    // which point the ActivityManager will enable dispatching.
    private boolean mInputDispatchEnabled;

    public InputManagerCallback(WindowManagerService service) {
        mService = service;
    }

    /**
     * Notifies the window manager about a broken input channel.
     *
     * Called by the InputManager.
     */
    @Override
    public void notifyInputChannelBroken(IBinder token) {
        if (token == null) {
            return;
        }

        synchronized (mService.mGlobalLock) {
            WindowState windowState = mService.mInputToWindowMap.get(token);
            if (windowState != null) {
                Slog.i(TAG_WM, "WINDOW DIED " + windowState);
                windowState.removeIfPossible();
            }
        }
    }

    /**
     * Notifies the window manager about an application that is not responding because it has
     * no focused window.
     *
     * Called by the InputManager.
     */
    @Override
    public void notifyNoFocusedWindowAnr(@NonNull InputApplicationHandle applicationHandle) {
        mService.mAnrController.notifyAppUnresponsive(
                applicationHandle, "Application does not have a focused window");
    }

    @Override
    public void notifyWindowUnresponsive(@NonNull IBinder token, @NonNull OptionalInt pid,
            @NonNull String reason) {
        mService.mAnrController.notifyWindowUnresponsive(token, pid, reason);
    }

    @Override
    public void notifyWindowResponsive(@NonNull IBinder token, @NonNull OptionalInt pid) {
        mService.mAnrController.notifyWindowResponsive(token, pid);
    }

    /** Notifies that the input device configuration has changed. */
    @Override
    public void notifyConfigurationChanged() {
        synchronized (mService.mGlobalLock) {
            mService.mRoot.forAllDisplays(DisplayContent::sendNewConfiguration);
        }

        synchronized (mInputDevicesReadyMonitor) {
            if (!mInputDevicesReady) {
                mInputDevicesReady = true;
                mInputDevicesReadyMonitor.notifyAll();
            }
        }
    }

    /** Notifies that the lid switch changed state. */
    @Override
    public void notifyLidSwitchChanged(long whenNanos, boolean lidOpen) {
        mService.mPolicy.notifyLidSwitchChanged(whenNanos, lidOpen);
    }

    /** Notifies that the camera lens cover state has changed. */
    @Override
    public void notifyCameraLensCoverSwitchChanged(long whenNanos, boolean lensCovered) {
        mService.mPolicy.notifyCameraLensCoverSwitchChanged(whenNanos, lensCovered);
    }

    /**
     * Provides an opportunity for the window manager policy to intercept early key
     * processing as soon as the key has been read from the device.
     */
    @Override
    public int interceptKeyBeforeQueueing(KeyEvent event, int policyFlags) {
        return mService.mPolicy.interceptKeyBeforeQueueing(event, policyFlags);
    }

    /** {@inheritDoc} */
    @Override
    public int interceptMotionBeforeQueueingNonInteractive(int displayId, long whenNanos,
            int policyFlags) {
        return mService.mPolicy.interceptMotionBeforeQueueingNonInteractive(
                displayId, whenNanos, policyFlags);
    }

    /**
     * Provides an opportunity for the window manager policy to process a key before
     * ordinary dispatch.
     */
    @Override
    public long interceptKeyBeforeDispatching(
            IBinder focusedToken, KeyEvent event, int policyFlags) {
        return mService.mPolicy.interceptKeyBeforeDispatching(focusedToken, event, policyFlags);
    }

    /**
     * Provides an opportunity for the window manager policy to process a key that
     * the application did not handle.
     */
    @Override
    public KeyEvent dispatchUnhandledKey(
            IBinder focusedToken, KeyEvent event, int policyFlags) {
        return mService.mPolicy.dispatchUnhandledKey(focusedToken, event, policyFlags);
    }

    /** Callback to get pointer layer. */
    @Override
    public int getPointerLayer() {
        return mService.mPolicy.getWindowLayerFromTypeLw(WindowManager.LayoutParams.TYPE_POINTER)
                * WindowManagerPolicyConstants.TYPE_LAYER_MULTIPLIER
                + WindowManagerPolicyConstants.TYPE_LAYER_OFFSET;
    }

    /** Callback to get pointer display id. */
    @Override
    public int getPointerDisplayId() {
        synchronized (mService.mGlobalLock) {
            // If desktop mode is not enabled, show on the default display.
            if (!mService.mForceDesktopModeOnExternalDisplays) {
                return DEFAULT_DISPLAY;
            }

            // Look for the topmost freeform display.
            int firstExternalDisplayId = DEFAULT_DISPLAY;
            for (int i = mService.mRoot.mChildren.size() - 1; i >= 0; --i) {
                final DisplayContent displayContent = mService.mRoot.mChildren.get(i);
                if (displayContent.getDisplayInfo().state == Display.STATE_OFF) {
                    continue;
                }
                // Heuristic solution here. Currently when "Freeform windows" developer option is
                // enabled we automatically put secondary displays in freeform mode and emulating
                // "desktop mode". It also makes sense to show the pointer on the same display.
                if (displayContent.getWindowingMode() == WINDOWING_MODE_FREEFORM) {
                    return displayContent.getDisplayId();
                }

                if (firstExternalDisplayId == DEFAULT_DISPLAY
                        && displayContent.getDisplayId() != DEFAULT_DISPLAY) {
                    firstExternalDisplayId = displayContent.getDisplayId();
                }
            }

            // Look for the topmost non-default display
            return firstExternalDisplayId;
        }
    }

    @Override
    public PointF getCursorPosition() {
        return mService.getLatestMousePosition();
    }

    @Override
    public void onPointerDownOutsideFocus(IBinder touchedToken) {
        mService.mH.obtainMessage(ON_POINTER_DOWN_OUTSIDE_FOCUS, touchedToken).sendToTarget();
    }

    @Override
    public void notifyFocusChanged(IBinder oldToken, IBinder newToken) {
        mService.mH.sendMessage(PooledLambda.obtainMessage(
                mService::reportFocusChanged, oldToken, newToken));
    }

    @Override
    public void notifyDropWindow(IBinder token, float x, float y) {
        mService.mH.sendMessage(PooledLambda.obtainMessage(
                mService.mDragDropController::reportDropWindow, token, x, y));
    }

    @Override
    public SurfaceControl getParentSurfaceForPointers(int displayId) {
        synchronized (mService.mGlobalLock) {
            final DisplayContent dc = mService.mRoot.getDisplayContent(displayId);
            if (dc == null) {
                Slog.e(TAG, "Failed to get parent surface for pointers on display " + displayId
                        + " - DisplayContent not found.");
                return null;
            }
            return dc.getOverlayLayer();
        }
    }

    @Override
    @Nullable
    public SurfaceControl createSurfaceForGestureMonitor(String name, int displayId) {
        synchronized (mService.mGlobalLock) {
            final DisplayContent dc = mService.mRoot.getDisplayContent(displayId);
            if (dc == null) {
                Slog.e(TAG, "Failed to create a gesture monitor on display: " + displayId
                        + " - DisplayContent not found.");
                return null;
            }
            return mService.makeSurfaceBuilder(dc.getSession())
                    .setContainerLayer()
                    .setName(name)
                    .setCallsite("createSurfaceForGestureMonitor")
                    .setParent(dc.getSurfaceControl())
                    .build();
        }
    }

    @Override
    public void notifyPointerDisplayIdChanged(int displayId, float x, float y) {
        synchronized (mService.mGlobalLock) {
            mService.setMousePointerDisplayId(displayId);
            if (displayId == Display.INVALID_DISPLAY) return;

            final DisplayContent dc = mService.mRoot.getDisplayContent(displayId);
            if (dc == null) {
                Slog.wtf(TAG, "The mouse pointer was moved to display " + displayId
                        + " that does not have a valid DisplayContent.");
                return;
            }
            mService.restorePointerIconLocked(dc, x, y);
        }
    }

    /** Waits until the built-in input devices have been configured. */
    public boolean waitForInputDevicesReady(long timeoutMillis) {
        synchronized (mInputDevicesReadyMonitor) {
            if (!mInputDevicesReady) {
                try {
                    mInputDevicesReadyMonitor.wait(timeoutMillis);
                } catch (InterruptedException ex) {
                }
            }
            return mInputDevicesReady;
        }
    }

    public void freezeInputDispatchingLw() {
        if (!mInputDispatchFrozen) {
            if (DEBUG_INPUT) {
                Slog.v(TAG_WM, "Freezing input dispatching");
            }

            mInputDispatchFrozen = true;

            if (DEBUG_INPUT) {
                mInputFreezeReason = Debug.getCallers(6);
            }
            updateInputDispatchModeLw();
        }
    }

    public void thawInputDispatchingLw() {
        if (mInputDispatchFrozen) {
            if (DEBUG_INPUT) {
                Slog.v(TAG_WM, "Thawing input dispatching");
            }

            mInputDispatchFrozen = false;
            mInputFreezeReason = null;
            updateInputDispatchModeLw();
        }
    }

    public void setEventDispatchingLw(boolean enabled) {
        if (mInputDispatchEnabled != enabled) {
            if (DEBUG_INPUT) {
                Slog.v(TAG_WM, "Setting event dispatching to " + enabled);
            }

            mInputDispatchEnabled = enabled;
            updateInputDispatchModeLw();
        }
    }

    private void updateInputDispatchModeLw() {
        mService.mInputManager.setInputDispatchMode(mInputDispatchEnabled, mInputDispatchFrozen);
    }

    void dump(PrintWriter pw, String prefix) {
        if (mInputFreezeReason != null) {
            pw.println(prefix + "mInputFreezeReason=" + mInputFreezeReason);
        }
    }
}
