/*
 * Copyright (C) 2012 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 com.android.server.wm.WindowManagerService.FORWARD_ITERATOR;
import static com.android.server.wm.WindowManagerService.REVERSE_ITERATOR;

import android.util.SparseArray;
import android.view.Display;
import android.view.DisplayInfo;

import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.NoSuchElementException;

class DisplayContentList extends ArrayList<DisplayContent> {
}

/**
 * Utility class for keeping track of the WindowStates and other pertinent contents of a
 * particular Display.
 *
 * IMPORTANT: No method from this class should ever be used without holding
 * WindowManagerService.mWindowMap.
 */
class DisplayContent {
//    private final static String TAG = "DisplayContent";

    /** Unique identifier of this stack. */
    private final int mDisplayId;

    /** Z-ordered (bottom-most first) list of all Window objects. Assigned to an element
     * from mDisplayWindows; */
    private WindowList mWindows = new WindowList();

    // This protects the following display size properties, so that
    // getDisplaySize() doesn't need to acquire the global lock.  This is
    // needed because the window manager sometimes needs to use ActivityThread
    // while it has its global state locked (for example to load animation
    // resources), but the ActivityThread also needs get the current display
    // size sometimes when it has its package lock held.
    //
    // These will only be modified with both mWindowMap and mDisplaySizeLock
    // held (in that order) so the window manager doesn't need to acquire this
    // lock when needing these values in its normal operation.
    final Object mDisplaySizeLock = new Object();
    int mInitialDisplayWidth = 0;
    int mInitialDisplayHeight = 0;
    int mInitialDisplayDensity = 0;
    int mBaseDisplayWidth = 0;
    int mBaseDisplayHeight = 0;
    int mBaseDisplayDensity = 0;
    private final DisplayInfo mDisplayInfo = new DisplayInfo();
    private final Display mDisplay;

    // Accessed directly by all users.
    boolean layoutNeeded;
    int pendingLayoutChanges;
    final boolean isDefaultDisplay;

    /**
     * Window tokens that are in the process of exiting, but still
     * on screen for animations.
     */
    final ArrayList<WindowToken> mExitingTokens = new ArrayList<WindowToken>();

    /**
     * Application tokens that are in the process of exiting, but still
     * on screen for animations.
     */
    final AppTokenList mExitingAppTokens = new AppTokenList();

    /**
     * Sorted most recent at top, oldest at [0].
     */
    ArrayList<TaskList> mTaskLists = new ArrayList<TaskList>();
    SparseArray<TaskList> mTaskIdToTaskList = new SparseArray<TaskList>();

    private final AppTokenIterator mTmpAppIterator = new AppTokenIterator();

    /**
     * @param display May not be null.
     */
    DisplayContent(Display display) {
        mDisplay = display;
        mDisplayId = display.getDisplayId();
        display.getDisplayInfo(mDisplayInfo);
        isDefaultDisplay = mDisplayId == Display.DEFAULT_DISPLAY;
    }

    int getDisplayId() {
        return mDisplayId;
    }

    WindowList getWindowList() {
        return mWindows;
    }

    Display getDisplay() {
        return mDisplay;
    }

    DisplayInfo getDisplayInfo() {
        return mDisplayInfo;
    }

    public void updateDisplayInfo() {
        mDisplay.getDisplayInfo(mDisplayInfo);
    }

    /**
     *  Find the location to insert a new AppWindowToken into the window-ordered app token list.
     * @param addPos The location the token was inserted into in mAppTokens.
     * @param wtoken The token to insert.
     */
    void addAppToken(final int addPos, final AppWindowToken wtoken) {
        TaskList task = mTaskIdToTaskList.get(wtoken.groupId);
        if (task == null) {
            task = new TaskList(wtoken, this);
            mTaskIdToTaskList.put(wtoken.groupId, task);
            mTaskLists.add(task);
        } else {
            task.mAppTokens.add(addPos, wtoken);
        }
    }

    void removeAppToken(final AppWindowToken wtoken) {
        final int taskId = wtoken.groupId;
        final TaskList task = mTaskIdToTaskList.get(taskId);
        if (task != null) {
            AppTokenList appTokens = task.mAppTokens;
            appTokens.remove(wtoken);
            if (appTokens.size() == 0) {
                mTaskLists.remove(task);
                mTaskIdToTaskList.delete(taskId);
            }
        }
    }

    void setAppTaskId(AppWindowToken wtoken, int newTaskId) {
        final int taskId = wtoken.groupId;
        TaskList task = mTaskIdToTaskList.get(taskId);
        if (task != null) {
            AppTokenList appTokens = task.mAppTokens;
            appTokens.remove(wtoken);
            if (appTokens.size() == 0) {
                mTaskIdToTaskList.delete(taskId);
            }
        }

        task = mTaskIdToTaskList.get(newTaskId);
        if (task == null) {
            task = new TaskList(wtoken, this);
            mTaskIdToTaskList.put(newTaskId, task);
        } else {
            task.mAppTokens.add(wtoken);
        }

        wtoken.groupId = newTaskId;
    }

    /**
     * Return the utility iterator so we don't have to construct new iterators every time we
     * iterate.
     * NOTE: Do not ever nest this call or you will have a bad time!
     * @param reverse Direction of iterator.
     * @return The utility iterator.
     */
    AppTokenIterator getTmpAppIterator(boolean reverse) {
        mTmpAppIterator.reset(reverse);
        return mTmpAppIterator;
    }

    class AppTokenIterator implements Iterator<AppWindowToken> {
        boolean mReverse;
        int mTasksNdx;
        int mActivityNdx;
        TaskList mTaskList;

        public AppTokenIterator() {
            this(FORWARD_ITERATOR);
        }

        public AppTokenIterator(boolean reverse) {
            reset(reverse);
        }

        void reset(boolean reverse) {
            mReverse = reverse;
            mTasksNdx = reverse ? mTaskLists.size() - 1 : 0;
            getNextTaskList();
        }

        private void getNextTaskList() {
            if (mReverse) {
                if (mTasksNdx >= 0) {
                    mTaskList = mTaskLists.get(mTasksNdx);
                    --mTasksNdx;
                    mActivityNdx = mTaskList.mAppTokens.size() - 1;
                }
            } else {
                if (mTasksNdx < mTaskLists.size()) {
                    mTaskList = mTaskLists.get(mTasksNdx);
                    ++mTasksNdx;
                    mActivityNdx = 0;
                }
            }
        }

        @Override
        public boolean hasNext() {
            if (mTaskList == null) {
                return false;
            }
            if (mReverse) {
                return mActivityNdx >= 0;
            }
            return mActivityNdx < mTaskList.mAppTokens.size();
        }

        @Override
        public AppWindowToken next() {
            if (hasNext()) {
                AppWindowToken wtoken = mTaskList.mAppTokens.get(mActivityNdx);
                mActivityNdx += mReverse ? -1 : 1;
                if (!hasNext()) {
                    getNextTaskList();
                }
                return wtoken;
            }
            throw new NoSuchElementException();
        }

        @Override
        public void remove() {
            throw new IllegalArgumentException();
        }

        int size() {
            int size = 0;
            for (int i = mTaskLists.size() - 1; i >= 0; --i) {
                size += mTaskLists.get(i).mAppTokens.size();
            }
            return size;
        }

        @Override public String toString() {
            return mTaskLists.toString();
        }
    }

    public void dump(String prefix, PrintWriter pw) {
        pw.print(prefix); pw.print("Display: mDisplayId="); pw.println(mDisplayId);
        final String subPrefix = "  " + prefix;
        pw.print(subPrefix); pw.print("init="); pw.print(mInitialDisplayWidth); pw.print("x");
            pw.print(mInitialDisplayHeight); pw.print(" "); pw.print(mInitialDisplayDensity);
            pw.print("dpi");
            if (mInitialDisplayWidth != mBaseDisplayWidth
                    || mInitialDisplayHeight != mBaseDisplayHeight
                    || mInitialDisplayDensity != mBaseDisplayDensity) {
                pw.print(" base=");
                pw.print(mBaseDisplayWidth); pw.print("x"); pw.print(mBaseDisplayHeight);
                pw.print(" "); pw.print(mBaseDisplayDensity); pw.print("dpi");
            }
            pw.print(" cur=");
            pw.print(mDisplayInfo.logicalWidth);
            pw.print("x"); pw.print(mDisplayInfo.logicalHeight);
            pw.print(" app=");
            pw.print(mDisplayInfo.appWidth);
            pw.print("x"); pw.print(mDisplayInfo.appHeight);
            pw.print(" rng="); pw.print(mDisplayInfo.smallestNominalAppWidth);
            pw.print("x"); pw.print(mDisplayInfo.smallestNominalAppHeight);
            pw.print("-"); pw.print(mDisplayInfo.largestNominalAppWidth);
            pw.print("x"); pw.println(mDisplayInfo.largestNominalAppHeight);
            pw.print(subPrefix); pw.print("layoutNeeded="); pw.println(layoutNeeded);
            AppTokenIterator iterator = getTmpAppIterator(REVERSE_ITERATOR);
            int ndx = iterator.size() - 1;
            if (ndx >= 0) {
                pw.println();
                pw.println("  Application tokens in Z order:");
                while (iterator.hasNext()) {
                    AppWindowToken wtoken = iterator.next();
                    pw.print("  App #"); pw.print(ndx--);
                            pw.print(' '); pw.print(wtoken); pw.println(":");
                    wtoken.dump(pw, "    ");
                }
            }
            if (mExitingTokens.size() > 0) {
                pw.println();
                pw.println("  Exiting tokens:");
                for (int i=mExitingTokens.size()-1; i>=0; i--) {
                    WindowToken token = mExitingTokens.get(i);
                    pw.print("  Exiting #"); pw.print(i);
                    pw.print(' '); pw.print(token);
                    pw.println(':');
                    token.dump(pw, "    ");
                }
            }
            if (mExitingAppTokens.size() > 0) {
                pw.println();
                pw.println("  Exiting application tokens:");
                for (int i=mExitingAppTokens.size()-1; i>=0; i--) {
                    WindowToken token = mExitingAppTokens.get(i);
                    pw.print("  Exiting App #"); pw.print(i);
                      pw.print(' '); pw.print(token);
                      pw.println(':');
                      token.dump(pw, "    ");
                }
            }
            if (mTaskIdToTaskList.size() > 0) {
                pw.println();
                for (int i = 0; i < mTaskIdToTaskList.size(); ++i) {
                    pw.print("  TaskList #"); pw.print(i);
                      pw.print(" taskId="); pw.println(mTaskIdToTaskList.keyAt(i));
                    pw.print("    mAppTokens=");
                      pw.println(mTaskIdToTaskList.valueAt(i).mAppTokens);
                    pw.println();
                }
            }
        pw.println();
    }
}