/*
 * 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.systemui.statusbar.notification;

import android.content.res.Resources;
import android.text.Layout;
import android.util.Pools;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.android.internal.widget.IMessagingLayout;
import com.android.internal.widget.MessagingGroup;
import com.android.internal.widget.MessagingImageMessage;
import com.android.internal.widget.MessagingLinearLayout;
import com.android.internal.widget.MessagingMessage;
import com.android.internal.widget.MessagingPropertyAnimator;
import com.android.systemui.animation.Interpolators;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

/**
 * A transform state of the action list
*/
public class MessagingLayoutTransformState extends TransformState {

    private static Pools.SimplePool<MessagingLayoutTransformState> sInstancePool
            = new Pools.SimplePool<>(40);
    private MessagingLinearLayout mMessageContainer;
    private IMessagingLayout mMessagingLayout;
    private HashMap<MessagingGroup, MessagingGroup> mGroupMap = new HashMap<>();
    private float mRelativeTranslationOffset;

    public static MessagingLayoutTransformState obtain() {
        MessagingLayoutTransformState instance = sInstancePool.acquire();
        if (instance != null) {
            return instance;
        }
        return new MessagingLayoutTransformState();
    }

    @Override
    public void initFrom(View view, TransformInfo transformInfo) {
        super.initFrom(view, transformInfo);
        if (mTransformedView instanceof MessagingLinearLayout) {
            mMessageContainer = (MessagingLinearLayout) mTransformedView;
            mMessagingLayout = mMessageContainer.getMessagingLayout();
            Resources resources = view.getContext().getResources();
            mRelativeTranslationOffset = resources.getDisplayMetrics().density * 8;
        }
    }

    @Override
    public boolean transformViewTo(TransformState otherState, float transformationAmount) {
        if (otherState instanceof MessagingLayoutTransformState) {
            // It's a party! Let's transform between these two layouts!
            transformViewInternal((MessagingLayoutTransformState) otherState, transformationAmount,
                    true /* to */);
            return true;
        } else {
            return super.transformViewTo(otherState, transformationAmount);
        }
    }

    @Override
    public void transformViewFrom(TransformState otherState, float transformationAmount) {
        if (otherState instanceof MessagingLayoutTransformState) {
            // It's a party! Let's transform between these two layouts!
            transformViewInternal((MessagingLayoutTransformState) otherState, transformationAmount,
                    false /* to */);
        } else {
            super.transformViewFrom(otherState, transformationAmount);
        }
    }

    private void transformViewInternal(MessagingLayoutTransformState mlt,
            float transformationAmount, boolean to) {
        ensureVisible();
        ArrayList<MessagingGroup> ownGroups = filterHiddenGroups(
                mMessagingLayout.getMessagingGroups());
        ArrayList<MessagingGroup> otherGroups = filterHiddenGroups(
                mlt.mMessagingLayout.getMessagingGroups());
        HashMap<MessagingGroup, MessagingGroup> pairs = findPairs(ownGroups, otherGroups);
        MessagingGroup lastPairedGroup = null;
        float currentTranslation = 0;
        for (int i = ownGroups.size() - 1; i >= 0; i--) {
            MessagingGroup ownGroup = ownGroups.get(i);
            MessagingGroup matchingGroup = pairs.get(ownGroup);
            if (!isGone(ownGroup)) {
                if (matchingGroup != null) {
                    int totalTranslation = transformGroups(ownGroup, matchingGroup,
                            transformationAmount, to);
                    if (lastPairedGroup == null) {
                        lastPairedGroup = ownGroup;
                        if (to){
                            currentTranslation = matchingGroup.getAvatar().getTranslationY()
                                    - totalTranslation;
                        } else {
                            currentTranslation = ownGroup.getAvatar().getTranslationY();
                        }
                    }
                } else {
                    float groupTransformationAmount = transformationAmount;
                    if (lastPairedGroup != null) {
                        adaptGroupAppear(ownGroup, transformationAmount, currentTranslation,
                                to);
                        float newPosition = ownGroup.getTop() + currentTranslation;

                        if (!mTransformInfo.isAnimating()) {
                            // We fade the group away as soon as 1/2 of it is translated away on top
                            float fadeStart = -ownGroup.getHeight() * 0.5f;
                            groupTransformationAmount = (newPosition - fadeStart)
                                    / Math.abs(fadeStart);
                        } else {
                            float fadeStart = -ownGroup.getHeight() * 0.75f;
                            // We want to fade out as soon as the animation starts, let's add the
                            // complete top in addition
                            groupTransformationAmount = (newPosition - fadeStart)
                                    / (Math.abs(fadeStart) + ownGroup.getTop());
                        }
                        groupTransformationAmount = Math.max(0.0f, Math.min(1.0f,
                                groupTransformationAmount));
                        if (to) {
                            groupTransformationAmount = 1.0f - groupTransformationAmount;
                        }
                    }
                    if (to) {
                        disappear(ownGroup, groupTransformationAmount);
                    } else {
                        appear(ownGroup, groupTransformationAmount);
                    }
                }
            }
        }
    }

    private void appear(MessagingGroup ownGroup, float transformationAmount) {
        MessagingLinearLayout ownMessages = ownGroup.getMessageContainer();
        for (int j = 0; j < ownMessages.getChildCount(); j++) {
            View child = ownMessages.getChildAt(j);
            if (isGone(child)) {
                continue;
            }
            appear(child, transformationAmount);
            setClippingDeactivated(child, true);
        }
        appear(ownGroup.getAvatar(), transformationAmount);
        appear(ownGroup.getSenderView(), transformationAmount);
        appear(ownGroup.getIsolatedMessage(), transformationAmount);
        setClippingDeactivated(ownGroup.getSenderView(), true);
        setClippingDeactivated(ownGroup.getAvatar(), true);
    }

    private void adaptGroupAppear(MessagingGroup ownGroup, float transformationAmount,
            float overallTranslation, boolean to) {
        float relativeOffset;
        if (to) {
            relativeOffset = transformationAmount * mRelativeTranslationOffset;
        } else {
            relativeOffset = (1.0f - transformationAmount) * mRelativeTranslationOffset;
        }
        if (ownGroup.getSenderView().getVisibility() != View.GONE) {
            relativeOffset *= 0.5f;
        }
        ownGroup.getMessageContainer().setTranslationY(relativeOffset);
        ownGroup.getSenderView().setTranslationY(relativeOffset);
        ownGroup.setTranslationY(overallTranslation * 0.9f);
    }

    private void disappear(MessagingGroup ownGroup, float transformationAmount) {
        MessagingLinearLayout ownMessages = ownGroup.getMessageContainer();
        for (int j = 0; j < ownMessages.getChildCount(); j++) {
            View child = ownMessages.getChildAt(j);
            if (isGone(child)) {
                continue;
            }
            disappear(child, transformationAmount);
            setClippingDeactivated(child, true);
        }
        disappear(ownGroup.getAvatar(), transformationAmount);
        disappear(ownGroup.getSenderView(), transformationAmount);
        disappear(ownGroup.getIsolatedMessage(), transformationAmount);
        setClippingDeactivated(ownGroup.getSenderView(), true);
        setClippingDeactivated(ownGroup.getAvatar(), true);
    }

    private void appear(View child, float transformationAmount) {
        if (child == null || child.getVisibility() == View.GONE) {
            return;
        }
        TransformState ownState = TransformState.createFrom(child, mTransformInfo);
        ownState.appear(transformationAmount, null);
        ownState.recycle();
    }

    private void disappear(View child, float transformationAmount) {
        if (child == null || child.getVisibility() == View.GONE) {
            return;
        }
        TransformState ownState = TransformState.createFrom(child, mTransformInfo);
        ownState.disappear(transformationAmount, null);
        ownState.recycle();
    }

    private ArrayList<MessagingGroup> filterHiddenGroups(
            ArrayList<MessagingGroup> groups) {
        ArrayList<MessagingGroup> result = new ArrayList<>(groups);
        for (int i = 0; i < result.size(); i++) {
            MessagingGroup messagingGroup = result.get(i);
            if (isGone(messagingGroup)) {
                result.remove(i);
                i--;
            }
        }
        return result;
    }

    private boolean hasEllipses(TextView textView) {
        Layout layout = textView.getLayout();
        return layout != null && layout.getEllipsisCount(layout.getLineCount() - 1) > 0;
    }

    private boolean needsReflow(TextView own, TextView other) {
        return hasEllipses(own) != hasEllipses(other);
    }

    /**
     * Transform two groups towards each other.
     *
     * @return the total transformation distance that the group goes through
     */
    private int transformGroups(MessagingGroup ownGroup, MessagingGroup otherGroup,
            float transformationAmount, boolean to) {
        boolean useLinearTransformation =
                otherGroup.getIsolatedMessage() == null && !mTransformInfo.isAnimating();
        TextView ownSenderView = ownGroup.getSenderView();
        TextView otherSenderView = otherGroup.getSenderView();
        transformView(transformationAmount, to, ownSenderView, otherSenderView,
                // Normally this would be handled by the TextViewMessageState#sameAs check, but in
                // this case it doesn't work because our text won't match, due to the appended colon
                // in the collapsed view.
                !needsReflow(ownSenderView, otherSenderView),
                useLinearTransformation);
        int totalAvatarTranslation = transformView(transformationAmount, to, ownGroup.getAvatar(),
                otherGroup.getAvatar(), true /* sameAsAny */, useLinearTransformation);
        List<MessagingMessage> ownMessages = ownGroup.getMessages();
        List<MessagingMessage> otherMessages = otherGroup.getMessages();
        float previousTranslation = 0;
        boolean isLastView = true;
        for (int i = 0; i < ownMessages.size(); i++) {
            View child = ownMessages.get(ownMessages.size() - 1 - i).getView();
            if (isGone(child)) {
                continue;
            }
            float messageAmount = transformationAmount;
            int otherIndex = otherMessages.size() - 1 - i;
            View otherChild = null;
            if (otherIndex >= 0) {
                otherChild = otherMessages.get(otherIndex).getView();
                if (isGone(otherChild)) {
                    otherChild = null;
                }
            }
            if (otherChild == null && previousTranslation < 0) {
                // Let's fade out as we approach the top of the screen. We can only do this if
                // we're actually moving up
                float distanceToTop = child.getTop() + child.getHeight() + previousTranslation;
                messageAmount = distanceToTop / child.getHeight();
                messageAmount = Math.max(0.0f, Math.min(1.0f, messageAmount));
                if (to) {
                    messageAmount = 1.0f - messageAmount;
                }
            }
            int totalTranslation = transformView(messageAmount, to, child, otherChild,
                    false /* sameAsAny */, useLinearTransformation);
            boolean otherIsIsolated = otherGroup.getIsolatedMessage() == otherChild;
            if (messageAmount == 0.0f
                    && (otherIsIsolated || otherGroup.isSingleLine())) {
                ownGroup.setClippingDisabled(true);
                mMessagingLayout.setMessagingClippingDisabled(true);
            }
            if (otherChild == null) {
                if (isLastView) {
                    previousTranslation = ownSenderView.getTranslationY();
                }
                child.setTranslationY(previousTranslation);
                setClippingDeactivated(child, true);
            } else if (ownGroup.getIsolatedMessage() == child || otherIsIsolated) {
                // We don't want to add any translation for the image that is transforming
            } else if (to) {
                previousTranslation = otherChild.getTranslationY() - totalTranslation;
            } else {
                previousTranslation = child.getTranslationY();
            }
            isLastView = false;
        }
        ownGroup.updateClipRect();
        return totalAvatarTranslation;
    }

    /**
     * Transform a view to another view.
     *
     * @return the total translationY this view goes through
     */
    private int transformView(float transformationAmount, boolean to, View ownView,
            View otherView, boolean sameAsAny, boolean useLinearTransformation) {
        TransformState ownState = TransformState.createFrom(ownView, mTransformInfo);
        if (useLinearTransformation) {
            ownState.setDefaultInterpolator(Interpolators.LINEAR);
        }
        ownState.setIsSameAsAnyView(sameAsAny && !isGone(otherView));
        int totalTranslationDistance = 0;
        if (to) {
            if (otherView != null) {
                TransformState otherState = TransformState.createFrom(otherView, mTransformInfo);
                if (!isGone(otherView)) {
                    ownState.transformViewTo(otherState, transformationAmount);
                } else {
                    if (!isGone(ownView)) {
                        ownState.disappear(transformationAmount, null);
                    }
                    // We still want to transform vertically if the view is gone,
                    // since avatars serve as anchors for the rest of the layout transition
                    ownState.transformViewVerticalTo(otherState, transformationAmount);
                }
                totalTranslationDistance = ownState.getLaidOutLocationOnScreen()[1]
                        - otherState.getLaidOutLocationOnScreen()[1];
                otherState.recycle();
            } else {
                ownState.disappear(transformationAmount, null);
            }
        } else {
            if (otherView != null) {
                TransformState otherState = TransformState.createFrom(otherView, mTransformInfo);
                if (!isGone(otherView)) {
                    ownState.transformViewFrom(otherState, transformationAmount);
                } else {
                    if (!isGone(ownView)) {
                        ownState.appear(transformationAmount, null);
                    }
                    // We still want to transform vertically if the view is gone,
                    // since avatars serve as anchors for the rest of the layout transition
                    ownState.transformViewVerticalFrom(otherState, transformationAmount);
                }
                totalTranslationDistance = ownState.getLaidOutLocationOnScreen()[1]
                        - otherState.getLaidOutLocationOnScreen()[1];
                otherState.recycle();
            } else {
                ownState.appear(transformationAmount, null);
            }
        }
        ownState.recycle();
        return totalTranslationDistance;
    }

    private HashMap<MessagingGroup, MessagingGroup> findPairs(ArrayList<MessagingGroup> ownGroups,
            ArrayList<MessagingGroup> otherGroups) {
        mGroupMap.clear();
        int lastMatch = Integer.MAX_VALUE;
        for (int i = ownGroups.size() - 1; i >= 0; i--) {
            MessagingGroup ownGroup = ownGroups.get(i);
            MessagingGroup bestMatch = null;
            int bestCompatibility = 0;
            for (int j = Math.min(otherGroups.size(), lastMatch) - 1; j >= 0; j--) {
                MessagingGroup otherGroup = otherGroups.get(j);
                int compatibility = ownGroup.calculateGroupCompatibility(otherGroup);
                if (compatibility > bestCompatibility) {
                    bestCompatibility = compatibility;
                    bestMatch = otherGroup;
                    lastMatch = j;
                }
            }
            if (bestMatch != null) {
                mGroupMap.put(ownGroup, bestMatch);
            }
        }
        return mGroupMap;
    }

    private boolean isGone(View view) {
        if (view == null) {
            return true;
        }
        if (view.getVisibility() == View.GONE) {
            return true;
        }
        if (view.getParent() == null) {
            return true;
        }
        if (view.getWidth() == 0) {
            return true;
        }
        final ViewGroup.LayoutParams lp = view.getLayoutParams();
        if (lp instanceof MessagingLinearLayout.LayoutParams
                && ((MessagingLinearLayout.LayoutParams) lp).hide) {
            return true;
        }
        return false;
    }

    @Override
    public void setVisible(boolean visible, boolean force) {
        super.setVisible(visible, force);
        resetTransformedView();
        ArrayList<MessagingGroup> ownGroups = mMessagingLayout.getMessagingGroups();
        for (int i = 0; i < ownGroups.size(); i++) {
            MessagingGroup ownGroup = ownGroups.get(i);
            if (!isGone(ownGroup)) {
                MessagingLinearLayout ownMessages = ownGroup.getMessageContainer();
                for (int j = 0; j < ownMessages.getChildCount(); j++) {
                    View child = ownMessages.getChildAt(j);
                    setVisible(child, visible, force);
                }
                setVisible(ownGroup.getAvatar(), visible, force);
                setVisible(ownGroup.getSenderView(), visible, force);
                MessagingImageMessage isolatedMessage = ownGroup.getIsolatedMessage();
                if (isolatedMessage != null) {
                    setVisible(isolatedMessage, visible, force);
                }
            }
        }
    }

    private void setVisible(View child, boolean visible, boolean force) {
        if (isGone(child) || MessagingPropertyAnimator.isAnimatingAlpha(child)) {
            return;
        }
        TransformState ownState = TransformState.createFrom(child, mTransformInfo);
        ownState.setVisible(visible, force);
        ownState.recycle();
    }

    @Override
    protected void resetTransformedView() {
        super.resetTransformedView();
        ArrayList<MessagingGroup> ownGroups = mMessagingLayout.getMessagingGroups();
        for (int i = 0; i < ownGroups.size(); i++) {
            MessagingGroup ownGroup = ownGroups.get(i);
            if (!isGone(ownGroup)) {
                MessagingLinearLayout ownMessages = ownGroup.getMessageContainer();
                for (int j = 0; j < ownMessages.getChildCount(); j++) {
                    View child = ownMessages.getChildAt(j);
                    if (isGone(child)) {
                        continue;
                    }
                    resetTransformedView(child);
                    setClippingDeactivated(child, false);
                }
                resetTransformedView(ownGroup.getAvatar());
                resetTransformedView(ownGroup.getSenderView());
                MessagingImageMessage isolatedMessage = ownGroup.getIsolatedMessage();
                if (isolatedMessage != null) {
                    resetTransformedView(isolatedMessage);
                }
                setClippingDeactivated(ownGroup.getAvatar(), false);
                setClippingDeactivated(ownGroup.getSenderView(), false);
                ownGroup.setTranslationY(0);
                ownGroup.getMessageContainer().setTranslationY(0);
                ownGroup.getSenderView().setTranslationY(0);
            }
            ownGroup.setClippingDisabled(false);
            ownGroup.updateClipRect();
        }
        mMessagingLayout.setMessagingClippingDisabled(false);
    }

    @Override
    public void prepareFadeIn() {
        super.prepareFadeIn();
        setVisible(true /* visible */, false /* force */);
    }

    private void resetTransformedView(View child) {
        TransformState ownState = TransformState.createFrom(child, mTransformInfo);
        ownState.resetTransformedView();
        ownState.recycle();
    }

    @Override
    protected void reset() {
        super.reset();
        mMessageContainer = null;
        mMessagingLayout = null;
    }

    @Override
    public void recycle() {
        super.recycle();
        mGroupMap.clear();;
        sInstancePool.release(this);
    }
}