/*
 * Copyright (C) 2015 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.launcher3.allapps;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Rect;
import android.os.Process;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.text.Selection;
import android.text.SpannableStringBuilder;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnLongClickListener;
import android.view.ViewGroup;
import android.widget.RelativeLayout;

import com.android.launcher3.AppInfo;
import com.android.launcher3.BubbleTextView;
import com.android.launcher3.BubbleTextView.BubbleTextShadowHandler;
import com.android.launcher3.ClickShadowView;
import com.android.launcher3.DeviceProfile;
import com.android.launcher3.DeviceProfile.OnDeviceProfileChangeListener;
import com.android.launcher3.DragSource;
import com.android.launcher3.DropTarget;
import com.android.launcher3.DropTarget.DragObject;
import com.android.launcher3.Insettable;
import com.android.launcher3.InsettableFrameLayout;
import com.android.launcher3.ItemInfo;
import com.android.launcher3.Launcher;
import com.android.launcher3.LauncherState;
import com.android.launcher3.R;
import com.android.launcher3.anim.SpringAnimationHandler;
import com.android.launcher3.config.FeatureFlags;
import com.android.launcher3.dragndrop.DragController;
import com.android.launcher3.dragndrop.DragOptions;
import com.android.launcher3.keyboard.FocusedItemDecorator;
import com.android.launcher3.userevent.nano.LauncherLogProto.Target;
import com.android.launcher3.util.ItemInfoMatcher;
import com.android.launcher3.views.BottomUserEducationView;

/**
 * The all apps view container.
 */
public class AllAppsContainerView extends RelativeLayout implements DragSource,
        OnLongClickListener, Insettable, BubbleTextShadowHandler, OnDeviceProfileChangeListener {

    private final Launcher mLauncher;
    private final AdapterHolder[] mAH;
    private final ClickShadowView mTouchFeedbackView;
    private final ItemInfoMatcher mPersonalMatcher = ItemInfoMatcher.ofUser(Process.myUserHandle());
    private final ItemInfoMatcher mWorkMatcher = ItemInfoMatcher.not(mPersonalMatcher);
    private final AllAppsStore mAllAppsStore = new AllAppsStore();

    private SearchUiManager mSearchUiManager;
    private View mSearchContainer;
    private AllAppsPagedView mViewPager;
    private FloatingHeaderView mHeader;

    private SpannableStringBuilder mSearchQueryBuilder = null;

    private boolean mUsingTabs;
    private boolean mSearchModeWhileUsingTabs = false;

    public AllAppsContainerView(Context context) {
        this(context, null);
    }

    public AllAppsContainerView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public AllAppsContainerView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);

        mLauncher = Launcher.getLauncher(context);
        mLauncher.addOnDeviceProfileChangeListener(this);

        mSearchQueryBuilder = new SpannableStringBuilder();

        Selection.setSelection(mSearchQueryBuilder, 0);

        mTouchFeedbackView = new ClickShadowView(context);
        // Make the feedback view large enough to hold the blur bitmap.
        int size = mLauncher.getDeviceProfile().allAppsIconSizePx
                + mTouchFeedbackView.getExtraSize();
        addView(mTouchFeedbackView, size, size);

        mAH = new AdapterHolder[2];
        mAH[AdapterHolder.MAIN] = new AdapterHolder(false /* isWork */);
        mAH[AdapterHolder.WORK] = new AdapterHolder(true /* isWork */);

        mAllAppsStore.addUpdateListener(this::onAppsUpdated);
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        applyTouchDelegate();
    }

    private void applyTouchDelegate() {
        // TODO: Reimplement once fast scroller is fixed.
    }

    public AllAppsStore getAppsStore() {
        return mAllAppsStore;
    }

    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
        super.onLayout(changed, left, top, right, bottom);
        applyTouchDelegate();
    }

    @Override
    public void onDeviceProfileChanged(DeviceProfile dp) {
        for (AdapterHolder holder : mAH) {
            if (holder.recyclerView != null) {
                // Remove all views and clear the pool, while keeping the data same. After this
                // call, all the viewHolders will be recreated.
                holder.recyclerView.swapAdapter(holder.recyclerView.getAdapter(), true);
                holder.recyclerView.getRecycledViewPool().clear();
            }
        }
    }

    private void onAppsUpdated() {
        if (FeatureFlags.ALL_APPS_TABS_ENABLED) {
            boolean hasWorkApps = false;
            for (AppInfo app : mAllAppsStore.getApps()) {
                if (mWorkMatcher.matches(app, null)) {
                    hasWorkApps = true;
                    break;
                }
            }
            rebindAdapters(hasWorkApps);
        }
    }

    @Override
    public void setPressedIcon(BubbleTextView icon, Bitmap background) {
        mTouchFeedbackView.setPressedIcon(icon, background);
    }

    /**
     * Returns whether the view itself will handle the touch event or not.
     */
    public boolean shouldContainerScroll(MotionEvent ev) {
        // IF the MotionEvent is inside the search box, and the container keeps on receiving
        // touch input, container should move down.
        if (mLauncher.getDragLayer().isEventOverView(mSearchContainer, ev)) {
            return true;
        }
        AllAppsRecyclerView rv = getActiveRecyclerView();
        return rv == null || rv.shouldContainerScroll(ev, mLauncher.getDragLayer());
    }

    public AllAppsRecyclerView getActiveRecyclerView() {
        if (!mUsingTabs || mViewPager.getNextPage() == 0) {
            return mAH[AdapterHolder.MAIN].recyclerView;
        } else {
            return mAH[AdapterHolder.WORK].recyclerView;
        }
    }

    /**
     * Resets the state of AllApps.
     */
    public void reset() {
        for (int i = 0; i < mAH.length; i++) {
            if (mAH[i].recyclerView != null) {
                mAH[i].recyclerView.scrollToTop();
            }
        }
        if (isHeaderVisible()) {
            mHeader.reset();
        }
        // Reset the search bar and base recycler view after transitioning home
        mSearchUiManager.reset();
    }

    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();

        // This is a focus listener that proxies focus from a view into the list view.  This is to
        // work around the search box from getting first focus and showing the cursor.
        setOnFocusChangeListener((v, hasFocus) -> {
            if (hasFocus && getActiveRecyclerView() != null) {
                getActiveRecyclerView().requestFocus();
            }
        });

        mHeader = findViewById(R.id.all_apps_header);
        rebindAdapters(mUsingTabs, true /* force */);

        mSearchContainer = findViewById(R.id.search_container_all_apps);
        mSearchUiManager = (SearchUiManager) mSearchContainer;
        mSearchUiManager.initialize(this);
    }

    public SearchUiManager getSearchUiManager() {
        return mSearchUiManager;
    }

    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        mSearchUiManager.preDispatchKeyEvent(event);
        return super.dispatchKeyEvent(event);
    }

    @Override
    public boolean onLongClick(final View v) {
        // When we have exited all apps or are in transition, disregard long clicks
        if (!mLauncher.isInState(LauncherState.ALL_APPS) ||
                mLauncher.getWorkspace().isSwitchingState()) return false;
        // Return if global dragging is not enabled or we are already dragging
        if (!mLauncher.isDraggingEnabled()) return false;
        if (mLauncher.getDragController().isDragging()) return false;

        // Start the drag
        final DragController dragController = mLauncher.getDragController();
        dragController.addDragListener(new DragController.DragListener() {
            @Override
            public void onDragStart(DropTarget.DragObject dragObject, DragOptions options) {
                v.setVisibility(INVISIBLE);
            }

            @Override
            public void onDragEnd() {
                v.setVisibility(VISIBLE);
                dragController.removeDragListener(this);
            }
        });

        DeviceProfile grid = mLauncher.getDeviceProfile();
        DragOptions options = new DragOptions();
        options.intrinsicIconScaleFactor = (float) grid.allAppsIconSizePx / grid.iconSizePx;
        mLauncher.getWorkspace().beginDragShared(v, this, options);
        return false;
    }

    @Override
    public void onDropCompleted(View target, DragObject d, boolean success) { }

    @Override
    public void fillInLogContainerData(View v, ItemInfo info, Target target, Target targetParent) {
        // This is filled in {@link AllAppsRecyclerView}
    }

    @Override
    public void setInsets(Rect insets) {
        DeviceProfile grid = mLauncher.getDeviceProfile();
        int leftRightPadding = grid.desiredWorkspaceLeftRightMarginPx
                + grid.cellLayoutPaddingLeftRightPx;

        for (int i = 0; i < mAH.length; i++) {
            mAH[i].padding.bottom = insets.bottom;
            mAH[i].padding.left = mAH[i].padding.right = leftRightPadding;
            mAH[i].applyPadding();
        }

        ViewGroup.MarginLayoutParams mlp = (MarginLayoutParams) getLayoutParams();
        if (grid.isVerticalBarLayout()) {
            mlp.leftMargin = insets.left;
            mlp.topMargin = insets.top;
            mlp.rightMargin = insets.right;
            setPadding(grid.workspacePadding.left, 0, grid.workspacePadding.right, 0);
        } else {
            mlp.leftMargin = mlp.rightMargin = mlp.topMargin = 0;
            setPadding(0, 0, 0, 0);
        }
        setLayoutParams(mlp);

        View navBarBg = findViewById(R.id.nav_bar_bg);
        ViewGroup.LayoutParams navBarBgLp = navBarBg.getLayoutParams();
        navBarBgLp.height = insets.bottom;
        navBarBg.setLayoutParams(navBarBgLp);

        InsettableFrameLayout.dispatchInsets(this, insets);
    }

    public SpringAnimationHandler getSpringAnimationHandler() {
        return mUsingTabs ? null : mAH[AdapterHolder.MAIN].animationHandler;
    }

    private void rebindAdapters(boolean showTabs) {
        rebindAdapters(showTabs, false /* force */);
    }

    private void rebindAdapters(boolean showTabs, boolean force) {
        if (showTabs == mUsingTabs && !force) {
            return;
        }
        replaceRVContainer(showTabs);
        mUsingTabs = showTabs;

        mAllAppsStore.unregisterIconContainer(mAH[AdapterHolder.MAIN].recyclerView);
        mAllAppsStore.unregisterIconContainer(mAH[AdapterHolder.WORK].recyclerView);

        if (mUsingTabs) {
            mAH[AdapterHolder.MAIN].setup(mViewPager.getChildAt(0), mPersonalMatcher);
            mAH[AdapterHolder.WORK].setup(mViewPager.getChildAt(1), mWorkMatcher);
            onTabChanged(mViewPager.getNextPage());
        } else {
            mAH[AdapterHolder.MAIN].setup(findViewById(R.id.apps_list_view), null);
            mAH[AdapterHolder.WORK].recyclerView = null;
        }
        setupHeader();

        mAllAppsStore.registerIconContainer(mAH[AdapterHolder.MAIN].recyclerView);
        mAllAppsStore.registerIconContainer(mAH[AdapterHolder.WORK].recyclerView);

        applyTouchDelegate();
    }

    private void replaceRVContainer(boolean showTabs) {
        for (int i = 0; i < mAH.length; i++) {
            if (mAH[i].recyclerView != null) {
                mAH[i].recyclerView.setLayoutManager(null);
            }
        }
        View oldView = getRecyclerViewContainer();
        int index = indexOfChild(oldView);
        removeView(oldView);
        int layout = showTabs ? R.layout.all_apps_tabs : R.layout.all_apps_rv_layout;
        View newView = LayoutInflater.from(getContext()).inflate(layout, this, false);
        addView(newView, index);
        if (showTabs) {
            mViewPager = (AllAppsPagedView) newView;
            mViewPager.initParentViews(this);
            mViewPager.getPageIndicator().setContainerView(this);
        } else {
            mViewPager = null;
        }
    }

    public View getRecyclerViewContainer() {
        return mViewPager != null ? mViewPager : findViewById(R.id.apps_list_view);
    }

    public void onTabChanged(int pos) {
        mHeader.setMainActive(pos == 0);
        reset();
        applyTouchDelegate();
        if (mAH[pos].recyclerView != null) {
            mAH[pos].recyclerView.bindFastScrollbar();

            findViewById(R.id.tab_personal)
                    .setOnClickListener((View view) -> mViewPager.snapToPage(AdapterHolder.MAIN));
            findViewById(R.id.tab_work)
                    .setOnClickListener((View view) -> mViewPager.snapToPage(AdapterHolder.WORK));

        }
        if (pos == AdapterHolder.WORK) {
            BottomUserEducationView.showIfNeeded(mLauncher);
        }
    }

    public AlphabeticalAppsList getApps() {
        return mAH[AdapterHolder.MAIN].appsList;
    }

    public FloatingHeaderView getFloatingHeaderView() {
        return mHeader;
    }

    public void setupHeader() {
        mHeader.setVisibility(View.VISIBLE);
        mHeader.setup(mAH, mAH[AllAppsContainerView.AdapterHolder.WORK].recyclerView == null);

        int padding = mHeader.getMaxTranslation();
        for (int i = 0; i < mAH.length; i++) {
            mAH[i].padding.top = padding;
            mAH[i].applyPadding();
        }
    }

    public void setLastSearchQuery(String query) {
        for (int i = 0; i < mAH.length; i++) {
            mAH[i].adapter.setLastSearchQuery(query);
        }
        if (mUsingTabs) {
            mSearchModeWhileUsingTabs = true;
            rebindAdapters(false); // hide tabs
        }
    }

    public void onClearSearchResult() {
        if (mSearchModeWhileUsingTabs) {
            rebindAdapters(true); // show tabs
            mSearchModeWhileUsingTabs = false;
        }
    }

    public void onSearchResultsChanged() {
        for (int i = 0; i < mAH.length; i++) {
            if (mAH[i].recyclerView != null) {
                mAH[i].recyclerView.onSearchResultsChanged();
            }
        }
    }

    public void setRecyclerViewVerticalFadingEdgeEnabled(boolean enabled) {
        for (int i = 0; i < mAH.length; i++) {
            mAH[i].applyVerticalFadingEdgeEnabled(enabled);
        }
    }

    public void addElevationController(RecyclerView.OnScrollListener scrollListener) {
        if (!mUsingTabs) {
            mAH[AdapterHolder.MAIN].recyclerView.addOnScrollListener(scrollListener);
        }
    }

    public boolean isHeaderVisible() {
        return mHeader != null && mHeader.getVisibility() == View.VISIBLE;
    }

    public void onScrollUpEnd() {
        if (mUsingTabs) {
            ((PersonalWorkSlidingTabStrip) findViewById(R.id.tabs)).highlightWorkTabIfNecessary();
        }
    }

    public class AdapterHolder {
        public static final int MAIN = 0;
        public static final int WORK = 1;

        public final AllAppsGridAdapter adapter;
        final LinearLayoutManager layoutManager;
        final SpringAnimationHandler animationHandler;
        final AlphabeticalAppsList appsList;
        final Rect padding = new Rect();
        AllAppsRecyclerView recyclerView;
        boolean verticalFadingEdge;

        AdapterHolder(boolean isWork) {
            appsList = new AlphabeticalAppsList(mLauncher, mAllAppsStore, isWork);
            adapter = new AllAppsGridAdapter(mLauncher, appsList, mLauncher,
                    AllAppsContainerView.this, true);
            appsList.setAdapter(adapter);
            animationHandler = adapter.getSpringAnimationHandler();
            layoutManager = adapter.getLayoutManager();
        }

        void setup(@NonNull View rv, @Nullable ItemInfoMatcher matcher) {
            appsList.updateItemFilter(matcher);
            recyclerView = (AllAppsRecyclerView) rv;
            recyclerView.setApps(appsList, mUsingTabs);
            recyclerView.setLayoutManager(layoutManager);
            recyclerView.setAdapter(adapter);
            recyclerView.setHasFixedSize(true);
            // No animations will occur when changes occur to the items in this RecyclerView.
            recyclerView.setItemAnimator(null);
            if (FeatureFlags.LAUNCHER3_PHYSICS && animationHandler != null) {
                recyclerView.setSpringAnimationHandler(animationHandler);
            }
            FocusedItemDecorator focusedItemDecorator = new FocusedItemDecorator(recyclerView);
            recyclerView.addItemDecoration(focusedItemDecorator);
            adapter.setIconFocusListener(focusedItemDecorator.getFocusListener());
            applyVerticalFadingEdgeEnabled(verticalFadingEdge);
            applyPadding();
        }

        void applyPadding() {
            if (recyclerView != null) {
                recyclerView.setPadding(padding.left, padding.top, padding.right, padding.bottom);
            }
        }

        public void applyVerticalFadingEdgeEnabled(boolean enabled) {
            verticalFadingEdge = enabled;
            mAH[AdapterHolder.MAIN].recyclerView.setVerticalFadingEdgeEnabled(!mUsingTabs
                    && verticalFadingEdge);
        }
    }
}