/**
 * Copyright 2016 Keepsafe Software, Inc.
 * <p>
 * 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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 ui.apptour.taptargetview;

import android.annotation.TargetApi;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.support.annotation.IdRes;
import android.support.annotation.Nullable;
import android.support.v7.widget.Toolbar;
import android.text.TextUtils;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.ImageView;

import java.util.ArrayList;
import java.util.Stack;

class ToolbarTapTarget extends ViewTapTarget {
    ToolbarTapTarget(Toolbar toolbar, @IdRes int menuItemId,
                     CharSequence title, @Nullable CharSequence description, @Nullable CharSequence buttonText) {
        super(toolbar.findViewById(menuItemId), title, description, buttonText);
    }

    ToolbarTapTarget(android.widget.Toolbar toolbar, @IdRes int menuItemId,
                     CharSequence title, @Nullable CharSequence description, @Nullable CharSequence buttonText) {
        super(toolbar.findViewById(menuItemId), title, description, buttonText);
    }

    ToolbarTapTarget(Toolbar toolbar, boolean findNavView,
                     CharSequence title, @Nullable CharSequence description, @Nullable CharSequence buttonText) {
        super(findNavView ? findNavView(toolbar) : findOverflowView(toolbar), title, description, buttonText);
    }

    ToolbarTapTarget(android.widget.Toolbar toolbar, boolean findNavView,
                     CharSequence title, @Nullable CharSequence description, @Nullable CharSequence buttonText) {
        super(findNavView ? findNavView(toolbar) : findOverflowView(toolbar), title, description, buttonText);
    }

    private static ToolbarProxy proxyOf(Object instance) {
        if (instance == null) {
            throw new IllegalArgumentException("Given null instance");
        }

        if (instance instanceof Toolbar) {
            return new SupportToolbarProxy((Toolbar) instance);
        } else if (instance instanceof android.widget.Toolbar) {
            return new StandardToolbarProxy((android.widget.Toolbar) instance);
        }

        throw new IllegalStateException("Couldn't provide proper toolbar proxy instance");
    }

    private static View findNavView(Object instance) {
        final ToolbarProxy toolbar = proxyOf(instance);

        // First we try to find the view via its content description
        final CharSequence currentDescription = toolbar.getNavigationContentDescription();
        final boolean hadContentDescription = !TextUtils.isEmpty(currentDescription);
        final CharSequence sentinel = hadContentDescription ? currentDescription : "taptarget-findme";
        toolbar.setNavigationContentDescription(sentinel);

        final ArrayList<View> possibleViews = new ArrayList<>(1);
        toolbar.findViewsWithText(possibleViews, sentinel, View.FIND_VIEWS_WITH_CONTENT_DESCRIPTION);

        if (!hadContentDescription) {
            toolbar.setNavigationContentDescription(null);
        }

        if (possibleViews.size() > 0) {
            return possibleViews.get(0);
        }

        // If that doesn't work, we try to grab it via matching its drawable
        final Drawable navigationIcon = toolbar.getNavigationIcon();
        if (navigationIcon == null) {
            throw new IllegalStateException("Toolbar does not have a navigation view set!");
        }

        final int size = toolbar.getChildCount();
        for (int i = 0; i < size; ++i) {
            final View child = toolbar.getChildAt(i);
            if (child instanceof ImageButton) {
                final Drawable childDrawable = ((ImageButton) child).getDrawable();
                if (childDrawable == navigationIcon) {
                    return child;
                }
            }
        }

        throw new IllegalStateException("Could not find navigation view for Toolbar!");
    }

    private static View findOverflowView(Object instance) {
        final ToolbarProxy toolbar = proxyOf(instance);

        // First we try to find the overflow menu view via drawable matching
        final Drawable overflowDrawable = toolbar.getOverflowIcon();
        if (overflowDrawable != null) {
            final Stack<ViewGroup> parents = new Stack<>();
            parents.push((ViewGroup) toolbar.internalToolbar());
            while (!parents.empty()) {
                ViewGroup parent = parents.pop();
                final int size = parent.getChildCount();
                for (int i = 0; i < size; ++i) {
                    final View child = parent.getChildAt(i);
                    if (child instanceof ViewGroup) {
                        parents.push((ViewGroup) child);
                        continue;
                    }
                    if (child instanceof ImageView) {
                        final Drawable childDrawable = ((ImageView) child).getDrawable();
                        if (childDrawable == overflowDrawable) {
                            return child;
                        }
                    }
                }
            }
        }

        // If that doesn't work, we fall-back to our last resort solution: Reflection
        // Toolbars contain an "ActionMenuView" which in turn contains an "ActionMenuPresenter".
        // The "ActionMenuPresenter" then holds a reference to an "OverflowMenuButton" which is the
        // desired target
        try {
            final Object actionMenuView = ReflectUtil.getPrivateField(toolbar.internalToolbar(), "mMenuView");
            final Object actionMenuPresenter = ReflectUtil.getPrivateField(actionMenuView, "mPresenter");
            return (View) ReflectUtil.getPrivateField(actionMenuPresenter, "mOverflowButton");
        } catch (NoSuchFieldException e) {
            throw new IllegalStateException("Could not find overflow view for Toolbar!", e);
        } catch (IllegalAccessException e) {
            throw new IllegalStateException("Unable to access overflow view for Toolbar!", e);
        }
    }

    private interface ToolbarProxy {
        CharSequence getNavigationContentDescription();

        void setNavigationContentDescription(CharSequence description);

        void findViewsWithText(ArrayList<View> out, CharSequence toFind, int flags);

        Drawable getNavigationIcon();

        @Nullable
        Drawable getOverflowIcon();

        int getChildCount();

        View getChildAt(int position);

        Object internalToolbar();
    }

    private static class SupportToolbarProxy implements ToolbarProxy {
        private final Toolbar toolbar;

        SupportToolbarProxy(Toolbar toolbar) {
            this.toolbar = toolbar;
        }

        @Override
        public CharSequence getNavigationContentDescription() {
            return toolbar.getNavigationContentDescription();
        }

        @Override
        public void setNavigationContentDescription(CharSequence description) {
            toolbar.setNavigationContentDescription(description);
        }

        @Override
        public void findViewsWithText(ArrayList<View> out, CharSequence toFind, int flags) {
            toolbar.findViewsWithText(out, toFind, flags);
        }

        @Override
        public Drawable getNavigationIcon() {
            return toolbar.getNavigationIcon();
        }

        @Override
        public Drawable getOverflowIcon() {
            return toolbar.getOverflowIcon();
        }

        @Override
        public int getChildCount() {
            return toolbar.getChildCount();
        }

        @Override
        public View getChildAt(int position) {
            return toolbar.getChildAt(position);
        }

        @Override
        public Object internalToolbar() {
            return toolbar;
        }
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    private static class StandardToolbarProxy implements ToolbarProxy {
        private final android.widget.Toolbar toolbar;

        StandardToolbarProxy(android.widget.Toolbar toolbar) {
            this.toolbar = toolbar;
        }

        @Override
        public CharSequence getNavigationContentDescription() {
            return toolbar.getNavigationContentDescription();
        }

        @Override
        public void setNavigationContentDescription(CharSequence description) {
            toolbar.setNavigationContentDescription(description);
        }

        @Override
        public void findViewsWithText(ArrayList<View> out, CharSequence toFind, int flags) {
            toolbar.findViewsWithText(out, toFind, flags);
        }

        @Override
        public Drawable getNavigationIcon() {
            return toolbar.getNavigationIcon();
        }

        @Nullable
        @Override
        public Drawable getOverflowIcon() {
            if (Build.VERSION.SDK_INT >= 23) {
                return toolbar.getOverflowIcon();
            }

            return null;
        }

        @Override
        public int getChildCount() {
            return toolbar.getChildCount();
        }

        @Override
        public View getChildAt(int position) {
            return toolbar.getChildAt(position);
        }

        @Override
        public Object internalToolbar() {
            return toolbar;
        }
    }
}