/*
 * Copyright (C) 2018 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.settings.homepage;

import android.animation.LayoutTransition;
import android.app.ActivityManager;
import android.app.settings.SettingsEnums;
import android.os.Bundle;
import android.util.FeatureFlagUtils;
import android.util.Log;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.Toolbar;

import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentActivity;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

import com.android.settings.R;
import com.android.settings.accounts.AvatarViewMixin;
import com.android.settings.core.CategoryMixin;
import com.android.settings.core.FeatureFlags;
import com.android.settings.homepage.contextualcards.ContextualCardsFragment;
import com.android.settings.overlay.FeatureFactory;
import com.android.settingslib.core.lifecycle.HideNonSystemOverlayMixin;

/** Settings homepage activity */
public class SettingsHomepageActivity extends FragmentActivity implements
        CategoryMixin.CategoryHandler {

    private static final String TAG = "SettingsHomepageActivity";

    private static final long HOMEPAGE_LOADING_TIMEOUT_MS = 300;

    private View mHomepageView;
    private View mSuggestionView;
    private CategoryMixin mCategoryMixin;

    @Override
    public CategoryMixin getCategoryMixin() {
        return mCategoryMixin;
    }

    /**
     * Shows the homepage and shows/hides the suggestion together. Only allows to be executed once
     * to avoid the flicker caused by the suggestion suddenly appearing/disappearing.
     */
    public void showHomepageWithSuggestion(boolean showSuggestion) {
        if (mHomepageView == null) {
            return;
        }
        Log.i(TAG, "showHomepageWithSuggestion: " + showSuggestion);
        mSuggestionView.setVisibility(showSuggestion ? View.VISIBLE : View.GONE);
        mHomepageView.setVisibility(View.VISIBLE);
        mHomepageView = null;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.settings_homepage_container);

        final View appBar = findViewById(R.id.app_bar_container);
        appBar.setMinimumHeight(getSearchBoxHeight());
        initHomepageContainer();

        final Toolbar toolbar = findViewById(R.id.search_action_bar);
        FeatureFactory.getFactory(this).getSearchFeatureProvider()
                .initSearchToolbar(this /* activity */, toolbar, SettingsEnums.SETTINGS_HOMEPAGE);

        getLifecycle().addObserver(new HideNonSystemOverlayMixin(this));
        mCategoryMixin = new CategoryMixin(this);
        getLifecycle().addObserver(mCategoryMixin);

        if (!getSystemService(ActivityManager.class).isLowRamDevice()) {
            // Only allow features on high ram devices.
            final ImageView avatarView = findViewById(R.id.account_avatar);
            if (AvatarViewMixin.isAvatarSupported(this)) {
                avatarView.setVisibility(View.VISIBLE);
                getLifecycle().addObserver(new AvatarViewMixin(this, avatarView));
            }

            showSuggestionFragment();

            if (FeatureFlagUtils.isEnabled(this, FeatureFlags.CONTEXTUAL_HOME)) {
                showFragment(new ContextualCardsFragment(), R.id.contextual_cards_content);
            }
        }
        showFragment(new TopLevelSettings(), R.id.main_content);
        ((FrameLayout) findViewById(R.id.main_content))
                .getLayoutTransition().enableTransitionType(LayoutTransition.CHANGING);
    }

    private void showSuggestionFragment() {
        final Class<? extends Fragment> fragment = FeatureFactory.getFactory(this)
                .getSuggestionFeatureProvider(this).getContextualSuggestionFragment();
        if (fragment == null) {
            return;
        }

        mSuggestionView = findViewById(R.id.suggestion_content);
        mHomepageView = findViewById(R.id.settings_homepage_container);
        // Hide the homepage for preparing the suggestion.
        mHomepageView.setVisibility(View.GONE);
        // Schedule a timer to show the homepage and hide the suggestion on timeout.
        mHomepageView.postDelayed(() -> showHomepageWithSuggestion(false),
                HOMEPAGE_LOADING_TIMEOUT_MS);
        try {
            showFragment(fragment.getConstructor().newInstance(), R.id.suggestion_content);
        } catch (Exception e) {
            Log.w(TAG, "Cannot show fragment", e);
        }
    }

    private void showFragment(Fragment fragment, int id) {
        final FragmentManager fragmentManager = getSupportFragmentManager();
        final FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        final Fragment showFragment = fragmentManager.findFragmentById(id);

        if (showFragment == null) {
            fragmentTransaction.add(id, fragment);
        } else {
            fragmentTransaction.show(showFragment);
        }
        fragmentTransaction.commit();
    }

    private void initHomepageContainer() {
        final View view = findViewById(R.id.homepage_container);
        // Prevent inner RecyclerView gets focus and invokes scrolling.
        view.setFocusableInTouchMode(true);
        view.requestFocus();
    }

    private int getSearchBoxHeight() {
        final int searchBarHeight = getResources().getDimensionPixelSize(R.dimen.search_bar_height);
        final int searchBarMargin = getResources().getDimensionPixelSize(R.dimen.search_bar_margin);
        return searchBarHeight + searchBarMargin * 2;
    }
}