/*
 * Copyright (C) 2023 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;

import static android.content.ClipDescription.MIMETYPE_TEXT_INTENT;
import static android.view.WindowInsets.Type.navigationBars;
import static android.view.WindowInsets.Type.statusBars;

import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
import static com.android.launcher3.util.Executors.MODEL_EXECUTOR;

import android.appwidget.AppWidgetManager;
import android.appwidget.AppWidgetProviderInfo;
import android.content.ClipData;
import android.content.ClipDescription;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.WindowInsetsController;
import android.view.WindowManager;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import com.android.launcher3.dragndrop.SimpleDragLayer;
import com.android.launcher3.model.WidgetItem;
import com.android.launcher3.model.WidgetPredictionsRequester;
import com.android.launcher3.model.WidgetsModel;
import com.android.launcher3.model.data.ItemInfo;
import com.android.launcher3.popup.PopupDataProvider;
import com.android.launcher3.util.PackageUserKey;
import com.android.launcher3.widget.BaseWidgetSheet;
import com.android.launcher3.widget.WidgetCell;
import com.android.launcher3.widget.model.WidgetsListBaseEntry;
import com.android.launcher3.widget.model.WidgetsListHeaderEntry;
import com.android.launcher3.widget.picker.WidgetsFullSheet;

import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

/** An Activity that can host Launcher's widget picker. */
public class WidgetPickerActivity extends BaseActivity {
    private static final String TAG = "WidgetPickerActivity";
    /**
     * Name of the extra that indicates that a widget being dragged.
     *
     * <p>When set to "true" in the result of startActivityForResult, the client that launched the
     * picker knows that activity was closed due to pending drag.
     */
    private static final String EXTRA_IS_PENDING_WIDGET_DRAG = "is_pending_widget_drag";

    // Intent extras that specify the desired widget width and height. If these are not specified in
    // the intent, then widgets will not be filtered for size.
    private static final String EXTRA_DESIRED_WIDGET_WIDTH = "desired_widget_width";
    private static final String EXTRA_DESIRED_WIDGET_HEIGHT = "desired_widget_height";
    /**
     * Widgets currently added by the user in the UI surface.
     * <p>This allows widget picker to exclude existing widgets from suggestions.</p>
     */
    private static final String EXTRA_ADDED_APP_WIDGETS = "added_app_widgets";
    /**
     * A unique identifier of the surface hosting the widgets;
     * <p>"widgets" is reserved for home screen surface.</p>
     * <p>"widgets_hub" is reserved for glanceable hub surface.</p>
     */
    private static final String EXTRA_UI_SURFACE = "ui_surface";
    private static final Pattern UI_SURFACE_PATTERN =
            Pattern.compile("^(widgets|widgets_hub)$");
    private SimpleDragLayer<WidgetPickerActivity> mDragLayer;
    private WidgetsModel mModel;
    private LauncherAppState mApp;
    private WidgetPredictionsRequester mWidgetPredictionsRequester;
    private final PopupDataProvider mPopupDataProvider = new PopupDataProvider(i -> {});

    private int mDesiredWidgetWidth;
    private int mDesiredWidgetHeight;
    private int mWidgetCategoryFilter;
    @Nullable
    private String mUiSurface;
    // Widgets existing on the host surface.
    @NonNull
    private List<AppWidgetProviderInfo> mAddedWidgets = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED);
        getWindow().clearFlags(WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER);

        mApp = LauncherAppState.getInstance(this);
        InvariantDeviceProfile idp = mApp.getInvariantDeviceProfile();
        mDeviceProfile = idp.getDeviceProfile(this);
        mModel = new WidgetsModel();

        setContentView(R.layout.widget_picker_activity);
        mDragLayer = findViewById(R.id.drag_layer);
        mDragLayer.recreateControllers();

        WindowInsetsController wc = mDragLayer.getWindowInsetsController();
        wc.hide(navigationBars() + statusBars());

        BaseWidgetSheet widgetSheet = WidgetsFullSheet.show(this, true);
        widgetSheet.disableNavBarScrim(true);
        widgetSheet.addOnCloseListener(this::finish);

        parseIntentExtras();
        refreshAndBindWidgets();
    }

    private void parseIntentExtras() {
        // A value of 0 for either size means that no filtering will occur in that dimension. If
        // both values are 0, then no size filtering will occur.
        mDesiredWidgetWidth =
                getIntent().getIntExtra(EXTRA_DESIRED_WIDGET_WIDTH, 0);
        mDesiredWidgetHeight =
                getIntent().getIntExtra(EXTRA_DESIRED_WIDGET_HEIGHT, 0);

        // Defaults to '0' to indicate that there isn't a category filter.
        mWidgetCategoryFilter =
                getIntent().getIntExtra(AppWidgetManager.EXTRA_CATEGORY_FILTER, 0);

        String uiSurfaceParam = getIntent().getStringExtra(EXTRA_UI_SURFACE);
        if (uiSurfaceParam != null && UI_SURFACE_PATTERN.matcher(uiSurfaceParam).matches()) {
            mUiSurface = uiSurfaceParam;
        }
        ArrayList<AppWidgetProviderInfo> addedWidgets = getIntent().getParcelableArrayListExtra(
                EXTRA_ADDED_APP_WIDGETS, AppWidgetProviderInfo.class);
        if (addedWidgets != null) {
            mAddedWidgets = addedWidgets;
        }
    }

    @NonNull
    @Override
    public PopupDataProvider getPopupDataProvider() {
        return mPopupDataProvider;
    }

    @Override
    public SimpleDragLayer<WidgetPickerActivity> getDragLayer() {
        return mDragLayer;
    }

    @Override
    public View.OnClickListener getItemOnClickListener() {
        return v -> {
            final AppWidgetProviderInfo info =
                    (v instanceof WidgetCell) ? ((WidgetCell) v).getWidgetItem().widgetInfo : null;
            if (info == null || info.provider == null) {
                return;
            }

            setResult(RESULT_OK, new Intent()
                    .putExtra(Intent.EXTRA_COMPONENT_NAME, info.provider)
                    .putExtra(Intent.EXTRA_USER, info.getProfile()));

            finish();
        };
    }

    @Override
    public View.OnLongClickListener getAllAppsItemLongClickListener() {
        return view -> {
            if (!(view instanceof WidgetCell widgetCell)) return false;

            if (widgetCell.getWidgetView().getDrawable() == null
                    && widgetCell.getAppWidgetHostViewPreview() == null) {
                // The widget preview hasn't been loaded; so, we abort the drag.
                return false;
            }

            final AppWidgetProviderInfo info = widgetCell.getWidgetItem().widgetInfo;
            if (info == null || info.provider == null) {
                return false;
            }

            View dragView = widgetCell.getDragAndDropView();
            if (dragView == null) {
                return false;
            }

            ClipData clipData = new ClipData(
                    new ClipDescription(
                            /* label= */ "", // not displayed anywhere; so, set to empty.
                            new String[]{MIMETYPE_TEXT_INTENT}
                    ),
                    new ClipData.Item(new Intent()
                            .putExtra(Intent.EXTRA_USER, info.getProfile())
                            .putExtra(Intent.EXTRA_COMPONENT_NAME, info.provider))
            );

            // Set result indicating activity was closed due a widget being dragged.
            setResult(RESULT_OK, new Intent()
                    .putExtra(EXTRA_IS_PENDING_WIDGET_DRAG, true));

            // DRAG_FLAG_GLOBAL permits dragging data beyond app window.
            return dragView.startDragAndDrop(
                    clipData,
                    new View.DragShadowBuilder(dragView),
                    /* myLocalState= */ null,
                    View.DRAG_FLAG_GLOBAL
            );
        };
    }

    /** Updates the model with widgets and provides them after applying the provided filter. */
    private void refreshAndBindWidgets() {
        MODEL_EXECUTOR.execute(() -> {
            LauncherAppState app = LauncherAppState.getInstance(this);
            mModel.update(app, null);
            final List<WidgetsListBaseEntry> allWidgets =
                    mModel.getFilteredWidgetsListForPicker(
                            app.getContext(),
                            /*widgetItemFilter=*/ widget -> {
                                final WidgetAcceptabilityVerdict verdict =
                                        isWidgetAcceptable(widget);
                                verdict.maybeLogVerdict();
                                return verdict.isAcceptable;
                            }
                    );
            bindWidgets(allWidgets);
            if (mUiSurface != null) {
                Map<PackageUserKey, List<WidgetItem>> allWidgetsMap = allWidgets.stream()
                        .filter(WidgetsListHeaderEntry.class::isInstance)
                        .collect(Collectors.toMap(
                                entry -> PackageUserKey.fromPackageItemInfo(entry.mPkgItem),
                                entry -> entry.mWidgets)
                        );
                mWidgetPredictionsRequester = new WidgetPredictionsRequester(app.getContext(),
                        mUiSurface, allWidgetsMap);
                mWidgetPredictionsRequester.request(mAddedWidgets, this::bindRecommendedWidgets);
            }
        });
    }

    private void bindWidgets(List<WidgetsListBaseEntry> widgets) {
        MAIN_EXECUTOR.execute(() -> mPopupDataProvider.setAllWidgets(widgets));
    }

    private void bindRecommendedWidgets(List<ItemInfo> recommendedWidgets) {
        MAIN_EXECUTOR.execute(() -> mPopupDataProvider.setRecommendedWidgets(recommendedWidgets));
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mWidgetPredictionsRequester != null) {
            mWidgetPredictionsRequester.clear();
        }
    }

    private WidgetAcceptabilityVerdict isWidgetAcceptable(WidgetItem widget) {
        final AppWidgetProviderInfo info = widget.widgetInfo;
        if (info == null) {
            return rejectWidget(widget, "shortcut");
        }

        if (mWidgetCategoryFilter > 0 && (info.widgetCategory & mWidgetCategoryFilter) == 0) {
            return rejectWidget(
                    widget,
                    "doesn't match category filter [filter=%d, widget=%d]",
                    mWidgetCategoryFilter,
                    info.widgetCategory);
        }

        if (mDesiredWidgetWidth == 0 && mDesiredWidgetHeight == 0) {
            // Accept the widget if the desired dimensions are unspecified.
            return acceptWidget(widget);
        }

        final boolean isHorizontallyResizable =
                (info.resizeMode & AppWidgetProviderInfo.RESIZE_HORIZONTAL) != 0;
        if (mDesiredWidgetWidth > 0 && isHorizontallyResizable) {
            if (info.maxResizeWidth > 0
                    && info.maxResizeWidth >= info.minWidth
                    && info.maxResizeWidth < mDesiredWidgetWidth) {
                return rejectWidget(
                        widget,
                        "maxResizeWidth[%d] < mDesiredWidgetWidth[%d]",
                        info.maxResizeWidth,
                        mDesiredWidgetWidth);
            }

            final int minWidth = Math.min(info.minResizeWidth, info.minWidth);
            if (minWidth > mDesiredWidgetWidth) {
                return rejectWidget(
                        widget,
                        "min(minWidth[%d], minResizeWidth[%d]) > mDesiredWidgetWidth[%d]",
                        info.minWidth,
                        info.minResizeWidth,
                        mDesiredWidgetWidth);
            }
        }

        final boolean isVerticallyResizable =
                (info.resizeMode & AppWidgetProviderInfo.RESIZE_VERTICAL) != 0;
        if (mDesiredWidgetHeight > 0 && isVerticallyResizable) {
            if (info.maxResizeHeight > 0
                    && info.maxResizeHeight >= info.minHeight
                    && info.maxResizeHeight < mDesiredWidgetHeight) {
                return rejectWidget(
                        widget,
                        "maxResizeHeight[%d] < mDesiredWidgetHeight[%d]",
                        info.maxResizeHeight,
                        mDesiredWidgetHeight);
            }

            final int minHeight = Math.min(info.minResizeHeight, info.minHeight);
            if (minHeight > mDesiredWidgetHeight) {
                return rejectWidget(
                        widget,
                        "min(minHeight[%d], minResizeHeight[%d]) > mDesiredWidgetHeight[%d]",
                        info.minHeight,
                        info.minResizeHeight,
                        mDesiredWidgetHeight);
            }
        }

        if (!isHorizontallyResizable || !isVerticallyResizable) {
            return rejectWidget(widget, "not resizeable");
        }

        return acceptWidget(widget);
    }

    private static WidgetAcceptabilityVerdict rejectWidget(
            WidgetItem widget, String rejectionReason, Object... args) {
        return new WidgetAcceptabilityVerdict(
                false,
                widget.widgetInfo != null
                        ? widget.widgetInfo.provider.flattenToShortString()
                        : widget.label,
                String.format(Locale.ENGLISH, rejectionReason, args));
    }

    private static WidgetAcceptabilityVerdict acceptWidget(WidgetItem widget) {
        return new WidgetAcceptabilityVerdict(
                true, widget.widgetInfo.provider.flattenToShortString(), "");
    }

    private record WidgetAcceptabilityVerdict(
            boolean isAcceptable, String widgetLabel, String reason) {
        void maybeLogVerdict() {
            // Only log a verdict if a reason is specified.
            if (Log.isLoggable(TAG, Log.DEBUG) && !reason.isEmpty()) {
                Log.i(TAG, String.format(
                        Locale.ENGLISH,
                        "%s: %s because %s",
                        widgetLabel,
                        isAcceptable ? "accepted" : "rejected",
                        reason));
            }
        }
    }
}