/*
 * Copyright (C) 2008 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 android.annotation.TargetApi;
import android.appwidget.AppWidgetManager;
import android.content.ComponentName;
import android.content.ContentProvider;
import android.content.ContentProviderOperation;
import android.content.ContentProviderResult;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.OperationApplicationException;
import android.database.Cursor;
import android.database.sqlite.SQLiteQueryBuilder;
import android.net.Uri;
import android.os.Binder;
import android.os.Build;
import android.os.Bundle;
import android.os.Process;
import android.text.TextUtils;
import android.util.Log;

import com.android.launcher3.LauncherSettings.Favorites;
import com.android.launcher3.config.FeatureFlags;
import com.android.launcher3.model.ModelDbController;
import com.android.launcher3.provider.LauncherDbUtils.SQLiteTransaction;
import com.android.launcher3.widget.LauncherWidgetHolder;

import java.io.FileDescriptor;
import java.io.PrintWriter;
import java.util.ArrayList;

public class LauncherProvider extends ContentProvider {
    private static final String TAG = "LauncherProvider";

    public static final String AUTHORITY = BuildConfig.APPLICATION_ID + ".settings";

    /**
     * $ adb shell dumpsys activity provider com.android.launcher3
     */
    @Override
    public void dump(FileDescriptor fd, PrintWriter writer, String[] args) {
        LauncherAppState appState = LauncherAppState.getInstanceNoCreate();
        if (appState == null || !appState.getModel().isModelLoaded()) {
            return;
        }
        appState.getModel().dumpState("", fd, writer, args);
    }

    @Override
    public boolean onCreate() {
        if (FeatureFlags.IS_STUDIO_BUILD) {
            Log.d(TAG, "Launcher process started");
        }

        // The content provider exists for the entire duration of the launcher main process and
        // is the first component to get created.
        MainProcessInitializer.initialize(getContext().getApplicationContext());
        return true;
    }

    public ModelDbController getModelDbController() {
        return LauncherAppState.getInstance(getContext()).getModel().getModelDbController();
    }

    @Override
    public String getType(Uri uri) {
        SqlArguments args = new SqlArguments(uri, null, null);
        if (TextUtils.isEmpty(args.where)) {
            return "vnd.android.cursor.dir/" + args.table;
        } else {
            return "vnd.android.cursor.item/" + args.table;
        }
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection,
            String[] selectionArgs, String sortOrder) {

        SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
        SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
        qb.setTables(args.table);

        Cursor result = getModelDbController().query(
                args.table, projection, args.where, args.args, sortOrder);
        result.setNotificationUri(getContext().getContentResolver(), uri);
        return result;
    }

    private void reloadLauncherIfExternal() {
        if (Binder.getCallingPid() != Process.myPid()) {
            LauncherAppState app = LauncherAppState.getInstanceNoCreate();
            if (app != null) {
                app.getModel().forceReload();
            }
        }
    }

    @Override
    public Uri insert(Uri uri, ContentValues initialValues) {
        // In very limited cases, we support system|signature permission apps to modify the db.
        if (Binder.getCallingPid() != Process.myPid()) {
            if (!initializeExternalAdd(initialValues)) {
                return null;
            }
        }

        SqlArguments args = new SqlArguments(uri);
        int rowId = getModelDbController().insert(args.table, initialValues);
        if (rowId < 0) return null;

        uri = ContentUris.withAppendedId(uri, rowId);
        reloadLauncherIfExternal();
        return uri;
    }

    private boolean initializeExternalAdd(ContentValues values) {
        // 1. Ensure that externally added items have a valid item id
        int id = getModelDbController().generateNewItemId();
        values.put(LauncherSettings.Favorites._ID, id);

        // 2. In the case of an app widget, and if no app widget id is specified, we
        // attempt allocate and bind the widget.
        Integer itemType = values.getAsInteger(LauncherSettings.Favorites.ITEM_TYPE);
        if (itemType != null &&
                itemType.intValue() == LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET &&
                !values.containsKey(LauncherSettings.Favorites.APPWIDGET_ID)) {

            final AppWidgetManager appWidgetManager = AppWidgetManager.getInstance(getContext());
            ComponentName cn = ComponentName.unflattenFromString(
                    values.getAsString(Favorites.APPWIDGET_PROVIDER));

            if (cn != null) {
                LauncherWidgetHolder widgetHolder = LauncherWidgetHolder.newInstance(getContext());
                try {
                    int appWidgetId = widgetHolder.allocateAppWidgetId();
                    values.put(LauncherSettings.Favorites.APPWIDGET_ID, appWidgetId);
                    if (!appWidgetManager.bindAppWidgetIdIfAllowed(appWidgetId,cn)) {
                        widgetHolder.deleteAppWidgetId(appWidgetId);
                        return false;
                    }
                } catch (RuntimeException e) {
                    Log.e(TAG, "Failed to initialize external widget", e);
                    return false;
                } finally {
                    // Necessary to destroy the holder to free up possible activity context
                    widgetHolder.destroy();
                }
            } else {
                return false;
            }
        }

        return true;
    }

    @Override
    public int bulkInsert(Uri uri, ContentValues[] values) {
        SqlArguments args = new SqlArguments(uri);
        getModelDbController().bulkInsert(args.table, values);
        reloadLauncherIfExternal();
        return values.length;
    }

    @TargetApi(Build.VERSION_CODES.M)
    @Override
    public ContentProviderResult[] applyBatch(ArrayList<ContentProviderOperation> operations)
            throws OperationApplicationException {
        try (SQLiteTransaction t = getModelDbController().newTransaction()) {
            final int numOperations = operations.size();
            final ContentProviderResult[] results = new ContentProviderResult[numOperations];
            for (int i = 0; i < numOperations; i++) {
                ContentProviderOperation op = operations.get(i);
                results[i] = op.apply(this, results, i);
            }
            t.commit();
            reloadLauncherIfExternal();
            return results;
        }
    }

    @Override
    public int delete(Uri uri, String selection, String[] selectionArgs) {
        SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
        int count = getModelDbController().delete(args.table, args.where, args.args);
        if (count > 0) {
            reloadLauncherIfExternal();
        }
        return count;
    }

    @Override
    public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
        SqlArguments args = new SqlArguments(uri, selection, selectionArgs);
        int count = getModelDbController().update(args.table, values, args.where, args.args);
        reloadLauncherIfExternal();
        return count;
    }

    @Override
    public Bundle call(String method, final String arg, final Bundle extras) {
        if (Binder.getCallingUid() != Process.myUid()) {
            return null;
        }

        switch (method) {
            case LauncherSettings.Settings.METHOD_CLEAR_EMPTY_DB_FLAG: {
                getModelDbController().clearEmptyDbFlag();
                return null;
            }
            case LauncherSettings.Settings.METHOD_DELETE_EMPTY_FOLDERS: {
                Bundle result = new Bundle();
                result.putIntArray(LauncherSettings.Settings.EXTRA_VALUE,
                        getModelDbController().deleteEmptyFolders().toArray());
                return result;
            }
            case LauncherSettings.Settings.METHOD_NEW_ITEM_ID: {
                Bundle result = new Bundle();
                result.putInt(LauncherSettings.Settings.EXTRA_VALUE,
                        getModelDbController().generateNewItemId());
                return result;
            }
            case LauncherSettings.Settings.METHOD_NEW_SCREEN_ID: {
                Bundle result = new Bundle();
                result.putInt(LauncherSettings.Settings.EXTRA_VALUE,
                        getModelDbController().getNewScreenId());
                return result;
            }
            case LauncherSettings.Settings.METHOD_CREATE_EMPTY_DB: {
                getModelDbController().createEmptyDB();
                return null;
            }
            case LauncherSettings.Settings.METHOD_LOAD_DEFAULT_FAVORITES: {
                getModelDbController().loadDefaultFavoritesIfNecessary();
                return null;
            }
            case LauncherSettings.Settings.METHOD_REMOVE_GHOST_WIDGETS: {
                getModelDbController().removeGhostWidgets();
                return null;
            }
            case LauncherSettings.Settings.METHOD_NEW_TRANSACTION: {
                Bundle result = new Bundle();
                result.putBinder(LauncherSettings.Settings.EXTRA_VALUE,
                        getModelDbController().newTransaction());
                return result;
            }
            case LauncherSettings.Settings.METHOD_REFRESH_HOTSEAT_RESTORE_TABLE: {
                getModelDbController().refreshHotseatRestoreTable();
                return null;
            }
        }
        return null;
    }

    static class SqlArguments {
        public final String table;
        public final String where;
        public final String[] args;

        SqlArguments(Uri url, String where, String[] args) {
            if (url.getPathSegments().size() == 1) {
                this.table = url.getPathSegments().get(0);
                this.where = where;
                this.args = args;
            } else if (url.getPathSegments().size() != 2) {
                throw new IllegalArgumentException("Invalid URI: " + url);
            } else if (!TextUtils.isEmpty(where)) {
                throw new UnsupportedOperationException("WHERE clause not supported: " + url);
            } else {
                this.table = url.getPathSegments().get(0);
                this.where = "_id=" + ContentUris.parseId(url);
                this.args = null;
            }
        }

        SqlArguments(Uri url) {
            if (url.getPathSegments().size() == 1) {
                table = url.getPathSegments().get(0);
                where = null;
                args = null;
            } else {
                throw new IllegalArgumentException("Invalid URI: " + url);
            }
        }
    }
}