/*
 * Copyright (C) 2013 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.providers.contacts.database;

import static android.provider.ContactsContract.Contacts;
import static com.android.providers.contacts.ContactsDatabaseHelper.Tables;

import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.provider.ContactsContract;
import android.text.TextUtils;

import com.android.common.io.MoreCloseables;
import com.android.providers.contacts.util.Clock;

import java.util.Set;

/**
 * Methods for operating on the contacts table.
 */
public class ContactsTableUtil {

    /**
     * Drop indexes if present.  Create indexes.
     *
     * @param db The sqlite database instance.
     */
    public static void createIndexes(SQLiteDatabase db) {
        final String table = Tables.CONTACTS;

        db.execSQL("CREATE INDEX contacts_has_phone_index ON " + table + " (" +
                Contacts.HAS_PHONE_NUMBER +
                ");");

        db.execSQL("CREATE INDEX contacts_name_raw_contact_id_index ON " + table + " (" +
                Contacts.NAME_RAW_CONTACT_ID +
                ");");

        db.execSQL(MoreDatabaseUtils.buildCreateIndexSql(table,
                Contacts.CONTACT_LAST_UPDATED_TIMESTAMP));
    }

    public static void updateContactLastUpdateByContactId(SQLiteDatabase db, long contactId) {
        final ContentValues values = new ContentValues();
        values.put(Contacts.CONTACT_LAST_UPDATED_TIMESTAMP,
                Clock.getInstance().currentTimeMillis());
        db.update(Tables.CONTACTS, values, Contacts._ID + " = ?",
                new String[] {String.valueOf(contactId)});
    }

    /**
     * Refreshes the last updated timestamp of the contact with the current time.
     *
     * @param db The sqlite database instance.
     * @param rawContactIds A set of raw contacts ids to refresh the contact for.
     */
    public static void updateContactLastUpdateByRawContactId(SQLiteDatabase db,
            Set<Long> rawContactIds) {
        if (rawContactIds.isEmpty()) {
            return;
        }

        db.execSQL(buildUpdateLastUpdateSql(rawContactIds));
    }

    /**
     * Build a sql to update the last updated timestamp for contacts.
     *
     * @param rawContactIds The raw contact ids that contacts should be updated for.
     * @return The update sql statement.
     */
    private static String buildUpdateLastUpdateSql(Set<Long> rawContactIds) {
        // Not using bind args here due to sqlite bind arg size limit.  Large number of bind args
        // will cause a sqlite error:
        //     android.database.sqlite.SQLiteException: too many SQL variables (code 1)
        // Sql injection is not possible because input is a set of Long.  If any part of the sql
        // is built with user input strings, then this must be converted to using bind args.
        final String sql = "UPDATE " + Tables.CONTACTS
                + " SET " + Contacts.CONTACT_LAST_UPDATED_TIMESTAMP + " = "
                + Clock.getInstance().currentTimeMillis()
                + " WHERE " + Contacts._ID + " IN ( "
                + "  SELECT " + ContactsContract.RawContacts.CONTACT_ID
                + "  FROM " + Tables.RAW_CONTACTS
                + "  WHERE " + ContactsContract.RawContacts._ID
                + " IN (" + TextUtils.join(",", rawContactIds) + ") "
                + ")";
        return sql;
    }

    /**
     * Delete a contact identified by the contact id.
     *
     * @param db The sqlite database instance.
     * @param contactId The contact id to delete.
     * @return The number of records deleted.
     */
    public static int deleteContact(SQLiteDatabase db, long contactId) {
        DeletedContactsTableUtil.insertDeletedContact(db, contactId);
        return db.delete(Tables.CONTACTS, Contacts._ID + " = ?", new String[]{contactId + ""});
    }

    /**
     * Delete the aggregate contact if it has no constituent raw contacts other than the supplied
     * one.
     */
    public static int deleteContactIfSingleton(SQLiteDatabase db, long rawContactId) {
        // This query will find a contact id if the contact has a raw contacts other than the one
        // passed in.
        final String sql = "select " + ContactsContract.RawContacts.CONTACT_ID + ", count(1)"
                + " from " + Tables.RAW_CONTACTS
                + " where " + ContactsContract.RawContacts.CONTACT_ID + " ="
                + "  (select " + ContactsContract.RawContacts.CONTACT_ID
                + "   from " + Tables.RAW_CONTACTS
                + "   where " + ContactsContract.RawContacts._ID + " = ?)"
                + " group by " + ContactsContract.RawContacts.CONTACT_ID;
        final Cursor cursor = db.rawQuery(sql, new String[]{rawContactId + ""});
        try {
            if (cursor.moveToNext()) {
                long contactId = cursor.getLong(0);
                long numRawContacts = cursor.getLong(1);

                if (numRawContacts == 1) {
                    // Only one raw contact, we can delete the parent.
                    return deleteContact(db, contactId);
                }
            }
        } finally {
            MoreCloseables.closeQuietly(cursor);
        }
        return 0;
    }
}