/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.flink.walkthrough.common.source;

import org.apache.flink.walkthrough.common.entity.Transaction;

import java.io.Serializable;
import java.sql.Timestamp;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

/** An iterator of transaction events. */
final class TransactionIterator implements Iterator<Transaction>, Serializable {

    private static final long serialVersionUID = 1L;

    private static final Timestamp INITIAL_TIMESTAMP = Timestamp.valueOf("2019-01-01 00:00:00");

    private static final long SIX_MINUTES = 6 * 60 * 1000;

    private final boolean bounded;

    private int index = 0;

    private long timestamp;

    static TransactionIterator bounded() {
        return new TransactionIterator(true);
    }

    static TransactionIterator unbounded() {
        return new TransactionIterator(false);
    }

    private TransactionIterator(boolean bounded) {
        this.bounded = bounded;
        this.timestamp = INITIAL_TIMESTAMP.getTime();
    }

    @Override
    public boolean hasNext() {
        if (index < data.size()) {
            return true;
        } else if (!bounded) {
            index = 0;
            return true;
        } else {
            return false;
        }
    }

    @Override
    public Transaction next() {
        Transaction transaction = data.get(index++);
        transaction.setTimestamp(timestamp);
        timestamp += SIX_MINUTES;
        return transaction;
    }

    private static List<Transaction> data =
            Arrays.asList(
                    new Transaction(1, 0L, 188.23),
                    new Transaction(2, 0L, 374.79),
                    new Transaction(3, 0L, 112.15),
                    new Transaction(4, 0L, 478.75),
                    new Transaction(5, 0L, 208.85),
                    new Transaction(1, 0L, 379.64),
                    new Transaction(2, 0L, 351.44),
                    new Transaction(3, 0L, 320.75),
                    new Transaction(4, 0L, 259.42),
                    new Transaction(5, 0L, 273.44),
                    new Transaction(1, 0L, 267.25),
                    new Transaction(2, 0L, 397.15),
                    new Transaction(3, 0L, 0.219),
                    new Transaction(4, 0L, 231.94),
                    new Transaction(5, 0L, 384.73),
                    new Transaction(1, 0L, 419.62),
                    new Transaction(2, 0L, 412.91),
                    new Transaction(3, 0L, 0.77),
                    new Transaction(4, 0L, 22.10),
                    new Transaction(5, 0L, 377.54),
                    new Transaction(1, 0L, 375.44),
                    new Transaction(2, 0L, 230.18),
                    new Transaction(3, 0L, 0.80),
                    new Transaction(4, 0L, 350.89),
                    new Transaction(5, 0L, 127.55),
                    new Transaction(1, 0L, 483.91),
                    new Transaction(2, 0L, 228.22),
                    new Transaction(3, 0L, 871.15),
                    new Transaction(4, 0L, 64.19),
                    new Transaction(5, 0L, 79.43),
                    new Transaction(1, 0L, 56.12),
                    new Transaction(2, 0L, 256.48),
                    new Transaction(3, 0L, 148.16),
                    new Transaction(4, 0L, 199.95),
                    new Transaction(5, 0L, 252.37),
                    new Transaction(1, 0L, 274.73),
                    new Transaction(2, 0L, 473.54),
                    new Transaction(3, 0L, 119.92),
                    new Transaction(4, 0L, 323.59),
                    new Transaction(5, 0L, 353.16),
                    new Transaction(1, 0L, 211.90),
                    new Transaction(2, 0L, 280.93),
                    new Transaction(3, 0L, 347.89),
                    new Transaction(4, 0L, 459.86),
                    new Transaction(5, 0L, 82.31),
                    new Transaction(1, 0L, 373.26),
                    new Transaction(2, 0L, 479.83),
                    new Transaction(3, 0L, 454.25),
                    new Transaction(4, 0L, 83.64),
                    new Transaction(5, 0L, 292.44));
}