/*
 * Copyright 2019 Scott Logic Ltd
 *
 * 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.scottlogic.datahelix.generator.core.generation.databags;

import com.google.inject.Inject;
import com.scottlogic.datahelix.generator.core.fieldspecs.RowSpec;
import com.scottlogic.datahelix.generator.core.generation.combinationstrategies.CombinationStrategy;
import com.scottlogic.datahelix.generator.core.generation.grouped.FieldSpecGroupValueGenerator;
import com.scottlogic.datahelix.generator.core.generation.grouped.RowSpecGrouper;

import java.util.function.Supplier;
import java.util.stream.Stream;

public class RowSpecDataBagGenerator {
    private final FieldSpecGroupValueGenerator generator;
    private final CombinationStrategy combinationStrategy;

    @Inject
    public RowSpecDataBagGenerator(
        FieldSpecGroupValueGenerator generator,
        CombinationStrategy combinationStrategy) {
        this.generator = generator;
        this.combinationStrategy = combinationStrategy;
    }

    public Stream<DataBag> createDataBags(RowSpec rowSpec) {
        Stream<Supplier<Stream<DataBag>>> dataBagsForGroups =
            RowSpecGrouper.createGroups(rowSpec).stream()
                .map(group -> () -> generator.generate(group));

        return combinationStrategy.permute(dataBagsForGroups);
    }

}
