/*
 * 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.ignite.examples.ml.util;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.file.Paths;
import java.text.NumberFormat;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.Scanner;
import java.util.UUID;
import org.apache.ignite.Ignite;
import org.apache.ignite.IgniteCache;
import org.apache.ignite.cache.affinity.rendezvous.RendezvousAffinityFunction;
import org.apache.ignite.configuration.CacheConfiguration;
import org.apache.ignite.internal.util.IgniteUtils;
import org.apache.ignite.ml.math.exceptions.datastructures.FileParsingException;
import org.apache.ignite.ml.math.primitives.vector.Vector;
import org.apache.ignite.ml.math.primitives.vector.VectorUtils;

/**
 * Common utility code used in some ML examples to set up test cache.
 */
public class SandboxMLCache {
    /** */
    private final Ignite ignite;

    /** */
    public SandboxMLCache(Ignite ignite) {
        this.ignite = ignite;
    }

    /**
     * Fills cache with data and returns it.
     *
     * @param data Data to fill the cache with.
     * @return Filled Ignite Cache.
     */
    public IgniteCache<Integer, double[]> fillCacheWith(double[][] data) {
        CacheConfiguration<Integer, double[]> cacheConfiguration = new CacheConfiguration<>();
        cacheConfiguration.setName("TEST_" + UUID.randomUUID());
        cacheConfiguration.setAffinity(new RendezvousAffinityFunction(false, 10));

        IgniteCache<Integer, double[]> cache = ignite.createCache(cacheConfiguration);

        for (int i = 0; i < data.length; i++)
            cache.put(i, data[i]);

        return cache;
    }

    /**
     * Loads dataset as a list of rows.
     *
     * @param dataset The chosen dataset.
     * @return List of rows.
     * @throws IOException If file not found.
     */
    public List<String> loadDataset(MLSandboxDatasets dataset) throws IOException {
        List<String> res = new ArrayList<>();

        String fileName = dataset.getFileName();

        File file = IgniteUtils.resolveIgnitePath(fileName);

        if (file == null)
            throw new FileNotFoundException(fileName);

        Scanner scanner = new Scanner(file);

        if (dataset.hasHeader() && scanner.hasNextLine())
            scanner.nextLine();

        while (scanner.hasNextLine()) {
            String row = scanner.nextLine();
            res.add(row);
        }
        return res;
    }

    /**
     * Fills cache with data and returns it.
     *
     * @param dataset The chosen dataset.
     * @return Filled Ignite Cache.
     * @throws FileNotFoundException If file not found.
     */
    public IgniteCache<Integer, Vector> fillCacheWith(MLSandboxDatasets dataset) throws FileNotFoundException {
        IgniteCache<Integer, Vector> cache = getCache();

        String fileName = dataset.getFileName();

        File file = IgniteUtils.resolveIgnitePath(fileName);

        if (file == null)
            throw new FileNotFoundException(fileName);

        Scanner scanner = new Scanner(file);

        int cnt = 0;
        while (scanner.hasNextLine()) {
            String row = scanner.nextLine();
            if(dataset.hasHeader() && cnt == 0) {
                cnt++;
                continue;
            }

            String[] cells = row.split(dataset.getSeparator());

            double[] data = new double[cells.length];
            NumberFormat format = NumberFormat.getInstance(Locale.FRANCE);

            for (int i = 0; i < cells.length; i++)
                try{
                    if(cells[i].isEmpty()) data[i] = Double.NaN;
                    else data[i] = Double.valueOf(cells[i]);
                } catch (NumberFormatException e) {
                    try {
                        data[i] = format.parse(cells[i]).doubleValue();
                    }
                    catch (ParseException e1) {
                        throw new FileParsingException(cells[i], i, Paths.get(dataset.getFileName()));
                    }
                }
            cache.put(cnt++, VectorUtils.of(data));
        }
        return cache;
    }

    /**
     * Fills cache with data and returns it.
     *
     * @param dataset The chosen dataset.
     * @return Filled Ignite Cache.
     * @throws FileNotFoundException If file not found.
     */
    public IgniteCache<Integer, Object[]> fillObjectCacheWithDoubleLabels(MLSandboxDatasets dataset) throws FileNotFoundException {
        IgniteCache<Integer, Object[]> cache = getCache2();

        String fileName = dataset.getFileName();

        File file = IgniteUtils.resolveIgnitePath(fileName);

        if (file == null)
            throw new FileNotFoundException(fileName);

        Scanner scanner = new Scanner(file);

        int cnt = 0;
        while (scanner.hasNextLine()) {
            String row = scanner.nextLine();
            if (dataset.hasHeader() && cnt == 0) {
                cnt++;
                continue;
            }

            String[] cells = row.split(dataset.getSeparator());

            Object[] res = new Object[cells.length];

            res[0] = cells[0].contains("p") ? 0.0 : 1.0;

            System.arraycopy(cells, 1, res, 1, cells.length - 1);

            cache.put(cnt++, res);
        }
        return cache;
    }

    /**
     * Fills cache with data and returns it.
     *
     * @param dataset The chosen dataset.
     * @return Filled Ignite Cache.
     * @throws FileNotFoundException If file not found.
     */
    public IgniteCache<Integer, Object[]> fillObjectCacheWithCategoricalData(MLSandboxDatasets dataset) throws FileNotFoundException {
        IgniteCache<Integer, Object[]> cache = getCache2();

        String fileName = dataset.getFileName();

        File file = IgniteUtils.resolveIgnitePath(fileName);

        if (file == null)
            throw new FileNotFoundException(fileName);

        Scanner scanner = new Scanner(file);

        int cnt = 0;
        while (scanner.hasNextLine()) {
            String row = scanner.nextLine();
            if (dataset.hasHeader() && cnt == 0) {
                cnt++;
                continue;
            }

            String[] cells = row.split(dataset.getSeparator());
            cache.put(cnt++, cells);
        }
        return cache;
    }

    /**
     * Fills cache with data and returns it.
     *
     * @return Filled Ignite Cache.
     */
    private IgniteCache<Integer, Vector> getCache() {
        CacheConfiguration<Integer, Vector> cacheConfiguration = new CacheConfiguration<>();
        cacheConfiguration.setName("ML_EXAMPLE_" + UUID.randomUUID());
        cacheConfiguration.setAffinity(new RendezvousAffinityFunction(false, 10));

        return ignite.createCache(cacheConfiguration);
    }

    /**
     * Fills cache with data and returns it.
     *
     * @return Filled Ignite Cache.
     */
    private IgniteCache<Integer, Object[]> getCache2() {
        CacheConfiguration<Integer, Object[]> cacheConfiguration = new CacheConfiguration<>();
        cacheConfiguration.setName("ML_EXAMPLE_" + UUID.randomUUID());
        cacheConfiguration.setAffinity(new RendezvousAffinityFunction(false, 10));

        return ignite.createCache(cacheConfiguration);
    }
}