/*
 * The MIT License
 *
 * Copyright (c) 2014 The Broad Institute
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package htsjdk.tribble.index.tabix;

import htsjdk.HtsjdkTest;
import com.google.common.io.Files;
import htsjdk.samtools.util.BlockCompressedOutputStream;
import htsjdk.samtools.util.FileExtensions;
import htsjdk.samtools.util.IOUtil;
import htsjdk.samtools.util.Interval;
import htsjdk.tribble.AbstractFeatureReader;
import htsjdk.tribble.FeatureReader;
import htsjdk.tribble.TestUtils;
import htsjdk.tribble.Tribble;
import htsjdk.tribble.bed.BEDCodec;
import htsjdk.tribble.bed.BEDFeature;
import htsjdk.tribble.index.IndexFactory;
import htsjdk.tribble.util.LittleEndianOutputStream;
import htsjdk.variant.variantcontext.VariantContext;
import htsjdk.variant.variantcontext.writer.VariantContextWriter;
import htsjdk.variant.variantcontext.writer.VariantContextWriterBuilder;
import htsjdk.variant.vcf.VCFCodec;
import htsjdk.variant.vcf.VCFFileReader;
import org.testng.Assert;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;

import java.io.File;
import java.io.IOException;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

public class TabixIndexTest extends HtsjdkTest {
    private static final File SMALL_TABIX_FILE = new File(TestUtils.DATA_DIR, "tabix/trioDup.vcf.gz.tbi");
    private static final File BIGGER_TABIX_FILE = new File(TestUtils.DATA_DIR, "tabix/bigger.vcf.gz.tbi");

    /**
     * Read an existing index from disk, write it to a temp file, read that in, and assert that both in-memory
     * representations are identical.  Disk representations may not be identical due to arbitrary bin order and
     * compression differences.
     */
    @Test(dataProvider = "readWriteTestDataProvider")
    public void readWriteTest(final File tabixFile) throws Exception {
        final TabixIndex index = new TabixIndex(tabixFile);
        final File indexFile = File.createTempFile("TabixIndexTest.", FileExtensions.TABIX_INDEX);
        indexFile.deleteOnExit();
        final LittleEndianOutputStream los = new LittleEndianOutputStream(new BlockCompressedOutputStream(indexFile));
        index.write(los);
        los.close();
        final TabixIndex index2 = new TabixIndex(indexFile);
        Assert.assertEquals(index, index2);
        // Unfortunately, can't do byte comparison of original file and temp file, because 1) different compression
        // levels; and more importantly, arbitrary order of bins in bin list.
    }

    @DataProvider(name = "readWriteTestDataProvider")
    public Object[][] readWriteTestDataProvider() {
        return new Object[][]{
                {SMALL_TABIX_FILE},
                {BIGGER_TABIX_FILE}
        };
    }

    //TODO: This test reads an existing .tbi on a .gz, but only writes a .tbi index for a plain vcf, which
    // tabix doesn't appear to even allow.
    @Test
    public void testQueryProvidedItemsAmount() throws IOException {
        final String VCF = "src/test/resources/htsjdk/tribble/tabix/YRI.trio.2010_07.indel.sites.vcf";
        // Note that we store only compressed files
        final File plainTextVcfInputFile = new File(VCF);
        plainTextVcfInputFile.deleteOnExit();
        final File plainTextVcfIndexFile = new File(VCF + ".tbi");
        plainTextVcfIndexFile.deleteOnExit();
        final File compressedVcfInputFile = new File(VCF + ".gz");
        final File compressedTbiIndexFile = new File(VCF + ".gz.tbi");
        final VCFFileReader compressedVcfReader = new VCFFileReader(compressedVcfInputFile, compressedTbiIndexFile);

        //create plain text VCF without "index on the fly" option
        final VariantContextWriter plainTextVcfWriter = new VariantContextWriterBuilder()
                .setOptions(VariantContextWriterBuilder.NO_OPTIONS)
                .setOutputFile(VCF)
                .build();
        plainTextVcfWriter.writeHeader(compressedVcfReader.getFileHeader());
        for (VariantContext vc : compressedVcfReader) {
            if (vc != null) plainTextVcfWriter.add(vc);
        }
        plainTextVcfWriter.close();

        IndexFactory.createTabixIndex(plainTextVcfInputFile,
                new VCFCodec(),
                TabixFormat.VCF,
                new VCFFileReader(plainTextVcfInputFile, false).getFileHeader().getSequenceDictionary()
        ) // create TabixIndex straight from plaintext VCF
                .write(plainTextVcfIndexFile); // write it

        //TODO: you can pass in a .tbi file as the index for a plain .vcf, but if you *don't* pass in the file name and
        //just require an index, VCFFleREader will only look for a .idx on a plain vcf
        final VCFFileReader plainTextVcfReader = new VCFFileReader(plainTextVcfInputFile, plainTextVcfIndexFile);
        // Now we have both plaintext and compressed VCFs with provided TabixIndex-es and could test their "queryability"

        // magic numbers chosen from just looking in provided VCF file
        try {
            // just somewhere in middle of chromosome
            Assert.assertEquals(42, countIteratedElements(compressedVcfReader.query("1", 868379 - 1, 1006891 + 1)));
            Assert.assertEquals(42, countIteratedElements(plainTextVcfReader.query("1", 868379 - 1, 1006891 + 1)));
            // chromosome start
            Assert.assertEquals(13, countIteratedElements(compressedVcfReader.query("1", 1, 836463 + 1)));
            Assert.assertEquals(13, countIteratedElements(plainTextVcfReader.query("1", 1, 836463 + 1)));
            // chromosome end
            Assert.assertEquals(36, countIteratedElements(compressedVcfReader.query("1", 76690833 - 1, 76837502 + 11111111)));
            Assert.assertEquals(36, countIteratedElements(plainTextVcfReader.query("1", 76690833 - 1, 76837502 + 11111111)));
            // where's no one feature in the middle of chromosome
            Assert.assertEquals(0, countIteratedElements(compressedVcfReader.query("1", 36606472 + 1, 36623523 - 1)));
            Assert.assertEquals(0, countIteratedElements(plainTextVcfReader.query("1", 36606472 + 1, 36623523 - 1)));
            // before chromosome
            Assert.assertEquals(0, countIteratedElements(compressedVcfReader.query("1", 1, 10)));
            Assert.assertEquals(0, countIteratedElements(plainTextVcfReader.query("1", 1, 10)));
            // after chromosome
            Assert.assertEquals(0, countIteratedElements(compressedVcfReader.query("1", 76837502 * 15, 76837502 * 16)));
            Assert.assertEquals(0, countIteratedElements(plainTextVcfReader.query("1", 76837502 * 15, 76837502 * 16)));
        } catch (NullPointerException e) {
            Assert.fail("Exception caught on querying: ", e);
            // before fix exception was thrown from 'TabixIndex.getBlocks()' on 'chunks.size()' while 'chunks == null' for plain files
        } finally {
            plainTextVcfReader.close();
            compressedVcfReader.close();
        }
    }

    @DataProvider(name = "bedTabixIndexTestData")
    public Object[][] getBedIndexFactory(){
        // These files have accompanying .tbi files created with tabix.
        return new Object[][] {
                new Object[] {
                        // BGZP BED file with no header, 2 features
                        new File(TestUtils.DATA_DIR, "bed/2featuresNoHeader.bed.gz"),
                        Arrays.asList(
                                new Interval("chr1", 1, 10),
                                new Interval("chr1", 100, 1000000))
                },
                new Object[] {
                        // BGZP BED file with no header, 3 features; one feature falls in between the query intervals
                        new File(TestUtils.DATA_DIR, "bed/3featuresNoHeader.bed.gz"),
                        Arrays.asList(
                                new Interval("chr1", 1, 10),
                                new Interval("chr1", 100, 1000000))
                },
                new Object[] {
                        // same file as above (BGZP BED file with no header, 3 features), but change the query to return
                        // only the single interval for the feature that falls in between the other features
                        new File(TestUtils.DATA_DIR, "bed/3featuresNoHeader.bed.gz"),
                        Arrays.asList(
                                new Interval("chr1", 15, 20))
                },
                new Object[] {
                        // BGZP BED file with one line header, 2 features
                        new File(TestUtils.DATA_DIR, "bed/2featuresWithHeader.bed.gz"),
                        Arrays.asList(
                                new Interval("chr1", 1, 10),
                                new Interval("chr1", 100, 1000000))
                },
        };
    }

    @Test(dataProvider = "bedTabixIndexTestData")
    public void testBedTabixIndex(
            final File inputBed,
            final List<Interval> queryIntervals
    ) throws Exception {
        // copy the input file and create an index for the copy
        final File tempDir = IOUtil.createTempDir("testBedTabixIndex.tmp").toFile();
        tempDir.deleteOnExit();
        final File tmpBed = new File(tempDir, inputBed.getName());
        Files.copy(inputBed, tmpBed);
        tmpBed.deleteOnExit();
        final TabixIndex tabixIndexGz = IndexFactory.createTabixIndex(tmpBed, new BEDCodec(), null);
        tabixIndexGz.writeBasedOnFeatureFile(tmpBed);
        final File tmpIndex = Tribble.tabixIndexFile(tmpBed);
        tmpIndex.deleteOnExit();

        // iterate over the query intervals and validate the query results
        try(final FeatureReader<BEDFeature> originalReader =
                    AbstractFeatureReader.getFeatureReader(inputBed.getAbsolutePath(), new BEDCodec());
            final FeatureReader<BEDFeature> createdReader =
                    AbstractFeatureReader.getFeatureReader(tmpBed.getAbsolutePath(), new BEDCodec()))
        {
            for (final Interval interval: queryIntervals) {
                final Iterator<BEDFeature> originalIt = originalReader.query(interval.getContig(), interval.getStart(), interval.getEnd());
                final Iterator<BEDFeature> createdIt = createdReader.query(interval.getContig(), interval.getStart(), interval.getEnd());
                while(originalIt.hasNext()) {
                    Assert.assertTrue(createdIt.hasNext(), "some features not returned from query");
                    BEDFeature bedOrig = originalIt.next();
                    BEDFeature bedTmp = createdIt.next();
                    Assert.assertEquals(bedOrig.getContig(), bedTmp.getContig());
                    Assert.assertEquals(bedOrig.getStart(), bedTmp.getStart());
                    Assert.assertEquals(bedOrig.getEnd(), bedTmp.getEnd());
                }
            }
        }
    }

    private static int countIteratedElements(final Iterator iterator) {
        int counter = 0;
        while (iterator.hasNext()) {
            iterator.next();
            counter++;
        }
        return counter;
    }
}
