/**
* Returns a context identical to this with the REF and ALT alleles reverse complemented.
*
* @param vc variant context
* @return new vc
*/
public static VariantContext reverseComplement(VariantContext vc) {
// create a mapping from original allele to reverse complemented allele
HashMap<Allele, Allele> alleleMap = new HashMap<Allele, Allele>(vc.getAlleles().size());
for (Allele originalAllele : vc.getAlleles()) {
Allele newAllele;
if (originalAllele.isNoCall() || originalAllele.isNull()) newAllele = originalAllele;
else
newAllele =
Allele.create(
BaseUtils.simpleReverseComplement(originalAllele.getBases()),
originalAllele.isReference());
alleleMap.put(originalAllele, newAllele);
}
// create new Genotype objects
GenotypesContext newGenotypes = GenotypesContext.create(vc.getNSamples());
for (final Genotype genotype : vc.getGenotypes()) {
List<Allele> newAlleles = new ArrayList<Allele>();
for (Allele allele : genotype.getAlleles()) {
Allele newAllele = alleleMap.get(allele);
if (newAllele == null) newAllele = Allele.NO_CALL;
newAlleles.add(newAllele);
}
newGenotypes.add(Genotype.modifyAlleles(genotype, newAlleles));
}
return new VariantContextBuilder(vc).alleles(alleleMap.values()).genotypes(newGenotypes).make();
}
public static VariantContext createVariantContextWithTrimmedAlleles(VariantContext inputVC) {
// see if we need to trim common reference base from all alleles
boolean trimVC;
// We need to trim common reference base from all alleles in all genotypes if a ref base is
// common to all alleles
Allele refAllele = inputVC.getReference();
if (!inputVC.isVariant()) trimVC = false;
else if (refAllele.isNull()) trimVC = false;
else {
trimVC =
(AbstractVCFCodec.computeForwardClipping(
new ArrayList<Allele>(inputVC.getAlternateAlleles()),
inputVC.getReference().getDisplayString())
> 0);
}
// nothing to do if we don't need to trim bases
if (trimVC) {
List<Allele> alleles = new ArrayList<Allele>();
GenotypesContext genotypes = GenotypesContext.create();
// set the reference base for indels in the attributes
Map<String, Object> attributes = new TreeMap<String, Object>(inputVC.getAttributes());
Map<Allele, Allele> originalToTrimmedAlleleMap = new HashMap<Allele, Allele>();
for (Allele a : inputVC.getAlleles()) {
if (a.isSymbolic()) {
alleles.add(a);
originalToTrimmedAlleleMap.put(a, a);
} else {
// get bases for current allele and create a new one with trimmed bases
byte[] newBases = Arrays.copyOfRange(a.getBases(), 1, a.length());
Allele trimmedAllele = Allele.create(newBases, a.isReference());
alleles.add(trimmedAllele);
originalToTrimmedAlleleMap.put(a, trimmedAllele);
}
}
// detect case where we're trimming bases but resulting vc doesn't have any null allele. In
// that case, we keep original representation
// example: mixed records such as {TA*,TGA,TG}
boolean hasNullAlleles = false;
for (Allele a : originalToTrimmedAlleleMap.values()) {
if (a.isNull()) hasNullAlleles = true;
if (a.isReference()) refAllele = a;
}
if (!hasNullAlleles) return inputVC;
// now we can recreate new genotypes with trimmed alleles
for (final Genotype genotype : inputVC.getGenotypes()) {
List<Allele> originalAlleles = genotype.getAlleles();
List<Allele> trimmedAlleles = new ArrayList<Allele>();
for (Allele a : originalAlleles) {
if (a.isCalled()) trimmedAlleles.add(originalToTrimmedAlleleMap.get(a));
else trimmedAlleles.add(Allele.NO_CALL);
}
genotypes.add(Genotype.modifyAlleles(genotype, trimmedAlleles));
}
final VariantContextBuilder builder = new VariantContextBuilder(inputVC);
return builder
.alleles(alleles)
.genotypes(genotypes)
.attributes(attributes)
.referenceBaseForIndel(new Byte(inputVC.getReference().getBases()[0]))
.make();
}
return inputVC;
}
