#include <iostream>
#include <seqan/sequence.h>
#include <seqan/stream.h>
#include <seqan/store.h>

using namespace seqan2;

int main()
{
    CharString fileName = getAbsolutePath("demos/tutorial/genome_annotations/assignment_annotations.gtf");
    GffFileIn file(toCString(fileName));

    FragmentStore<> store;
    readRecords(store, file);
    // Create iterator
    Iterator<FragmentStore<>, AnnotationTree<> >::Type it;
    it = begin(store, AnnotationTree<>());
    unsigned countGenes = 0;
    unsigned countmRNAs = 0;
    unsigned countExons = 0;
    unsigned length = 0;
    // Iterate over annotation tree and count different elements and compute exon lengths
    while (!atEnd(it))
    {
        if (getType(it) == "gene")
        {
            ++countGenes;
        }
        else if (getType(it) == "mRNA")
        {
            ++countmRNAs;
        }
        else if (getType(it) == "exon")
        {
            ++countExons;
            length += abs((int)getAnnotation(it).endPos - (int)getAnnotation(it).beginPos);
        }
        goNext(it);
    }
    if (countGenes == 0u)  // prevent div-by-zero below
        countGenes = 1;
    if (countmRNAs == 0u)  // prevent div-by-zero below
        countmRNAs = 1;
    if (countExons == 0u)  // prevent div-by-zero below
        countExons = 1;
    // Ouput some stats:
    std::cout << "Average number of mRNAs for genes: " << (float)countmRNAs / (float)countGenes << std::endl;
    std::cout << "Average number of exons for mRNAs: " << (float)countExons / (float)countmRNAs << std::endl;
    std::cout << "Average length of exons: " << (float)length / (float)countExons << std::endl;
    return 0;
}
