#include <algorithm>
#include <iterator>

#include "HitUtilities.hxx"

namespace hits {
    bool Equal(const COMET::IHandle<COMET::IHit>& a, const COMET::IHandle<COMET::IHit>& b) {
        return a == b;
    }
    
    bool Equiv(const COMET::IHandle<COMET::IHit>& a, const COMET::IHandle<COMET::IHit>& b) {
        // short circuit equal hits.
        if (a==b) return true;
        
        // Unpack the hits into the most basic hits.
        COMET::IHitSelection aHits;
        UnpackHits(a,std::back_inserter(aHits));
        
        COMET::IHitSelection bHits;
        UnpackHits(b,std::back_inserter(bHits));
        
        // Check to see if any of the basic hits are equal.
        for (COMET::IHitSelection::const_iterator A = aHits.begin();
             A != aHits.end();
             ++A) {
            for (COMET::IHitSelection::const_iterator B = bHits.begin();
                 B != bHits.end();
                 ++B) {
                if (*A == *B) return true;
            }
        }
        
        return false;
    }
    
    void Subtract(COMET::IHitSelection& a, const COMET::IHitSelection& b) {
        COMET::IHitSelection::iterator r = copy_hits_if(a.begin(), a.end(),
                                                 a.begin(),
                                                 IOverlappedHitFilter(b));
        if (r!=a.end()) a.erase(r,a.end());
    }

    void Unique(COMET::IHitSelection& a) {
        std::sort(a.begin(), a.end(), hits::geomIdLessThan());
        COMET::IHitSelection::iterator newEnd 
            = std::unique(a.begin(), a.end(), hits::geomIdEquals());
        a.erase(newEnd,a.end());
    }
};