/*++
  Copyright (c) 2011 Microsoft Corporation

  Module Name:

  iz3scopes.h

  Abstract:

  Calculations with scopes, for both sequence and tree interpolation.

  Author:

  Ken McMillan (kenmcmil)

  Revision History:

  --*/


#ifndef IZ3SOPES_H
#define IZ3SOPES_H

#include <vector>
#include <limits.h>
#include "iz3hash.h"

class scopes {

 public:
    /** Construct from parents vector. */
    scopes(const std::vector<int> &_parents){
        parents = _parents;
    }

    scopes(){
    }
  
    void initialize(const std::vector<int> &_parents){
        parents = _parents;
    }

    /** The parents vector defining the tree structure */
    std::vector<int> parents;

    // #define FULL_TREE
#ifndef FULL_TREE
    struct range {
        range(){
            lo = SHRT_MAX;
            hi = SHRT_MIN;
        }
        short lo, hi;
    };

    /** computes the lub (smallest containing subtree) of two ranges */
    range range_lub(const range &rng1, const range &rng2);
  
    /** computes the glb (intersection) of two ranges */
    range range_glb(const range &rng1, const range &rng2);

    /** is this range empty? */
    bool range_is_empty(const range &rng){
        return rng.hi < rng.lo;
    }

    /** is this range full? */
    bool range_is_full(const range &rng){
        return rng.lo == SHRT_MIN && rng.hi == SHRT_MAX;
    }

    /** return an empty range */
    range range_empty(){
        range res;
        res.lo = SHRT_MAX;
        res.hi = SHRT_MIN;
        return res;
    }

    /** return an empty range */
    range range_full(){
        range res;
        res.lo = SHRT_MIN;
        res.hi = SHRT_MAX;
        return res;
    }

    /** return the maximal element of a range */
    int range_max(const range &rng){
        return rng.hi;
    }

    /** return a minimal (not necessarily unique) element of a range */
    int range_min(const range &rng){
        return rng.lo;
    }

    /** return range consisting of downward closure of a point */
    range range_downward(int _hi){
        range foo;
        foo.lo = SHRT_MIN;
        foo.hi = _hi;
        return foo;
    }

    void range_add(int i, range &n){
#if 0
	if(i < n.lo) n.lo = i;
        if(i > n.hi) n.hi = i;
#else
        range rng; rng.lo = i; rng.hi = i;
        n = range_lub(rng,n);
#endif
    }

    /** Choose an element of rng1 that is near to rng2 */
    int range_near(const range &rng1, const range &rng2){
        int frame;
        int thing = tree_lca(rng1.lo,rng2.hi);
        if(thing == rng1.lo) frame = rng1.lo;
        else frame = tree_gcd(thing,rng1.hi);
	return frame;
    }
#else

    struct range_lo {
        int lo;
        range_lo *next;
        range_lo(int _lo, range_lo *_next){
            lo = _lo;
            next = _next;
        }
    };

    struct range {
        int hi;
        range_lo *lo;
        range(int _hi, range_lo *_lo){
            hi = _hi;
            lo = _lo;
        }
        range(){
            hi = SHRT_MIN;
            lo = 0;
        }
    };

    range_tables *rt;

    /** computes the lub (smallest containing subtree) of two ranges */
    range range_lub(const range &rng1, const range &rng2);
  
    /** computes the glb (intersection) of two ranges */
    range range_glb(const range &rng1, const range &rng2);

    /** is this range empty? */
    bool range_is_empty(const range &rng);

    /** return an empty range */
    range range_empty();

    /** return a full range */
    range range_full();

    /** return the maximal element of a range */
    int range_max(const range &rng);

    /** return a minimal (not necessarily unique) element of a range */
    int range_min(const range &rng);

    /** return range consisting of downward closure of a point */
    range range_downward(int _hi);

    /** add an element to a range */
    void range_add(int i, range &n);

    /** Choose an element of rng1 that is near to rng2 */
    int range_near(const range &rng1, const range &rng2);

    range_lo *find_range_lo(int lo, range_lo *next);
    range_lo *range_lub_lo(range_lo *rng1, range_lo *rng2);
    range_lo *range_glb_lo(range_lo *rng1, range_lo *rng2, int lim);

#endif
  
    /** test whether a tree node is contained in a range */
    bool in_range(int n, const range &rng);
  
    /** test whether two ranges of tree nodes intersect */
    bool ranges_intersect(const range &rng1, const range &rng2);

    /** test whether range rng1 contained in range rng2 */
    bool range_contained(const range &rng1, const range &rng2);

 private:
    int tree_lca(int n1, int n2);
    int tree_gcd(int n1, int n2);
    bool tree_mode(){return parents.size() != 0;}



};

// let us hash on ranges

#ifndef FULL_TREE
namespace hash_space {
    template <>
        class hash<scopes::range> {
    public:
        size_t operator()(const scopes::range &p) const {
            return (size_t)p.lo + (size_t)p.hi;
        }
    };
}

inline bool operator==(const scopes::range &x, const scopes::range &y){
    return x.lo == y.lo && x.hi == y.hi;
}
#endif

#endif
