//
// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
//
// The contents of this file are covered under the licence agreement in the
// file "LICENCE" distributed with Cforall.
//
// vector -- A growable array, with full-service iterators
//
// Author           : Michael Brooks
// Created On       : Thu Jun 23 22:00:00 2021
// Last Modified By : Michael Brooks
// Last Modified On : Thu Jun 23 22:00:00 2021
// Update Count     : 1
//

#include <stdlib.hfa>
#include "list.hfa"

forall( T ) {
    struct vector;
    
    struct vector_transit {
        vector(T) * col_$;
        ptrdiff_t idx_$;
    };

    struct vector_exit {
        vector(T) * invec_$;
        T * item_$;
    };

    struct vector_permit {
        vector(T) * invec_$;
        T * item_$;
        inline dlink(vector_permit(T));
    };
    P9_EMBEDDED(vector_permit(T), dlink(vector_permit(T)))

    struct vector {
        T * buffer_first_$;
        T * buffer_end_$;
        T * elems_first_$;
        T * elems_end_$; // wrapped before storing, never == buffer_end_$
        size_t exit_refcount_$;
        dlist(vector_permit(T)) live_iters_$;
    };
}

static inline
forall( T ) {
    
    // vector

    void ?{}( vector( T ) &, size_t capacity );
    void ^?{}( vector( T ) & );

    void ?{}( vector( T ) & ) = void;
    void ?{}( vector( T ) &, vector( T ) & ) = void;
    vector( T ) & ?=?( vector( T ) &, vector( T ) & ) = void;

    // transit

    void ?{}( vector_transit(T) & ) = void;
    void ?{}( vector_transit(T) &, vector_transit(T) & );
    void ^?{}( vector_transit(T) & );

    T ?`val( vector_transit(T) & src );
    void ?=?( vector_transit(T) & dst, T val );

    // exit

    void ?{}( vector_exit(T) & ) = void;
    void ?{}( vector_exit(T) &, vector(T) * ) = void;

    void ^?{}( vector_exit(T) & );
    void ?{}( vector_exit(T) &, vector_transit(T) & );
    void ?{}( vector_exit(T) &, vector_exit(T) & );

    T ?`val( vector_exit(T) & src );
    void ?=?( vector_exit(T) & dst, T val );
    T & ?=?( T & dst, vector_exit(T) & src );
    void ?*=?( T & dst, vector_exit(T) & src );

    bool ?`moveNext( vector_exit(T) & it );

    // permit

    void ?{}( vector_permit(T) & ) = void;

    void ^?{}( vector_permit(T) & );
    void ?{}( vector_permit(T) &, vector_transit(T) & );
    void ?{}( vector_permit(T) &, vector_exit(T) & );
    void ?{}( vector_permit(T) &, vector_permit(T) & ) = void;

    T ?`val( vector_permit(T) & src );

    // api

    vector_transit(T) push_last( vector( T ) & col, T val );
    vector_transit(T) ?[?]( vector( T ) &, ptrdiff_t );
    vector_exit(T) ?`origin( vector( T ) & );
    size_t ?`capacity( vector(T) & );
    size_t ?`length( vector(T) & );

    void insert_before( vector( T ) & col, ptrdiff_t idx, T val );

}

static inline
forall( T ) {

    // vector

    void ?{}( vector( T ) & this, size_t capacity ) {
        (this.buffer_first_$){ aalloc( capacity ) };
        (this.buffer_end_$){ this.buffer_first_$ + capacity};
        (this.elems_first_$){ 0p };
        (this.elems_end_$){ this.buffer_first_$ };
        (this.exit_refcount_$){ 0 };
        (this.live_iters_$){};
    }

    void ^?{}( vector( T ) & this ) {
        assert( this.exit_refcount_$ == 0 );
        free( this.buffer_first_$ );
        this.buffer_first_$ = 0p;
        this.buffer_end_$ = 0p;
        this.elems_first_$ = 0p;
        this.elems_end_$ = 0p;
    }

    // transit 

    void ?{}( vector_transit(T) & this, vector_transit(T) & other ) {
        // call autogen constructor deleted at end of hfa
        (this){ other.col_$, other.idx_$ };
    }

    void ^?{}( vector_transit(T) & ) {}


    vector_transit(T) ?[?]( vector( T ) & vec, ptrdiff_t idx ) {
        // call autogen constructor deleted at end of hfa
        vector_transit(T) ret = { & vec, idx };
        return ret;
    }

    T & findElemMem_$( vector(T) & v, ptrdiff_t idx ) {
        size_t len = v`length;
        while (idx > len) idx -= len;
        while (idx < 0  ) idx += len;
        T * ret = v.elems_first_$ + idx;
        if (ret < v.buffer_end_$) return *ret;
        ret -= (v.buffer_end_$ - v.buffer_first_$);
        assert( v.buffer_first_$ <= ret && ret < v.elems_end_$ );
        return *ret;
    }

    T ?`val( vector_transit(T) & src ) {
        T ret = findElemMem_$( *src.col_$, src.idx_$ );
        return ret;
    }

    void ?=?( vector_transit(T) & src, T val ) {
        findElemMem_$( *src.col_$, src.idx_$ ) = val;
    }

    // exit

    void ?{}( vector_exit(T) & this, vector_transit(T) & src ) {
        ( this.invec_$ ){ src.col_$ };
        ( this.item_$ ){ & findElemMem_$( *src.col_$, src.idx_$ ) };

        this.invec_$->exit_refcount_$ ++;
    }
    void ?{}( vector_exit(T) & this, vector_exit(T) & src ){
        ( this.invec_$ ){ src.invec_$ };
        ( this.item_$ ){ src.item_$ };

        this.invec_$->exit_refcount_$ ++;
    }

    void ^?{}( vector_exit(T) & it ) {
        it.invec_$->exit_refcount_$ --;
    }

    T ?`val( vector_exit(T) & src ) {
        return *src.item_$;
    }

    void ?*=?( T & dst, vector_exit(T) & src ) {
        dst = *src.item_$;
    }

    bool ?`moveNext( vector_exit(T) & it ) {
        if (it.invec_$->elems_first_$ == 0p) {
            // vector is empty
            assert ( it.item_$ == 0p ); // it was at origin
            return false;
        }
        assert( it.invec_$->elems_first_$ < it.invec_$->elems_end_$ && "can't handle wraparound yet" ); // temporary: must implement
        if( it.item_$ == 0p ) {
            // moving from origin
            it.item_$ = it.invec_$->elems_first_$;
        } else {
            it.item_$ += 1;
            if( it.item_$ > it.invec_$->buffer_end_$ )
                it.item_$ = it.invec_$->buffer_first_$;
        }
        if ( it.item_$ >= it.invec_$->elems_end_$ ) {
            // moving to origin
            it.item_$ = 0p;
            return false;
        } else {
            return true;
        }
    }

    // permit

    void ^?{}( vector_permit(T) & this ) {
        remove(this);
    }

    void ?{}( vector_permit(T) & this, vector_transit(T) & src ) {
        ( this.invec_$ ){ src.col_$ };
        ( this.item_$ ){ & findElemMem_$( *src.col_$, src.idx_$ ) };
        insert_first( src.col_$->live_iters_$, this );
    }

    void ?{}( vector_permit(T) & this, vector_exit(T) & src ) {
        ( this.invec_$ ){ src.invec_$ };
        ( this.item_$ ){ src.item_$ };
        insert_first( src.invec_$->live_iters_$, this );
    }

    T ?`val( vector_permit(T) & src ){
        return *src.item_$;
    }

    // vec internals

    void grow( vector( T ) & this ) {
        size_t newCapacity = 2 * (this.buffer_end_$ - this.buffer_first_$);
        T * newItems = aalloc( newCapacity );
        size_t elemCount = this`length;
        for ( ptrdiff_t pos = 0; pos < elemCount; pos += 1 ) {
            newItems[pos] = findElemMem_$(this, pos);
        }

        while ( vector_permit(T) & liveIter = this.live_iters_$`elems; liveIter`moveNext ) {
            liveIter.item_$ += (newItems - this.buffer_first_$);
        }

        free( this.buffer_first_$ );
        this.buffer_first_$ = newItems;
        this.buffer_end_$ = newItems + newCapacity;
        this.elems_first_$ = this.buffer_first_$;
        this.elems_end_$ = this.buffer_first_$ + elemCount;
        assert (this.elems_end_$ < this.buffer_end_$);
    }

    // vec api

    vector_transit(T) push_last( vector( T ) & col, T val ) {
        assert (col.exit_refcount_$ == 0);
        if (col`length >= col`capacity) {
            assert (col`length == col`capacity);
            grow(col);
        }
        // call autogen constructor deleted at end of hfa
        vector_transit(T) ret = { & col, col`length };
        *col.elems_end_$ = val;
        if (col.elems_first_$ == 0p) col.elems_first_$ = col.elems_end_$;
        col.elems_end_$ += 1;
        if (col.elems_end_$ >= col.buffer_end_$) col.elems_end_$ = col.buffer_first_$;
        return ret;
    }

    vector_exit(T) ?`origin( vector( T ) & vec ) {

        // private memberwise constructor, deleted from global namespace at end
        // autogen constructor would not do the raii
        void ?{}( vector_exit(T) & this, vector(T) * invec_$, T * item_$ ) {
            ( this.invec_$ ){ invec_$ };
            ( this.item_$ ){ item_$ };
            this.invec_$->exit_refcount_$ ++;
        }

        vector_exit(T) ret = { &vec, 0p };
        return ret;
    }

    bool inRange_$( T * query, T * from, T * to) {
        if (from == to) return false;
        if (from < to) return from <= query && query < to;
        return query < to || from <= query;
    }

    void insert_before( vector( T ) & col, ptrdiff_t idx, T val ) {
        assert (col.exit_refcount_$ == 0);
        if (col`length >= col`capacity) {
            assert (col`length == col`capacity);
            grow(col);
        }
        
        T & insertTargetR = findElemMem_$( col, idx );
        T * insertTarget = & insertTargetR; // doesn't work in one line; must be a bug

        // bubble toward back
        if ( col.elems_end_$ < insertTarget ) {
            // two phases of bubbling, to wrap around
            for (T * tgt = col.elems_end_$; tgt > col.buffer_first_$; tgt--) {
                *tgt = *(tgt-1);
            }
            *col.buffer_first_$ = *(col.buffer_end_$ - 1);
            for (T * tgt = col.buffer_end_$ - 1; tgt > insertTarget; tgt--) {
                *tgt = *(tgt-1);
            }
        } else {
            for (T * tgt = col.elems_end_$; tgt > insertTarget; tgt--) {
                *tgt = *(tgt-1);
            }
        }

        col.elems_end_$ += 1;
        if (col.elems_end_$ == col.buffer_end_$) col.elems_end_$ = col.buffer_first_$;

        *insertTarget = val;

        while ( vector_permit(T) & liveIter = col.live_iters_$`elems; liveIter`moveNext ) {
            if ( inRange_$(liveIter.item_$, insertTarget, col.elems_end_$) ) {
                liveIter.item_$ += 1;
                if (liveIter.item_$ >= col.buffer_end_$) liveIter.item_$ = col.buffer_first_$;
            }
        }
    }

    size_t ?`capacity( vector(T) & v ) {
        return v.buffer_end_$ - v.buffer_first_$;
    }

    size_t ?`length( vector(T) & v ) {
        if (v.elems_first_$ == 0p) return 0;
        if (v.elems_first_$ < v.elems_end_$ ) return v.elems_end_$ - v.elems_first_$;
        return v.buffer_end_$ - v.elems_first_$ + v.elems_end_$ - v.buffer_first_$;
    }


} // forall T

forall( T ) {
    void ?{}( vector_exit(T) &, vector(T) *, T * ) = void;
    void ?{}( vector_transit(T) & this, vector( T ) * col, ptrdiff_t idx ) = void;
}