/*
 * Main program
 * Reads and stores variables.
 * Invokes graph operations to build and colour the graph of variables.
 */

#include <stdio.h>
#include <stdlib.h>
#include "token.h"
#include "symbol.h"
#include "graph.h"

int main()
{
    struct token t;
    GRAPH g;
    int stmt;
    extern void storeSymbols(GRAPH g);
    extern void storeAdjacencies(GRAPH g);

    token_init(stdin);
    stmt = 0;
    while (t = get_next_token(), t.type != EOF) {
        switch (t.type) {
        case TOKEN_IDENT:
            symbol_set_seen(t.symvalue, stmt);
            break;
        case ';':
            stmt++;
            break;
        /* ignore all else */
        }
    }

    g = new_graph(symbol_count());
    storeSymbols(g);
    storeAdjacencies(g);

    colour_graph(g);

    print_graph(g);

    return 0;
}


void storeSymbols(GRAPH g)
{
    SYMBOL_ITER i = new_symbol_iter();
    SYMBOL x;

    for (x = first_symbol(i); x; x = next_symbol(i))
        symbol_setindex(x, add_vertex(g, symbol_getname(x)));
}


void storeAdjacencies(GRAPH g)
{
    SYMBOL_ITER i = new_symbol_iter();
    SYMBOL_ITER j = new_symbol_iter();
    SYMBOL x, y;

    for (x = first_symbol(i); x; x = next_symbol(i)) {
        for (y = first_symbol(j); y; y = next_symbol(j)) {
            if (x != y && live_range_is_overlapping(x, y)) {
                add_edge(g, symbol_getindex(x), symbol_getindex(y));
                add_edge(g, symbol_getindex(y), symbol_getindex(x));
            }
        }
    }
}