#include "rc.h"

// -----------------------------------------------------------------------
// globals

static Tree *nodes;

// -----------------------------------------------------------------------
// exported funcs

Tree*
newtree(void)
{
    Tree *t;

    alloc(t);
    t->str = nil;
    t->child[0] = t->child[1] = t->child[2] = nil;
    t->redir.fd[0] = t->redir.fd[1] = t->redir.type = 0;

    t->link = nodes, nodes = t;
    return t;
}

void
freetree(Tree *t)
{
    if (!t)
        return;

    freetree(t->child[0]);
    freetree(t->child[1]);
    freetree(t->child[2]);

    if (t->str)
        efree(t->str);
    efree(t);
}

void
freenodes(void)
{
    Tree *t, *u;

    for (t = nodes;t;t = u) {
        u = t->link;
        if (t->str)
            efree(t->str);
        efree(t);
    }
    nodes = nil;
}

/* tree creation */
Tree*
tree3(int type, Tree *c0, Tree *c1, Tree *c2)
{
    Tree *t;

    t = newtree();
    t->type = type;
    t->child[0] = c0;
    t->child[1] = c1;
    t->child[2] = c2;

    return t;
}

Tree*
tree2(int type, Tree *c0, Tree *c1)
{
	return tree3(type, c0, c1, nil);
}

Tree*
tree1(int type, Tree *c0)
{
	return tree3(type, c0, nil, nil);
}

/* tree hang */
Tree*
hang1(Tree *p, Tree *c0)
{
    p->child[0] = c0;
    return p;
}

Tree*
hang2(Tree *p, Tree *c0, Tree *c1)
{
    p->child[0] = c0;
    p->child[1] = c1;
    return p;
}

Tree*
hang3(Tree *p, Tree *c0, Tree *c1, Tree *c2)
{
    p->child[0] = c0;
    p->child[1] = c1;
    p->child[2] = c2;
    return p;
}

/* hangs the cmd underneath the epilogue */
Tree*
epihang(Tree *c, Tree *epi)
{
    Tree *p;
    if(!epi)
        return c;
    for(p=epi;p->child[1];p = p->child[1])
        ;
    p->child[1] = c;
    return epi;
}

/* hangs tree t from a new simple node. percolates redirections to root */
Tree*
simplehang(Tree *t)
{
    Tree *u;
    t = tree1(Tsimple, t);
    for(u = t->child[0];u->type==Targs;u=u->child[0]) {
        if (u->child[1]->type==Tdup
        ||  u->child[1]->type==Tredir){
            u->child[1]->child[1] = t;
            t = u->child[1];
            u->child[1] = nil;
        }
    }
    return t;
}

Tree*
wordnode(char *w)
{
    Tree *t = newtree();
    t->type = Tword;
    t->str  = strdup(w);

    return t;
}