#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#include "lceb.h"

static TREE *trees=NULL;
static int ntrees=0;
static NODE *freenodes=NULL;
static int totnodes=0;

NODE *get_node()
{
    NODE *ret;

    if (!freenodes) {
        register int i;
        freenodes=malloc(ALLOCSIZE*sizeof(NODE));
        totnodes+=ALLOCSIZE;
        printf("allocating %d nodes - total nodes=%d\n", ALLOCSIZE, totnodes);
        for (i=0; i<ALLOCSIZE-1; ++i) {           /* create chained list */
            (freenodes+i)->left=NULL;
            (freenodes+i)->right=NULL;
            (freenodes+i)->next=freenodes+i+1;
        }
        (freenodes+ALLOCSIZE-1)->next=NULL;
    }
    ret=freenodes;
    freenodes=ret->next;
    ret->op=Nop;
    ret->val=-1;
    ret->eval=-1;
    ret->next=NULL;
    ret->left=NULL;
    ret->right=NULL;

    return ret;
}

void free_node(node)
    NODE *node;
{
    if (node->left) {
        free_node(node->left);
        node->left=NULL;
    }
    if (node->right) {
        free_node(node->right);
        node->right=NULL;
    }
    node->next=freenodes;
    freenodes=node;
}

void print_node(node, side, depth, details)
    NODE *node;
    char side;
    int depth;
    int details;
{
    int i;

    if (details) {
        /* left padding */
        for (i=0; i<=depth; ++i)
            printf("  ");
        printf("%c: type:%s ", side, node->type==TREE_NODE? "node": "leaf");
        if (details) {
            printf("op=%c val=%d eval=%d", node->op, node->val, node->eval);
        }
        putchar('\n');
    } else {
        if (node->type==TREE_NODE) {
            printf("* ");
        } else {
            printf("x ");
        }
    }
    if (node->left)
        print_node(node->left, TREE_LEFT, depth+1, details);
    if (node->right)
        print_node(node->right, TREE_RIGHT, depth+1, details);
}

void print_tree(tree, details)
    TREE *tree;
    int details;
{
    int i;
    if (details) {
        printf("Tree [%s] nodes:%d leaves:%d depth:%d\n",
               tree->name, tree->nodes, tree->leaves, tree->depth);

        print_node(tree->head, TREE_TOP, 0, 1);
    } else {
        printf("Tree [%s] : ", tree->name);
        print_node(tree->head, TREE_TOP, 0, 0);
//        for (i=0; )
        printf("\n");
    }
}

void print_trees(details)
    int details;
{
    TREE *tree=trees;
    printf("There are %d trees:\n", ntrees);
    while (tree) {
        print_tree(tree, details);
        tree=tree->next;
    }
}

TREE *new_tree(name)
    char *name;
{
    TREE *tree;

    tree=malloc(sizeof(TREE));
    strcpy(tree->name, name);
    tree->nodes=0;
    tree->leaves=0;
    tree->depth=0;
    tree->head=NULL;
    tree->next=trees;
    trees=tree;
    return tree;
}

NODE *dup_node(src)
    NODE *src;
{
    NODE *dst;
    dst=get_node();
    dst->type=src->type;
    if (src->type==TREE_NODE) {
        dst->op=src->op;
        dst->left=dup_node(src->left);
        dst->right=dup_node(src->right);
    } else {
        dst->val=src->val;
    }
    return dst;
}

/*void free_node(node)
    NODE *node;
{
    if (node->type==TREE_LEAF) {
        node->next=freenodes;
        freenodes=node;
    } else {
        free_node(node->left);
        free_node(node->right);
        node->next=freenodes;
        freenodes=node;
    }
    }*/

NODE *build_tree(desc, size)
    int *desc;
    int size;
{
    NODE *root, *node;
    NODE *nodestack[1024];      /* TODO: make it dynamic */
    int i, curnode=0;

    root=get_node();
    root->type=TREE_NODE;
    nodestack[curnode++]=root;

    for(i=1; i<size; ++i) {
        node = get_node();
        if (desc[i-1]) {
            nodestack[curnode-1]->left = node;
        } else {
            nodestack[curnode-1]->right = node;
            curnode--;
        }
        if (desc[i]) {
            node->type=TREE_NODE;
            nodestack[curnode++]=node;
        } else {
            node->type=TREE_LEAF;
        }
    }

    return root;
}

void gen_tree(seq, n, nb1, nb0)
    int *seq;
    int n;                      /* number of nodes */
    int nb1;                    /* number of "1" */
    int nb0;                    /* number of "0" */
{
    int i;
    char name[80];
    TREE *tree;

    if((nb1 + nb0) == 2*n) {   /* end */
        seq[2*n] = 0;
        ntrees++;
        printf("tree %d desc=", ntrees);
        for (i=0; i<=2*n; ++i)
            printf("%d", seq[i]);
        putchar('\n');
        sprintf(name, "Tree %d", ntrees);
        tree=new_tree(name);
        tree->head=build_tree(seq, 2*n+1);
        return;
    }

    if(nb1 >= nb0 && nb1 < n) {
        seq[nb1+nb0] = 1;
        gen_tree(seq, n, nb1+1, nb0);
    }

    if(nb0 < nb1 && nb1 <=n) {
        seq[nb1+nb0] = 0;
        gen_tree(seq, n, nb1, nb0+1);
    }
}

TREE *nth_tree(n)
    int n;
{
    int i;
    TREE *tree=trees;
    for (i=0; i<n && tree; ++i) {
        tree=tree->next;
    }
    return tree;
}

int n_trees()
{
    return ntrees;
}

#ifdef STANDALONE
main(ac, av)
    int ac;
    char **av;
{
    int n;
    int array[1024];
    n=atoi(av[1]);
    gen_tree(array, n, 0, 0);
    print_trees(1);
    exit(0);
}
#endif