#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "streecmp.h"

static int strs_cnt = 1; 

void frenod(struct nod *nod) {
    for (int i = 0; i < POOL_SIZE; i++) {
        struct nod *p = nod->pool[i]; 
        if (p == NULL) {
            continue;
        }

        frenod(p);
    }

    free(nod->pool);
    memset(nod, 0, sizeof(struct nod));
    free(nod); 
}

struct nod *allocnod(void) {
    struct nod *nod = (struct nod *) calloc(1, sizeof(struct nod));
    if (nod == NULL) {
        return NULL;
    }

    nod->pool = (struct nod **) calloc(POOL_SIZE, sizeof(struct nod *));
    if (nod->pool == NULL) {
        free(nod); 
        return NULL;
    }

    return nod;
}

struct nod *mknod(struct nod *nod, int loc) {
    if (nod == NULL) {
        return allocnod();
    }

    if (nod->pool == NULL) {
        return NULL;
    }

    nod->pool_size++; 
    nod->pool[loc] = allocnod();
    
    return nod->pool[loc];
}

int mkstr(struct nod *nod, char *str, int val) {
    struct nod *target = nod->pool[*str];
    if (target != NULL) {
        if (*str == '\0') {
            return 0;
        }

        return mkstr(target, str+1, val);
    }

    struct nod *new = mknod(nod, *str);
    if (new == NULL) {
        return -1;
    }

    new->val.cval = *str;
    if (*str != '\0') {
        return mkstr(new, str+1, val);
    }

    new->val.ival = val;
    return val;
}

int gentree(struct nod *nod, char *strs, char *delim) {
    strs_cnt = 1;
    
    char *strs_cpy = strdup(strs);
    if (strs_cpy == NULL) {
        goto _err;
    }

    if (delim == NULL) {
        delim = DEF_DELIM;
    }

    for (char *tok = strtok(strs_cpy, delim); tok != NULL; tok
            = strtok(NULL, delim)) {
        int ret = mkstr(nod, tok, strs_cnt);
        if (ret < 0) {
            goto _err_mkstr;
        }
        strs_cnt++;
    }

    free(strs_cpy);
    return 0;

_err_mkstr:
    free(strs_cpy);
_err:
    return -1;
}

int streecmp(struct nod *nod, char *str) {
    struct nod *target = nod->pool[*str];
    if (target == NULL) {
        return 0;
    }

    if (target->val.cval == '\0') {
        return target->val.ival;
    }

    return streecmp(target, str+1);
}

int streencmp(struct nod *nod, char *str, int len) {
    struct nod *nptr = nod;
    char *sptr = str;

    for (int i = 0; i < len; i++) {
        struct nod *target = nptr->pool[*sptr];
        if (target == NULL) {
            goto _not_found;
        }

        nptr = target;
        sptr++;
    }
    
    nptr = nptr->pool['\0'];
    if (nptr == NULL) {
        goto _not_found;
    }

    return nptr->val.ival;

_not_found:
    return 0;
}