#include "tor_os.h"

void tor_os_create(struct tor_os_str* os, char* file, size_t size) {
    os->size = size;
    os->filled = 0;

    os->file = malloc(sizeof(char) * (strlen(file) + 1));
    if (os->file == NULL) goto mem_error;
    strcpy(os->file, file);

    os->list = malloc(size * sizeof(char*));
    if (os->list == NULL) goto mem_error;
    return;

mem_error:
    fprintf(stderr, "unable to allocate memory\n");
    exit(EXIT_FAILURE);
}

char** tor_os_append_cursor(struct tor_os_str* os) {
    if (os->filled == os->size) {
        return NULL;
    }
    char** cur = os->list + os->filled;
    os->filled++;
    *cur = NULL;
    return cur;
}

void tor_os_read (struct tor_os_str* os) {
    FILE* fd = NULL;
    fd = fopen(os->file, "r");
    if (fd == NULL) {
        return;
    }
    size_t len = 0;
    size_t str_len = 0;
    int n = 0;
    while (1) {
        char** dst = tor_os_append_cursor(os);
        if (dst == NULL) break;
        if (getline(dst,&len,fd) == -1) break;
        str_len = strlen(*dst);
        if (str_len < 1) break;
        if ((*dst)[str_len - 1] == '\n') {
          (*dst)[str_len - 1] = '\0';
        }
    }
    fclose(fd);
}

void tor_os_free(struct tor_os_str* os) {
    for (int i = 0; i < os->filled; i++) {
        free(os->list[i]);
    }
    free(os->list);
    free(os->file);
}

void tor_os_persist(struct tor_os_str* os) {
    FILE* fd = NULL;
    fd = fopen(os->file, "w");
    if (fd == NULL) {
      fprintf(stderr, "unable to open file for writing\n");
      exit(EXIT_FAILURE);
    }

    for (int i = 0; i < os->filled; i++) {
      fprintf(fd, "%s\n", os->list[i]);
    }

    fclose(fd);
}

int tor_os_append(struct tor_os_str* os, char* entry) {
    char** target = tor_os_append_cursor (os);
    if (target == NULL) return -1;
    *target = malloc(sizeof(char) * (strlen(entry) + 1));
    if (*target == NULL) return -1;
    strcpy (*target, entry);
    return 0;
}