#include "fio.h"
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

/*
================================
struct LList *dirToLList(const char *dir_name, int opts)

This function takes a given directory path and attempts to populate a linked list(LList) with the contents of the directory (excluding ".." and "."). The opts argument must be provided with F_DIRS, F_FILES, or both F_DIRS|F_FILES. This limits the items added to the linked list to only directories, only files, or both.

================================
*/
struct LList *dirToLList(const char *dir_name, int opts) {
  struct dirent *entry;
  DIR *dir = opendir(dir_name);
  if (dir == NULL)
    return NULL;

  struct LList *start = NULL;
  struct LList *llist = NULL;
  struct LList *llist_last = NULL;
  while ((entry = readdir(dir)) != NULL) {
    if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
      continue;
    int entry_size = strlen(entry->d_name)+1;
    // ugly
    char file_path[strlen(dir_name)+entry_size];
    strcpy(file_path, dir_name);
    file_path[strlen(dir_name)] = '/';
    memcpy(file_path+strlen(dir_name)+1, entry->d_name, entry_size);
    // ok, let's get file properties and see if we want it
    struct stat file_stat;
    stat(file_path, &file_stat);
    switch(file_stat.st_mode & S_IFMT) {
      case S_IFDIR:
        if (~opts & F_DIRS)
          continue;
        break;
      case S_IFREG:
        if (~opts & F_FILES)
          continue;
        break;
    }
    // if we got here, then the entry is valid
    llist = newLList();
    llist->data = malloc(entry_size);
    llist->size = entry_size;
    memcpy(llist->data, entry->d_name, entry_size);
    if (start == NULL)
      start = llist;
    if (llist_last != NULL)
      llist_last->next = llist;
    llist_last = llist;
  }
  closedir(dir);
  return start;
}

/*
================================
int fileExists(const char *filename)

A simple function that checks if the given filename exists.
================================
*/
int fileExists(const char *filename) {
  struct stat buffer;
  return (stat (filename, &buffer) == 0);
}

/*
================================
int fileToMemory(char **buffer, const char *file_name)

This function takes a pointer to an uninitialized char array, along with a char array for a file name. It then attempts to read the provided file into the passed buffer, returning the size on completion.
================================
*/
int fileToMemory(char **buffer, const char *file_name) {
  int i, n, pos = 0;
  char t_buf[16];

  FILE *file = fopen(file_name, "r");
  if (file == NULL) {
    return -1;
  }
  fseek(file, 0, SEEK_END);
  int size = ftell(file);
  fseek(file, 0, SEEK_SET);

  char *new_buffer = malloc(size);
  while ((n = fread(t_buf, 1, 16, file))) {
    for (i = 0; i < n; i++) {
      new_buffer[pos++] = t_buf[i];
    }
  }
  fclose(file);
  *buffer = new_buffer;
  return size;
}