#include "file.h"

#include <errno.h>
#include <stdio.h>

// Up to 256 files can be open
FILE *files[256];

int openFile(int fd, const char *path, const char *mode) {
  if (files[fd] != NULL) {
    return STATUS_READY | STATUS_ERROR;
  }

  files[fd] = fopen(path, mode);
  if (files[fd] == NULL) {
    return STATUS_READY | STATUS_ERROR;
  }

  return STATUS_READY;
}

int closeFile(int fd) {
  FILE *f = files[fd];

  if (f == NULL) {
    return STATUS_READY | STATUS_ERROR;
  }

  int ret = fclose(files[fd]);
  if (ret != 0) {
    return STATUS_READY | STATUS_ERROR;
  }

  files[fd] = NULL;

  return STATUS_READY;
}

int readByte(const int fd, uint8_t *data) {
  if (files[fd] == NULL) {
    return STATUS_READY | STATUS_ERROR;
  }

  int status = 0;
  int count = fread(data, 1, 1, files[fd]);
  // Error or EOF
  if (count != 1) {
    int error = ferror(files[fd]);
    int eof = feof(files[fd]);
    if (error != 0) {
      status = STATUS_ERROR;
    } else if (eof != 0) {
      status = STATUS_EOF;
    }
  }

  return STATUS_READY | status;
}

int writeByte(const int fd, const uint8_t data) {
  if (files[fd] == NULL) {
    return STATUS_READY | STATUS_ERROR;
  }

  int status = 0;
  int count = fwrite(&data, 1, 1, files[fd]);
  // Error or EOF
  if (count != 1 && ferror(files[fd]) != 0) {
    return STATUS_READY | STATUS_ERROR;
  }
  if (fflush(files[fd]) != 0) {
    return STATUS_READY | STATUS_ERROR;
  }

  return STATUS_READY | status;
}