text: /*
   * This file is part of the Micro Python project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2013, 2014 Damien P. George
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  #include <stdio.h>
  #include <errno.h>
  
  #include "py/nlr.h"
  #include "py/runtime.h"
  #include "py/stream.h"
  #include "file.h"
  #include "ff.h"
  
  extern const mp_obj_type_t mp_type_fileio;
  extern const mp_obj_type_t mp_type_textio;
  
  // this table converts from FRESULT to POSIX errno
  const byte fresult_to_errno_table[20] = {
      [FR_OK] = 0,
      [FR_DISK_ERR] = EIO,
      [FR_INT_ERR] = EIO,
      [FR_NOT_READY] = EBUSY,
      [FR_NO_FILE] = ENOENT,
      [FR_NO_PATH] = ENOENT,
      [FR_INVALID_NAME] = EINVAL,
      [FR_DENIED] = EACCES,
      [FR_EXIST] = EEXIST,
      [FR_INVALID_OBJECT] = EINVAL,
      [FR_WRITE_PROTECTED] = EROFS,
      [FR_INVALID_DRIVE] = ENODEV,
      [FR_NOT_ENABLED] = ENODEV,
      [FR_NO_FILESYSTEM] = ENODEV,
      [FR_MKFS_ABORTED] = EIO,
      [FR_TIMEOUT] = EIO,
      [FR_LOCKED] = EIO,
      [FR_NOT_ENOUGH_CORE] = ENOMEM,
      [FR_TOO_MANY_OPEN_FILES] = EMFILE,
      [FR_INVALID_PARAMETER] = EINVAL,
  };
  
  typedef struct _pyb_file_obj_t {
      mp_obj_base_t base;
      FIL fp;
  } pyb_file_obj_t;
  
  void file_obj_print(void (*print)(void *env, const char *fmt, ...), void *env, mp_obj_t self_in, mp_print_kind_t kind) {
      print(env, "<io.%s %p>", mp_obj_get_type_str(self_in), self_in);
  }
  
  STATIC mp_uint_t file_obj_read(mp_obj_t self_in, void *buf, mp_uint_t size, int *errcode) {
      pyb_file_obj_t *self = self_in;
      UINT sz_out;
      FRESULT res = f_read(&self->fp, buf, size, &sz_out);
      if (res != FR_OK) {
          *errcode = fresult_to_errno_table[res];
          return MP_STREAM_ERROR;
      }
      return sz_out;
  }
  
  STATIC mp_uint_t file_obj_write(mp_obj_t self_in, const void *buf, mp_uint_t size, int *errcode) {
      pyb_file_obj_t *self = self_in;
      UINT sz_out;
      FRESULT res = f_write(&self->fp, buf, size, &sz_out);
      if (res != FR_OK) {
          *errcode = fresult_to_errno_table[res];
          return MP_STREAM_ERROR;
      }
      return sz_out;
  }
  
  STATIC mp_obj_t file_obj_flush(mp_obj_t self_in) {
      pyb_file_obj_t *self = self_in;
      f_sync(&self->fp);
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_1(file_obj_flush_obj, file_obj_flush);
  
  mp_obj_t file_obj_close(mp_obj_t self_in) {
      pyb_file_obj_t *self = self_in;
      f_close(&self->fp);
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_1(file_obj_close_obj, file_obj_close);
  
  mp_obj_t file_obj___exit__(mp_uint_t n_args, const mp_obj_t *args) {
      return file_obj_close(args[0]);
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(file_obj___exit___obj, 4, 4, file_obj___exit__);
  
  STATIC mp_uint_t file_obj_ioctl(mp_obj_t o_in, mp_uint_t request, mp_uint_t arg, int *errcode) {
      pyb_file_obj_t *self = o_in;
  
      if (request == MP_STREAM_SEEK) {
          struct mp_stream_seek_t *s = (struct mp_stream_seek_t*)arg;
  
          switch (s->whence) {
              case 0: // SEEK_SET
                  f_lseek(&self->fp, s->offset);
                  break;
  
              case 1: // SEEK_CUR
                  if (s->offset != 0) {
                      *errcode = ENOTSUP;
                      return MP_STREAM_ERROR;
                  }
                  // no-operation
                  break;
  
              case 2: // SEEK_END
                  f_lseek(&self->fp, f_size(&self->fp) + s->offset);
                  break;
          }
  
          s->offset = f_tell(&self->fp);
          return 0;
  
      } else {
          *errcode = EINVAL;
          return MP_STREAM_ERROR;
      }
  }
  
  mp_obj_t file_obj_tell(mp_obj_t self_in) {
      pyb_file_obj_t *self = self_in;
      return mp_obj_new_int_from_uint(f_tell(&self->fp));
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_1(file_obj_tell_obj, file_obj_tell);
  
  // Note: encoding is ignored for now; it's also not a valid kwarg for CPython's FileIO,
  // but by adding it here we can use one single mp_arg_t array for open() and FileIO's constructor
  STATIC const mp_arg_t file_open_args[] = {
      { MP_QSTR_file, MP_ARG_OBJ | MP_ARG_REQUIRED, {.u_obj = mp_const_none} },
      { MP_QSTR_mode, MP_ARG_OBJ, {.u_obj = MP_OBJ_NEW_QSTR(MP_QSTR_r)} },
      { MP_QSTR_encoding, MP_ARG_OBJ | MP_ARG_KW_ONLY, {.u_obj = mp_const_none} },
  };
  #define FILE_OPEN_NUM_ARGS MP_ARRAY_SIZE(file_open_args)
  
  STATIC mp_obj_t file_open(mp_obj_t type, mp_arg_val_t *args) {
      int mode = 0;
      const char *mode_s = mp_obj_str_get_str(args[1].u_obj);
      // TODO make sure only one of r, w, x, a, and b, t are specified
      while (*mode_s) {
          switch (*mode_s++) {
              case 'r':
                  mode |= FA_READ;
                  break;
              case 'w':
                  mode |= FA_WRITE | FA_CREATE_ALWAYS;
                  break;
              case 'x':
                  mode |= FA_WRITE | FA_CREATE_NEW;
                  break;
              case 'a':
                  mode |= FA_WRITE | FA_OPEN_ALWAYS;
                  break;
              case '+':
                  mode |= FA_READ | FA_WRITE;
                  break;
              #if MICROPY_PY_IO_FILEIO
              case 'b':
                  type = (mp_obj_t)&mp_type_fileio;
                  break;
              #endif
              case 't':
                  type = (mp_obj_t)&mp_type_textio;
                  break;
          }
      }
  
      pyb_file_obj_t *o = m_new_obj_with_finaliser(pyb_file_obj_t);
      o->base.type = type;
  
      const char *fname = mp_obj_str_get_str(args[0].u_obj);
      FRESULT res = f_open(&o->fp, fname, mode);
      if (res != FR_OK) {
          m_del_obj(pyb_file_obj_t, o);
          nlr_raise(mp_obj_new_exception_arg1(&mp_type_OSError, MP_OBJ_NEW_SMALL_INT(fresult_to_errno_table[res])));
      }
  
      // for 'a' mode, we must begin at the end of the file
      if ((mode & FA_OPEN_ALWAYS) != 0) {
          f_lseek(&o->fp, f_size(&o->fp));
      }
  
      return o;
  }
  
  STATIC mp_obj_t file_obj_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n_kw, const mp_obj_t *args) {
      mp_arg_val_t arg_vals[FILE_OPEN_NUM_ARGS];
      mp_arg_parse_all_kw_array(n_args, n_kw, args, FILE_OPEN_NUM_ARGS, file_open_args, arg_vals);
      return file_open(type_in, arg_vals);
  }
  
  // TODO gc hook to close the file if not already closed
  
  STATIC const mp_map_elem_t rawfile_locals_dict_table[] = {
      { MP_OBJ_NEW_QSTR(MP_QSTR_read), (mp_obj_t)&mp_stream_read_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_readall), (mp_obj_t)&mp_stream_readall_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_readinto), (mp_obj_t)&mp_stream_readinto_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_readline), (mp_obj_t)&mp_stream_unbuffered_readline_obj},
      { MP_OBJ_NEW_QSTR(MP_QSTR_readlines), (mp_obj_t)&mp_stream_unbuffered_readlines_obj},
      { MP_OBJ_NEW_QSTR(MP_QSTR_write), (mp_obj_t)&mp_stream_write_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_flush), (mp_obj_t)&file_obj_flush_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_close), (mp_obj_t)&file_obj_close_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_seek), (mp_obj_t)&mp_stream_seek_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR_tell), (mp_obj_t)&file_obj_tell_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR___del__), (mp_obj_t)&file_obj_close_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR___enter__), (mp_obj_t)&mp_identity_obj },
      { MP_OBJ_NEW_QSTR(MP_QSTR___exit__), (mp_obj_t)&file_obj___exit___obj },
  };
  
  STATIC MP_DEFINE_CONST_DICT(rawfile_locals_dict, rawfile_locals_dict_table);
  
  #if MICROPY_PY_IO_FILEIO
  STATIC const mp_stream_p_t fileio_stream_p = {
      .read = file_obj_read,
      .write = file_obj_write,
      .ioctl = file_obj_ioctl,
  };
  
  const mp_obj_type_t mp_type_fileio = {
      { &mp_type_type },
      .name = MP_QSTR_FileIO,
      .print = file_obj_print,
      .make_new = file_obj_make_new,
      .getiter = mp_identity,
      .iternext = mp_stream_unbuffered_iter,
      .stream_p = &fileio_stream_p,
      .locals_dict = (mp_obj_t)&rawfile_locals_dict,
  };
  #endif
  
  STATIC const mp_stream_p_t textio_stream_p = {
      .read = file_obj_read,
      .write = file_obj_write,
      .ioctl = file_obj_ioctl,
      .is_text = true,
  };
  
  const mp_obj_type_t mp_type_textio = {
      { &mp_type_type },
      .name = MP_QSTR_TextIOWrapper,
      .print = file_obj_print,
      .make_new = file_obj_make_new,
      .getiter = mp_identity,
      .iternext = mp_stream_unbuffered_iter,
      .stream_p = &textio_stream_p,
      .locals_dict = (mp_obj_t)&rawfile_locals_dict,
  };
  
  // Factory function for I/O stream classes
  mp_obj_t mp_builtin_open(mp_uint_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
      // TODO: analyze buffering args and instantiate appropriate type
      mp_arg_val_t arg_vals[FILE_OPEN_NUM_ARGS];
      mp_arg_parse_all(n_args, args, kwargs, FILE_OPEN_NUM_ARGS, file_open_args, arg_vals);
      return file_open((mp_obj_t)&mp_type_textio, arg_vals);
  }
  MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_open_obj, 1, mp_builtin_open);
  