#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include "py/runtime.h"

#include "py/stream.h"

#include "py/reader.h"

#include "extmod/vfs.h"

#if MICROPY_READER_VFS

#ifndef MICROPY_READER_VFS_DEFAULT_BUFFER_SIZE

#define MICROPY_READER_VFS_DEFAULT_BUFFER_SIZE (2 * MICROPY_BYTES_PER_GC_BLOCK - offsetof(mp_reader_vfs_t, buf))

#define MICROPY_READER_VFS_MIN_BUFFER_SIZE (MICROPY_BYTES_PER_GC_BLOCK - offsetof(mp_reader_vfs_t, buf))

#define MICROPY_READER_VFS_MAX_BUFFER_SIZE (255)

typedef struct _mp_reader_vfs_t {

} mp_reader_vfs_t;

static mp_uint_t mp_reader_vfs_readbyte(void *data) {

mp_reader_vfs_t *reader = (mp_reader_vfs_t *)data;

if (reader->bufpos >= reader->buflen) {

if (reader->buflen < reader->bufsize) {

return MP_READER_EOF;

} else {

int errcode;

reader->buflen = mp_stream_rw(reader->file, reader->buf, reader->bufsize, &errcode, MP_STREAM_RW_READ | MP_STREAM_RW_ONCE);

if (errcode != 0) {

// TODO handle errors properly

return MP_READER_EOF;

}

if (reader->buflen == 0) {

return MP_READER_EOF;

}

reader->bufpos = 0;

}

}

return reader->buf[reader->bufpos++];

}

static void mp_reader_vfs_close(void *data) {

mp_reader_vfs_t *reader = (mp_reader_vfs_t *)data;

mp_stream_close(reader->file);

m_del_obj(mp_reader_vfs_t, reader);

}

void mp_reader_new_file(mp_reader_t *reader, qstr filename) {

mp_obj_t args[2] = {

MP_OBJ_NEW_QSTR(filename),

MP_OBJ_NEW_QSTR(MP_QSTR_rb),

};

mp_obj_t file = mp_vfs_open(MP_ARRAY_SIZE(args), &args[0], (mp_map_t *)&mp_const_empty_map);

const mp_stream_p_t *stream_p = mp_get_stream(file);

int errcode = 0;

mp_uint_t bufsize = stream_p->ioctl(file, MP_STREAM_GET_BUFFER_SIZE, 0, &errcode);

if (bufsize == MP_STREAM_ERROR || bufsize == 0) {

// bufsize == 0 is included here to support mpremote v1.21 and older where mount file ioctl

// returned 0 by default.

bufsize = MICROPY_READER_VFS_DEFAULT_BUFFER_SIZE;

} else {

bufsize = MIN(MICROPY_READER_VFS_MAX_BUFFER_SIZE, MAX(MICROPY_READER_VFS_MIN_BUFFER_SIZE, bufsize));

}

mp_reader_vfs_t *rf = m_new_obj_var(mp_reader_vfs_t, buf, byte, bufsize);

rf->file = file;

rf->bufsize = bufsize;

rf->buflen = mp_stream_rw(rf->file, rf->buf, rf->bufsize, &errcode, MP_STREAM_RW_READ | MP_STREAM_RW_ONCE);

if (errcode != 0) {

mp_raise_OSError(errcode);

}

rf->bufpos = 0;

reader->data = rf;

reader->readbyte = mp_reader_vfs_readbyte;

reader->close = mp_reader_vfs_close;

}

#endif // MICROPY_READER_VFS