// SPDX-FileCopyrightText: 2014 MicroPython & CircuitPython contributors (https://github.com/adafruit/circuitpython/graphs/contributors)
// SPDX-FileCopyrightText: Copyright (c) 2013-2018 Damien P. George
//
// SPDX-License-Identifier: MIT

#include "py/mphal.h"
#include "py/mpthread.h"
#include "py/runtime.h"
#include "py/stream.h"
#include "extmod/vfs_posix.h"
#include "supervisor/shared/translate.h"

#if (defined(MICROPY_VFS_POSIX) && MICROPY_VFS_POSIX) || (defined(MICROPY_VFS_POSIX_FILE) && MICROPY_VFS_POSIX_FILE)

#include <fcntl.h>
#include <unistd.h>

#ifdef _WIN32
#define fsync _commit
#endif

typedef struct _mp_obj_vfs_posix_file_t {
    mp_obj_base_t base;
    int fd;
} mp_obj_vfs_posix_file_t;

#ifdef MICROPY_CPYTHON_COMPAT
STATIC void check_fd_is_open(const mp_obj_vfs_posix_file_t *o) {
    if (o->fd < 0) {
        mp_raise_ValueError(MP_ERROR_TEXT("I/O operation on closed file"));
    }
}
#else
#define check_fd_is_open(o)
#endif

STATIC void vfs_posix_file_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind) {
    (void)kind;
    mp_obj_vfs_posix_file_t *self = MP_OBJ_TO_PTR(self_in);
    mp_printf(print, "<io.%q %d>", mp_obj_get_type_qstr(self_in), self->fd);
}

mp_obj_t mp_vfs_posix_file_open(const mp_obj_type_t *type, mp_obj_t file_in, mp_obj_t mode_in) {
    mp_obj_vfs_posix_file_t *o = m_new_obj(mp_obj_vfs_posix_file_t);
    const char *mode_s = mp_obj_str_get_str(mode_in);

    int mode_rw = 0, mode_x = 0;
    while (*mode_s) {
        switch (*mode_s++) {
            case 'r':
                mode_rw = O_RDONLY;
                break;
            case 'w':
                mode_rw = O_WRONLY;
                mode_x = O_CREAT | O_TRUNC;
                break;
            case 'a':
                mode_rw = O_WRONLY;
                mode_x = O_CREAT | O_APPEND;
                break;
            case '+':
                mode_rw = O_RDWR;
                break;
                #if MICROPY_PY_IO_FILEIO
            // If we don't have io.FileIO, then files are in text mode implicitly
            case 'b':
                type = &mp_type_vfs_posix_fileio;
                break;
            case 't':
                type = &mp_type_vfs_posix_textio;
                break;
                #endif
        }
    }

    o->base.type = type;

    mp_obj_t fid = file_in;

    if (mp_obj_is_small_int(fid)) {
        o->fd = MP_OBJ_SMALL_INT_VALUE(fid);
        return MP_OBJ_FROM_PTR(o);
    }

    const char *fname = mp_obj_str_get_str(fid);
    int fd;
    MP_HAL_RETRY_SYSCALL(fd, open(fname, mode_x | mode_rw, 0644), mp_raise_OSError(err));
    o->fd = fd;
    return MP_OBJ_FROM_PTR(o);
}

STATIC mp_obj_t vfs_posix_file_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *args, mp_map_t *kw_args) {
    static const mp_arg_t allowed_args[] = {
        { MP_QSTR_file, MP_ARG_OBJ | MP_ARG_REQUIRED, {.u_rom_obj = MP_ROM_NONE} },
        { MP_QSTR_mode, MP_ARG_OBJ, {.u_rom_obj = MP_ROM_QSTR(MP_QSTR_r)} },
    };

    mp_arg_val_t arg_vals[MP_ARRAY_SIZE(allowed_args)];
    mp_arg_parse_all(n_args, args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, arg_vals);
    return mp_vfs_posix_file_open(type, arg_vals[0].u_obj, arg_vals[1].u_obj);
}

STATIC mp_obj_t vfs_posix_file_fileno(mp_obj_t self_in) {
    mp_obj_vfs_posix_file_t *self = MP_OBJ_TO_PTR(self_in);
    check_fd_is_open(self);
    return MP_OBJ_NEW_SMALL_INT(self->fd);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(vfs_posix_file_fileno_obj, vfs_posix_file_fileno);

STATIC mp_obj_t vfs_posix_file___exit__(size_t n_args, const mp_obj_t *args) {
    (void)n_args;
    return mp_stream_close(args[0]);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(vfs_posix_file___exit___obj, 4, 4, vfs_posix_file___exit__);

STATIC mp_uint_t vfs_posix_file_read(mp_obj_t o_in, void *buf, mp_uint_t size, int *errcode) {
    mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);
    check_fd_is_open(o);
    ssize_t r;
    MP_HAL_RETRY_SYSCALL(r, read(o->fd, buf, size), {
        *errcode = err;
        return MP_STREAM_ERROR;
    });
    return (mp_uint_t)r;
}

STATIC mp_uint_t vfs_posix_file_write(mp_obj_t o_in, const void *buf, mp_uint_t size, int *errcode) {
    mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);
    check_fd_is_open(o);
    ssize_t r;
    MP_HAL_RETRY_SYSCALL(r, write(o->fd, buf, size), {
        *errcode = err;
        return MP_STREAM_ERROR;
    });
    return (mp_uint_t)r;
}

STATIC mp_uint_t vfs_posix_file_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_t arg, int *errcode) {
    mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);

    if (request != MP_STREAM_CLOSE) {
        check_fd_is_open(o);
    }

    switch (request) {
        case MP_STREAM_FLUSH: {
            int ret;
            MP_HAL_RETRY_SYSCALL(ret, fsync(o->fd), {
                if (err == EINVAL
                    && (o->fd == STDIN_FILENO || o->fd == STDOUT_FILENO || o->fd == STDERR_FILENO)) {
                    // fsync(stdin/stdout/stderr) may fail with EINVAL, but don't propagate that
                    // error out.  Because data is not buffered by us, and stdin/out/err.flush()
                    // should just be a no-op.
                    return 0;
                }
                *errcode = err;
                return MP_STREAM_ERROR;
            });
            return 0;
        }
        case MP_STREAM_SEEK: {
            struct mp_stream_seek_t *s = (struct mp_stream_seek_t *)arg;
            MP_THREAD_GIL_EXIT();
            off_t off = lseek(o->fd, s->offset, s->whence);
            MP_THREAD_GIL_ENTER();
            if (off == (off_t)-1) {
                *errcode = errno;
                return MP_STREAM_ERROR;
            }
            s->offset = off;
            return 0;
        }
        case MP_STREAM_CLOSE:
            MP_THREAD_GIL_EXIT();
            close(o->fd);
            MP_THREAD_GIL_ENTER();
            #ifdef MICROPY_CPYTHON_COMPAT
            o->fd = -1;
            #endif
            return 0;
        case MP_STREAM_GET_FILENO:
            return o->fd;
        default:
            *errcode = EINVAL;
            return MP_STREAM_ERROR;
    }
}

STATIC const mp_rom_map_elem_t vfs_posix_rawfile_locals_dict_table[] = {
    { MP_ROM_QSTR(MP_QSTR_fileno), MP_ROM_PTR(&vfs_posix_file_fileno_obj) },
    { MP_ROM_QSTR(MP_QSTR_read), MP_ROM_PTR(&mp_stream_read_obj) },
    { MP_ROM_QSTR(MP_QSTR_readinto), MP_ROM_PTR(&mp_stream_readinto_obj) },
    { MP_ROM_QSTR(MP_QSTR_readline), MP_ROM_PTR(&mp_stream_unbuffered_readline_obj) },
    { MP_ROM_QSTR(MP_QSTR_readlines), MP_ROM_PTR(&mp_stream_unbuffered_readlines_obj) },
    { MP_ROM_QSTR(MP_QSTR_write), MP_ROM_PTR(&mp_stream_write_obj) },
    { MP_ROM_QSTR(MP_QSTR_seek), MP_ROM_PTR(&mp_stream_seek_obj) },
    { MP_ROM_QSTR(MP_QSTR_tell), MP_ROM_PTR(&mp_stream_tell_obj) },
    { MP_ROM_QSTR(MP_QSTR_flush), MP_ROM_PTR(&mp_stream_flush_obj) },
    { MP_ROM_QSTR(MP_QSTR_close), MP_ROM_PTR(&mp_stream_close_obj) },
    { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&mp_identity_obj) },
    { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&vfs_posix_file___exit___obj) },
};

STATIC MP_DEFINE_CONST_DICT(vfs_posix_rawfile_locals_dict, vfs_posix_rawfile_locals_dict_table);

#if MICROPY_PY_IO_FILEIO
STATIC const mp_stream_p_t vfs_posix_fileio_stream_p = {
    MP_PROTO_IMPLEMENT(MP_QSTR_protocol_stream)
    .read = vfs_posix_file_read,
    .write = vfs_posix_file_write,
    .ioctl = vfs_posix_file_ioctl,
};

const mp_obj_type_t mp_type_vfs_posix_fileio = {
    { &mp_type_type },
    .flags = MP_TYPE_FLAG_FULL,
    .name = MP_QSTR_FileIO,
    .print = vfs_posix_file_print,
    .make_new = vfs_posix_file_make_new,
    .getiter = mp_identity_getiter,
    .iternext = mp_stream_unbuffered_iter,
    .protocol = &vfs_posix_fileio_stream_p,
    .locals_dict = (mp_obj_dict_t *)&vfs_posix_rawfile_locals_dict,
};
#endif

STATIC const mp_stream_p_t vfs_posix_textio_stream_p = {
    MP_PROTO_IMPLEMENT(MP_QSTR_protocol_stream)
    .read = vfs_posix_file_read,
    .write = vfs_posix_file_write,
    .ioctl = vfs_posix_file_ioctl,
    .is_text = true,
};

const mp_obj_type_t mp_type_vfs_posix_textio = {
    { &mp_type_type },
    .name = MP_QSTR_TextIOWrapper,
    .print = vfs_posix_file_print,
    .make_new = vfs_posix_file_make_new,
    .getiter = mp_identity_getiter,
    .iternext = mp_stream_unbuffered_iter,
    .protocol = &vfs_posix_textio_stream_p,
    .locals_dict = (mp_obj_dict_t *)&vfs_posix_rawfile_locals_dict,
};

const mp_obj_vfs_posix_file_t mp_sys_stdin_obj = {{&mp_type_textio}, STDIN_FILENO};
const mp_obj_vfs_posix_file_t mp_sys_stdout_obj = {{&mp_type_textio}, STDOUT_FILENO};
const mp_obj_vfs_posix_file_t mp_sys_stderr_obj = {{&mp_type_textio}, STDERR_FILENO};

#endif // MICROPY_VFS_POSIX || MICROPY_VFS_POSIX_FILE