/* stat.h interface
 *
 * The module defines all S_IF*, S_I*, UF_*, SF_* and ST_* constants to
 * sensible default values as well as defines S_IS*() macros in order to keep
 * backward compatibility with the old stat.py module.
 *
 * New constants and macros such as S_IFDOOR / S_ISDOOR() are always defined
 * as int 0.
 *
 * NOTE: POSIX only defines the values of the S_I* permission bits.
 *
 */

// Need limited C API version 3.13 for PyModule_Add() on Windows
#include "pyconfig.h"   // Py_GIL_DISABLED
#ifndef Py_GIL_DISABLED
#  define Py_LIMITED_API 0x030d0000
#endif

#include "Python.h"

#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif /* HAVE_SYS_TYPES_H */

#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif /* HAVE_SYS_STAT_H */

#ifdef MS_WINDOWS
#include <windows.h>
typedef unsigned short mode_t;

/* FILE_ATTRIBUTE_INTEGRITY_STREAM and FILE_ATTRIBUTE_NO_SCRUB_DATA
   are not present in VC2010, so define them manually */
#ifndef FILE_ATTRIBUTE_INTEGRITY_STREAM
#  define FILE_ATTRIBUTE_INTEGRITY_STREAM 0x8000
#endif

#ifndef FILE_ATTRIBUTE_NO_SCRUB_DATA
#  define FILE_ATTRIBUTE_NO_SCRUB_DATA 0x20000
#endif

#ifndef IO_REPARSE_TAG_APPEXECLINK
#  define IO_REPARSE_TAG_APPEXECLINK 0x8000001BL
#endif

#endif /* MS_WINDOWS */

/* From Python's stat.py */
#ifndef S_IMODE
#  define S_IMODE 07777
#endif

/* S_IFXXX constants (file types)
 *
 * Only the names are defined by POSIX but not their value. All common file
 * types seems to have the same numeric value on all platforms, though.
 *
 * fileutils.h guarantees S_IFMT, S_IFDIR, S_IFCHR, S_IFREG and S_IFLNK
 */

#ifndef S_IFBLK
#  define S_IFBLK 0060000
#endif

#ifndef S_IFIFO
#  define S_IFIFO 0010000
#endif

#ifndef S_IFSOCK
#  define S_IFSOCK 0140000
#endif

#ifndef S_IFDOOR
#  define S_IFDOOR 0
#endif

#ifndef S_IFPORT
#  define S_IFPORT 0
#endif

#ifndef S_IFWHT
#  define S_IFWHT 0
#endif


/* S_ISXXX()
 * fileutils.h defines S_ISDIR(), S_ISREG() and S_ISCHR()
 */

#ifndef S_ISBLK
#  define S_ISBLK(mode) (((mode) & S_IFMT) == S_IFBLK)
#endif

#ifndef S_ISFIFO
#  define S_ISFIFO(mode) (((mode) & S_IFMT) == S_IFIFO)
#endif

#ifndef S_ISLNK
#  define S_ISLNK(mode) (((mode) & S_IFMT) == S_IFLNK)
#endif

#ifndef S_ISSOCK
#  define S_ISSOCK(mode) (((mode) & S_IFMT) == S_IFSOCK)
#endif

#ifndef S_ISDOOR
#  define S_ISDOOR(mode) 0
#endif

#ifndef S_ISPORT
#  define S_ISPORT(mode) 0
#endif

#ifndef S_ISWHT
#  define S_ISWHT(mode) 0
#endif


/* S_I* file permission
 *
 * The permission bit value are defined by POSIX standards.
 */
#ifndef S_ISUID
#  define S_ISUID 04000
#endif

#ifndef S_ISGID
#  define S_ISGID 02000
#endif

/* what is S_ENFMT? */
#ifndef S_ENFMT
#  define S_ENFMT S_ISGID
#endif

#ifndef S_ISVTX
#  define S_ISVTX 01000
#endif

#ifndef S_IREAD
#  define S_IREAD 00400
#endif

#ifndef S_IWRITE
#  define S_IWRITE 00200
#endif

#ifndef S_IEXEC
#  define S_IEXEC 00100
#endif

#ifndef S_IRWXU
#  define S_IRWXU 00700
#endif

#ifndef S_IRUSR
#  define S_IRUSR 00400
#endif

#ifndef S_IWUSR
#  define S_IWUSR 00200
#endif

#ifndef S_IXUSR
#  define S_IXUSR 00100
#endif

#ifndef S_IRWXG
#  define S_IRWXG 00070
#endif

#ifndef S_IRGRP
#  define S_IRGRP 00040
#endif

#ifndef S_IWGRP
#  define S_IWGRP 00020
#endif

#ifndef S_IXGRP
#  define S_IXGRP 00010
#endif

#ifndef S_IRWXO
#  define S_IRWXO 00007
#endif

#ifndef S_IROTH
#  define S_IROTH 00004
#endif

#ifndef S_IWOTH
#  define S_IWOTH 00002
#endif

#ifndef S_IXOTH
#  define S_IXOTH 00001
#endif


/* Names for file flags */
#ifndef UF_SETTABLE
#  define UF_SETTABLE 0x0000ffff
#endif

#ifndef UF_NODUMP
#  define UF_NODUMP 0x00000001
#endif

#ifndef UF_IMMUTABLE
#  define UF_IMMUTABLE 0x00000002
#endif

#ifndef UF_APPEND
#  define UF_APPEND 0x00000004
#endif

#ifndef UF_OPAQUE
#  define UF_OPAQUE 0x00000008
#endif

#ifndef UF_NOUNLINK
#  define UF_NOUNLINK 0x00000010
#endif

#ifndef UF_COMPRESSED
#  define UF_COMPRESSED 0x00000020
#endif

#ifndef UF_TRACKED
#  define UF_TRACKED 0x00000040
#endif

#ifndef UF_DATAVAULT
#  define UF_DATAVAULT 0x00000080
#endif

#ifndef UF_HIDDEN
#  define UF_HIDDEN 0x00008000
#endif

#ifndef SF_SETTABLE
#  define SF_SETTABLE 0xffff0000
#endif

#ifndef SF_ARCHIVED
#  define SF_ARCHIVED 0x00010000
#endif

#ifndef SF_IMMUTABLE
#  define SF_IMMUTABLE 0x00020000
#endif

#ifndef SF_APPEND
#  define SF_APPEND 0x00040000
#endif

#ifndef SF_NOUNLINK
#  define SF_NOUNLINK 0x00100000
#endif

#ifndef SF_SNAPSHOT
#  define SF_SNAPSHOT 0x00200000
#endif

#ifndef SF_FIRMLINK
#  define SF_FIRMLINK 0x00800000
#endif

#ifndef SF_DATALESS
#  define SF_DATALESS 0x40000000
#endif

#if defined(__APPLE__) && !defined(SF_SUPPORTED)
   /* On older macOS versions the definition of SF_SUPPORTED is different
    * from that on newer versions.
    *
    * Provide a consistent experience by redefining.
    *
    * None of bit bits set in the actual SF_SUPPORTED but not in this
    * definition are defined on these versions of macOS.
    */
#  undef SF_SETTABLE
#  define SF_SUPPORTED 0x009f0000
#  define SF_SETTABLE 0x3fff0000
#  define SF_SYNTHETIC 0xc0000000
#endif


static mode_t
_PyLong_AsMode_t(PyObject *op)
{
    unsigned long value;
    mode_t mode;

    if (PyLong_Check(op)) {
        value = PyLong_AsUnsignedLong(op);
    }
    else {
        op = PyNumber_Index(op);
        if (op == NULL) {
            return (mode_t)-1;
        }
        value = PyLong_AsUnsignedLong(op);
        Py_DECREF(op);
    }

    if ((value == (unsigned long)-1) && PyErr_Occurred()) {
        return (mode_t)-1;
    }

    mode = (mode_t)value;
    if ((unsigned long)mode != value) {
        PyErr_SetString(PyExc_OverflowError, "mode out of range");
        return (mode_t)-1;
    }
    return mode;
}


#define stat_S_ISFUNC(isfunc, doc)                             \
    static PyObject *                                          \
    stat_ ##isfunc (PyObject *self, PyObject *omode)           \
    {                                                          \
       mode_t mode = _PyLong_AsMode_t(omode);                   \
       if ((mode == (mode_t)-1) && PyErr_Occurred())           \
           return NULL;                                        \
       return PyBool_FromLong(isfunc(mode));                   \
    }                                                          \
    PyDoc_STRVAR(stat_ ## isfunc ## _doc, doc)

stat_S_ISFUNC(S_ISDIR,
    "S_ISDIR(mode) -> bool\n\n"
    "Return True if mode is from a directory.");

stat_S_ISFUNC(S_ISCHR,
    "S_ISCHR(mode) -> bool\n\n"
    "Return True if mode is from a character special device file.");

stat_S_ISFUNC(S_ISBLK,
    "S_ISBLK(mode) -> bool\n\n"
    "Return True if mode is from a block special device file.");

stat_S_ISFUNC(S_ISREG,
    "S_ISREG(mode) -> bool\n\n"
    "Return True if mode is from a regular file.");

stat_S_ISFUNC(S_ISFIFO,
    "S_ISFIFO(mode) -> bool\n\n"
    "Return True if mode is from a FIFO (named pipe).");

stat_S_ISFUNC(S_ISLNK,
    "S_ISLNK(mode) -> bool\n\n"
    "Return True if mode is from a symbolic link.");

stat_S_ISFUNC(S_ISSOCK,
    "S_ISSOCK(mode) -> bool\n\n"
    "Return True if mode is from a socket.");

stat_S_ISFUNC(S_ISDOOR,
    "S_ISDOOR(mode) -> bool\n\n"
    "Return True if mode is from a door.");

stat_S_ISFUNC(S_ISPORT,
    "S_ISPORT(mode) -> bool\n\n"
    "Return True if mode is from an event port.");

stat_S_ISFUNC(S_ISWHT,
    "S_ISWHT(mode) -> bool\n\n"
    "Return True if mode is from a whiteout.");


PyDoc_STRVAR(stat_S_IMODE_doc,
"Return the portion of the file's mode that can be set by os.chmod().");

static PyObject *
stat_S_IMODE(PyObject *self, PyObject *omode)
{
    mode_t mode = _PyLong_AsMode_t(omode);
    if ((mode == (mode_t)-1) && PyErr_Occurred())
        return NULL;
    return PyLong_FromUnsignedLong(mode & S_IMODE);
}


PyDoc_STRVAR(stat_S_IFMT_doc,
"Return the portion of the file's mode that describes the file type.");

static PyObject *
stat_S_IFMT(PyObject *self, PyObject *omode)
{
    mode_t mode = _PyLong_AsMode_t(omode);
    if ((mode == (mode_t)-1) && PyErr_Occurred())
        return NULL;
    return PyLong_FromUnsignedLong(mode & S_IFMT);
}

/* file type chars according to
   http://en.wikibooks.org/wiki/C_Programming/POSIX_Reference/sys/stat.h */

static char
filetype(mode_t mode)
{
    /* common cases first */
    if (S_ISREG(mode))  return '-';
    if (S_ISDIR(mode))  return 'd';
    if (S_ISLNK(mode))  return 'l';
    /* special files */
    if (S_ISBLK(mode))  return 'b';
    if (S_ISCHR(mode))  return 'c';
    if (S_ISFIFO(mode)) return 'p';
    if (S_ISSOCK(mode)) return 's';
    /* non-standard types */
    if (S_ISDOOR(mode)) return 'D';
    if (S_ISPORT(mode)) return 'P';
    if (S_ISWHT(mode))  return 'w';
    /* unknown */
    return '?';
}

static void
fileperm(mode_t mode, char *buf)
{
    buf[0] = mode & S_IRUSR ? 'r' : '-';
    buf[1] = mode & S_IWUSR ? 'w' : '-';
    if (mode & S_ISUID) {
        buf[2] = mode & S_IXUSR ? 's' : 'S';
    } else {
        buf[2] = mode & S_IXUSR ? 'x' : '-';
    }
    buf[3] = mode & S_IRGRP ? 'r' : '-';
    buf[4] = mode & S_IWGRP ? 'w' : '-';
    if (mode & S_ISGID) {
        buf[5] = mode & S_IXGRP ? 's' : 'S';
    } else {
        buf[5] = mode & S_IXGRP ? 'x' : '-';
    }
    buf[6] = mode & S_IROTH ? 'r' : '-';
    buf[7] = mode & S_IWOTH ? 'w' : '-';
    if (mode & S_ISVTX) {
        buf[8] = mode & S_IXOTH ? 't' : 'T';
    } else {
        buf[8] = mode & S_IXOTH ? 'x' : '-';
    }
}

PyDoc_STRVAR(stat_filemode_doc,
"Convert a file's mode to a string of the form '-rwxrwxrwx'");

static PyObject *
stat_filemode(PyObject *self, PyObject *omode)
{
    char buf[10];
    mode_t mode;

    mode = _PyLong_AsMode_t(omode);
    if ((mode == (mode_t)-1) && PyErr_Occurred())
        return NULL;

    buf[0] = filetype(mode);
    fileperm(mode, &buf[1]);
    return PyUnicode_FromStringAndSize(buf, 10);
}


static PyMethodDef stat_methods[] = {
    {"S_ISDIR",         stat_S_ISDIR,  METH_O, stat_S_ISDIR_doc},
    {"S_ISCHR",         stat_S_ISCHR,  METH_O, stat_S_ISCHR_doc},
    {"S_ISBLK",         stat_S_ISBLK,  METH_O, stat_S_ISBLK_doc},
    {"S_ISREG",         stat_S_ISREG,  METH_O, stat_S_ISREG_doc},
    {"S_ISFIFO",        stat_S_ISFIFO, METH_O, stat_S_ISFIFO_doc},
    {"S_ISLNK",         stat_S_ISLNK,  METH_O, stat_S_ISLNK_doc},
    {"S_ISSOCK",        stat_S_ISSOCK, METH_O, stat_S_ISSOCK_doc},
    {"S_ISDOOR",        stat_S_ISDOOR, METH_O, stat_S_ISDOOR_doc},
    {"S_ISPORT",        stat_S_ISPORT, METH_O, stat_S_ISPORT_doc},
    {"S_ISWHT",         stat_S_ISWHT,  METH_O, stat_S_ISWHT_doc},
    {"S_IMODE",         stat_S_IMODE,  METH_O, stat_S_IMODE_doc},
    {"S_IFMT",          stat_S_IFMT,   METH_O, stat_S_IFMT_doc},
    {"filemode",        stat_filemode, METH_O, stat_filemode_doc},
    {NULL,              NULL}           /* sentinel */
};


PyDoc_STRVAR(module_doc,
"S_IFMT_: file type bits\n\
S_IFDIR: directory\n\
S_IFCHR: character device\n\
S_IFBLK: block device\n\
S_IFREG: regular file\n\
S_IFIFO: fifo (named pipe)\n\
S_IFLNK: symbolic link\n\
S_IFSOCK: socket file\n\
S_IFDOOR: door\n\
S_IFPORT: event port\n\
S_IFWHT: whiteout\n\
\n"

"S_ISUID: set UID bit\n\
S_ISGID: set GID bit\n\
S_ENFMT: file locking enforcement\n\
S_ISVTX: sticky bit\n\
S_IREAD: Unix V7 synonym for S_IRUSR\n\
S_IWRITE: Unix V7 synonym for S_IWUSR\n\
S_IEXEC: Unix V7 synonym for S_IXUSR\n\
S_IRWXU: mask for owner permissions\n\
S_IRUSR: read by owner\n\
S_IWUSR: write by owner\n\
S_IXUSR: execute by owner\n\
S_IRWXG: mask for group permissions\n\
S_IRGRP: read by group\n\
S_IWGRP: write by group\n\
S_IXGRP: execute by group\n\
S_IRWXO: mask for others (not in group) permissions\n\
S_IROTH: read by others\n\
S_IWOTH: write by others\n\
S_IXOTH: execute by others\n\
\n"

"UF_SETTABLE: mask of owner changeable flags\n\
UF_NODUMP: do not dump file\n\
UF_IMMUTABLE: file may not be changed\n\
UF_APPEND: file may only be appended to\n\
UF_OPAQUE: directory is opaque when viewed through a union stack\n\
UF_NOUNLINK: file may not be renamed or deleted\n\
UF_COMPRESSED: macOS: file is hfs-compressed\n\
UF_TRACKED: used for dealing with document IDs\n\
UF_DATAVAULT: entitlement required for reading and writing\n\
UF_HIDDEN: macOS: file should not be displayed\n\
SF_SETTABLE: mask of super user changeable flags\n\
SF_ARCHIVED: file may be archived\n\
SF_IMMUTABLE: file may not be changed\n\
SF_APPEND: file may only be appended to\n\
SF_RESTRICTED: entitlement required for writing\n\
SF_NOUNLINK: file may not be renamed or deleted\n\
SF_SNAPSHOT: file is a snapshot file\n\
SF_FIRMLINK: file is a firmlink\n\
SF_DATALESS: file is a dataless object\n\
\n\
On macOS:\n\
SF_SUPPORTED: mask of super user supported flags\n\
SF_SYNTHETIC: mask of read-only synthetic flags\n\
\n"

"ST_MODE\n\
ST_INO\n\
ST_DEV\n\
ST_NLINK\n\
ST_UID\n\
ST_GID\n\
ST_SIZE\n\
ST_ATIME\n\
ST_MTIME\n\
ST_CTIME\n\
\n"

"FILE_ATTRIBUTE_*: Windows file attribute constants\n\
                   (only present on Windows)\n\
");


static int
stat_exec(PyObject *module)
{
#define ADD_INT_MACRO(module, macro)                                  \
    do {                                                              \
        if (PyModule_AddIntConstant(module, #macro, macro) < 0) {     \
            return -1;                                                \
        }                                                             \
    } while (0)

    ADD_INT_MACRO(module, S_IFDIR);
    ADD_INT_MACRO(module, S_IFCHR);
    ADD_INT_MACRO(module, S_IFBLK);
    ADD_INT_MACRO(module, S_IFREG);
    ADD_INT_MACRO(module, S_IFIFO);
    ADD_INT_MACRO(module, S_IFLNK);
    ADD_INT_MACRO(module, S_IFSOCK);
    ADD_INT_MACRO(module, S_IFDOOR);
    ADD_INT_MACRO(module, S_IFPORT);
    ADD_INT_MACRO(module, S_IFWHT);

    ADD_INT_MACRO(module, S_ISUID);
    ADD_INT_MACRO(module, S_ISGID);
    ADD_INT_MACRO(module, S_ISVTX);
    ADD_INT_MACRO(module, S_ENFMT);

    ADD_INT_MACRO(module, S_IREAD);
    ADD_INT_MACRO(module, S_IWRITE);
    ADD_INT_MACRO(module, S_IEXEC);

    ADD_INT_MACRO(module, S_IRWXU);
    ADD_INT_MACRO(module, S_IRUSR);
    ADD_INT_MACRO(module, S_IWUSR);
    ADD_INT_MACRO(module, S_IXUSR);

    ADD_INT_MACRO(module, S_IRWXG);
    ADD_INT_MACRO(module, S_IRGRP);
    ADD_INT_MACRO(module, S_IWGRP);
    ADD_INT_MACRO(module, S_IXGRP);

    ADD_INT_MACRO(module, S_IRWXO);
    ADD_INT_MACRO(module, S_IROTH);
    ADD_INT_MACRO(module, S_IWOTH);
    ADD_INT_MACRO(module, S_IXOTH);

    ADD_INT_MACRO(module, UF_SETTABLE);
    ADD_INT_MACRO(module, UF_NODUMP);
    ADD_INT_MACRO(module, UF_IMMUTABLE);
    ADD_INT_MACRO(module, UF_APPEND);
    ADD_INT_MACRO(module, UF_OPAQUE);
    ADD_INT_MACRO(module, UF_NOUNLINK);
    ADD_INT_MACRO(module, UF_COMPRESSED);
    ADD_INT_MACRO(module, UF_TRACKED);
    ADD_INT_MACRO(module, UF_DATAVAULT);
    ADD_INT_MACRO(module, UF_HIDDEN);
    ADD_INT_MACRO(module, SF_SETTABLE);
    ADD_INT_MACRO(module, SF_ARCHIVED);
    ADD_INT_MACRO(module, SF_IMMUTABLE);
    ADD_INT_MACRO(module, SF_APPEND);
    ADD_INT_MACRO(module, SF_NOUNLINK);
    ADD_INT_MACRO(module, SF_SNAPSHOT);
    ADD_INT_MACRO(module, SF_FIRMLINK);
    ADD_INT_MACRO(module, SF_DATALESS);

#ifdef SF_SUPPORTED
    ADD_INT_MACRO(module, SF_SUPPORTED);
#endif
#ifdef SF_SYNTHETIC
    ADD_INT_MACRO(module, SF_SYNTHETIC);
#endif


    const char* st_constants[] = {
        "ST_MODE",
        "ST_INO",
        "ST_DEV",
        "ST_NLINK",
        "ST_UID",
        "ST_GID",
        "ST_SIZE",
        "ST_ATIME",
        "ST_MTIME",
        "ST_CTIME"
    };

    for (int i = 0; i < (int)Py_ARRAY_LENGTH(st_constants); i++) {
        if (PyModule_AddIntConstant(module, st_constants[i], i) < 0) {
            return -1;
        }
    }

#ifdef MS_WINDOWS
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_ARCHIVE);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_COMPRESSED);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_DEVICE);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_DIRECTORY);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_ENCRYPTED);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_HIDDEN);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_INTEGRITY_STREAM);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_NORMAL);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_NOT_CONTENT_INDEXED);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_NO_SCRUB_DATA);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_OFFLINE);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_READONLY);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_REPARSE_POINT);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_SPARSE_FILE);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_SYSTEM);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_TEMPORARY);
    ADD_INT_MACRO(module, FILE_ATTRIBUTE_VIRTUAL);

    if (PyModule_Add(module, "IO_REPARSE_TAG_SYMLINK",
            PyLong_FromUnsignedLong(IO_REPARSE_TAG_SYMLINK)) < 0) {
        return -1;
    }
    if (PyModule_Add(module, "IO_REPARSE_TAG_MOUNT_POINT",
            PyLong_FromUnsignedLong(IO_REPARSE_TAG_MOUNT_POINT)) < 0) {
        return -1;
    }
    if (PyModule_Add(module, "IO_REPARSE_TAG_APPEXECLINK",
            PyLong_FromUnsignedLong(IO_REPARSE_TAG_APPEXECLINK)) < 0) {
        return -1;
    }
#endif

    return 0;
}


static PyModuleDef_Slot stat_slots[] = {
    {Py_mod_exec, stat_exec},
    {Py_mod_multiple_interpreters, Py_MOD_PER_INTERPRETER_GIL_SUPPORTED},
    {Py_mod_gil, Py_MOD_GIL_NOT_USED},
    {0, NULL}
};


static struct PyModuleDef statmodule = {
    PyModuleDef_HEAD_INIT,
    .m_name = "_stat",
    .m_doc = module_doc,
    .m_size = 0,
    .m_methods = stat_methods,
    .m_slots = stat_slots,
};


PyMODINIT_FUNC
PyInit__stat(void)
{
    return PyModuleDef_Init(&statmodule);
}