"""
Generate a Python extension module with the constants defined in linux/input.h.
"""

import getopt
import os
import re
import sys

# -----------------------------------------------------------------------------
# The default header file locations to try.
headers = [
    "/usr/include/linux/input.h",
    "/usr/include/linux/input-event-codes.h",
    "/usr/include/linux/uinput.h",
]

opts, args = getopt.getopt(sys.argv[1:], "", ["ecodes", "stubs"])
if not opts:
    print("usage: genecodes.py [--ecodes|--stubs] <headers>")
    exit(2)

if args:
    headers = args


# -----------------------------------------------------------------------------
macro_regex = r"#define\s+((?:KEY|ABS|REL|SW|MSC|LED|BTN|REP|SND|ID|EV|BUS|SYN|FF|UI_FF|INPUT_PROP)_\w+)"
macro_regex = re.compile(macro_regex)

# Uname without hostname.
uname = list(os.uname())
uname = " ".join((uname[0], *uname[2:]))


# -----------------------------------------------------------------------------
template_ecodes = r"""
#include <Python.h>
#ifdef __FreeBSD__
#include <dev/evdev/input.h>
#include <dev/evdev/uinput.h>
#else
#include <linux/input.h>
#include <linux/uinput.h>
#endif

/* Automatically generated by evdev.genecodes */
/* Generated on   %s */
/* Generated from %s */

#define MODULE_NAME "_ecodes"
#define MODULE_HELP "linux/input.h macros"

static PyMethodDef MethodTable[] = {
    { NULL, NULL, 0, NULL}
};

static struct PyModuleDef moduledef = {
    PyModuleDef_HEAD_INIT,
    MODULE_NAME,
    MODULE_HELP,
    -1,          /* m_size */
    MethodTable, /* m_methods */
    NULL,        /* m_reload */
    NULL,        /* m_traverse */
    NULL,        /* m_clear */
    NULL,        /* m_free */
};

PyMODINIT_FUNC
PyInit__ecodes(void)
{
    PyObject* m = PyModule_Create(&moduledef);
    if (m == NULL) return NULL;

%s

    return m;
}
"""


template_stubs = r"""
# Automatically generated by evdev.genecodes
# Generated on %s
# Generated from %s

# pylint: skip-file

ecodes: dict[str, int]
keys: dict[int, str|list[str]]
bytype: dict[int, dict[int, str|list[str]]]

KEY: dict[int, str|list[str]]
ABS: dict[int, str|list[str]]
REL: dict[int, str|list[str]]
SW:  dict[int, str|list[str]]
MSC: dict[int, str|list[str]]
LED: dict[int, str|list[str]]
BTN: dict[int, str|list[str]]
REP: dict[int, str|list[str]]
SND: dict[int, str|list[str]]
ID:  dict[int, str|list[str]]
EV:  dict[int, str|list[str]]
BUS: dict[int, str|list[str]]
SYN: dict[int, str|list[str]]
FF_STATUS:     dict[int, str|list[str]]
FF_INPUT_PROP: dict[int, str|list[str]]

%s
"""


def parse_headers(headers=headers):
    for header in headers:
        try:
            fh = open(header)
        except (IOError, OSError):
            continue

        for line in fh:
            macro = macro_regex.search(line)
            if macro:
                yield macro.group(1)


all_macros = list(parse_headers())
if not all_macros:
    print("no input macros found in: %s" % " ".join(headers), file=sys.stderr)
    sys.exit(1)

# pylint: disable=possibly-used-before-assignment, used-before-assignment
if ("--ecodes", "") in opts:
    body = ("    PyModule_AddIntMacro(m, %s);" % macro for macro in all_macros)
    template = template_ecodes
elif ("--stubs", "") in opts:
    body = ("%s: int" % macro for macro in all_macros)
    template = template_stubs

body = os.linesep.join(body)
text = template % (uname, headers, body)
print(text.strip())