#!/usr/bin/env python3

"""
Convert X11 keysyms headers into our keysyms header.
"""

from __future__ import print_function

import os
import re
from pathlib import Path

XORG_KEY_PREFIX = "XK_"
KEY_PREFIX = "XKB_KEY_"
EVDEV_MACRO = "_EVDEVK"
EXTRA_SPACES = " " * (len(KEY_PREFIX) - len(XORG_KEY_PREFIX))

# Expected format:
#     #define XF86XK_FooBar 0x1234         /* some optional comment */
# or:
#     #define XF86XK_FooBar _EVDEVK(0x123) /* some optional comment */
# We also need to match commented evdev entries:
#     /* Use: XF86XK_FooBar _EVDEVK(0x123)    some optional comment */
#     /* TODO: …            _EVDEVK(0x123)    some optional comment */
keysym_entry_pattern = re.compile(
    rf"""^
    (?:(?P<define>\#define)\s+|(?P<use>/\*\s+Use:)\s+|(?P<todo>/\*\s+TODO:))
    (?(todo)
        (?P<todo_comment>(?:\s+(?!{EVDEV_MACRO}|0x)\S+)+) |
        (?:(?P<prefix>\w*){XORG_KEY_PREFIX}|(?=NoSymbol))(?P<name>\w+)
    )
    (?P<spacing>\s+)
    (?P<evdev>{EVDEV_MACRO}\()?(?P<value>0x[0-9A-Fa-f]+)(?(evdev)\))
    """,
    re.VERBOSE,
)

# Match keysym guarded by #ifndef
keysym_ifndef_pattern = re.compile(
    rf"^#ifndef\s+(?P<prefix>\w*){XORG_KEY_PREFIX}(?P<name>\w+)\s*$"
)

# Match remaining XK_ references in the comments, e.g we will replace:
#       XF86XK_CamelCaseKernelName	_EVDEVK(kernel value)
#       #define XKB_KEY_SunCompose		0x0000FF20	/* Same as XK_Multi_key */
# with:
#       XKB_KEY_XF86CamelCaseKernelName	_EVDEVK(kernel value)
#       #define XKB_KEY_SunCompose		0x0000FF20	/* Same as XKB_KEY_Multi_key */
xorgproto_keysym_prefix_pattern = re.compile(
    rf"\b(?P<prefix>\w*){XORG_KEY_PREFIX}(?!KOREAN\b)"
)

alias_pattern = re.compile(
    rf"(?P<alias>(?:(?:D|d)eprecated )?(?:a|A)lias for ){KEY_PREFIX}(?P<comment>[^\*]+)"
)


def make_keysym_name(m: re.Match[str]) -> str:
    return m.group("prefix") + m.group("name")


def make_keysym_entry(m: re.Match[str]) -> str:
    """
    Perform the substitutions
    """
    if m.group("evdev"):
        if m.group("define"):
            # Replace the xorgproto _EVDEVK macro with the actual value:
            # 0x10081000 is the base, the evdev hex code is added to that.
            # We replace to make parsing of the keys later easier.
            value = 0x10081000 + int(m.group("value"), 16)
            value_str = f"{value:#x}    "
        else:
            value_str = f"""{EVDEV_MACRO}({m.group("value")})"""
    else:
        value_str = m.group("value")
    spacing = m.group("spacing")
    if todo := m.group("todo"):
        todo_comment = m.group("todo_comment")
        todo_commentʹ = xorgproto_keysym_prefix_pattern.sub(
            rf"{KEY_PREFIX}\1", todo_comment
        )
        if todo_commentʹ != todo_comment:
            diff = len(todo_commentʹ) - len(todo_comment)
            if diff != len(EXTRA_SPACES):
                raise ValueError()
            todo_comment = todo_commentʹ
        else:
            spacing += EXTRA_SPACES
        return f"""{todo}{todo_comment}{spacing}{value_str}"""
    else:
        prefix = m.group("prefix") or ""
        name = m.group("name")
        define = m.group("define") or m.group("use")
        if m.group("use") and name == "NoSymbol":
            spacing += EXTRA_SPACES
            key_prefix = ""
        else:
            key_prefix = KEY_PREFIX
        return f"""{define} {key_prefix}{prefix}{name}{spacing}{value_str}"""


def fix_alias(m: re.Match[str]) -> str:
    alias = m.group("alias")
    comment = m.group("comment")
    if len(comment) - len(comment.rstrip()) > 1:
        spaces = " " * len(XORG_KEY_PREFIX)
    else:
        spaces = ""
    return f"{alias}{comment}{spaces}"


prefix = Path(os.environ.get("X11_HEADERS_PREFIX", "/usr"))
HEADERS = (
    prefix / "include/X11/keysymdef.h",
    prefix / "include/X11/XF86keysym.h",
    prefix / "include/X11/Sunkeysym.h",
    prefix / "include/X11/DECkeysym.h",
    prefix / "include/X11/HPkeysym.h",
)

print(
    f"""#ifndef _XKBCOMMON_KEYSYMS_H
#define _XKBCOMMON_KEYSYMS_H

/* This file is autogenerated; please do not commit directly. */

/**
 * @file
 * Key symbols (keysyms) definitions.
 */

#define {KEY_PREFIX}NoSymbol                    0x000000  /* Special KeySym */
"""
)

keysyms: set[str] = set()
for path in HEADERS:
    pending_guarded_keysym: str | None = None
    with path.open("rt", encoding="utf-8") as header:
        for line in header:
            # Duplicate keysym name guard
            if m := keysym_ifndef_pattern.match(line):
                if pending_guarded_keysym:
                    raise ValueError(f"Nested #ifndef {pending_guarded_keysym}")
                pending_guarded_keysym = make_keysym_name(m)
                continue

            # Ignore C macro #ifdef/#ifndef
            elif line.startswith("#ifdef") or line.startswith("#ifndef"):
                if pending_guarded_keysym:
                    raise ValueError(f"Nested C macro {pending_guarded_keysym}")
                continue

            # Ignore C macro #endif and check end of keysym name guard
            elif line.startswith("#endif"):
                if pending_guarded_keysym:
                    pending_guarded_keysym = None
                continue

            # Ignore C macro #undef
            elif line.startswith("#undef"):
                continue

            # Remove #define _OSF_Keysyms and such.
            elif line.startswith("#define _"):
                continue

            # Keysym entry: proceed various tests
            if line.startswith("#") and (m := keysym_entry_pattern.match(line)):
                name = make_keysym_name(m)
                # Check expected guarded keysym, if relevant
                if pending_guarded_keysym and name != pending_guarded_keysym:
                    raise ValueError(f"{path}: Malformed keysym name guard: {line}")
                # Check if name already defined
                elif name in keysyms:
                    if pending_guarded_keysym:
                        # Ignore guarded keysym
                        continue
                    else:
                        raise ValueError(f"{path}: Unguarded redefinition: {line}")
                else:
                    keysyms.add(name)

            # Perform _EVDEV and XK_ substitutions
            line = keysym_entry_pattern.sub(make_keysym_entry, line)
            line = xorgproto_keysym_prefix_pattern.sub(rf"{KEY_PREFIX}\1", line)
            line = alias_pattern.sub(fix_alias, line)

            print(line.rstrip(), end="\n")
    print()
print("#endif")