#!/usr/bin/env python3
"""Patch lv_font_conv output for LVGL 9.

`lv_font_conv` emits font .c files wrapped in `#if LVGL_VERSION_MAJOR` guards and
(for v8) a `.cache` field. On LVGL 9 the project wants the plain, unguarded struct
with `.release_glyph` / `.kerning` / `.static_bitmap` present (see the "LVGL 9 font
patching" note in README.md). Without this the font compiles but renders invisible.

Usage:
    python tools/patch_lvgl9_font.py firmware/src/font_foo.c [more.c ...]

Idempotent: running it on an already-patched file is a no-op.
"""
import re
import sys

SUBS = [
    # drop the v8-only glyph cache declaration
    (r'#if LVGL_VERSION_MAJOR == 8\n/\*Store all the custom data of the font\*/\n'
     r'static  lv_font_fmt_txt_glyph_cache_t cache;\n#endif\n\n', ''),
    # collapse the font_dsc storage-class guard
    (r'#if LVGL_VERSION_MAJOR >= 8\nstatic const lv_font_fmt_txt_dsc_t font_dsc = \{\n'
     r'#else\nstatic lv_font_fmt_txt_dsc_t font_dsc = \{\n#endif\n',
     'static const lv_font_fmt_txt_dsc_t font_dsc = {\n'),
    # drop the v8 .cache member
    (r'#if LVGL_VERSION_MAJOR == 8\n    \.cache = &cache\n#endif\n', ''),
    # collapse the public-font const guard
    (r'#if LVGL_VERSION_MAJOR >= 8\n(const lv_font_t \w+ = \{)\n'
     r'#else\nlv_font_t \w+ = \{\n#endif\n', r'\1\n'),
    # keep .subpx and add the three LVGL 9 fields
    (r'#if !\(LVGL_VERSION_MAJOR == 6 && LVGL_VERSION_MINOR == 0\)\n'
     r'    \.subpx = LV_FONT_SUBPX_NONE,\n#endif\n',
     '    .subpx = LV_FONT_SUBPX_NONE,\n    .release_glyph = NULL,\n'
     '    .kerning = 0,\n    .static_bitmap = 0,\n'),
    # unwrap underline fields
    (r'#if LV_VERSION_CHECK\(7, 4, 0\) \|\| LVGL_VERSION_MAJOR >= 8\n'
     r'(    \.underline_position = -1,\n    \.underline_thickness = 2,\n)#endif\n', r'\1'),
    # unwrap .fallback
    (r'#if LV_VERSION_CHECK\(8, 2, 0\) \|\| LVGL_VERSION_MAJOR >= 9\n'
     r'(    \.fallback = NULL,\n)#endif\n', r'\1'),
]


def patch(path: str) -> None:
    s = open(path, encoding="utf-8").read()
    for pat, repl in SUBS:
        s = re.sub(pat, repl, s)
    open(path, "w", encoding="utf-8").write(s)
    leftover = len(re.findall(r'LVGL_VERSION_MAJOR|LV_VERSION_CHECK|\.cache = &cache', s))
    print(f"patched {path}  leftover_guards={leftover}")


if __name__ == "__main__":
    if len(sys.argv) < 2:
        sys.exit(__doc__)
    for p in sys.argv[1:]:
        patch(p)