#!/usr/bin/env python3
# Regenerate the [icon] block of theme.toml against a newer Yazi preset.
#   git clone --depth 1 https://github.com/sxyazi/yazi
#   awk "/^\[icon\]/{f=1} f" yazi/yazi-config/preset/theme-dark.toml > icons-src.toml
#   ./regen-icons.py icons-src.toml   # writes icon-gruvbox.toml, paste over the [icon] block
import re, sys, math

SRC = sys.argv[1] if len(sys.argv) > 1 else "theme-dark.toml"

# Gruvbox dark palette, split so chromatic sources never collapse into grey
# and desaturated sources never turn into a vivid accent.
CHROMATIC = {
    "#fb4934": "red",
    "#b8bb26": "green",    "#98971a": "green dim",
    "#fabd2f": "yellow",   "#d79921": "yellow dim",
    "#83a598": "blue",     "#458588": "blue dim",
    "#d3869b": "purple",   "#b16286": "purple dim",
    "#8ec07c": "aqua",     "#689d6a": "aqua dim",
    "#fe8019": "orange",   "#d65d0e": "orange dim",
}
NEUTRAL = {
    "#fbf1c7": "fg0", "#ebdbb2": "fg1", "#d5c4a1": "fg2",
    "#bdae93": "fg3", "#a89984": "fg4", "#928374": "gray",
}

def hex2rgb(h):
    h = h.lstrip("#")
    return tuple(int(h[i:i+2], 16) / 255 for i in (0, 2, 4))

def srgb_to_linear(c):
    return c / 12.92 if c <= 0.04045 else ((c + 0.055) / 1.055) ** 2.4

def oklab(h):
    r, g, b = (srgb_to_linear(c) for c in hex2rgb(h))
    l = 0.4122214708*r + 0.5363325363*g + 0.0514459929*b
    m = 0.2119034982*r + 0.6806995451*g + 0.1073969566*b
    s = 0.0883024619*r + 0.2817188376*g + 0.6299787005*b
    l, m, s = (math.copysign(abs(v) ** (1/3), v) for v in (l, m, s))
    return (
        0.2104542553*l + 0.7936177850*m - 0.0040720468*s,
        1.9779984951*l - 2.4285922050*m + 0.4505937099*s,
        0.0259040371*l + 0.7827717662*m - 0.8086757660*s,
    )

def chroma(h):
    _, a, b = oklab(h)
    return math.hypot(a, b)

CHROMA_FLOOR = 0.04  # below this a source colour reads as grey/white/black

def nearest(src):
    pool = NEUTRAL if chroma(src) < CHROMA_FLOOR else CHROMATIC
    sl, sa, sb = oklab(src)
    best, bestd = None, None
    for cand in pool:
        cl, ca, cb = oklab(cand)
        # lightness weighted down so hue drives the match
        d = (0.7*(sl-cl))**2 + (sa-ca)**2 + (sb-cb)**2
        if bestd is None or d < bestd:
            best, bestd = cand, d
    return best

text = open(SRC).read()
seen = {}

def sub(m):
    src = m.group(1).lower()
    dst = seen.setdefault(src, nearest(src))
    return 'fg = "%s"' % dst

out = re.sub(r'fg = "(#[0-9a-fA-F]{6})"', sub, text)
open("icon-gruvbox.toml", "w").write(out)

# report
from collections import Counter
c = Counter(seen.values())
names = {**CHROMATIC, **NEUTRAL}
print("distinct source colours:", len(seen))
print("mapped onto %d gruvbox tones:" % len(c))
for col, n in c.most_common():
    print("  %-9s %-11s %3d sources" % (col, names[col], n))