"""Source-color analysis only; no application rendering or screenshot modification.
Run: python .local/palette-contrast-20260912.py
WCAG sRGB definition: https://www.w3.org/WAI/WCAG22/Understanding/contrast-minimum.html
Float source constants are retained. Hex labels are rounded display conveniences.
"""
import json

def rgb(h):
    return tuple(int(h[i:i+2], 16)/255 for i in (0, 2, 4))

def linear(c):
    return c/12.92 if c <= .04045 else ((c+.055)/1.055)**2.4

def encoded(c):
    return 12.92*c if c <= .0031308 else 1.055*c**(1/2.4)-.055

def lum(c):
    return sum(w*linear(v) for w, v in zip((.2126, .7152, .0722), c))

def contrast(a, b):
    x, y = sorted((lum(a), lum(b)))
    return (y+.05)/(x+.05)

def hexcode(c):
    return '#' + ''.join(f'{round(v*255):02X}' for v in c)

C = dict(white=(1,1,1), BG=(.945,.956,.969), INK=(.13,.18,.25),
         MUTED=(.43,.48,.55), TEAL=(0,.48,.43), LINE=(.86,.89,.91),
         amber=(.72,.47,.10), entity=(.16,.4,.71), actor=(.58,.35,.7),
         scenario=(.65,.33,.4), state=(.38,.39,.68), other=(.25,.48,.56))
for name, h in dict(canvas='F6F8FB', activation='F3F8F8', region='F7FAFD',
                    machine='EAF1F8', navfill='DAEEEB', navborder='97CBC3',
                    rowfill='E0F7F2', edge='909EAD', trace='866BA8',
                    keyword='763EA0', identifier='145D8B', string='18714F',
                    number='A34E1E', comment='6F7984', error='BA263E',
                    punctuation='5B6575', diagnostic_error='AE2E40',
                    diagnostic_warning='915D17').items():
    C[name] = rgb(h)
# iced_core 0.14 palette::Primary::generate and mix use linear-light blending.
C['editor_selection'] = tuple(encoded(.6*linear(a)+.4*linear(b))
                              for a,b in zip(C['TEAL'], C['BG']))
pairs = [('INK','white'), ('MUTED','white'), ('MUTED','BG'),
         ('MUTED','machine'), ('TEAL','white'), ('TEAL','rowfill'),
         ('LINE','white'), ('LINE','activation'), ('edge','canvas'),
         ('navfill','white'), ('navborder','navfill'), ('navborder','white'),
         ('activation','white'), ('region','machine')]
for name in ('entity','actor','TEAL','amber','scenario','state','other'):
    C[name+'_tint'] = tuple(.94+.06*v for v in C[name])
    pairs.append((name,name+'_tint'))
for name in ('keyword','identifier','string','number','comment','error','punctuation'):
    pairs += [(name,'BG'), (name,'editor_selection')]
for name in ('diagnostic_error','diagnostic_warning'):
    pairs.append((name,'BG'))
# Candidate A retains category accents. Candidate B uses neutral content and blue selection.
for name,h in dict(A_ink='202C3A', A_secondary='4B5968', A_boundary='667586',
                   A_accent='00665C', A_selection='D9EEE8', A_amber='865B00',
                   A_actor='754499', A_other='326B80',
                   B_ink='202020', B_secondary='494949', B_boundary='595959',
                   B_accent='124E96', B_selection='E2ECFA').items(): C[name]=rgb(h)
for prefix in ('A','B'):
    pairs += [(prefix+'_ink','white'), (prefix+'_secondary','BG'),
              (prefix+'_boundary','white'), (prefix+'_boundary','machine'),
              (prefix+'_accent','white'), (prefix+'_accent',prefix+'_selection'),
              (prefix+'_ink',prefix+'_selection')]
pairs += [('A_amber','white'), ('A_amber','BG')]
for name in ('A_actor','A_other','A_amber'):
    C[name+'_tint']=tuple(.94+.06*v for v in C[name])
    pairs.append((name,name+'_tint'))
for name in ('keyword','identifier','string','number','A_secondary','error','punctuation'):
    pairs.append((name,'A_selection'))
result=[]
for a,b in pairs:
    ratio=contrast(C[a],C[b])
    result.append(dict(foreground=a, background=b, fg_hex=hexcode(C[a]),
                       bg_hex=hexcode(C[b]), ratio=round(ratio,6),
                       normal_text_4_5=ratio>=4.5, meaningful_graphic_3=ratio>=3))
print(json.dumps(result,indent=2))