import sys, os

src = os.path.join(os.path.dirname(__file__), '../../frontend/js/labs/opticsbench.js')

with open(src, 'r', encoding='utf-8') as f:
    content = f.read()

# ─────────────────────────────────────────────────────────────────────────────
# PATCH: In MirrorSim.draw(), after _drawFanRays, add aberration fan for _useR mode
# ─────────────────────────────────────────────────────────────────────────────

OLD = ('    this._drawFanRays(ctx, mx, ay, f, dPrime, hPrime, showRay, showFill);\n'
       '    /* spherical aberration overlay (Agent OB-A3) */\n'
       '    if (this._showSpherical && this.type !== \'flat\' && isFinite(f))\n'
       '      this._drawMirrorSphericalAberration(ctx, mx, ay, f);\n'
       '    this._drawMirror(ctx, mx, ay);')

NEW = ('    this._drawFanRays(ctx, mx, ay, f, dPrime, hPrime, showRay, showFill);\n'
       '    /* spherical aberration overlay (Agent OB-A3) */\n'
       '    if (this._showSpherical && this.type !== \'flat\' && isFinite(f))\n'
       '      this._drawMirrorSphericalAberration(ctx, mx, ay, f);\n'
       '    /* Feature 2: parabolic/spherical aberration fan */\n'
       '    if (this._useR && this.type !== \'flat\' && isFinite(f))\n'
       '      this._drawAberrationFan(ctx, mx, ay, f);\n'
       '    this._drawMirror(ctx, mx, ay);\n'
       '    /* Feature 2: R and f labels on mirror */\n'
       '    if (this._useR && this.type !== \'flat\' && isFinite(f)) {\n'
       '      ctx.save();\n'
       '      ctx.font = \'bold 11px Manrope, system-ui, sans-serif\';\n'
       '      ctx.fillStyle = \'rgba(6,214,224,0.9)\';\n'
       '      ctx.textAlign = \'right\'; ctx.textBaseline = \'bottom\';\n'
       '      ctx.fillText(\'R=\' + this._R.toFixed(0) + \'  f=\' + f.toFixed(0), mx - 4, ay - 6);\n'
       '      ctx.restore();\n'
       '    }')

if OLD not in content:
    print('ERROR: draw fan/mirror block not found'); sys.exit(1)

content = content.replace(OLD, NEW, 1)

with open(src, 'w', encoding='utf-8') as f:
    f.write(content)

print('OK lines:', content.count('\n'))