import React, { useMemo } from 'react';
import { SeasonalOverlayProps } from '../types';
import {
animCloverTumble,
animCloverSway,
animVerdantBreathe,
animRainbowShimmer,
animCoinGlint,
animMoteTwinkle,
} from './StPatricks.css';
// Deterministic pseudo-random so the scene is identical every mount (no React
// state per frame). Large primes keep the distribution well spread.
const rand = (seed: number) => {
const x = Math.sin(seed * 127.1 + 311.7) * 43758.5453;
return x - Math.floor(x);
};
// Shamrock (three-leaf) and lucky four-leaf clover silhouettes as inline SVG
// data-URIs — pure CSS, no external assets, Tauri/CSP-safe. The `fill` color is
// baked per-variant in oklch-adjacent sRGB (data-URIs can't carry oklch), kept
// luminous green so the glyphs read as foliage even at low opacity.
const cloverSvg = (leaves: 3 | 4, fill: string) => {
// Each leaf is a heart-ish lobe; petals arranged radially around the stem.
const heart = 'M0,-2 C5,-12 18,-9 14,2 C12,8 4,9 0,3 C-4,9 -12,8 -14,2 C-18,-9 -5,-12 0,-2 Z';
// Rotations for the lobes; 3-leaf = 120° spread, 4-leaf = 90° spread.
const rots = leaves === 4 ? [0, 90, 180, 270] : [-90, 30, 150];
const lobes = rots
.map((r) => ``)
.join('');
const stem = ``;
const svg =
``;
return `url("data:image/svg+xml,${encodeURIComponent(svg)}")`;
};
// Three foliage greens for parallax depth — far/dim through near/bright. These
// are the sRGB siblings of the brief's oklch emerald / shamrock-green targets.
const CLOVER_FILLS = [
'#1f9e54', // deep shamrock (far)
'#2db866', // emerald (mid)
'#48d97f', // bright clover (near)
];
type Clover = {
left: number;
size: number;
duration: number;
delay: number;
swayDuration: number;
opacity: number;
blur: number;
fill: string;
leaves: 3 | 4;
// Resting position + tilt for the static (reduced) settled scene.
restTop: number;
restRot: number;
};
type Coin = {
left: number;
top: number;
size: number;
duration: number;
delay: number;
};
type Mote = {
left: number;
top: number;
size: number;
duration: number;
delay: number;
};
export function StPatricksOverlay({ reduced }: SeasonalOverlayProps) {
// Three parallax bands of clovers: far (small/slow/dim) -> near (large/fast).
// ~22 clovers total; one lucky four-leaf seeded in for charm.
const clovers = useMemo(() => {
const bands = [
{ count: 8, size: [12, 18], dur: [20, 26], op: [0.22, 0.34], blur: 0.8, fill: 0 },
{ count: 8, size: [18, 26], dur: [15, 20], op: [0.34, 0.5], blur: 0.4, fill: 1 },
{ count: 6, size: [26, 38], dur: [11, 15], op: [0.46, 0.62], blur: 0, fill: 2 },
];
const out: Clover[] = [];
let s = 1;
bands.forEach((b) => {
for (let i = 0; i < b.count; i += 1) {
const r1 = rand(s);
const r2 = rand(s + 0.37);
const r3 = rand(s + 0.71);
const r4 = rand(s + 0.91);
const r5 = rand(s + 1.13);
out.push({
left: r1 * 100,
size: b.size[0] + r2 * (b.size[1] - b.size[0]),
duration: b.dur[0] + r3 * (b.dur[1] - b.dur[0]),
delay: -r4 * (b.dur[1] + 5),
swayDuration: 5 + r2 * 6,
opacity: b.op[0] + r3 * (b.op[1] - b.op[0]),
blur: b.blur,
// The single lucky four-leaf: one mid-band clover.
leaves: s === 10 ? 4 : 3,
fill: CLOVER_FILLS[b.fill],
restTop: 6 + r5 * 88,
restRot: (r4 - 0.5) * 80,
});
s += 1;
}
});
return out;
}, []);
// Gold-coin glints scattered low — a faint pot-of-gold sparkle. ~5 discs.
const coins = useMemo(() => {
const count = 5;
const out: Coin[] = [];
for (let i = 0; i < count; i += 1) {
out.push({
left: 8 + rand(i + 40) * 84,
top: 58 + rand(i + 47) * 36,
size: 8 + rand(i + 51) * 9,
duration: 4 + rand(i + 55) * 3,
delay: -rand(i + 61) * 6,
});
}
return out;
}, []);
// Golden sparkle motes drifting through the scene. ~7 points.
const motes = useMemo(() => {
const count = 7;
const out: Mote[] = [];
for (let i = 0; i < count; i += 1) {
out.push({
left: rand(i + 70) * 100,
top: 8 + rand(i + 77) * 82,
size: 2 + rand(i + 83) * 3,
duration: 3 + rand(i + 89) * 3.5,
delay: -rand(i + 97) * 6,
});
}
return out;
}, []);
return (
<>
{/* Emerald ambient wash — layered radial + linear oklch gradients for
depth. Kept low-opacity so chat text stays legible (WCAG-AA). */}
{/* Verdant vignette frame — green edges, clear center. A single cheap
backdrop-filter adds a faint warm-emerald haze around the rim. */}
{/* Soft rainbow shimmer arc tucked into the top-right corner — a faint
luck-of-the-Irish band. Heavily blurred + screen-blended so it reads
as light, never as a hard stripe over chat. */}
{/* Gold-coin glints — small metallic discs that catch the light. */}
{coins.map((c, i) => (
))}
{/* Golden sparkle motes — tiny four-point glints of luck. */}
{motes.map((m, i) => (
))}
{/* Drifting clovers (motion only) — three parallax bands tumbling down.
Settled static scatter is rendered below for reduced/preview. */}
{!reduced &&
clovers.map((c, i) => (
))}
{/* Static settled clovers for the reduced-motion / preview scene — a
gentle scatter resting at varied tilts so the thumbnail reads as a
lucky, still field of shamrocks. */}
{reduced &&
clovers.map((c, i) => (
))}
>
);
}