Ink bleed

// Ink Bleed presets + Remix. Each preset is a tinted ink on a suited paper, with its own
// bleed amount / distortion / grain. Remix keeps the stamp-and-bleed mechanic but rolls a
// fresh ink colour on a matching paper and varies the amount + wetness.

import { INK_DEFAULTS, type InkParams } from "./engine";

export type InkPreset = { id: string; name: string; params: Partial<InkParams> };

export const INK_PRESETS: InkPreset[] = [
  {
    id: "black",
    name: "Black",
    // classic black ink on warm off-white paper (the default)
    params: { ink: [0.08, 0.07, 0.07], paper: [0.95, 0.93, 0.87], amount: 0.55, distort: 0.5, grain: 0.18 },
  },
  {
    id: "oxblood",
    name: "Oxblood",
    // deep red ink on cream
    params: { ink: [0.42, 0.08, 0.09], paper: [0.96, 0.93, 0.85], amount: 0.62, distort: 0.55, grain: 0.2 },
  },
  {
    id: "indigo",
    name: "Indigo",
    // dark blue ink on cool paper
    params: { ink: [0.1, 0.12, 0.38], paper: [0.92, 0.94, 0.96], amount: 0.5, distort: 0.45, grain: 0.16 },
  },
  {
    id: "sepia",
    name: "Sepia",
    // warm brown ink on aged paper
    params: { ink: [0.32, 0.2, 0.09], paper: [0.94, 0.89, 0.78], amount: 0.58, distort: 0.5, grain: 0.22 },
  },
  {
    id: "forest",
    name: "Forest",
    // deep green ink on pale paper
    params: { ink: [0.09, 0.28, 0.16], paper: [0.93, 0.95, 0.89], amount: 0.6, distort: 0.6, grain: 0.18 },
  },
  {
    id: "whiteout",
    name: "White",
    // white ink on near-black paper (the "white ink" side of the set)
    params: { ink: [0.94, 0.93, 0.9], paper: [0.09, 0.09, 0.1], amount: 0.55, distort: 0.5, grain: 0.16 },
  },
];

export function defaultInkParams(): InkParams {
  return { ...INK_DEFAULTS, ...INK_PRESETS[0].params };
}

// rgb 0..1 <-> #hex for the ColorControl (which speaks hex)
export const toHex = (c: [number, number, number]) =>
  "#" + c.map((v) => Math.round(Math.min(1, Math.max(0, v)) * 255).toString(16).padStart(2, "0")).join("");
export const fromHex = (h: string): [number, number, number] => {
  const n = h.replace("#", "");
  return [0, 2, 4].map((i) => parseInt(n.slice(i, i + 2) || "0", 16) / 255) as [number, number, number];
};

// a saturated-but-dark ink hue (reads as real ink, never a pastel)
function inkHue(hue: number): [number, number, number] {
  const c = 1;
  const x = c * (1 - Math.abs(((hue / 60) % 2) - 1));
  const seg = [
    [c, x, 0], [x, c, 0], [0, c, x], [0, x, c], [x, 0, c], [c, 0, x],
  ][Math.floor(hue / 60) % 6];
  // darken toward ink: scale down + a little floor so it isn't pure black
  return [seg[0] * 0.42 + 0.05, seg[1] * 0.42 + 0.05, seg[2] * 0.42 + 0.05];
}

// Remix: a fresh ink colour + a paper tinted the OPPOSITE way (warm ink -> cool paper),
// with varied bleed amount / wetness / grain.
export function remixInkParams(): Partial<InkParams> {
  const h = Math.random() * 360;
  const ink = inkHue(h);
  // a light paper faintly tinted toward the complementary hue so ink + sheet feel paired
  const pc = inkHue((h + 180) % 360);
  const pm = Math.max(pc[0], pc[1], pc[2], 0.001);
  const paper: [number, number, number] = [
    0.9 + (pc[0] / pm) * 0.06,
    0.9 + (pc[1] / pm) * 0.06,
    0.9 + (pc[2] / pm) * 0.06,
  ];
  return {
    ink,
    paper,
    amount: 0.4 + Math.random() * 0.4,   // 0.4 - 0.8
    distort: 0.35 + Math.random() * 0.4, // 0.35 - 0.75
    grain: 0.12 + Math.random() * 0.14,  // 0.12 - 0.26
  };
}