// Stable per-session accent colour, used to map a sidebar row to the pane
// showing that session (issue #33). Hash the session id into a fixed OKLCH
// palette tuned to the maestro tokens; collisions are tolerated when there are
// more open sessions than hues — the colour is a hint, not an identity.

import type { Uuid } from "./types.js";

const PALETTE = [
  "oklch(0.80 0.13 152)", // green (the house accent)
  "oklch(0.80 0.12 90)", // amber
  "oklch(0.76 0.13 30)", // coral
  "oklch(0.78 0.11 210)", // teal
  "oklch(0.74 0.13 265)", // blue
  "oklch(0.76 0.14 320)", // magenta
  "oklch(0.80 0.11 60)", // gold
  "oklch(0.78 0.12 185)", // cyan
];

export function sessionColor(id: Uuid): string {
  let h = 0;
  for (let i = 0; i < id.length; i++) h = (h * 31 + id.charCodeAt(i)) >>> 0;
  return PALETTE[h % PALETTE.length];
}