import { ChatBgVariants } from './types';

// Herringbone — a refined, tactile broken-zigzag weave (the classic parquet / tweed
// motif) rather than a flat hairline grid. Each plank is drawn twice in a compact SVG
// data-URI tile: a lit "thread" and a 0.6px-offset shadow companion, so every plank
// reads as a beveled, three-dimensional strand of fabric instead of a line.
//
// SEAMLESS TILING: planks live on a 12px lattice and their orientation follows the true
// herringbone rule orient(cx, cy) = '/'  when (cx - cy) mod 4 in {0, 1}, else '\\'.
// That rule is exactly periodic every 4 cells in BOTH axes, so the 48x48px tile repeats
// with no seam at any scroll offset; segment endpoints all land on lattice corners, so
// the broken V's interlock perfectly across tile edges.
//
// DEPTH: beneath the weave sit two very low-contrast oklch layers — a diagonal two-tone
// wash that gives the fabric a faint lit/shadowed side, plus a soft vignette that lets
// the centre (where text lives) stay calmest. Everything is kept in the "felt, not read"
// opacity band so WCAG-AA body text sits comfortably on top in both themes.

const WEAVE_DARK =
  'data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%2248%22%20height%3D%2248%22%20viewBox%3D%220%200%2048%2048%22%3E%3Cpath%20d%3D%22M-11.4%200.6L0.6%20-11.4M0.6%200.6L12.6%20-11.4M12.6%20-11.4L24.6%200.6M24.6%20-11.4L36.6%200.6M36.6%200.6L48.6%20-11.4M48.6%200.6L60.6%20-11.4M-11.4%200.6L0.6%2012.6M0.6%2012.6L12.6%200.6M12.6%2012.6L24.6%200.6M24.6%200.6L36.6%2012.6M36.6%200.6L48.6%2012.6M48.6%2012.6L60.6%200.6M-11.4%2012.6L0.6%2024.6M0.6%2012.6L12.6%2024.6M12.6%2024.6L24.6%2012.6M24.6%2024.6L36.6%2012.6M36.6%2012.6L48.6%2024.6M48.6%2012.6L60.6%2024.6M-11.4%2036.6L0.6%2024.6M0.6%2024.6L12.6%2036.6M12.6%2024.6L24.6%2036.6M24.6%2036.6L36.6%2024.6M36.6%2036.6L48.6%2024.6M48.6%2024.6L60.6%2036.6M-11.4%2048.6L0.6%2036.6M0.6%2048.6L12.6%2036.6M12.6%2036.6L24.6%2048.6M24.6%2036.6L36.6%2048.6M36.6%2048.6L48.6%2036.6M48.6%2048.6L60.6%2036.6M-11.4%2048.6L0.6%2060.6M0.6%2060.6L12.6%2048.6M12.6%2060.6L24.6%2048.6M24.6%2048.6L36.6%2060.6M36.6%2048.6L48.6%2060.6M48.6%2060.6L60.6%2048.6%22%20fill%3D%22none%22%20stroke%3D%22rgb%2810%2C8%2C6%29%22%20stroke-width%3D%221.1%22%20stroke-opacity%3D%220.085%22%20stroke-linecap%3D%22round%22%2F%3E%3Cpath%20d%3D%22M-12%200L0%20-12M0%200L12%20-12M12%20-12L24%200M24%20-12L36%200M36%200L48%20-12M48%200L60%20-12M-12%200L0%2012M0%2012L12%200M12%2012L24%200M24%200L36%2012M36%200L48%2012M48%2012L60%200M-12%2012L0%2024M0%2012L12%2024M12%2024L24%2012M24%2024L36%2012M36%2012L48%2024M48%2012L60%2024M-12%2036L0%2024M0%2024L12%2036M12%2024L24%2036M24%2036L36%2024M36%2036L48%2024M48%2024L60%2036M-12%2048L0%2036M0%2048L12%2036M12%2036L24%2048M24%2036L36%2048M36%2048L48%2036M48%2048L60%2036M-12%2048L0%2060M0%2060L12%2048M12%2060L24%2048M24%2048L36%2060M36%2048L48%2060M48%2060L60%2048%22%20fill%3D%22none%22%20stroke%3D%22rgb%28210%2C199%2C180%29%22%20stroke-width%3D%221.1%22%20stroke-opacity%3D%220.111%22%20stroke-linecap%3D%22round%22%2F%3E%3C%2Fsvg%3E';
const WEAVE_LIGHT =
  'data:image/svg+xml;charset=utf-8,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20width%3D%2248%22%20height%3D%2248%22%20viewBox%3D%220%200%2048%2048%22%3E%3Cpath%20d%3D%22M-11.4%200.6L0.6%20-11.4M0.6%200.6L12.6%20-11.4M12.6%20-11.4L24.6%200.6M24.6%20-11.4L36.6%200.6M36.6%200.6L48.6%20-11.4M48.6%200.6L60.6%20-11.4M-11.4%200.6L0.6%2012.6M0.6%2012.6L12.6%200.6M12.6%2012.6L24.6%200.6M24.6%200.6L36.6%2012.6M36.6%200.6L48.6%2012.6M48.6%2012.6L60.6%200.6M-11.4%2012.6L0.6%2024.6M0.6%2012.6L12.6%2024.6M12.6%2024.6L24.6%2012.6M24.6%2024.6L36.6%2012.6M36.6%2012.6L48.6%2024.6M48.6%2012.6L60.6%2024.6M-11.4%2036.6L0.6%2024.6M0.6%2024.6L12.6%2036.6M12.6%2024.6L24.6%2036.6M24.6%2036.6L36.6%2024.6M36.6%2036.6L48.6%2024.6M48.6%2024.6L60.6%2036.6M-11.4%2048.6L0.6%2036.6M0.6%2048.6L12.6%2036.6M12.6%2036.6L24.6%2048.6M24.6%2036.6L36.6%2048.6M36.6%2048.6L48.6%2036.6M48.6%2048.6L60.6%2036.6M-11.4%2048.6L0.6%2060.6M0.6%2060.6L12.6%2048.6M12.6%2060.6L24.6%2048.6M24.6%2048.6L36.6%2060.6M36.6%2048.6L48.6%2060.6M48.6%2060.6L60.6%2048.6%22%20fill%3D%22none%22%20stroke%3D%22rgb%28126%2C116%2C98%29%22%20stroke-width%3D%221.1%22%20stroke-opacity%3D%220.075%22%20stroke-linecap%3D%22round%22%2F%3E%3Cpath%20d%3D%22M-12%200L0%20-12M0%200L12%20-12M12%20-12L24%200M24%20-12L36%200M36%200L48%20-12M48%200L60%20-12M-12%200L0%2012M0%2012L12%200M12%2012L24%200M24%200L36%2012M36%200L48%2012M48%2012L60%200M-12%2012L0%2024M0%2012L12%2024M12%2024L24%2012M24%2024L36%2012M36%2012L48%2024M48%2012L60%2024M-12%2036L0%2024M0%2024L12%2036M12%2024L24%2036M24%2036L36%2024M36%2036L48%2024M48%2024L60%2036M-12%2048L0%2036M0%2048L12%2036M12%2036L24%2048M24%2036L36%2048M36%2048L48%2036M48%2048L60%2036M-12%2048L0%2060M0%2060L12%2048M12%2060L24%2048M24%2048L36%2060M36%2048L48%2060M48%2060L60%2048%22%20fill%3D%22none%22%20stroke%3D%22rgb%28255%2C253%2C247%29%22%20stroke-width%3D%221.1%22%20stroke-opacity%3D%220.098%22%20stroke-linecap%3D%22round%22%2F%3E%3C%2Fsvg%3E';

export const herringbone: ChatBgVariants = {
  // Warm taupe threads (~oklch(0.79 0.02 75)) over a charcoal base. The two-tone wash
  // runs cool-charcoal -> slightly warmer charcoal across the diagonal so the weave has
  // a gentle light side; the vignette darkens the far corners a touch for depth.
  dark: {
    backgroundColor: '#14120f',
    backgroundImage: [
      `url("${WEAVE_DARK}")`,
      'linear-gradient(135deg, oklch(0.26 0.012 70 / 0.5) 0%, oklch(0.2 0.008 60 / 0.5) 100%)',
      'radial-gradient(120% 120% at 50% 40%, oklch(0.24 0.01 65 / 0) 55%, oklch(0.12 0.006 55 / 0.45) 100%)',
    ].join(','),
    backgroundSize: '48px 48px, 100% 100%, 100% 100%',
    backgroundRepeat: 'repeat, no-repeat, no-repeat',
  },

  // Greige threads (shadow ~oklch(0.6 0.015 75)) with a warm-white highlight over a warm
  // off-white base. The wash tilts warm-white -> faint greige across the diagonal for the
  // lit/shadow side; a whisper-soft vignette keeps corners from going flat.
  light: {
    backgroundColor: '#f6f3ec',
    backgroundImage: [
      `url("${WEAVE_LIGHT}")`,
      'linear-gradient(135deg, oklch(0.99 0.006 85 / 0.6) 0%, oklch(0.93 0.01 80 / 0.6) 100%)',
      'radial-gradient(120% 120% at 50% 40%, oklch(0.98 0.006 85 / 0) 58%, oklch(0.87 0.012 78 / 0.4) 100%)',
    ].join(','),
    backgroundSize: '48px 48px, 100% 100%, 100% 100%',
    backgroundRepeat: 'repeat, no-repeat, no-repeat',
  },
};