thi-ng/umbrella

import { U8 } from "@thi.ng/hex";
import { memoizeO } from "@thi.ng/memoize/memoizeo";
import type { HtmlFormatOpts, StringFormat } from "./api.js";

const F5 = 255 / 31;
const F6 = 255 / 63;

/**
 * Constructs an HTML formatter using given config options and for use w/
 * default format IDs only.
 *
 * @param opts -
 */
export const formatHtml = ({
    colors,
    attrib,
    delim,
    fg,
    bg,
    bold,
    dim,
    underline,
}: HtmlFormatOpts): StringFormat => {
    const start = memoizeO((x: number) => {
        let y = x & 0xf;
        let res = `<span ${attrib}="${fg}${
            colors[(y - 1) | ((x >> 1) & 0x8)]
        }${delim}`;
        y = (x >> 5) & 0x0f;
        y && (res += `${bg}${colors[(y - 1) | ((x >> 6) & 0x8)]}${delim}`);
        x & 0x400 && (res += bold + delim);
        x & 0x800 && (res += dim + delim);
        x & 0x1000 && (res += underline + delim);
        return res + '">';
    });
    const end = "</span>";
    return {
        format: (code, x) => start(code) + x + end,
        start,
        end,
        prefix: "",
        suffix: "<br/>",
    };
};

/**
 * Preset HTML string formatter for use w/ default format IDs, generating
 * `<span>` elements with inline CSS.
 */
export const FMT_HTML_INLINE_CSS = formatHtml({
    colors: [
        "#000",
        "#a00",
        "#0a0",
        "#aa0",
        "#00a",
        "#a0a",
        "#0aa",
        "#aaa",
        "#555",
        "#f55",
        "#5f5",
        "#ff5",
        "#55f",
        "#f5f",
        "#5ff",
        "#fff",
    ],
    attrib: "style",
    delim: ";",
    fg: "color:",
    bg: "background:",
    bold: "font-weight:bold",
    dim: "opacity:0.5",
    underline: "text-decoration:underline",
});

/** @internal */
const TACHYON_COLORS = [
    "black",
    "dark-red",
    "dark-green",
    "gold",
    "dark-blue",
    "dark-pink",
    "light-blue",
    "moon-gray",
    "mid-gray",
    "red",
    "green",
    "yellow",
    "blue",
    "hot-pink",
    "lightest-blue",
    "white",
];

/**
 * Preset HTML formatter for use w/ default format IDs, generating `<span>`
 * elements with Tachyons CSS classes.
 */
export const FMT_HTML_TACHYONS = formatHtml({
    colors: TACHYON_COLORS,
    attrib: "class",
    delim: " ",
    fg: "",
    bg: "bg-",
    bold: "b",
    dim: "o-50",
    underline: "underline",
});

/**
 * Preset HTML formatter for use w/ default text format IDs, generating `<span>`
 * elements with thi.ng/meta-css base framework color classes.
 */
export const FMT_HTML_MCSS = formatHtml({
    colors: TACHYON_COLORS,
    attrib: "class",
    delim: " ",
    fg: "color-",
    bg: "bg-color-",
    bold: "b",
    dim: "o-50",
    underline: "underline",
});

/**
 * Preset HTML formatter for use w/ default text format IDs, generating `<span>`
 * elements with `style` attributes and given CSS variable names for defining
 * colors.
 *
 * @remarks
 * The color variable names must be given in this order:
 *
 * - black
 * - red
 * - green
 * - yellow
 * - blue
 * - magenta
 * - cyan
 * - light gray
 * - gray
 * - light red
 * - light green
 * - light yellow
 * - light blue
 * - light magenta
 * - light cyan
 * - white
 *
 * @param varNames
 */
export const FMT_HTML_CSS_VARS = (varNames: string[]) =>
    formatHtml({
        colors: varNames.map((x) => `var(--${x})`),
        attrib: "style",
        delim: ";",
        fg: "color:",
        bg: "background:",
        bold: "font-weight:bold",
        dim: "opacity:0.5",
        underline: "text-decoration:underline",
    });

/**
 * Higher order custom HTML formatter for 16bit (RGB565) colors (without
 * additional formatting flags). By default assigns text color, but can be
 * assigned to any CSS property via given `prop` argument.
 *
 * @param prop -
 */
export const FMT_HTML565 = (prop = "color"): StringFormat => {
    const start = memoizeO(
        (x: number) =>
            `<span style="${prop}:#${U8((x >> 11) * F5)}${U8(
                ((x >> 5) & 0x3f) * F6
            )}${U8((x & 0x1f) * F5)}">`
    );
    const end = "</span>";
    return {
        format: (code, x) => start(code) + x + end,
        start,
        end,
        prefix: "",
        suffix: "<br/>",
        zero: true,
    };
};