thi-ng/umbrella

import { encode } from "@thi.ng/blurhash";
import { isNumber, isPlainObject } from "@thi.ng/checks";
import { writeFile, writeJSON } from "@thi.ng/file-io";
import { join, resolve } from "node:path";
import type { Sharp } from "sharp";
import type { ImgProcCtx, OutputSpec, Processor } from "../api.js";
import { formatPath } from "../path.js";
import { illegalArgs } from "@thi.ng/errors";

export const outputProc: Processor = async (spec, input, ctx) => {
    const opts = <OutputSpec>spec;
    const outDir = resolve(ctx.opts.outDir || ".");
    let output = input.clone();
    if (opts.blurhash) {
        await __outputBlurHash(opts, output, ctx);
        return [input, false];
    }
    if (!opts.path) illegalArgs("output path missing");
    if (opts.raw) {
        await __outputRaw(opts, output, ctx, outDir);
        return [input, false];
    }
    if (ctx.meta.exif && ctx.opts.keepEXIF) {
        ctx.logger.warn(
            "TODO injecting & merging EXIF in output still not supported"
        );
    }
    if (Object.keys(ctx.exif).length) {
        ctx.logger.debug("setting custom EXIF", ctx.exif);
        output = output.withExif(ctx.exif);
    }
    if (ctx.iccFile && ctx.opts.keepICC) {
        ctx.logger.debug("using stored ICC profile:", ctx.iccFile);
        output = output.withIccProfile(ctx.iccFile);
    }
    let format = /\.(\w+)$/.exec(opts.path)?.[1];
    switch (format) {
        case "avif":
            if (opts.avif) output = output.avif(opts.avif);
            break;
        case "gif":
            if (opts.gif) output = output.gif(opts.gif);
            break;
        case "jpg":
        case "jpeg":
            if (opts.jpeg) output = output.jpeg(opts.jpeg);
            break;
        case "jp2":
            if (opts.jp2) output = output.jp2(opts.jp2);
            break;
        case "jxl":
            if (opts.jxl) output = output.jxl(opts.jxl);
            break;
        case "png":
            if (opts.png) output = output.png(opts.png);
            break;
        case "tiff":
            if (opts.tiff) output = output.tiff(opts.tiff);
            break;
        case "webp":
            if (opts.webp) output = output.webp(opts.webp);
            break;
    }
    if (opts.tile) output = output.tile(opts.tile);
    if (format) output = output.toFormat(<any>format);
    const result = await output.toBuffer();
    if (opts.path !== undefined) {
        const path = join(
            outDir,
            formatPath(opts.path, ctx, <OutputSpec>spec, result)
        );
        writeFile(path, result, null, ctx.logger);
        ctx.outputs[opts.id] = path;
    } else {
        ctx.outputs[opts.id] = result;
    }
    return [input, false];
};

/** @internal */
const __outputRaw = async (
    opts: OutputSpec,
    output: Sharp,
    ctx: ImgProcCtx,
    outDir: string
) => {
    const { alpha = false, meta = false } = isPlainObject(opts.raw)
        ? opts.raw
        : {};
    if (alpha) output = output.ensureAlpha();
    const { data, info } = await output
        .raw()
        .toBuffer({ resolveWithObject: true });
    if (opts.path !== undefined) {
        const path = join(outDir, formatPath(opts.path!, ctx, opts, data));
        writeFile(path, data, null, ctx.logger);
        ctx.outputs[opts.id] = path;
        if (meta) {
            writeJSON(
                path + ".meta.json",
                { ...info, exif: ctx.exif },
                undefined,
                undefined,
                ctx.logger
            );
        }
    } else {
        ctx.outputs[opts.id] = data;
    }
};

/** @internal */
const __outputBlurHash = async (
    opts: OutputSpec,
    output: Sharp,
    ctx: ImgProcCtx
) => {
    const { data, info } = await output
        .ensureAlpha()
        .raw()
        .toBuffer({ resolveWithObject: true });
    const detail = opts.blurhash === true ? 4 : opts.blurhash!;
    const [dx, dy] = isNumber(detail) ? [detail, detail] : detail;
    const hash = encode(
        new Uint32Array(data.buffer),
        info.width,
        info.height,
        dx,
        dy
    );
    ctx.logger.debug("computed blurhash:", hash);
    ctx.outputs[opts.id] = hash;
};