thebespokepixel/truwrap

/* ───────────────────────╮
 │ truwrap images handler │
 ╰────────────────────────┴───────────────────────────────────────────────────── */

import {Buffer} from 'node:buffer'
import {fileURLToPath} from 'node:url'
import {readFileSync, statSync} from 'node:fs'
import {dirname, basename, extname, join} from 'node:path'

const prefix = '\u001B]1337;File=inline=1;'
const suffix = '\u0007'
const broken = join(dirname(fileURLToPath(import.meta.url)), '/media/broken.png')

/**
 * Provides an image formatted for inclusion in the TTY
 * @private
 */
class Image {
    /**
     * Create a new image reference
     * @param  {string} $0.file   - The filename of the image.
     * @param  {string} $0.name   - The name of the image
     *                              [will be taken from image if missing]
     * @param  {string} $0.width  - Can be X(chars), Xpx(pixels),
     *                              X%(% width of window) or 'auto'
     * @param  {string} $0.height - Can be Y(chars), Ypx(pixels),
     *                              Y%(% width of window) or 'auto'
     */
    constructor({
        file,
        name,
        width = 'auto',
        height = 'auto',
    }) {
        const extName = extname(file)
        const fileName = name || basename(file, extName)

        const lineNameBase64 = Buffer.from(fileName).toString('base64')

        this.config = `width=${width};height=${height};name=${lineNameBase64}`

        this.filePath = (function () {
            try {
                if (statSync(file).isFile()) {
                    return file
                }
            } catch (error) {
                switch (error.code) {
                    case 'ENOENT':
                        console.error('Warning:', `${file} not found.`)
                        break
                    default:
                        console.error(error)
                }

                return broken
            }
        })()
    }

    /**
     * Load and render the image into the CLI
     * @param  {Object} options    - The options to set
     * @property {number} align    - The line count needed to realign the cursor.
     * @property {boolean} stretch - Do we stretch the image to match the width
     *                               and height.
     * @property {boolean} nobreak - Do we clear the image with a newline?
     * @return {string} The string to insert into the output buffer, with base64
     *                  encoded image.
     */
    render(options) {
        const {align, stretch = false, nobreak, spacing = ''} = options

        const content = Buffer.from(readFileSync(this.filePath))

        const aspect = stretch ? 'preserveAspectRatio=0;' : ''
        const linebreak = nobreak ? '' : '\n'
        const newline = align > 1 ? `\u001BH\u001B[${align}A` : linebreak

        return `${prefix}${aspect}size=${content.length}${this.config}:${
            content.toString('base64')
        }${suffix}${newline}${spacing}`
    }
}

/**
 * Creates an image.
 * @private
 * @param      {string}  source  The source
 * @return     {Image}   A configured (but not yet loaded) image.
 */
export default function createImage(source) {
    return new Image(source)
}