bot-hub/server/og/ogAssets.ts

import { readFile } from 'node:fs/promises'
import { pathToFileURL } from 'node:url'

export const FONT_SANS = 'Bricolage Grotesque'
export const FONT_MONO = 'IBM Plex Mono'

type GlobalNitroMain = {
  __nitro_main__?: unknown
}

let markDataUrlPromise: Promise<string> | null = null
let resvgWasmPromise: Promise<Uint8Array> | null = null
let fontBuffersPromise: Promise<Uint8Array[]> | null = null

function getServerRootUrl() {
  const nitroMain = (globalThis as unknown as GlobalNitroMain).__nitro_main__
  if (typeof nitroMain === 'string') {
    try {
      return new URL('./', nitroMain)
    } catch {
      // fall through
    }
  }
  return pathToFileURL(`${process.cwd()}/`)
}

function getServerUrl(pathname: string) {
  return new URL(pathname.replace(/^\//, ''), getServerRootUrl())
}

export async function getMarkDataUrl() {
  if (!markDataUrlPromise) {
    markDataUrlPromise = (async () => {
      const candidates = [getServerUrl('clawd-mark.png'), getServerUrl('public/clawd-mark.png')]
      let lastError: unknown = null
      for (const url of candidates) {
        try {
          const buffer = await readFile(url)
          return `data:image/png;base64,${buffer.toString('base64')}`
        } catch (error) {
          lastError = error
        }
      }
      throw lastError
    })()
  }
  return markDataUrlPromise
}

export async function getResvgWasm() {
  if (!resvgWasmPromise) {
    resvgWasmPromise = readFile(getServerUrl('node_modules/@resvg/resvg-wasm/index_bg.wasm')).then(
      (buffer) => new Uint8Array(buffer),
    )
  }
  return resvgWasmPromise
}

export async function getFontBuffers() {
  if (!fontBuffersPromise) {
    fontBuffersPromise = Promise.all([
      readFile(
        getServerUrl(
          'node_modules/@fontsource/bricolage-grotesque/files/bricolage-grotesque-latin-800-normal.woff2',
        ),
      ),
      readFile(
        getServerUrl(
          'node_modules/@fontsource/bricolage-grotesque/files/bricolage-grotesque-latin-500-normal.woff2',
        ),
      ),
      readFile(
        getServerUrl(
          'node_modules/@fontsource/ibm-plex-mono/files/ibm-plex-mono-latin-500-normal.woff2',
        ),
      ),
    ]).then((buffers) => buffers.map((buffer) => new Uint8Array(buffer)))
  }
  return fontBuffersPromise
}