stacker.news/lib/lnurl.js

54 lines
1.8 KiB
JavaScript

import { createHash } from 'crypto'
import { bech32 } from 'bech32'
import { lnAddrSchema } from './validate'
export function encodeLNUrl (url) {
const words = bech32.toWords(Buffer.from(url.toString(), 'utf8'))
return bech32.encode('lnurl', words, 1023)
}
export function lnurlPayMetadataString (username) {
return JSON.stringify([[
'text/plain',
`Funding @${username} on stacker.news`
], [
'text/identifier',
`${username}@stacker.news`
]])
}
export function lnurlPayDescriptionHashForUser (username) {
return lnurlPayDescriptionHash(lnurlPayMetadataString(username))
}
export function lnurlPayDescriptionHash (data) {
return createHash('sha256').update(data).digest('hex')
}
export async function lnAddrOptions (addr) {
await lnAddrSchema().fields.addr.validate(addr)
const [name, domain] = addr.split('@')
let protocol = 'https'
if (process.env.NODE_ENV === 'development') {
// support HTTP and HTTPS during development
protocol = process.env.NEXT_PUBLIC_URL.split('://')[0]
}
const unexpectedErrorMessage = `An unexpected error occurred fetching the Lightning Address metadata for ${addr}. Check the address and try again.`
let res
try {
const req = await fetch(`${protocol}://${domain}/.well-known/lnurlp/${name}`)
res = await req.json()
} catch (err) {
// If `fetch` fails, or if `req.json` fails, catch it here and surface a reasonable error
console.log('Error fetching lnurlp', err)
throw new Error(unexpectedErrorMessage)
}
if (res.status === 'ERROR') {
// if the response doesn't adhere to spec by providing a `reason` entry, returns a default error message
throw new Error(res.reason ?? unexpectedErrorMessage)
}
const { minSendable, maxSendable, ...leftOver } = res
return { min: minSendable / 1000, max: maxSendable / 1000, ...leftOver }
}