#!/usr/bin/env node

const commandLineArgs = require ("command-line-args")
const temml = require ("temml")
const fs = require ("node:fs")
const path = require ("node:path")
const { DecoderStream, EncoderStream } = require ("cbor-x")
const { Transform } = require('node:stream')

const cli_spec =
      [ { name: "preamble" }
      ]

function load_preambles (preamble) {
    const data = fs.readFileSync (preamble, "utf8") .toString ()
    return temml.definePreamble (data)
}

let macros = {}

function is_render_command (cmd) {
    return cmd instanceof Array
	       && cmd.length === 1
	       && typeof cmd[0] === "string"
}

function do_command (cmd) {
    try {
	if (typeof cmd === "string") {
	    return temml.renderToString (cmd, {macros})
	} else if (is_render_command (cmd)) {
	    return temml.renderToString (cmd[0], {displayMode: true,macros})
	} else {
	    return null
	}
    } catch (e) {
	console.error (e)
	return {type: "error", error: e}
    }
}

function main () {
    const options = commandLineArgs (cli_spec)
    macros = load_preambles (options.preamble)
    const decoder = new DecoderStream ()
    const encoder = new EncoderStream ()
    process.stdin.pipe (decoder)
    const command_responses = decoder.map (do_command)
    decoder
	.map (do_command)
	.pipe (encoder)
	.pipe (process.stdout)
}

main ()