import { rnxExit } from '../run-rnx'
import { runScreenshotMode } from './screenshot-mode'
import { runThreeMode } from './three-mode'

interface ModeOptions {
  port?: number
  verbose?: boolean
}

const VALUE_FLAGS = new Set(['--sim', '--port', '-p'])
const SUBCOMMANDS = new Set(['screenshot', 'three'])

function findSubcommand(args: string[]): { name: string; index: number } | null {
  for (let i = 0; i < args.length; i++) {
    const arg = args[i]
    if (arg.startsWith('-')) {
      if (VALUE_FLAGS.has(arg)) i++
      continue
    }
    return SUBCOMMANDS.has(arg) ? { name: arg, index: i } : null
  }
  return null
}

function withoutSubcommand(args: string[], index: number): string[] {
  return [...args.slice(0, index), ...args.slice(index + 1)]
}

function printHelp(): void {
  console.log(`
rnx mode — toggle live display modes

usage:
  rnx mode screenshot [on|off|toggle]
  rnx mode three [on|off|toggle]
  rnx mode three configure [options]
`)
}

export async function runMode(args: string[], opts: ModeOptions): Promise<void> {
  if (args.includes('--help') || args.includes('-h')) {
    printHelp()
    return
  }

  const sub = findSubcommand(args)
  if (!sub) {
    printHelp()
    rnxExit(1)
  }

  const rest = withoutSubcommand(args, sub.index)
  if (sub.name === 'screenshot') {
    await runScreenshotMode(rest, opts)
    return
  }
  await runThreeMode(rest, opts)
}