import * as fs from 'fs'
import * as ejs from 'ejs'
import * as yaml from 'js-yaml'
import { writeToDisk } from './helpers'
import template from './templates/CliTemplate'
import type { CliSpec } from './types/CliSpec'

export default async function gen(inputFileName: string, outputDir: string) {
  const spec = yaml.load(fs.readFileSync(inputFileName, 'utf8')) as any

  switch (spec.clispec) {
    case '001':
      await gen_v001(spec, outputDir)
      break

    default:
      console.log('Unrecognized specification version:', spec.clispec)
      break
  }
}

/**
 * Versioned Generator
 */
async function gen_v001(spec: CliSpec, dest: string) {
  let commandMap = new Map(spec.commands.map((item) => [item.id, item]))

  const commands = spec.commands.map((x) => {
    const isChild = x.subcommands.length < 1
    const heading = isChild ? `### ${x.summary} [#${x.id}]` : `## ${x.summary} [#${x.id}]`

    return {
      ...x,
      heading,
      subcommandList: x.subcommands.map((c) => commandMap.get(c)),
    }
  })

  const content = ejs.render(template, {
    info: spec.info,
    commands,
  })
  // console.log(content)
  // Write to disk
  await writeToDisk(dest, content)
  console.log('Saved: ', dest)
}