indented-data-reference.ts

import assert from 'assert'

import { type TagToken, type Liquid } from 'liquidjs'
import { THROW_ON_EMPTY, IndentedDataReferenceError } from './error-handling'
import { getDataByLanguage } from '@/data-directory/lib/get-data'
import { createLogger } from '@/observability/logger'

const logger = createLogger(import.meta.url)

interface LiquidScope {
  environments: {
    currentLanguage: string
    [key: string]: unknown
  }
}

// This class supports a tag that expects two parameters, a data reference and `spaces=NUMBER`:
//
// {% indented_data_reference foo.bar spaces=NUMBER %}
// Example: {% indented_data_reference reusables.pages.wildcard-dns-warning spaces=3 %}
//
// This tag renders the given data reference with the specified number of spaces
// prepended to each line. This results in correct formatting when the data
// reference is used inside a block element (like a list or nested list) without
// affecting the formatting when the reference is used elsewhere via {{ site.data.foo.bar }}.

const IndentedDataReference = {
  markup: '',
  liquid: null as Liquid | null,

  parse(tagToken: TagToken): void {
    this.markup = tagToken.args.trim()
  },

  async render(scope: LiquidScope): Promise<string | undefined> {
    // obfuscate first legit space, remove all other spaces, then restore legit space
    // this way we can support spaces=NUMBER as well as spaces = NUMBER
    const input = this.markup
      .replace(/\s/, 'REALSPACE')
      .replace(/\s/g, '')
      .replace('REALSPACE', ' ')

    const [dataReference, spaces] = input.split(' ')

    // if no spaces are specified, default to 2
    const numSpaces: string = spaces ? spaces.replace(/spaces=/, '') : '2'

    assert(parseInt(numSpaces) || numSpaces === '0', '"spaces=NUMBER" must include a number')

    // Get the referenced value from the context
    const text: string | undefined = getDataByLanguage(
      dataReference,
      scope.environments.currentLanguage,
    )
    if (text === undefined) {
      if (scope.environments.currentLanguage === 'en') {
        const message = `Can't find the key 'indented_data_reference ${dataReference}' in the scope.`
        if (THROW_ON_EMPTY) {
          throw new IndentedDataReferenceError(message)
        }
        logger.warn(message)
      }
      return
    }

    // add spaces to each line
    const renderedReferenceWithIndent: string = text.replace(/^/gm, ' '.repeat(parseInt(numSpaces)))

    return this.liquid.parseAndRender(renderedReferenceWithIndent, scope.environments)
  },
}

export default IndentedDataReference