module.exports = (config) => {

  // add collection for pages
  config.addCollection('pages', (collection) => {
    return collection.getFilteredByGlob("**/*.md");
  })

  // custom filters
  config.addFilter("makeLowercase", (value) => {
    if (typeof value === 'string' || value instanceof String) {
      return value.toLowerCase()
    }
  })

  // added passthrough for global assets
  config.addPassthroughCopy("assets")
  // added passthrough for images in their respective folders
  config.addPassthroughCopy("_content/**/images/**")

  // reutrn updated config
  return {
    dir: {
      input: "_content", // content
      includes: "../_includes", // templates
      output: "_site", // rendered site
      data: "../_data" // global data files
    }
  }
}