module.exports = (config) => {

  // add collection for pages
  config.addCollection('pages', (collection) => {
    let sorted = []
    let unsorted = []
    const pages = collection.getFilteredByGlob('**/*.md')

    for (let page of pages) {
      if (page.data.sort) {
        if (sorted[page.data.sort]) {
          sorted.splice(page.data.sort)
        } else {
          sorted[page.data.sort] = page
        }
      } else {
        unsorted.push(page)
      }
    }



    return sorted.concat(unsorted)
  })

// 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
  }
}
}