import fs from 'fs'
import { join } from 'path'
import matter from 'gray-matter'

const trainingDir = join(process.cwd(), 'content/training')

export const getTrainingSlugs = () => {
  return fs.readdirSync(trainingDir)
}

export const getTrainingBySlug = (slug: string, fields: string[] = []) => {
  const realSlug = slug.replace(/\.md$/, '')
  const fullPath = join(trainingDir, `${realSlug}.md`)
  const fileContents = fs.readFileSync(fullPath, 'utf8')
  const { data, content } = matter(fileContents)

  type Items = {
    [key: string]: string
  }

  const items: Items = {}

  // Ensure only the minimal needed data is exposed
  fields.forEach((field) => {
    if (field === 'slug') {
      items[field] = realSlug
    }
    if (field === 'content') {
      items[field] = content
    }

    if (typeof data[field] !== 'undefined') {
      items[field] = data[field]
    }
  })

  return items

}

export const getAllTraining = (fields: string[] = []) => {
  const slugs = getTrainingSlugs()
  const trainingList = slugs
    .map((slug) => getTrainingBySlug(slug, fields))
    .sort((tr1, tr2) => {
      const tr1w = parseInt(tr1.weight)
      const tr2w = parseInt(tr2.weight)
      return tr1w > tr2w ? -1 : 1
    })

  return trainingList
}