const R = require("ramda")

const fs = require("fs")

const path = require("path")

const revealOpt = require("../reveal-md.json")

const EOL = require("os").EOL

const SRC_PATH = path.join(__dirname, "../presentation/")

const VERTICAL_SEPARATOR = `${EOL}${revealOpt.verticalSeparator}${EOL}`

const SEPARATOR = `${EOL}${revealOpt.separator}${EOL}`

const SLIDES_PATH = path.join(__dirname, "../slides.md")

const isMdFile = name => name.includes(".md")

const folders = R.pipe(R.unary(fs.readdirSync), R.reject(isMdFile))

const makeVerticalSliders = src => {

const slides = fs.readdirSync(src)

const verticalSliders = slides

.map(R.concat(src + "/"))

.map(R.unary(fs.readFileSync))

return R.intersperse(VERTICAL_SEPARATOR, verticalSliders)

}

const makeSliders = (src, dest) => {

const mainSlider = fs.createWriteStream(dest)

const horizontalSliders = folders(src).map(R.concat(src))

const verticalSliders = R.map(makeVerticalSliders, horizontalSliders)

for (const content of verticalSliders) {

mainSlider.write(content.join(""))

mainSlider.write(SEPARATOR)

}

mainSlider.end()

}

makeSliders(SRC_PATH, SLIDES_PATH)