// Part 2 about Alcohol-Consumption Worldwide

//============================================

object CW6b {

import io.Source

import scala.util._

val url_alcohol =

  "https://raw.githubusercontent.com/fivethirtyeight/data/master/alcohol-consumption/drinks.csv"

val file_population =

  "population.csv"

//(1) Complete the get_csv_page function below. It takes a URL-string

//    as argument and generates a list of strings corresponding to each

//    line in the downloaded csv-list. The URL url_alcohol above is one

//    possible argument.

//def get_csv_page(url: String) : List[String] = ...

def get_csv_page(url: String) : List[String] = {

  val csv = Source.fromURL(url)

  val contents = csv.mkString.split("\n")

  contents.toList

}

//    Complete the get_csv_file function below. It takes a file name

//    as argument and reads the content of the given file. Like above,

//    it should generate a list of strings corresponding to each

//    line in the csv-list. The filename file_population is one possible

//    argument.

//def get_csv_file(file: String) : List[String] = ...

def get_csv_file(file: String) : List[String] = {

  val csv = Source.fromFile(file)

  val contents = csv.mkString.split("\n")

  contents.toList

}

//(2) Complete the functions that process the csv-lists. For

//    process_alcs extract the country name (as String) and the

//    pure alcohol consumption (as Double). For process_pops

//    generate a Map of Strings (country names) to Long numbers

//    (population sizes).

//def process_alcs(lines: List[String]) : List[(String, Double)] = ...

def process_alcs(lines: List[String]) : List[(String, Double)] = {

  val beheaded = lines.drop(1)

  val splitEntries = for (n <- beheaded) yield n.split(",").toList

  for (n <- splitEntries) yield (n.take(1).mkString, n.drop(4).mkString.toDouble)

}

//def process_pops(lines: List[String]) : Map[String, Long] = ...

def process_pops(lines: List[String]) : Map[String, Long] = {

  val beheaded = lines.drop(1);

  def toOnePair(line: String) : (String, Long) = {

    val splitAsList = line.split(",").toList

    (splitAsList.take(1).mkString, splitAsList.drop(1).mkString.toLong)

  }

  val splitEntries = for (n <- beheaded) yield toOnePair(n)

  splitEntries.toMap

}

//(3) Calculate for each country the overall alcohol_consumption using

//    the data from the alcohol list and the population sizes list. You

//    should only include countries on the alcohol list that are also

//    on the population sizes list with the exact same name. Note that

//    the spelling of some names in the alcohol list differs from the

//    population sizes list. You can ignore entries where the names differ.

//    Sort the resulting list according to the country with the highest alcohol

//    consumption to the country with the lowest alcohol consumption.

//def sorted_country_consumption() : List[(String, Long)] = ...

def sorted_country_consumption() : List[(String, Long)] = {

  val countryToPop = process_pops(get_csv_file(file_population))

  val countryAndAlc = process_alcs(get_csv_page(url_alcohol))

  val countryAndConsumption = countryAndAlc.collect {

    case oneCountryAndAlc

    if countryToPop.isDefinedAt(oneCountryAndAlc._1) =>

    (oneCountryAndAlc._1, (oneCountryAndAlc._2*countryToPop.get(oneCountryAndAlc._1).get).toLong)

  }

  countryAndConsumption.sortWith(_._2 > _._2)

}

//   Calculate the world consumption of pure alcohol of all countries, which

//   should be the first element in the tuple below. The second element is

//   the overall consumption of the first n countries in the sorted list

//   from above; and finally the double should be the percentage of the

//   first n countries drinking from the the world consumption of alcohol.

//def percentage(n: Int) : (Long, Long, Double) = ...

def percentage(n: Int) : (Long, Long, Double) = {

  val ctryConsump = sorted_country_consumption()

  val totalAlc = ctryConsump.map(_._2).sum

  val firstNAlc = ctryConsump.take(n).map(_._2).sum

  val pcntage = (firstNAlc*1.0/totalAlc)*100;

  (ctryConsump.map(_._2).sum, ctryConsump.take(n).map(_._2).sum, pcntage)

}

}