32.10 Lufthavne

Mix.install([
  {:maplibre, "~> 0.1.9"},
  {:req, "~> 0.5.8"},
  {:kino_maplibre, "~> 0.1.13"},
  {:kino, "~> 0.14.2"}
])

Section

alias MapLibre, as: Ml

# List of countries of various categories
# source: https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Glossary:Country_codes
countries_eu =
  "BE,BG,CZ,DK,DE,EE,IE,EL,ES,FR,GR,HR,IT,CY,LV,LT,LU,HU,MT,NL,AT,PL,PT,RO,DI,DK,FI,SE"
  |> String.split(",")

countries_efta =
  "IS,LI,NO,CH"
  |> String.split(",")

countries_eu_cand =
  "BA,ME,MD,MK,GE,AL,RS,TR,UA"
  |> String.split(",")

countries_enp =
  "AM,BY,AZ,DZ,EG,IL,JO,LB,LY,MA,PS,SY,TN"
  |> String.split(",")

countries_other =
  "AR,AU,BR,CA,CN,CM_X_HK,HK,IN,JP,MX,NG,NZ,RU,SG,ZA,KR,TW,UK,US"
  |> String.split(",")

countries_interest =
  [
    countries_eu,
    countries_efta,
    countries_eu_cand,
    countries_enp,
    countries_other
  ]
  |> List.flatten()

# data source
url = "https://raw.githubusercontent.com/ip2location/ip2location-iata-icao/master/iata-icao.csv"

# fetch data and split it into lines
file =
  url
  |> Req.get!()
  |> Map.get(:body)
  |> String.replace("\",\"", "\"|\"", global: true)
  |> String.replace("\"", "", global: true)
  |> String.split("\r\n")

# split lines into header and data lines
[header_line | contents_lines] = file
# parse the header into a name-to-index map
index =
  header_line
  |> String.split("|")
  |> Enum.with_index()
  |> Map.new()

# parse data lines according to header map to obtain a list of airports
airports =
  contents_lines
  |> Enum.filter(fn line -> line != "" end)
  |> Enum.map(fn line ->
    elements =
      line
      |> String.split("|")

    index
    |> Enum.reduce(
      %{},
      fn {key, i}, acc ->
        Map.put(
          acc,
          key,
          case {key, Enum.at(elements, i)} do
            {"latitude", value} -> Float.parse(value) |> elem(0)
            {"longitude", value} -> Float.parse(value) |> elem(0)
            {_, value} -> value
          end
        )
      end
    )
  end)

# define list of markers to place on map
markers =
  airports
  |> Enum.map(fn %{
                   "latitude" => lat,
                   "longitude" => long,
                   "airport" => _name,
                   "country_code" => country
                 } ->
    [
      {long, lat},
      scale: 0.5,
      color:
        cond do
          Enum.member?(countries_eu, country) -> "blue"
          Enum.member?(countries_efta, country) -> "cyan"
          Enum.member?(countries_eu_cand, country) -> "green"
          Enum.member?(countries_enp, country) -> "orange"
          Enum.member?(countries_other, country) -> "white"
          true -> "black"
        end
    ]
  end)

# produce map
Ml.new()
|> Kino.MapLibre.add_markers(markers)