openweatherquery.nim

const
  ForecastUrlFormat = "http://api.openweathermap.org/data/2.5/forecast/daily?APPID=$1&lang=en&q=$2&cnt=$3"

  ResultFormat = """$1:
    $2
    Temperature: $3 °C
    Humidity: $4%
    Clouds: $5%
    Wind speed: $6 m/s""".unindent

  Key = "78b50ffaf45be011ccc5fccca4d836d8"

proc getData() {.async.} =
  let client = newAsyncHttpClient()
  let city = "Moscow"
  let resp = await client.get(ForecastUrlFormat % [Key, city, $(1)])
  # First "await" of resp.body.
  # If you comment this - gc.nim disappears from stacktrace
  echo await resp.body
  let
    # Second "await" of resp.body
    bd = await resp.body
    day = parseJson(bd)["list"].getElems()[^1]
    temp = int round day["temp"]["day"].getFNum() - 273
    humidity = int round day["humidity"].getFNum()
    desc = unicode.capitalize day["weather"].getElems()[0]["description"].getStr()
    wind = int round day["speed"].getFNum()
    cloud = int(round(day["clouds"].getFNum()))
    date = int64 day["dt"].getNum()
    time = fromSeconds(date).getLocalTime().format("d'.'MM'.'yyyy")
  echo ResultFormat % [time, desc, $temp, $humidity, $cloud, $wind]

waitFor getData()