Initial commit with weather data fetcher and parser

src/main/scala/fetch/FileName.scala

@@ -0,0 +1,40 @@
+package fetch
+
+import java.time.format.DateTimeFormatter
+import java.time.{LocalDateTime, Duration}
+
+object FileName {
+  private val interval = Duration.ofMinutes(30)
+  private val formatter = DateTimeFormatter.ofPattern("yyyyMMdd_HHmm")s
+
+  def generateLastHour(): List[String] = {
+    val now = LocalDateTime.now
+    generate(now.minusHours(1), now)
+  }
+
+  def generateLast5Hours(): List[String] = {
+    val now = roundToInterval(LocalDateTime.now, false)
+    generate(now.minusHours(5), now)
+  }
+
+  private def roundToInterval(time: LocalDateTime, roundUp: Boolean): LocalDateTime = {
+    val minutes = time.getMinute
+    val adjustment = if (roundUp) (interval.toMinutes - minutes % interval.toMinutes) % interval.toMinutes
+    else -minutes % interval.toMinutes
+
+    time.plusMinutes(adjustment)
+  }
+
+  // not sure either data are each 10 minutes or each 30 mins of hour
+  def generate(startTime: LocalDateTime, endTime: LocalDateTime): List[String] = {
+    val roundStartTime = roundToInterval(startTime, true)
+    val roundEndTime = roundToInterval(endTime, false)
+
+    Iterator.iterate(roundStartTime) { time =>
+      time.plus(interval)
+    }.takeWhile(!_.isAfter(roundEndTime))
+      .filter(_.getMinute == 30)
+      .map(time => s"${formatter.format(time)}.csv")
+      .toList
+  }
+}