DateTime: Difference between Hour and Integer - scala

Question

I have some mistakes, in my code in the 2 lines where a comment above them:
import java.time.temporal.ChronoUnit
import java.time.LocalTime
import scala.concurrent.duration._
val t = LocalTime.now()
def toStart(t: LocalTime) = {
val start = LocalTime.of(9, 0)
val midEnd = LocalTime.of(13, 0)
val midStart = LocalTime.of(14, 0)
val end = LocalTime.of(18, 0)
if (t.isBefore(start)) 0.hours
// if (9 > myHour < 13 ==> myHour + 9 Hours, I wrote: - 9.hours instead of + 4.hours
else if (t.isBefore(midEnd)) t.until(midEnd, ChronoUnit.MILLIS).millis - 9.hours
else if (t.isBefore(midStart)) 4.hours
// if (14 > myHour < 18 Then (myhour - 14) + 4
else if (t.isBefore(end)) t.until(end, ChronoUnit.MILLIS).millis
else 8.hours
}
implicit class formatter(d: FiniteDuration) {
def withMinutes = {
val l = d.toMinutes
s"${l / 60}:${l % 60}"
}
def withSeconds = s"${d.toHours}:${d.toMinutes % 60}:${d.toSeconds % 60}"
}
The test of the function ToStart, is false in these tow cases:
scala> toStart(LocalTime.of(9, 30, 24)).withSeconds
res89: String = -5:-30:-24
scala> toStart(LocalTime.of(12, 30, 32)).withSeconds
res90: String = -8:-30:-32
scala> toStart(LocalTime.of(14, 30, 45)).withSeconds
res92: String = 3:29:15
scala> toStart(LocalTime.of(16, 22, 44)).withSeconds
res93: String = 1:37:16
How can I change my code to find the best result ?

Answer 1

Code should be similar to my answer to you here, but you need to understand what I did. You definitely need to check api calls I used, but I added some additional comments:
import java.time.temporal.ChronoUnit
import java.time.LocalTime
import scala.concurrent.duration._
val t = LocalTime.now()
// start of the day
val start = LocalTime.of(9, 0)
// end of first half
val midEnd = LocalTime.of(13, 0)
// start of second half
val midStart = LocalTime.of(14, 0)
// end of the day
val end = LocalTime.of(18, 0)
// here we define duration of first half a day: diff between start of a day and midEnd (end of first half)
val firstHalf = start.until(midEnd, ChronoUnit.MILLIS).millis
// here we define duration of second half a day: diff between start of second half a day and end of a day
val secondHalf = midStart.until(end, ChronoUnit.MILLIS).millis
def toStart(t: LocalTime) = {
// when checked time is before start of a day
if (t.isBefore(start)) 0.hours
// otherwise when checked time is before end of first half (will be diff between start time and checked time)
else if (t.isBefore(midEnd)) start.until(t, ChronoUnit.MILLIS).millis
// otherwise when checked time is before start of second half (will be duration of first half)
else if (t.isBefore(midStart)) firstHalf
// otherwise when checked time is before end of a day (will be duration of first half + duration of diff between checked time and start of second half)
else if (t.isBefore(end)) firstHalf + midStart.until(t, ChronoUnit.MILLIS).millis
// otherwise sum of durations
else firstHalf + secondHalf
}
// here you can add any specific format for evaluated duration
implicit class formatter(d: FiniteDuration) {
def withMinutes = {
// convert to minutes
val l = d.toMinutes
// format
s"${l / 60}:${l % 60}"
}
}
toStart(t).withMinutes
toStart(LocalTime.of(9, 30)).withMinutes
toStart(LocalTime.of(12, 30)).withMinutes
toStart(LocalTime.of(13, 30)).withMinutes
toStart(LocalTime.of(14, 30)).withMinutes
Spend some time and check java.time api (specifically LocalTime.until). Check FiniteDuration api to understand .millis suffix I used