package de.szimnau;

import de.szimnau.tools.FormatTools;
import java.math.BigDecimal;
import java.time.LocalTime;
import java.time.temporal.ChronoUnit;
import java.util.concurrent.TimeUnit;

import static de.szimnau.tools.CommonTools.print;
import static de.szimnau.tools.CommonTools.println;


public abstract class AbstractLoadingBar {

   private final LocalTime startTime;
   private LocalTime endTime;
   private long totalMinutes;
   private BigDecimal totalMinutesBD;


   protected AbstractLoadingBar(LocalTime startTime) {
      this.startTime = startTime;
   }


   protected AbstractLoadingBar(LocalTime startTime, LocalTime endTime) {
      this.startTime = startTime;
      setEndTime(endTime);
   }


   protected AbstractLoadingBar(LocalTime startTime, long totalMinutes) {
      this.startTime = startTime;
      setTotalMinutes(totalMinutes);
   }


   public LocalTime getStartTime() {
      return startTime;
   }


   public LocalTime getEndTime() {
      return endTime;
   }


   protected final void setEndTime(LocalTime endTime) {
      this.endTime = endTime;
      this.totalMinutes = startTime.until(endTime, ChronoUnit.MINUTES);
      this.totalMinutesBD = BigDecimal.valueOf(totalMinutes);
      extraInitEndTimeTotalMinutes();
   }


   protected void extraInitEndTimeTotalMinutes() {}


   protected long getTotalMinutes() {
      return totalMinutes;
   }


   protected final void setTotalMinutes(long totalMinutes) {
      this.totalMinutes = totalMinutes;
      this.totalMinutesBD = BigDecimal.valueOf(totalMinutes);
      this.endTime = startTime.plusMinutes(totalMinutes);
      extraInitEndTimeTotalMinutes();
   }


   protected BigDecimal getTotalMinutesBD() {
      return totalMinutesBD;
   }


   protected long getPassedMinutes() {
      return getPassedMinutes(false);
   }


   protected long getPassedMinutes(boolean passedMinutesZero) {
      return passedMinutesZero ? 0 : startTime.until(LocalTime.now().truncatedTo(ChronoUnit.MINUTES), ChronoUnit.MINUTES);
   }


   public void showLoadingBar() {
      showLoadingBar(false, false, 0);
   }


   public void showLoadingBar(boolean debug, boolean passedMinutesZero) {
      showLoadingBar(debug, passedMinutesZero, 100L);
   }


   public void showLoadingBarDebug() {
      showLoadingBar(true, true, 100L);
   }


   public void showLoadingBarDebug(long millisWaiting) {
      showLoadingBar(true, true, millisWaiting);
   }


   public void showLoadingBarDebug(boolean passedMinutesZero) {
      showLoadingBar(true, passedMinutesZero, 100L);
   }


   public void showLoadingBarDebug(boolean passedMinutesZero, long millisWaiting) {
      showLoadingBar(true, passedMinutesZero, millisWaiting);
   }


   private void showLoadingBar(boolean debug, boolean passedMinutesZero, long millisWaiting) {
      long passedMinutes = getPassedMinutes(debug && passedMinutesZero);
      if (passedMinutes > totalMinutes) {
         passedMinutes = totalMinutes;
      } else if (passedMinutes < 0) {
         var now = LocalTime.now().truncatedTo(ChronoUnit.SECONDS);
         println("!ACHTUNG! Startzeit \"" + startTime + ":00\" liegt in der Zukunft von jetzt an (" + now + ") gesehen.");
      }
      println(FormatTools.minutesToTimeString(totalMinutes) + " gesamt; Endzeit: " + FormatTools.TIME_FORMATTER.format(endTime));
      while (passedMinutes < totalMinutes) {
         print(fillLoadingBar(passedMinutes, true));
         waitUntilNextMinute(debug, millisWaiting);
         passedMinutes++;
      }
      println(fillLoadingBar(passedMinutes, false));
   }


   protected abstract String fillLoadingBar(long passedMinutes, boolean progressive);


   protected void waitUntilNextMinute() {
      waitUntilNextMinute(false, 0L);
   }


   protected void waitUntilNextMinuteDebug() {
      waitUntilNextMinute(true, 100L);
   }


   protected void waitUntilNextMinuteDebug(long millisWaiting) {
      waitUntilNextMinute(true, millisWaiting);
   }


   private void waitUntilNextMinute(boolean debug, long millisWaiting) {
      try {
         if (debug) {
            TimeUnit.MILLISECONDS.sleep(millisWaiting);
            return;
         }
         var now = LocalTime.now();
         var oneMinuteLater = now.plusMinutes(1).truncatedTo(ChronoUnit.MINUTES);
         /* We wait whole seconds to not make it overly complicated.
            That results in cut milliseconds: if we would have to wait 1 second and 526 milliseconds, we wait only 1 second.
            So, adjust for ignored milliseconds, add +1 second as it is better to switch between 00 and 01 as between 59 and 00 */
         TimeUnit.SECONDS.sleep(now.until(oneMinuteLater, ChronoUnit.SECONDS) + 1);
      } catch (InterruptedException ie) {
         Thread.currentThread().interrupt();
         throw new RuntimeException(ie);
      }
   }
}