feat: Tankstände vom Vortag bei neuem Reisetag mit Bestätigung übernehmen.

Abendstände werden als Morgenstände vorgeschlagen; der Nutzer kann übernehmen oder mit 0 starten.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/utils/logEntryTankLevels.ts

@@ -0,0 +1,64 @@
+export interface TankLevels {
+  morning: number
+  refilled: number
+  evening: number
+  consumption: number
+}
+
+export interface TravelDaySortable {
+  date?: string
+  dayOfTravel?: string | number
+}
+
+/** Chronological order: date ascending, then day of travel ascending. */
+export function compareTravelDaysChronological(a: TravelDaySortable, b: TravelDaySortable): number {
+  const dateCompare = new Date(a.date || 0).getTime() - new Date(b.date || 0).getTime()
+  if (dateCompare !== 0) return dateCompare
+  return Number(a.dayOfTravel || 0) - Number(b.dayOfTravel || 0)
+}
+
+export function getNextTravelDayNumber(entries: TravelDaySortable[]): string {
+  const maxDay = entries.reduce((max, entry) => Math.max(max, Number(entry.dayOfTravel) || 0), 0)
+  return String(maxDay + 1)
+}
+
+/** Closing level at end of travel day: evening stand, else calculated balance, else morning. */
+export function getClosingTankLevel(tank?: Partial<TankLevels> | null): number {
+  if (!tank) return 0
+
+  const evening = Number(tank.evening) || 0
+  if (evening > 0) return evening
+
+  const morning = Number(tank.morning) || 0
+  const refilled = Number(tank.refilled) || 0
+  const consumption = Number(tank.consumption) || 0
+  const fromBalance = morning + refilled - consumption
+  if (fromBalance > 0) return fromBalance
+
+  return morning
+}
+
+export interface LogEntryTankSource {
+  freshwater?: Partial<TankLevels>
+  fuel?: Partial<TankLevels>
+}
+
+export function emptyTankLevels(morning = 0): TankLevels {
+  return { morning, refilled: 0, evening: 0, consumption: 0 }
+}
+
+export function formatTankLiters(liters: number): string {
+  if (!Number.isFinite(liters) || liters <= 0) return '0'
+  return Number.isInteger(liters) ? String(liters) : liters.toFixed(1)
+}
+
+export function carryOverTankLevelsFromPreviousDay(previousEntry?: LogEntryTankSource | null): { freshwater: TankLevels; fuel: TankLevels } {
+  if (!previousEntry) {
+    return { freshwater: emptyTankLevels(), fuel: emptyTankLevels() }
+  }
+
+  return {
+    freshwater: emptyTankLevels(getClosingTankLevel(previousEntry.freshwater)),
+    fuel: emptyTankLevels(getClosingTankLevel(previousEntry.fuel))
+  }
+}