wip

packages/racing/domain/services/ScheduleCalculator.ts

@@ -0,0 +1,147 @@
+import type { Weekday } from '../value-objects/Weekday';
+
+export type RecurrenceStrategy = 'weekly' | 'everyNWeeks' | 'monthlyNthWeekday';
+
+export interface ScheduleConfig {
+  weekdays: Weekday[];
+  frequency: RecurrenceStrategy;
+  rounds: number;
+  startDate: Date;
+  endDate?: Date;
+  intervalWeeks?: number;
+}
+
+export interface ScheduleResult {
+  raceDates: Date[];
+  seasonDurationWeeks: number;
+}
+
+/**
+ * JavaScript getDay(): 0=Sunday, 1=Monday, 2=Tuesday, etc.
+ */
+const DAY_MAP: Record<Weekday, number> = {
+  'Sun': 0, 'Mon': 1, 'Tue': 2, 'Wed': 3, 'Thu': 4, 'Fri': 5, 'Sat': 6
+};
+
+/**
+ * Calculate race dates based on schedule configuration.
+ * 
+ * If both startDate and endDate are provided, races are evenly distributed
+ * across the selected weekdays within that range.
+ * 
+ * If only startDate is provided, races are scheduled according to the
+ * recurrence strategy (weekly or bi-weekly).
+ */
+export function calculateRaceDates(config: ScheduleConfig): ScheduleResult {
+  const { weekdays, frequency, rounds, startDate, endDate, intervalWeeks } = config;
+  const dates: Date[] = [];
+  
+  if (weekdays.length === 0 || rounds <= 0) {
+    return { raceDates: [], seasonDurationWeeks: 0 };
+  }
+
+  // Convert weekday names to day numbers for faster lookup
+  const selectedDayNumbers = new Set(weekdays.map(wd => DAY_MAP[wd]));
+
+  // If we have both start and end dates, evenly distribute races
+  if (endDate && endDate > startDate) {
+    const allPossibleDays: Date[] = [];
+    const currentDate = new Date(startDate);
+    currentDate.setHours(12, 0, 0, 0);
+    
+    const endDateTime = new Date(endDate);
+    endDateTime.setHours(12, 0, 0, 0);
+
+    while (currentDate <= endDateTime) {
+      const dayOfWeek = currentDate.getDay();
+      if (selectedDayNumbers.has(dayOfWeek)) {
+        allPossibleDays.push(new Date(currentDate));
+      }
+      currentDate.setDate(currentDate.getDate() + 1);
+    }
+
+    // Evenly distribute the rounds across available days
+    const totalPossible = allPossibleDays.length;
+    if (totalPossible >= rounds) {
+      const spacing = totalPossible / rounds;
+      for (let i = 0; i < rounds; i++) {
+        const index = Math.min(Math.floor(i * spacing), totalPossible - 1);
+        dates.push(allPossibleDays[index]);
+      }
+    } else {
+      // Not enough days - use all available
+      dates.push(...allPossibleDays);
+    }
+
+    const seasonDurationWeeks = dates.length > 1
+      ? Math.ceil((dates[dates.length - 1].getTime() - dates[0].getTime()) / (7 * 24 * 60 * 60 * 1000))
+      : 0;
+
+    return { raceDates: dates, seasonDurationWeeks };
+  }
+
+  // Schedule based on frequency (no end date)
+  const currentDate = new Date(startDate);
+  currentDate.setHours(12, 0, 0, 0);
+  let roundsScheduled = 0;
+
+  // Generate race dates for up to 2 years to ensure we can schedule all rounds
+  const maxDays = 365 * 2;
+  let daysChecked = 0;
+  const seasonStart = new Date(startDate);
+  seasonStart.setHours(12, 0, 0, 0);
+
+  while (roundsScheduled < rounds && daysChecked < maxDays) {
+    const dayOfWeek = currentDate.getDay();
+    const isSelectedDay = selectedDayNumbers.has(dayOfWeek);
+
+    // Calculate which week this is from the start
+    const daysSinceStart = Math.floor((currentDate.getTime() - seasonStart.getTime()) / (24 * 60 * 60 * 1000));
+    const currentWeek = Math.floor(daysSinceStart / 7);
+
+    if (isSelectedDay) {
+      let shouldRace = false;
+
+      if (frequency === 'weekly') {
+        // Weekly: race every week on selected days
+        shouldRace = true;
+      } else if (frequency === 'everyNWeeks') {
+        // Every N weeks: race only on matching week intervals
+        const interval = intervalWeeks ?? 2;
+        shouldRace = currentWeek % interval === 0;
+      } else {
+        // Default to weekly if frequency not set
+        shouldRace = true;
+      }
+
+      if (shouldRace) {
+        dates.push(new Date(currentDate));
+        roundsScheduled++;
+      }
+    }
+
+    currentDate.setDate(currentDate.getDate() + 1);
+    daysChecked++;
+  }
+
+  const seasonDurationWeeks = dates.length > 1
+    ? Math.ceil((dates[dates.length - 1].getTime() - dates[0].getTime()) / (7 * 24 * 60 * 60 * 1000))
+    : 0;
+
+  return { raceDates: dates, seasonDurationWeeks };
+}
+
+/**
+ * Get the next occurrence of a specific weekday from a given date.
+ */
+export function getNextWeekday(fromDate: Date, weekday: Weekday): Date {
+  const targetDay = DAY_MAP[weekday];
+  const result = new Date(fromDate);
+  result.setHours(12, 0, 0, 0);
+  
+  const currentDay = result.getDay();
+  const daysUntilTarget = (targetDay - currentDay + 7) % 7 || 7;
+  
+  result.setDate(result.getDate() + daysUntilTarget);
+  return result;
+}