added recurrence (#35)

lib/utils.ts

@@ -1,7 +1,9 @@
 import { clsx, type ClassValue } from "clsx"
 import { twMerge } from "tailwind-merge"
 import { DateTime } from "luxon"
-import { Habit, CoinTransaction } from '@/lib/types'
+import { datetime, RRule } from 'rrule'
+import { Freq, Habit, CoinTransaction } from '@/lib/types'
+import { INITIAL_RECURRENCE_RULE, RECURRENCE_RULE_MAP } from "./constants"
 
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs))
@@ -14,8 +16,8 @@ export function getTodayInTimezone(timezone: string): string {
 }
 
 // get datetime object of now
-export function getNow({ timezone = 'utc' }: { timezone?: string }) {
-  return DateTime.now().setZone(timezone);
+export function getNow({ timezone = 'utc', keepLocalTime }: { timezone?: string, keepLocalTime?: boolean }) {
+  return DateTime.now().setZone(timezone, { keepLocalTime });
 }
 
 // get current time in epoch milliseconds
@@ -97,18 +99,6 @@ export function getCompletedHabitsForDate({
   })
 }
 
-export function isHabitCompletedToday({
-  habit,
-  timezone
-}: {
-  habit: Habit,
-  timezone: string
-}): boolean {
-  const today = getTodayInTimezone(timezone)
-  const completionsToday = getCompletionsForDate({ habit, date: today, timezone })
-  return completionsToday >= (habit.targetCompletions || 1)
-}
-
 export function getHabitProgress({
   habit,
   timezone
@@ -135,7 +125,7 @@ export function calculateCoinsEarnedToday(transactions: CoinTransaction[], timez
 
 export function calculateTotalEarned(transactions: CoinTransaction[]): number {
   return transactions
-    .filter(transaction => 
+    .filter(transaction =>
       transaction.amount > 0 || transaction.type === 'HABIT_UNDO'
     )
     .reduce((sum, transaction) => sum + transaction.amount, 0);
@@ -144,7 +134,7 @@ export function calculateTotalEarned(transactions: CoinTransaction[]): number {
 export function calculateTotalSpent(transactions: CoinTransaction[]): number {
   return Math.abs(
     transactions
-      .filter(transaction => 
+      .filter(transaction =>
         transaction.amount < 0 &&
         transaction.type !== 'HABIT_UNDO'
       )
@@ -173,3 +163,61 @@ export function calculateTransactionsToday(transactions: CoinTransaction[], time
       t2d({ timestamp: today, timezone }))
   ).length;
 }
+
+export function getRRuleUTC(recurrenceRule: string) {
+  return RRule.fromString(recurrenceRule); // this returns UTC
+}
+
+export function parseNaturalLanguageRRule(ruleText: string) {
+  ruleText = ruleText.trim()
+  if (RECURRENCE_RULE_MAP[ruleText]) {
+    return RRule.fromString(RECURRENCE_RULE_MAP[ruleText])
+  }
+
+  return RRule.fromText(ruleText)
+}
+
+export function parseRRule(ruleText: string) {
+  ruleText = ruleText.trim()
+  if (RECURRENCE_RULE_MAP[ruleText]) {
+    return RRule.fromString(RECURRENCE_RULE_MAP[ruleText])
+  }
+
+  return RRule.fromString(ruleText)
+}
+
+export function serializeRRule(rrule: RRule) {
+  return rrule.toString()
+}
+
+export function isHabitDueToday(habit: Habit, timezone: string): boolean {
+  const startOfDay = DateTime.now().setZone(timezone).startOf('day')
+  const endOfDay = DateTime.now().setZone(timezone).endOf('day')
+
+  const ruleText = habit.frequency
+  const rrule = parseRRule(ruleText)
+
+  rrule.origOptions.tzid = timezone // set the target timezone, rrule will do calculation in this timezone
+  rrule.options.tzid = rrule.origOptions.tzid
+  rrule.origOptions.dtstart = datetime(startOfDay.year, startOfDay.month, startOfDay.day, startOfDay.hour, startOfDay.minute, startOfDay.second) // set the start time to 00:00:00 of timezone's today
+  rrule.options.dtstart = rrule.origOptions.dtstart
+  rrule.origOptions.count = 1
+  rrule.options.count = rrule.origOptions.count
+
+  const matches = rrule.all() // this is given as local time, we need to convert back to timezone time
+  if (!matches.length) return false
+  const t = DateTime.fromJSDate(matches[0]).toUTC().setZone('local', { keepLocalTime: true }).setZone(timezone) // this is the formula to convert local time matches[0] to tz time
+  return startOfDay <= t && t <= endOfDay
+}
+
+export function getHabitFreq(habit: Habit): Freq {
+  const rrule = parseRRule(habit.frequency)
+  const freq = rrule.origOptions.freq
+  switch (freq) {
+    case RRule.DAILY: return 'daily'
+    case RRule.WEEKLY: return 'weekly'
+    case RRule.MONTHLY: return 'monthly'
+    case RRule.YEARLY: return 'yearly'
+    default: throw new Error(`Invalid frequency: ${freq}`)
+  }
+}