Implement comprehensive recurring event support

- Add RRULE parsing for DAILY, WEEKLY, MONTHLY, YEARLY frequencies
- Support INTERVAL, COUNT, and BYDAY recurrence parameters
- Generate event occurrences across 30 days past to 365 days future
- Update event refresh to regenerate all recurring occurrences
- Clean up unused imports for cleaner compilation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/app.rs

@@ -138,16 +138,33 @@ fn CalendarView() -> Html {
                     
                     match calendar_service.refresh_event(&token, &uid).await {
                         Ok(Some(refreshed_event)) => {
-                            // Update the event in the existing events map
+                            // If this is a recurring event, we need to regenerate all occurrences
                             let mut updated_events = (*events).clone();
+                            
+                            // First, remove all existing occurrences of this event
                             for (_, day_events) in updated_events.iter_mut() {
-                                for existing_event in day_events.iter_mut() {
-                                    if existing_event.uid == uid {
-                                        *existing_event = refreshed_event.clone();
-                                        break;
-                                    }
-                                }
+                                day_events.retain(|e| e.uid != uid);
                             }
+                            
+                            // Then, if it's a recurring event, generate new occurrences
+                            if refreshed_event.recurrence_rule.is_some() {
+                                let new_occurrences = CalendarService::expand_recurring_events(vec![refreshed_event.clone()]);
+                                
+                                // Add all new occurrences to the appropriate dates
+                                for occurrence in new_occurrences {
+                                    let date = occurrence.get_date();
+                                    updated_events.entry(date)
+                                        .or_insert_with(Vec::new)
+                                        .push(occurrence);
+                                }
+                            } else {
+                                // Non-recurring event, just add it to the appropriate date
+                                let date = refreshed_event.get_date();
+                                updated_events.entry(date)
+                                    .or_insert_with(Vec::new)
+                                    .push(refreshed_event);
+                            }
+                            
                             events.set(updated_events);
                         }
                         Ok(None) => {

src/services/calendar_service.rs

@@ -1,4 +1,4 @@
-use chrono::{DateTime, Utc, NaiveDate};
+use chrono::{DateTime, Utc, NaiveDate, Datelike, Weekday, Duration};
 use serde::{Deserialize, Serialize};
 use wasm_bindgen::JsCast;
 use wasm_bindgen_futures::JsFuture;
@@ -183,7 +183,10 @@ impl CalendarService {
     pub fn group_events_by_date(events: Vec<CalendarEvent>) -> HashMap<NaiveDate, Vec<CalendarEvent>> {
         let mut grouped = HashMap::new();
         
-        for event in events {
+        // Expand recurring events first
+        let expanded_events = Self::expand_recurring_events(events);
+        
+        for event in expanded_events {
             let date = event.get_date();
             
             grouped.entry(date)
@@ -194,6 +197,215 @@ impl CalendarService {
         grouped
     }
 
+    /// Expand recurring events to show on all occurrence dates within a reasonable range
+    pub fn expand_recurring_events(events: Vec<CalendarEvent>) -> Vec<CalendarEvent> {
+        let mut expanded_events = Vec::new();
+        let today = chrono::Utc::now().date_naive();
+        let start_range = today - Duration::days(30); // Show past 30 days
+        let end_range = today + Duration::days(365);   // Show next 365 days
+        
+        for event in events {
+            if let Some(ref rrule) = event.recurrence_rule {
+                // Generate occurrences for recurring events
+                let occurrences = Self::generate_occurrences(&event, rrule, start_range, end_range);
+                expanded_events.extend(occurrences);
+            } else {
+                // Non-recurring event - add as-is
+                expanded_events.push(event);
+            }
+        }
+        
+        expanded_events
+    }
+
+    /// Generate occurrence dates for a recurring event based on RRULE
+    fn generate_occurrences(
+        base_event: &CalendarEvent,
+        rrule: &str,
+        start_range: NaiveDate,
+        end_range: NaiveDate,
+    ) -> Vec<CalendarEvent> {
+        let mut occurrences = Vec::new();
+        
+        // Parse RRULE components
+        let rrule_upper = rrule.to_uppercase();
+        let components: HashMap<String, String> = rrule_upper
+            .split(';')
+            .filter_map(|part| {
+                let mut split = part.split('=');
+                if let (Some(key), Some(value)) = (split.next(), split.next()) {
+                    Some((key.to_string(), value.to_string()))
+                } else {
+                    None
+                }
+            })
+            .collect();
+
+        // Get frequency
+        let freq = components.get("FREQ").map(|s| s.as_str()).unwrap_or("DAILY");
+        
+        // Get interval (default 1)
+        let interval: i32 = components.get("INTERVAL")
+            .and_then(|s| s.parse().ok())
+            .unwrap_or(1);
+
+        // Get count limit (default 100 to prevent infinite loops)
+        let count: usize = components.get("COUNT")
+            .and_then(|s| s.parse().ok())
+            .unwrap_or(100)
+            .min(365); // Cap at 365 occurrences for performance
+
+        let start_date = base_event.start.date_naive();
+        let mut current_date = start_date;
+        let mut occurrence_count = 0;
+
+        // Generate occurrences based on frequency
+        while current_date <= end_range && occurrence_count < count {
+            if current_date >= start_range {
+                // Create occurrence event
+                let mut occurrence_event = base_event.clone();
+                
+                // Adjust dates
+                let days_diff = current_date.signed_duration_since(start_date).num_days();
+                occurrence_event.start = base_event.start + Duration::days(days_diff);
+                
+                if let Some(end) = base_event.end {
+                    occurrence_event.end = Some(end + Duration::days(days_diff));
+                }
+                
+                occurrences.push(occurrence_event);
+            }
+            
+            // Calculate next occurrence date
+            match freq {
+                "DAILY" => {
+                    current_date = current_date + Duration::days(interval as i64);
+                }
+                "WEEKLY" => {
+                    if let Some(byday) = components.get("BYDAY") {
+                        // Handle specific days of week
+                        current_date = Self::next_weekday_occurrence(current_date, byday, interval);
+                    } else {
+                        current_date = current_date + Duration::weeks(interval as i64);
+                    }
+                }
+                "MONTHLY" => {
+                    // Simple monthly increment (same day of month)
+                    if let Some(next_month) = Self::add_months(current_date, interval) {
+                        current_date = next_month;
+                    } else {
+                        break; // Invalid date
+                    }
+                }
+                "YEARLY" => {
+                    if let Some(next_year) = Self::add_years(current_date, interval) {
+                        current_date = next_year;
+                    } else {
+                        break; // Invalid date
+                    }
+                }
+                _ => break, // Unsupported frequency
+            }
+            
+            occurrence_count += 1;
+        }
+        
+        occurrences
+    }
+
+    /// Calculate next weekday occurrence for WEEKLY frequency with BYDAY
+    fn next_weekday_occurrence(current_date: NaiveDate, byday: &str, interval: i32) -> NaiveDate {
+        let weekdays = Self::parse_byday(byday);
+        if weekdays.is_empty() {
+            return current_date + Duration::weeks(interval as i64);
+        }
+
+        let current_weekday = current_date.weekday();
+        
+        // Find next occurrence within current week
+        for &target_weekday in &weekdays {
+            let days_until = Self::days_until_weekday(current_weekday, target_weekday);
+            if days_until > 0 {
+                return current_date + Duration::days(days_until as i64);
+            }
+        }
+        
+        // No more occurrences this week, move to next interval
+        let next_week_start = current_date + Duration::weeks(interval as i64) - Duration::days(current_weekday.num_days_from_monday() as i64);
+        next_week_start + Duration::days(weekdays[0].num_days_from_monday() as i64)
+    }
+
+    /// Parse BYDAY parameter (e.g., "MO,WE,FR" -> [Monday, Wednesday, Friday])
+    fn parse_byday(byday: &str) -> Vec<Weekday> {
+        byday
+            .split(',')
+            .filter_map(|day| match day {
+                "MO" => Some(Weekday::Mon),
+                "TU" => Some(Weekday::Tue),
+                "WE" => Some(Weekday::Wed),
+                "TH" => Some(Weekday::Thu),
+                "FR" => Some(Weekday::Fri),
+                "SA" => Some(Weekday::Sat),
+                "SU" => Some(Weekday::Sun),
+                _ => None,
+            })
+            .collect()
+    }
+
+    /// Calculate days until target weekday
+    fn days_until_weekday(from: Weekday, to: Weekday) -> i32 {
+        let from_num = from.num_days_from_monday();
+        let to_num = to.num_days_from_monday();
+        
+        if to_num > from_num {
+            (to_num - from_num) as i32
+        } else if to_num < from_num {
+            (7 + to_num - from_num) as i32
+        } else {
+            0 // Same day
+        }
+    }
+
+    /// Add months to a date (handling month boundary issues)
+    fn add_months(date: NaiveDate, months: i32) -> Option<NaiveDate> {
+        let mut year = date.year();
+        let mut month = date.month() as i32 + months;
+        
+        while month > 12 {
+            year += 1;
+            month -= 12;
+        }
+        while month < 1 {
+            year -= 1;
+            month += 12;
+        }
+        
+        // Handle day overflow (e.g., Jan 31 -> Feb 28)
+        let day = date.day().min(Self::days_in_month(year, month as u32));
+        
+        NaiveDate::from_ymd_opt(year, month as u32, day)
+    }
+
+    /// Add years to a date
+    fn add_years(date: NaiveDate, years: i32) -> Option<NaiveDate> {
+        NaiveDate::from_ymd_opt(date.year() + years, date.month(), date.day())
+    }
+
+    /// Get number of days in a month
+    fn days_in_month(year: i32, month: u32) -> u32 {
+        match month {
+            1 | 3 | 5 | 7 | 8 | 10 | 12 => 31,
+            4 | 6 | 9 | 11 => 30,
+            2 => if Self::is_leap_year(year) { 29 } else { 28 },
+            _ => 30,
+        }
+    }
+
+    /// Check if year is leap year
+    fn is_leap_year(year: i32) -> bool {
+        (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)
+    }
+
     /// Refresh a single event by UID from the CalDAV server
     pub async fn refresh_event(&self, token: &str, uid: &str) -> Result<Option<CalendarEvent>, String> {
         let window = web_sys::window().ok_or("No global window exists")?;

src/services/mod.rs

@@ -1,3 +1,3 @@
 pub mod calendar_service;
 
-pub use calendar_service::{CalendarService, CalendarEvent, EventStatus, EventClass, EventReminder, ReminderAction};
+pub use calendar_service::{CalendarService, CalendarEvent, EventReminder, ReminderAction};