WIP: Preparation for recurrence expansion

crates/store/src/calendar/event.rs

@@ -2,7 +2,7 @@ use super::{
     CalDateTime, parse_duration,
     rrule::{ParserError, RecurrenceRule},
 };
-use crate::Error;
+use crate::{Error, calendar::ComponentMut};
 use chrono::Duration;
 use ical::{
     generator::IcalEvent,
@@ -15,12 +15,13 @@ use std::collections::HashMap;
 pub struct EventObject {
     pub(crate) event: IcalEvent,
     pub(crate) timezones: HashMap<String, IcalTimeZone>,
+    pub(crate) ics: String,
 }
 
 impl EventObject {
     pub fn get_first_occurence(&self) -> Result<Option<CalDateTime>, Error> {
         if let Some(dtstart) = self.event.get_property("DTSTART") {
-            CalDateTime::parse_prop(dtstart, &self.timezones)
+            Ok(CalDateTime::parse_prop(dtstart, &self.timezones)?)
         } else {
             Ok(None)
         }
@@ -33,21 +34,25 @@ impl EventObject {
         }
 
         if let Some(dtend) = self.event.get_property("DTEND") {
-            return CalDateTime::parse_prop(dtend, &self.timezones);
+            return Ok(CalDateTime::parse_prop(dtend, &self.timezones)?);
         };
 
-        let duration = if let Some(Property {
+        let duration = self.get_duration()?.unwrap_or(Duration::days(1));
+
+        let first_occurence = self.get_first_occurence()?;
+        Ok(first_occurence.map(|first_occurence| first_occurence + duration))
+    }
+
+    pub fn get_duration(&self) -> Result<Option<Duration>, Error> {
+        if let Some(Property {
             value: Some(duration),
             ..
         }) = self.event.get_property("DURATION")
         {
-            parse_duration(duration)?
+            Ok(Some(parse_duration(duration)?))
         } else {
-            Duration::days(1)
-        };
-
-        let first_occurence = self.get_first_occurence()?;
-        Ok(first_occurence.map(|first_occurence| first_occurence + duration))
+            Ok(None)
+        }
     }
 
     pub fn recurrence_rule(&self) -> Result<Option<RecurrenceRule>, ParserError> {
@@ -62,10 +67,73 @@ impl EventObject {
         RecurrenceRule::parse(rrule).map(Some)
     }
 
-    pub fn expand_recurrence(&self) -> Result<(), Error> {
-        let rrule = self.event.get_property("RRULE").unwrap();
-        dbg!(rrule);
-        Ok(())
+    pub fn expand_recurrence(&self) -> Result<Vec<IcalEvent>, Error> {
+        if let Some(rrule) = self.recurrence_rule()? {
+            let mut events = vec![];
+            let first_occurence = self.get_first_occurence()?.unwrap();
+            let dates = rrule.between(first_occurence, None);
+
+            for date in dates {
+                let dtstart_utc = date.cal_utc();
+                let mut ev = self.event.clone();
+                ev.remove_property("RRULE");
+                ev.set_property(Property {
+                    name: "RECURRENCE-ID".to_string(),
+                    value: Some(dtstart_utc.format()),
+                    params: None,
+                });
+                ev.set_property(Property {
+                    name: "DTSTART".to_string(),
+                    value: Some(dtstart_utc.format()),
+                    params: None,
+                });
+                if let Some(duration) = self.get_duration()? {
+                    ev.set_property(Property {
+                        name: "DTEND".to_string(),
+                        value: Some((dtstart_utc + duration).format()),
+                        params: None,
+                    });
+                }
+                events.push(ev);
+            }
+            Ok(events)
+        } else {
+            Ok(vec![self.event.clone()])
+        }
     }
 }
 
+#[cfg(test)]
+mod tests {
+    use crate::CalendarObject;
+
+    const ICS: &str = r#"BEGIN:VCALENDAR
+CALSCALE:GREGORIAN
+VERSION:2.0
+BEGIN:VTIMEZONE
+TZID:Europe/Berlin
+X-LIC-LOCATION:Europe/Berlin
+END:VTIMEZONE
+
+BEGIN:VEVENT
+UID:318ec6503573d9576818daf93dac07317058d95c
+DTSTAMP:20250502T132758Z
+DTSTART;TZID=Europe/Berlin:20250506T090000
+DTEND;TZID=Europe/Berlin:20250506T092500
+SEQUENCE:2
+SUMMARY:weekly stuff
+TRANSP:OPAQUE
+RRULE:FREQ=WEEKLY;COUNT=4;INTERVAL=2;BYDAY=TU,TH,SU
+END:VEVENT
+END:VCALENDAR"#;
+
+    #[test]
+    fn test_expand_recurrence() {
+        let event = CalendarObject::from_ics(
+            "318ec6503573d9576818daf93dac07317058d95c".to_string(),
+            ICS.to_string(),
+        )
+        .unwrap();
+        assert_eq!(event.expand_recurrence().unwrap(), "asd".to_string());
+    }
+}

crates/store/src/calendar/ical.rs

@@ -1,3 +1,5 @@
+use ical::{generator::IcalEvent, property::Property};
+
 pub trait IcalProperty {
     fn get_param(&self, name: &str) -> Option<Vec<&str>>;
     fn get_value_type(&self) -> Option<&str>;
@@ -23,3 +25,22 @@ impl IcalProperty for ical::property::Property {
             .and_then(|params| params.into_iter().next())
     }
 }
+
+pub trait ComponentMut {
+    fn remove_property(&mut self, name: &str);
+    fn set_property(&mut self, prop: Property);
+    fn push_property(&mut self, prop: Property);
+}
+
+impl ComponentMut for IcalEvent {
+    fn remove_property(&mut self, name: &str) {
+        self.properties.retain(|prop| prop.name != name);
+    }
+    fn set_property(&mut self, prop: Property) {
+        self.remove_property(&prop.name);
+        self.push_property(prop);
+    }
+    fn push_property(&mut self, prop: Property) {
+        self.properties.push(prop);
+    }
+}

crates/store/src/calendar/journal.rs

@@ -3,4 +3,5 @@ use ical::parser::ical::component::IcalJournal;
 #[derive(Debug, Clone)]
 pub struct JournalObject {
     pub journal: IcalJournal,
+    pub(crate) ics: String,
 }

crates/store/src/calendar/mod.rs

@@ -3,7 +3,7 @@ mod event;
 mod ical;
 mod journal;
 mod object;
-mod rrule;
+pub mod rrule;
 mod timestamp;
 mod todo;
 

crates/store/src/calendar/object.rs

@@ -1,6 +1,9 @@
 use super::{CalDateTime, EventObject, JournalObject, TodoObject};
 use crate::Error;
-use ical::parser::{Component, ical::component::IcalTimeZone};
+use ical::{
+    generator::{Emitter, IcalCalendar},
+    parser::{Component, ical::component::IcalTimeZone},
+};
 use serde::Serialize;
 use sha2::{Digest, Sha256};
 use std::{collections::HashMap, io::BufReader};
@@ -55,8 +58,8 @@ pub enum CalendarObjectComponent {
 #[derive(Debug, Clone)]
 pub struct CalendarObject {
     id: String,
-    ics: String,
     data: CalendarObjectComponent,
+    cal: IcalCalendar,
 }
 
 impl CalendarObject {
@@ -95,26 +98,31 @@ impl CalendarObject {
         if let Some(event) = cal.events.first() {
             return Ok(CalendarObject {
                 id: object_id,
-                ics,
+                cal: cal.clone(),
                 data: CalendarObjectComponent::Event(EventObject {
                     event: event.clone(),
                     timezones,
+                    ics,
                 }),
             });
         }
         if let Some(todo) = cal.todos.first() {
             return Ok(CalendarObject {
                 id: object_id,
-                ics,
-                data: CalendarObjectComponent::Todo(TodoObject { todo: todo.clone() }),
+                cal: cal.clone(),
+                data: CalendarObjectComponent::Todo(TodoObject {
+                    todo: todo.clone(),
+                    ics,
+                }),
             });
         }
         if let Some(journal) = cal.journals.first() {
             return Ok(CalendarObject {
                 id: object_id,
-                ics,
+                cal: cal.clone(),
                 data: CalendarObjectComponent::Journal(JournalObject {
                     journal: journal.clone(),
+                    ics,
                 }),
             });
         }
@@ -135,7 +143,11 @@ impl CalendarObject {
     }
 
     pub fn get_ics(&self) -> &str {
-        &self.ics
+        match &self.data {
+            CalendarObjectComponent::Todo(todo) => &todo.ics,
+            CalendarObjectComponent::Event(event) => &event.ics,
+            CalendarObjectComponent::Journal(journal) => &journal.ics,
+        }
     }
 
     pub fn get_component_name(&self) -> &str {
@@ -167,4 +179,16 @@ impl CalendarObject {
             _ => Ok(None),
         }
     }
+
+    pub fn expand_recurrence(&self) -> Result<String, Error> {
+        // Only events can be expanded
+        match &self.data {
+            CalendarObjectComponent::Event(event) => {
+                let mut cal = self.cal.clone();
+                cal.events = event.expand_recurrence()?;
+                Ok(cal.generate())
+            }
+            _ => Ok(self.get_ics().to_string()),
+        }
+    }
 }

crates/store/src/calendar/rrule/iter.rs

@@ -0,0 +1,41 @@
+use crate::calendar::CalDateTime;
+
+use super::{RecurrenceLimit, RecurrenceRule};
+
+impl RecurrenceRule {
+    pub fn between(
+        &self,
+        start: CalDateTime,
+        end: Option<CalDateTime>,
+    ) -> impl IntoIterator<Item = CalDateTime> {
+        let start = start.cal_utc();
+        // Terrible code, should clean this up later.
+        let mut end = end.map(|end| CalDateTime::cal_utc(&end));
+        if let Some(RecurrenceLimit::Until(until)) = &self.limit {
+            let until = until.cal_utc();
+            let mut _end = end.unwrap_or(until.clone());
+            if until.utc() < _end.utc() {
+                _end = until;
+            }
+            end = Some(_end);
+        }
+        let count = if let Some(RecurrenceLimit::Count(count)) = &self.limit {
+            *count
+        } else {
+            2048
+        };
+
+        let mut datetimes = vec![start.clone()];
+        let mut datetime_utc = start.utc();
+        while datetimes.len() < count {
+            if let Some(end) = &end {
+                if datetime_utc > end.utc() {
+                    break;
+                }
+                datetimes.push(CalDateTime::Utc(datetime_utc));
+            }
+        }
+
+        datetimes
+    }
+}

crates/store/src/calendar/rrule/mod.rs

@@ -1,7 +1,9 @@
-use super::CalDateTime;
+use super::{CalDateTime, CalDateTimeError};
 use std::{num::ParseIntError, str::FromStr};
 use strum_macros::EnumString;
 
+mod iter;
+
 #[derive(Debug, thiserror::Error)]
 pub enum ParserError {
     #[error("Missing RRULE FREQ")]
@@ -12,9 +14,8 @@ pub enum ParserError {
     StrumError(#[from] strum::ParseError),
     #[error(transparent)]
     ParseIntError(#[from] ParseIntError),
-    // A little dumb :(
     #[error(transparent)]
-    StoreError(#[from] crate::Error),
+    CalDateTimeError(#[from] CalDateTimeError),
 }
 
 #[derive(Debug, Clone, EnumString, Default, PartialEq)]

crates/store/src/calendar/timestamp.rs

@@ -1,6 +1,5 @@
 use super::IcalProperty;
-use crate::Error;
-use chrono::{DateTime, Duration, NaiveDate, NaiveDateTime, NaiveTime, Utc};
+use chrono::{DateTime, Duration, Local, NaiveDate, NaiveDateTime, NaiveTime, Utc};
 use chrono_tz::Tz;
 use derive_more::derive::Deref;
 use ical::{
@@ -22,6 +21,24 @@ const LOCAL_DATE_TIME: &str = "%Y%m%dT%H%M%S";
 const UTC_DATE_TIME: &str = "%Y%m%dT%H%M%SZ";
 pub const LOCAL_DATE: &str = "%Y%m%d";
 
+#[derive(Debug, thiserror::Error)]
+pub enum CalDateTimeError {
+    #[error(
+        "Timezone has X-LIC-LOCATION property to specify a timezone from the Olson database, however its value {0} is invalid"
+    )]
+    InvalidOlson(String),
+    #[error("TZID {0} does not refer to a valid timezone")]
+    InvalidTZID(String),
+    #[error("Timestamp doesn't exist because of gap in local time")]
+    LocalTimeGap,
+    #[error("Datetime string {0} has an invalid format")]
+    InvalidDatetimeFormat(String),
+    #[error("Could not parse datetime {0}")]
+    ParseError(String),
+    #[error("Duration string {0} has an invalid format")]
+    InvalidDurationFormat(String),
+}
+
 #[derive(Debug, Clone, Deref, PartialEq)]
 pub struct UtcDateTime(DateTime<Utc>);
 
@@ -49,7 +66,7 @@ impl ValueSerialize for UtcDateTime {
 #[derive(Debug, Clone, PartialEq)]
 pub enum CalDateTime {
     // Form 1, example: 19980118T230000
-    Local(NaiveDateTime),
+    Local(DateTime<Local>),
     // Form 2, example: 19980119T070000Z
     Utc(DateTime<Utc>),
     // Form 3, example: TZID=America/New_York:19980119T020000
@@ -66,7 +83,13 @@ impl Add<Duration> for CalDateTime {
             Self::Local(datetime) => Self::Local(datetime + duration),
             Self::Utc(datetime) => Self::Utc(datetime + duration),
             Self::OlsonTZ(datetime) => Self::OlsonTZ(datetime + duration),
-            Self::Date(date) => Self::Local(date.and_time(NaiveTime::default()) + duration),
+            Self::Date(date) => Self::Local(
+                date.and_time(NaiveTime::default())
+                    .and_local_timezone(Local)
+                    .earliest()
+                    .expect("Local timezone has constant offset")
+                    + duration,
+            ),
         }
     }
 }
@@ -75,7 +98,7 @@ impl CalDateTime {
     pub fn parse_prop(
         prop: &Property,
         timezones: &HashMap<String, IcalTimeZone>,
-    ) -> Result<Option<Self>, Error> {
+    ) -> Result<Option<Self>, CalDateTimeError> {
         let prop_value = if let Some(value) = prop.value.as_ref() {
             value
         } else {
@@ -95,9 +118,7 @@ impl CalDateTime {
                     if let Ok(tz) = olson_name.parse::<Tz>() {
                         Some(tz)
                     } else {
-                        return Err(Error::InvalidData(format!(
-                            "Timezone has X-LIC-LOCATION property to specify a timezone from the Olson database, however its value {olson_name} is invalid"
-                        )));
+                        return Err(CalDateTimeError::InvalidOlson(olson_name));
                     }
                 } else {
                     // If the TZID matches a name from the Olson database (e.g. Europe/Berlin) we
@@ -108,9 +129,7 @@ impl CalDateTime {
                 }
             } else {
                 // TZID refers to timezone that does not exist
-                return Err(Error::InvalidData(format!(
-                    "Timezone {tzid} does not exist"
-                )));
+                return Err(CalDateTimeError::InvalidTZID(tzid.to_string()));
             }
         } else {
             // No explicit timezone specified.
@@ -134,25 +153,27 @@ impl CalDateTime {
         match self {
             Self::Utc(utc) => utc.date_naive(),
             Self::Date(date) => date.to_owned(),
-            Self::Local(datetime) => datetime.date(),
+            Self::Local(datetime) => datetime.date_naive(),
             Self::OlsonTZ(datetime) => datetime.date_naive(),
         }
     }
 
-    pub fn parse(value: &str, timezone: Option<Tz>) -> Result<Self, Error> {
+    pub fn parse(value: &str, timezone: Option<Tz>) -> Result<Self, CalDateTimeError> {
         if let Ok(datetime) = NaiveDateTime::parse_from_str(value, LOCAL_DATE_TIME) {
             if let Some(timezone) = timezone {
-                let result = datetime.and_local_timezone(timezone);
-                if let Some(datetime) = result.earliest() {
-                    return Ok(CalDateTime::OlsonTZ(datetime));
-                } else {
-                    // This time does not exist because there's a gap in local time
-                    return Err(Error::InvalidData(
-                        "Timestamp doesn't exist because of gap in local time".to_owned(),
-                    ));
-                }
+                return Ok(CalDateTime::OlsonTZ(
+                    datetime
+                        .and_local_timezone(timezone)
+                        .earliest()
+                        .ok_or(CalDateTimeError::LocalTimeGap)?,
+                ));
             }
-            return Ok(CalDateTime::Local(datetime));
+            return Ok(CalDateTime::Local(
+                datetime
+                    .and_local_timezone(chrono::Local)
+                    .earliest()
+                    .ok_or(CalDateTimeError::LocalTimeGap)?,
+            ));
         }
 
         if let Ok(datetime) = NaiveDateTime::parse_from_str(value, UTC_DATE_TIME) {
@@ -177,21 +198,25 @@ impl CalDateTime {
 
             return Ok(CalDateTime::Date(
                 NaiveDate::from_ymd_opt(year, month, day)
-                    .ok_or(Error::InvalidData(format!("Could not parse date {value}")))?,
+                    .ok_or(CalDateTimeError::ParseError(value.to_string()))?,
             ));
         }
 
-        Err(Error::InvalidData("Invalid datetime format".to_owned()))
+        Err(CalDateTimeError::InvalidDatetimeFormat(value.to_string()))
     }
 
     pub fn utc(&self) -> DateTime<Utc> {
         match &self {
-            CalDateTime::Local(local_datetime) => local_datetime.and_utc(),
+            CalDateTime::Local(local_datetime) => local_datetime.to_utc(),
             CalDateTime::Utc(utc_datetime) => utc_datetime.to_owned(),
             CalDateTime::OlsonTZ(datetime) => datetime.to_utc(),
             CalDateTime::Date(date) => date.and_time(NaiveTime::default()).and_utc(),
         }
     }
+
+    pub fn cal_utc(&self) -> Self {
+        Self::Utc(self.utc())
+    }
 }
 
 impl From<CalDateTime> for DateTime<Utc> {
@@ -200,10 +225,10 @@ impl From<CalDateTime> for DateTime<Utc> {
     }
 }
 
-pub fn parse_duration(string: &str) -> Result<Duration, Error> {
+pub fn parse_duration(string: &str) -> Result<Duration, CalDateTimeError> {
     let captures = RE_DURATION
         .captures(string)
-        .ok_or(Error::InvalidData("Invalid duration format".to_owned()))?;
+        .ok_or(CalDateTimeError::InvalidDurationFormat(string.to_string()))?;
 
     let mut duration = Duration::zero();
     if let Some(weeks) = captures.name("W") {

crates/store/src/calendar/todo.rs

@@ -3,4 +3,5 @@ use ical::parser::ical::component::IcalTodo;
 #[derive(Debug, Clone)]
 pub struct TodoObject {
     pub todo: IcalTodo,
+    pub(crate) ics: String,
 }

crates/store/src/error.rs

@@ -1,4 +1,6 @@
-use actix_web::{http::StatusCode, ResponseError};
+use actix_web::{ResponseError, http::StatusCode};
+
+use crate::calendar::CalDateTimeError;
 
 #[derive(Debug, thiserror::Error)]
 pub enum Error {
@@ -11,6 +13,9 @@ pub enum Error {
     #[error("Invalid ics/vcf input: {0}")]
     InvalidData(String),
 
+    #[error(transparent)]
+    RRuleParserError(#[from] crate::calendar::rrule::ParserError),
+
     #[error("Read-only")]
     ReadOnly,
 
@@ -25,6 +30,9 @@ pub enum Error {
 
     #[error(transparent)]
     Other(#[from] anyhow::Error),
+
+    #[error(transparent)]
+    CalDateTimeError(#[from] CalDateTimeError),
 }
 
 impl ResponseError for Error {