add a new aero-ical module

4 files changed, 441 insertions, 0 deletions

diff --git a/aero-ical/Cargo.toml b/aero-ical/Cargo.toml
new file mode 100644
index 0000000..6cfe882
--- /dev/null
+++ b/aero-ical/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "aero-ical"
+version = "0.3.0"
+authors = ["Alex Auvolat <alex@adnab.me>", "Quentin Dufour <quentin@dufour.io>"]
+edition = "2021"
+license = "EUPL-1.2"
+description = "An iCalendar parser"
+
+[dependencies]
+aero-dav.workspace = true
+
+icalendar.workspace = true
+nom.workspace = true
+chrono.workspace = true
+tracing.workspace = true
diff --git a/aero-ical/src/lib.rs b/aero-ical/src/lib.rs
new file mode 100644
index 0000000..808c885
--- /dev/null
+++ b/aero-ical/src/lib.rs
@@ -0,0 +1,8 @@
+/// The iCalendar module is not yet properly rewritten
+/// Instead we heavily rely on the icalendar library
+/// However, for many reason, it's not satisfying:
+/// the goal will be to rewrite it in the end so it better
+/// integrates into Aerogramme
+
+pub mod parser;
+pub mod query;
diff --git a/aero-ical/src/parser.rs b/aero-ical/src/parser.rs
new file mode 100644
index 0000000..4354737
--- /dev/null
+++ b/aero-ical/src/parser.rs
@@ -0,0 +1,138 @@
+use chrono::TimeDelta;
+
+use nom::IResult;
+use nom::branch::alt;
+use nom::bytes::complete::{tag, tag_no_case};
+use nom::combinator::{value, opt, map, map_opt};
+use nom::sequence::{pair, tuple};
+use nom::character::complete as nomchar;
+
+use aero_dav::caltypes as cal;
+
+//@FIXME too simple, we have 4 cases in practices:
+// - floating datetime
+// - floating datetime with a tzid as param so convertible to tz datetime
+// - utc datetime
+// - floating(?) date (without time)
+pub fn date_time(dt: &str) -> Option<chrono::DateTime<chrono::Utc>> {
+    tracing::trace!(raw_time = dt, "VEVENT raw time");
+    let tmpl = match dt.chars().last() {
+        Some('Z') => cal::UTC_DATETIME_FMT,
+        Some(_) => {
+            tracing::warn!(raw_time=dt, "floating datetime is not properly supported yet");
+            cal::FLOATING_DATETIME_FMT
+        },
+        None => return None
+    };
+
+    chrono::NaiveDateTime::parse_from_str(dt, tmpl)
+        .ok()
+        .map(|v| v.and_utc())
+}
+
+/// RFC3389 Duration Value
+///
+/// ```abnf
+/// dur-value  = (["+"] / "-") "P" (dur-date / dur-time / dur-week)
+/// dur-date   = dur-day [dur-time]
+/// dur-time   = "T" (dur-hour / dur-minute / dur-second)
+/// dur-week   = 1*DIGIT "W"
+/// dur-hour   = 1*DIGIT "H" [dur-minute]
+/// dur-minute = 1*DIGIT "M" [dur-second]
+/// dur-second = 1*DIGIT "S"
+/// dur-day    = 1*DIGIT "D"
+/// ```
+pub fn dur_value(text: &str) -> IResult<&str, TimeDelta> {
+    map_opt(tuple((
+        dur_sign, 
+        tag_no_case("P"), 
+        alt((
+            dur_date,
+            dur_time,
+            dur_week,
+        ))
+    )), |(sign, _, delta)| {
+        delta.checked_mul(sign)
+    })(text)
+}
+
+fn dur_sign(text: &str) -> IResult<&str, i32> {
+    map(opt(alt((value(1, tag("+")), value(-1, tag("-"))))), |x| x.unwrap_or(1))(text)
+}
+fn dur_date(text: &str) -> IResult<&str, TimeDelta> {
+    map(pair(dur_day, opt(dur_time)), |(day, time)| day + time.unwrap_or(TimeDelta::zero()))(text)
+}
+fn dur_time(text: &str) -> IResult<&str, TimeDelta> {
+    map(pair(tag_no_case("T"), alt((dur_hour, dur_minute, dur_second))), |(_, x)| x)(text)
+}
+fn dur_week(text: &str) -> IResult<&str, TimeDelta> {
+    map_opt(pair(nomchar::i64, tag_no_case("W")), |(i, _)| TimeDelta::try_weeks(i))(text)
+}
+fn dur_day(text: &str) -> IResult<&str, TimeDelta> {
+    map_opt(pair(nomchar::i64, tag_no_case("D")), |(i, _)| TimeDelta::try_days(i))(text)
+}
+fn dur_hour(text: &str) -> IResult<&str, TimeDelta> {
+    map_opt(tuple((nomchar::i64, tag_no_case("H"), opt(dur_minute))), |(i, _, mm)| {
+        TimeDelta::try_hours(i).map(|hours| hours + mm.unwrap_or(TimeDelta::zero()))
+    })(text)
+}
+fn dur_minute(text: &str) -> IResult<&str, TimeDelta> {
+    map_opt(tuple((nomchar::i64, tag_no_case("M"), opt(dur_second))), |(i, _, ms)| {
+        TimeDelta::try_minutes(i).map(|min| min + ms.unwrap_or(TimeDelta::zero()))
+    })(text)
+}
+fn dur_second(text: &str) -> IResult<&str, TimeDelta> {
+    map_opt(pair(nomchar::i64, tag_no_case("S")), |(i, _)| TimeDelta::try_seconds(i))(text)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn rfc5545_example1() {
+        // A duration of 15 days, 5 hours, and 20 seconds would be:
+        let to_parse = "P15DT5H0M20S";
+        let (_, time_delta) = dur_value(to_parse).unwrap();
+        assert_eq!(
+            time_delta, 
+            TimeDelta::try_days(15).unwrap() + TimeDelta::try_hours(5).unwrap() + TimeDelta::try_seconds(20).unwrap());
+    }
+
+    #[test]
+    fn rfc5545_example2() {
+        // A duration of 7 weeks would be:
+        let to_parse = "P7W";
+        let (_, time_delta) = dur_value(to_parse).unwrap();
+        assert_eq!(
+            time_delta, 
+            TimeDelta::try_weeks(7).unwrap()
+        );
+    }
+
+    #[test]
+    fn rfc4791_example1()  {
+        // 10 minutes before
+        let to_parse = "-PT10M";
+
+        let (_, time_delta) = dur_value(to_parse).unwrap();
+        assert_eq!(
+            time_delta, 
+            TimeDelta::try_minutes(-10).unwrap()
+        );
+    }
+
+
+    #[test]
+    fn ical_org_example1() {
+        // The following example is for a "VALARM" calendar component that specifies an email alarm 
+        // that will trigger 2 days before the scheduled due DATE-TIME of a to-do with which it is associated.
+        let to_parse = "-P2D";
+
+        let (_, time_delta) = dur_value(to_parse).unwrap();
+        assert_eq!(
+            time_delta, 
+            TimeDelta::try_days(-2).unwrap()
+        );
+    }
+}
diff --git a/aero-ical/src/query.rs b/aero-ical/src/query.rs
new file mode 100644
index 0000000..5d857bb
--- /dev/null
+++ b/aero-ical/src/query.rs
@@ -0,0 +1,280 @@
+use aero_dav::caltypes as cal;
+use crate::parser as parser;
+
+pub fn is_component_match(
+    parent: &icalendar::parser::Component,
+    components: &[icalendar::parser::Component],
+    filter: &cal::CompFilter,
+) -> bool {
+    // Find the component among the list
+    let maybe_comp = components
+        .iter()
+        .find(|candidate| candidate.name.as_str() == filter.name.as_str());
+
+    // Filter according to rules
+    match (maybe_comp, &filter.additional_rules) {
+        (Some(_), None) => true,
+        (None, Some(cal::CompFilterRules::IsNotDefined)) => true,
+        (None, None) => false,
+        (Some(_), Some(cal::CompFilterRules::IsNotDefined)) => false,
+        (None, Some(cal::CompFilterRules::Matches(_))) => false,
+        (Some(component), Some(cal::CompFilterRules::Matches(matcher))) => {
+            // check time range
+            if let Some(time_range) = &matcher.time_range {
+                if !is_in_time_range(&filter.name, parent, component.properties.as_ref(), time_range) {
+                    return false;
+                }
+            }
+
+            // check properties
+            if !is_properties_match(component.properties.as_ref(), matcher.prop_filter.as_ref()) {
+                return false;
+            }
+
+            // check inner components
+            matcher.comp_filter.iter().all(|inner_filter| {
+                is_component_match(component, component.components.as_ref(), &inner_filter)
+            })
+        }
+    }
+}
+
+fn prop_date(
+    properties: &[icalendar::parser::Property],
+    name: &str,
+) -> Option<chrono::DateTime<chrono::Utc>> {
+    properties
+        .iter()
+        .find(|candidate| candidate.name.as_str() == name)
+        .map(|p| p.val.as_str())
+        .map(parser::date_time)
+        .flatten()
+}
+
+fn prop_parse<T: std::str::FromStr>(
+    properties: &[icalendar::parser::Property],
+    name: &str,
+) -> Option<T> {
+    properties
+        .iter()
+        .find(|candidate| candidate.name.as_str() == name)
+        .map(|p| p.val.as_str().parse::<T>().ok())
+        .flatten()
+}
+
+fn is_properties_match(props: &[icalendar::parser::Property], filters: &[cal::PropFilter]) -> bool {
+    filters.iter().all(|single_filter| {
+        // Find the property
+        let single_prop = props
+            .iter()
+            .find(|candidate| candidate.name.as_str() == single_filter.name.0.as_str());
+        match (&single_filter.additional_rules, single_prop) {
+            (None, Some(_)) | (Some(cal::PropFilterRules::IsNotDefined), None) => true,
+            (None, None)
+            | (Some(cal::PropFilterRules::IsNotDefined), Some(_))
+            | (Some(cal::PropFilterRules::Match(_)), None) => false,
+            (Some(cal::PropFilterRules::Match(pattern)), Some(prop)) => {
+                // check value
+                match &pattern.time_or_text {
+                    Some(cal::TimeOrText::Time(time_range)) => {
+                        let maybe_parsed_date = parser::date_time(prop.val.as_str()); 
+
+                        let parsed_date = match maybe_parsed_date {
+                            None => return false,
+                            Some(v) => v,
+                        };
+
+                        // see if entry is in range
+                        let is_in_range = match time_range {
+                            cal::TimeRange::OnlyStart(after) => &parsed_date >= after,
+                            cal::TimeRange::OnlyEnd(before) => &parsed_date <= before,
+                            cal::TimeRange::FullRange(after, before) => {
+                                &parsed_date >= after && &parsed_date <= before
+                            }
+                        };
+                        if !is_in_range {
+                            return false;
+                        }
+
+                        // if you are here, this subcondition is valid
+                    }
+                    Some(cal::TimeOrText::Text(txt_match)) => {
+                        //@FIXME ignoring collation
+                        let is_match = match txt_match.negate_condition {
+                            None | Some(false) => {
+                                prop.val.as_str().contains(txt_match.text.as_str())
+                            }
+                            Some(true) => !prop.val.as_str().contains(txt_match.text.as_str()),
+                        };
+                        if !is_match {
+                            return false;
+                        }
+                    }
+                    None => (), // if not filter on value is set, continue
+                };
+
+                // check parameters
+                pattern.param_filter.iter().all(|single_param_filter| {
+                    let maybe_param = prop.params.iter().find(|candidate| {
+                        candidate.key.as_str() == single_param_filter.name.as_str()
+                    });
+
+                    match (maybe_param, &single_param_filter.additional_rules) {
+                        (Some(_), None) => true,
+                        (None, None) => false,
+                        (Some(_), Some(cal::ParamFilterMatch::IsNotDefined)) => false,
+                        (None, Some(cal::ParamFilterMatch::IsNotDefined)) => true,
+                        (None, Some(cal::ParamFilterMatch::Match(_))) => false,
+                        (Some(param), Some(cal::ParamFilterMatch::Match(txt_match))) => {
+                            let param_val = match &param.val {
+                                Some(v) => v,
+                                None => return false,
+                            };
+
+                            match txt_match.negate_condition {
+                                None | Some(false) => {
+                                    param_val.as_str().contains(txt_match.text.as_str())
+                                }
+                                Some(true) => !param_val.as_str().contains(txt_match.text.as_str()),
+                            }
+                        }
+                    }
+                })
+            }
+        }
+    })
+}
+
+fn resolve_trigger(
+    parent: &icalendar::parser::Component, 
+    properties: &[icalendar::parser::Property]
+) -> Option<chrono::DateTime<chrono::Utc>> {
+    // A. Do we have a TRIGGER property? If not, returns early
+    let maybe_trigger_prop = properties
+        .iter()
+        .find(|candidate| candidate.name.as_str() == "TRIGGER");
+
+    let trigger_prop = match maybe_trigger_prop {
+        None => return None,
+        Some(v) => v,
+    };
+
+    // B.1 Is it an absolute datetime? If so, returns early
+    let maybe_absolute = trigger_prop.params.iter()
+        .find(|param| param.key.as_str() == "VALUE")
+        .map(|param| param.val.as_ref()).flatten()
+        .map(|v| v.as_str() == "DATE-TIME");
+
+    if maybe_absolute.is_some() {
+        return prop_date(properties, "TRIGGER");
+    }
+
+    // B.2 Otherwise it's a timedelta relative to a parent field.
+    // C.1 Parse the timedelta value, returns early if invalid
+
+    // C.2 Get the parent reference absolute datetime, returns early if invalid
+    let maybe_related_field = trigger_prop
+        .params
+        .iter()
+        .find(|param| param.key.as_str() == "RELATED")
+        .map(|param| param.val.as_ref())
+        .flatten();
+    let related_field = maybe_related_field.map(|v| v.as_str()).unwrap_or("DTSTART");
+    let parent_date = match prop_date(parent.properties.as_ref(), related_field) {
+        Some(v) => v,
+        _ => return None,
+    };
+
+    // C.3 Compute the final date from the base date + timedelta
+
+    todo!()
+}
+
+fn is_in_time_range(
+    component: &cal::Component,
+    parent: &icalendar::parser::Component,
+    properties: &[icalendar::parser::Property],
+    time_range: &cal::TimeRange,
+) -> bool {
+    //@FIXME timezones are not properly handled currently (everything is UTC)
+    //@FIXME does not support repeat
+    //ref: https://datatracker.ietf.org/doc/html/rfc4791#section-9.9
+    let (start, end) = match time_range {
+        cal::TimeRange::OnlyStart(start) => (start, &chrono::DateTime::<chrono::Utc>::MAX_UTC),
+        cal::TimeRange::OnlyEnd(end) => (&chrono::DateTime::<chrono::Utc>::MIN_UTC, end),
+        cal::TimeRange::FullRange(start, end) => (start, end),
+    };
+
+    match component {
+        cal::Component::VEvent => {
+            let dtstart = match prop_date(properties, "DTSTART") {
+                Some(v) => v,
+                _ => return false, 
+            };
+            let maybe_dtend = prop_date(properties, "DTEND");
+            let maybe_duration = prop_parse::<i64>(properties, "DURATION").map(|d| chrono::TimeDelta::new(std::cmp::max(d, 0), 0)).flatten();
+
+            //@FIXME missing "date" management (only support "datetime")
+            match (&maybe_dtend, &maybe_duration) {
+                //       | Y | N | N | * | (start <  DTEND AND end > DTSTART)            |
+                (Some(dtend), _) => start < dtend && end > &dtstart,
+                //       | N | Y | Y | * | (start <  DTSTART+DURATION AND end > DTSTART) |
+                (_, Some(duration)) => *start <= dtstart + *duration && end > &dtstart,
+                //       | N | N | N | Y | (start <= DTSTART AND end > DTSTART)          |
+                _ => start <= &dtstart && end > &dtstart,
+            }
+        },
+        cal::Component::VTodo => {
+            let maybe_dtstart = prop_date(properties, "DTSTART");
+            let maybe_due = prop_date(properties, "DUE");
+            let maybe_completed = prop_date(properties, "COMPLETED");
+            let maybe_created = prop_date(properties, "CREATED");
+            let maybe_duration = prop_parse::<i64>(properties, "DURATION").map(|d| chrono::TimeDelta::new(d, 0)).flatten();
+
+            match (maybe_dtstart, maybe_duration, maybe_due, maybe_completed, maybe_created) {
+                //    | Y | Y | N | * | * | (start  <= DTSTART+DURATION)  AND             |
+                //    |   |   |   |   |   | ((end   >  DTSTART)  OR                       |
+                //    |   |   |   |   |   |  (end   >= DTSTART+DURATION))                 |
+                (Some(dtstart), Some(duration), None, _, _) => *start <= dtstart + duration && (*end > dtstart || *end >= dtstart + duration),
+                //    | Y | N | Y | * | * | ((start <  DUE)      OR  (start <= DTSTART))  |
+                //    |   |   |   |   |   | AND                                           |
+                //    |   |   |   |   |   | ((end   >  DTSTART)  OR  (end   >= DUE))      |
+                (Some(dtstart), None, Some(due), _, _) => (*start < due || *start <= dtstart) && (*end > dtstart || *end >= due),
+                //    | Y | N | N | * | * | (start  <= DTSTART)  AND (end >  DTSTART)     |
+                (Some(dtstart), None, None, _, _) => *start <= dtstart && *end > dtstart,
+                //    | N | N | Y | * | * | (start  <  DUE)      AND (end >= DUE)         |
+                (None, None, Some(due), _, _) => *start < due && *end >= due,
+                //    | N | N | N | Y | Y | ((start <= CREATED)  OR  (start <= COMPLETED))|
+                //    |   |   |   |   |   | AND                                           |
+                //    |   |   |   |   |   | ((end   >= CREATED)  OR  (end   >= COMPLETED))|
+                (None, None, None, Some(completed), Some(created)) => (*start <= created || *start <= completed) && (*end >= created || *end >= completed),
+                //    | N | N | N | Y | N | (start  <= COMPLETED) AND (end  >= COMPLETED) |
+                (None, None, None, Some(completed), None) => *start <= completed && *end >= completed,
+                //    | N | N | N | N | Y | (end    >  CREATED)                           |
+                (None, None, None, None, Some(created)) => *end > created,
+                //    | N | N | N | N | N | TRUE                                          |
+                _ => true,
+            }
+        },
+        cal::Component::VJournal => {
+            let maybe_dtstart = prop_date(properties, "DTSTART");
+            match maybe_dtstart {
+                //    | Y | Y | (start <= DTSTART)     AND (end > DTSTART) |
+                Some(dtstart) => *start <= dtstart && *end > dtstart,
+                //    | N | * | FALSE                                      |
+                None => false,
+            }
+        },
+        cal::Component::VFreeBusy => {
+            //@FIXME freebusy is not supported yet
+            false
+        },
+        cal::Component::VAlarm => {
+            //@FIXME does not support REPEAT
+            let maybe_trigger = resolve_trigger(parent, properties);
+            //  (start <= trigger-time) AND (end > trigger-time)
+            false
+        },
+        _ => false,
+    }
+}