1 files changed, 112 insertions, 0 deletions
diff --git a/src/gui/update.rs b/src/gui/update.rs
new file mode 100644
index 0000000..91102bf
--- /dev/null
+++ b/src/gui/update.rs
@@ -0,0 +1,112 @@
+use async_channel::{Receiver, Sender};
+use chrono::NaiveDate;
+use std::collections::HashSet;
+
+use crate::{
+    gui::{calendar, form, utils, App},
+    model::{event, event::Event},
+};
+
+pub fn send(tx: Sender<Msg>, msg: Msg) {
+    utils::spawn(async move {
+        let _ = tx.send(msg).await;
+    })
+}
+
+pub enum Msg {
+    ShowAddForm { date: NaiveDate },
+    ShowUpdateForm { event: Event },
+    AddEvent { new: Event },
+    UpdateEvent { old: Event, new: Event },
+    DeleteEvent { event: Event },
+}
+
+pub async fn event_handler(rx: Receiver<Msg>, mut app: App) {
+    while let Ok(msg) = rx.recv().await {
+        match msg {
+            Msg::ShowAddForm { date } => {
+                form::show(&app, event::init(date), true).await;
+            }
+            Msg::ShowUpdateForm { event } => {
+                form::show(&app, event, false).await;
+            }
+            Msg::AddEvent { new } => {
+                let refresh_dates = add(&mut app, &new);
+                refresh(&app, &refresh_dates)
+            }
+            Msg::UpdateEvent { old, new } => {
+                let refresh_dates_1 = remove(&mut app, &old);
+                let refresh_dates_2 = add(&mut app, &new);
+                refresh(
+                    &app,
+                    &refresh_dates_1
+                        .union(&refresh_dates_2)
+                        .copied()
+                        .collect::<HashSet<NaiveDate>>(),
+                )
+            }
+            Msg::DeleteEvent { event } => {
+                let refresh_dates = remove(&mut app, &event);
+                refresh(&app, &refresh_dates)
+            }
+        }
+    }
+}
+
+/// Remove event and return dates  that should be refreshed.
+fn remove(app: &mut App, event: &Event) -> HashSet<NaiveDate> {
+    if event.repetition.is_some() {
+        match app.repeated_events.iter().position(|e| e.id == event.id) {
+            Some(index) => {
+                app.repeated_events.remove(index);
+                let mut dates = repetition_dates(app, event);
+                dates.insert(event.date);
+                dates
+            }
+            None => {
+                eprintln!("Event not found when trying to delete {:?}", event);
+                HashSet::new()
+            }
+        }
+    } else {
+        match app.events.iter().position(|e| e.id == event.id) {
+            Some(index) => {
+                app.events.remove(index);
+                HashSet::from([event.date])
+            }
+            None => {
+                eprintln!("Event not found when trying to delete {:?}", event);
+                HashSet::new()
+            }
+        }
+    }
+}
+
+/// Add event and return dates that should be refreshed.
+fn add(app: &mut App, event: &Event) -> HashSet<NaiveDate> {
+    if event.repetition.is_some() {
+        app.repeated_events.push(event.clone());
+        let mut dates = repetition_dates(app, event);
+        dates.insert(event.date);
+        dates
+    } else {
+        app.events.push(event.clone());
+        HashSet::from([event.date])
+    }
+}
+
+/// Repetition dates of a repetead event.
+fn repetition_dates(app: &App, event: &Event) -> HashSet<NaiveDate> {
+    let event_reps = event::repetitions_between(&[event.clone()], app.start_date, app.end_date);
+    HashSet::from_iter(event_reps.keys().copied())
+}
+
+/// Refresh app for the given dates.
+fn refresh(app: &App, dates: &HashSet<NaiveDate>) {
+    let repetitions =
+        event::repetitions_between(&app.repeated_events, app.start_date, app.end_date);
+
+    for date in dates {
+        calendar::refresh_date(app, *date, &repetitions)
+    }
+}