Implement download feature for calendars and addressbooks

Fixes #70

crates/caldav/src/calendar/methods/get.rs

@@ -0,0 +1,96 @@
+use crate::Error;
+use crate::calendar::CalendarResourceService;
+use axum::body::Body;
+use axum::extract::State;
+use axum::{extract::Path, response::Response};
+use headers::{ContentType, HeaderMapExt};
+use http::{HeaderValue, StatusCode, header};
+use ical::generator::{Emitter, IcalCalendarBuilder};
+use ical::property::Property;
+use percent_encoding::{CONTROLS, utf8_percent_encode};
+use rustical_ical::{CalendarObjectComponent, EventObject, JournalObject, TodoObject};
+use rustical_store::{CalendarStore, SubscriptionStore, auth::User};
+use std::collections::HashMap;
+use std::str::FromStr;
+use tracing::instrument;
+
+#[instrument(skip(cal_store))]
+pub async fn route_get<C: CalendarStore, S: SubscriptionStore>(
+    Path((principal, calendar_id)): Path<(String, String)>,
+    State(CalendarResourceService { cal_store, .. }): State<CalendarResourceService<C, S>>,
+    user: User,
+) -> Result<Response, Error> {
+    if !user.is_principal(&principal) {
+        return Err(crate::Error::Unauthorized);
+    }
+
+    let calendar = cal_store.get_calendar(&principal, &calendar_id).await?;
+    if !user.is_principal(&calendar.principal) {
+        return Err(crate::Error::Unauthorized);
+    }
+
+    let calendar = cal_store.get_calendar(&principal, &calendar_id).await?;
+
+    let mut timezones = HashMap::new();
+    let objects = cal_store.get_objects(&principal, &calendar_id).await?;
+
+    let mut ical_calendar_builder = IcalCalendarBuilder::version("4.0")
+        .gregorian()
+        .prodid("RustiCal");
+    if calendar.displayname.is_some() {
+        ical_calendar_builder = ical_calendar_builder.set(Property {
+            name: "X-WR-CALNAME".to_owned(),
+            value: calendar.displayname,
+            params: None,
+        });
+    }
+    if calendar.description.is_some() {
+        ical_calendar_builder = ical_calendar_builder.set(Property {
+            name: "X-WR-CALDESC".to_owned(),
+            value: calendar.description,
+            params: None,
+        });
+    }
+    if calendar.timezone_id.is_some() {
+        ical_calendar_builder = ical_calendar_builder.set(Property {
+            name: "X-WR-TIMEZONE".to_owned(),
+            value: calendar.timezone_id,
+            params: None,
+        });
+    }
+    let mut ical_calendar = ical_calendar_builder.build();
+
+    for object in &objects {
+        match object.get_data() {
+            CalendarObjectComponent::Event(EventObject {
+                event,
+                timezones: object_timezones,
+                ..
+            }) => {
+                timezones.extend(object_timezones);
+                ical_calendar.events.push(event.clone());
+            }
+            CalendarObjectComponent::Todo(TodoObject { todo, .. }) => {
+                ical_calendar.todos.push(todo.clone());
+            }
+            CalendarObjectComponent::Journal(JournalObject { journal, .. }) => {
+                ical_calendar.journals.push(journal.clone());
+            }
+        }
+    }
+
+    let mut resp = Response::builder().status(StatusCode::OK);
+    let hdrs = resp.headers_mut().unwrap();
+    hdrs.typed_insert(ContentType::from_str("text/calendar").unwrap());
+
+    let filename = format!("{}_{}.ics", calendar.principal, calendar.id);
+    let filename = utf8_percent_encode(&filename, CONTROLS);
+    hdrs.insert(
+        header::CONTENT_DISPOSITION,
+        HeaderValue::from_str(&format!(
+            "attachement; filename*=UTF-8''{filename}; filename={filename}",
+        ))
+        .unwrap(),
+    );
+    Ok(resp.body(Body::new(ical_calendar.generate())).unwrap())
+}