From 5cc85faf5bb1d99d94679b87512c95a7ba4e44f0 Mon Sep 17 00:00:00 2001
From: James Maes <jmaes@dmdbrands.com>
Date: Wed, 22 Jul 2026 19:49:40 -0500
Subject: [PATCH] feat(cal): add CalDavClient for WebDAV REPORT calendar
 queries

---
 Cargo.toml                      |   3 +
 crates/nuncio-cal/Cargo.toml    |   3 +
 crates/nuncio-cal/src/caldav.rs | 109 ++++++++++++++++++++++++++++++++
 crates/nuncio-cal/src/lib.rs    |   2 +
 4 files changed, 117 insertions(+)
 create mode 100644 crates/nuncio-cal/src/caldav.rs

diff --git a/Cargo.toml b/Cargo.toml
index 02560df..9ac6593 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -43,6 +43,9 @@ icalendar = "0.15"
 chrono-tz = "0.9"
 rrule = "0.10"
 chrono = "0.4"
+reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }
+quick-xml = "0.36"
+
 
 
 
diff --git a/crates/nuncio-cal/Cargo.toml b/crates/nuncio-cal/Cargo.toml
index 371dffa..22bb938 100644
--- a/crates/nuncio-cal/Cargo.toml
+++ b/crates/nuncio-cal/Cargo.toml
@@ -17,4 +17,7 @@ icalendar.workspace = true
 chrono-tz.workspace = true
 rrule.workspace = true
 chrono.workspace = true
+reqwest.workspace = true
+quick-xml.workspace = true
+
 
diff --git a/crates/nuncio-cal/src/caldav.rs b/crates/nuncio-cal/src/caldav.rs
new file mode 100644
index 0000000..9d96a95
--- /dev/null
+++ b/crates/nuncio-cal/src/caldav.rs
@@ -0,0 +1,109 @@
+//! CalDAV (RFC 4791) / WebDAV REPORT client and XML query generator.
+
+use nuncio_core::model::CalendarEvent;
+
+use crate::parser::{CalendarError, IcalParserAdapter};
+
+/// CalDAV client protocol engine managing WebDAV REPORT queries.
+pub struct CalDavClient {
+    account_id: String,
+}
+
+impl CalDavClient {
+    /// Create a new `CalDavClient` bound to an account ID.
+    pub fn new(account_id: &str) -> Self {
+        Self {
+            account_id: account_id.to_string(),
+        }
+    }
+
+    /// Construct a standard CalDAV `<c:calendar-query>` XML payload for a time range window.
+    pub fn build_report_query(start_iso: &str, end_iso: &str) -> String {
+        format!(
+            r#"<?xml version="1.0" encoding="utf-8" ?>
+<c:calendar-query xmlns:d="DAV:" xmlns:c="urn:ietf:params:xml:ns:caldav">
+    <d:prop>
+        <d:getetag />
+        <c:calendar-data />
+    </d:prop>
+    <c:filter>
+        <c:comp-filter name="VCALENDAR">
+            <c:comp-filter name="VEVENT">
+                <c:time-range start="{}" end="{}"/>
+            </c:comp-filter>
+        </c:comp-filter>
+    </c:filter>
+</c:calendar-query>"#,
+            start_iso, end_iso
+        )
+    }
+
+    /// Parse CalDAV WebDAV XML `<multistatus>` response containing embedded VEVENT data.
+    pub fn parse_multistatus_response(
+        &self,
+        calendar_id: &str,
+        raw_xml: &str,
+    ) -> Result<Vec<CalendarEvent>, CalendarError> {
+        let mut events = Vec::new();
+
+        // Extract <c:calendar-data> or <calendar-data> text blocks
+        for block in raw_xml.split("<c:calendar-data>") {
+            if let Some((ics_data, _)) = block.split_once("</c:calendar-data>") {
+                let clean_ics = ics_data.trim();
+                if !clean_ics.is_empty() {
+                    let event_id = format!("caldav-evt-{}", events.len() + 1);
+                    if let Ok(event) =
+                        IcalParserAdapter::parse_ical(&event_id, &self.account_id, calendar_id, clean_ics)
+                    {
+                        events.push(event);
+                    }
+                }
+            }
+        }
+
+        Ok(events)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn build_report_query_format() {
+        let query = CalDavClient::build_report_query("20240101T000000Z", "20240201T000000Z");
+        assert!(query.contains("20240101T000000Z"));
+        assert!(query.contains("20240201T000000Z"));
+        assert!(query.contains("<c:calendar-query"));
+    }
+
+    #[test]
+    fn parse_multistatus_response_extracts_events() {
+        let client = CalDavClient::new("acct-1");
+        let xml_response = r#"<?xml version="1.0" encoding="utf-8"?>
+        <d:multistatus xmlns:d="DAV:" xmlns:c="urn:ietf:params:xml:ns:caldav">
+            <d:response>
+                <d:href>/calendars/user/work/evt1.ics</d:href>
+                <d:propstat>
+                    <d:prop>
+                        <c:calendar-data>BEGIN:VCALENDAR
+VERSION:2.0
+BEGIN:VEVENT
+SUMMARY:Product Planning
+LOCATION:Boardroom
+END:VEVENT
+END:VCALENDAR</c:calendar-data>
+                    </d:prop>
+                </d:propstat>
+            </d:response>
+        </d:multistatus>"#;
+
+        let events = client
+            .parse_multistatus_response("cal-work", xml_response)
+            .expect("parse succeeds");
+
+        assert_eq!(events.len(), 1);
+        assert_eq!(events[0].summary, "Product Planning");
+        assert_eq!(events[0].location, Some("Boardroom".to_string()));
+    }
+}
diff --git a/crates/nuncio-cal/src/lib.rs b/crates/nuncio-cal/src/lib.rs
index 2d21c6d..6ec3c23 100644
--- a/crates/nuncio-cal/src/lib.rs
+++ b/crates/nuncio-cal/src/lib.rs
@@ -1,7 +1,9 @@
 //! iCalendar (RFC 5545), CalDAV (RFC 4791), and recurrence engine for Nuncio.
 
+pub mod caldav;
 pub mod parser;
 pub mod rrule;
 
+pub use caldav::CalDavClient;
 pub use parser::{CalendarError, IcalParserAdapter};
 pub use rrule::RecurrenceEngine;
-- 
2.54.0