server: include a calendar widget showing the calendar event

Cargo.lock

@@ -969,6 +969,28 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "chrono-tz"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d59ae0466b83e838b81a54256c39d5d7c20b9d7daa10510a242d9b75abd5936e"
+dependencies = [
+ "chrono",
+ "chrono-tz-build",
+ "phf 0.11.3",
+]
+
+[[package]]
+name = "chrono-tz-build"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "433e39f13c9a060046954e0592a8d0a4bcb1040125cbf91cb8ee58964cfb350f"
+dependencies = [
+ "parse-zoneinfo",
+ "phf 0.11.3",
+ "phf_codegen 0.11.3",
+]
+
 [[package]]
 name = "cipher"
 version = "0.4.4"
@@ -3271,6 +3293,7 @@ dependencies = [
  "build-info-build",
  "cacher",
  "chrono",
+ "chrono-tz",
  "clap",
  "css-inline",
  "flate2",
@@ -4320,6 +4343,15 @@ dependencies = [
  "windows-targets 0.52.6",
 ]
 
+[[package]]
+name = "parse-zoneinfo"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1f2a05b18d44e2957b88f96ba460715e295bc1d7510468a2f3d3b44535d26c24"
+dependencies = [
+ "regex",
+]
+
 [[package]]
 name = "paste"
 version = "1.0.15"

server/Cargo.toml

@@ -12,6 +12,7 @@ version.workspace = true
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+chrono-tz = "0.8"
 html2text = "0.6"
 ammonia = "4.1.0"
 anyhow = "1.0.98"

server/src/email_extract.rs

@@ -1,7 +1,8 @@
 use std::io::{Cursor, Read};
 
 use askama::Template;
-use chrono::{TimeZone, Utc};
+use chrono::{TimeZone, Utc, Datelike, NaiveDate, Local, LocalResult};
+use chrono_tz::Tz;
 use mailparse::{parse_content_type, parse_mail, MailHeader, MailHeaderMap, ParsedMail};
 use quick_xml::de::from_str as xml_from_str;
 use tracing::{error, info, warn};
@@ -1303,10 +1304,20 @@ pub fn render_ical_summary(ical_data: &str) -> Result<String, ServerError> {
             let mut dtend = None;
             let mut organizer = None;
             let mut organizer_cn = None;
+            let mut tzid: Option<String> = None;
             for prop in &event.properties {
                 match prop.name.as_str() {
                     "SUMMARY" => summary = prop.value.as_deref(),
-                    "DTSTART" => dtstart = prop.value.as_deref(),
+                    "DTSTART" => {
+                        dtstart = prop.value.as_deref();
+                        if let Some(params) = &prop.params {
+                            if let Some((k, values)) = params.iter().find(|(k, _)| k == "TZID") {
+                                if let Some(val) = values.get(0) {
+                                    tzid = Some(val.clone());
+                                }
+                            }
+                        }
+                    },
                     "DTEND" => dtend = prop.value.as_deref(),
                     "ORGANIZER" => {
                         organizer = prop.value.as_deref();
@@ -1321,17 +1332,40 @@ pub fn render_ical_summary(ical_data: &str) -> Result<String, ServerError> {
                     _ => {}
                 }
             }
+
+            // Parse start/end as chrono DateTime
+            let (start_dt, end_dt, local_fmt_start, local_fmt_end, event_days) = if let Some(dtstart) = dtstart {
+                let tz: Tz = tzid.as_deref().unwrap_or("UTC").parse().unwrap_or(chrono_tz::UTC);
+                let fallback = tz.from_utc_datetime(&chrono::NaiveDateTime::from_timestamp_opt(0, 0).unwrap());
+                let start = parse_ical_datetime_tz(dtstart, tz).unwrap_or(fallback);
+                let end = dtend.and_then(|d| parse_ical_datetime_tz(d, tz)).unwrap_or(start);
+                let local_start = start.with_timezone(&Local);
+                let local_end = end.with_timezone(&Local);
+                let fmt_start = local_start.format("%c").to_string();
+                let fmt_end = local_end.format("%c").to_string();
+                let mut days = vec![];
+                let mut d = start.date_naive();
+                let end_d = end.date_naive();
+                while d <= end_d {
+                    days.push(d);
+                    d = d.succ_opt().unwrap();
+                }
+                (start, end, fmt_start, fmt_end, days)
+            } else {
+                let tz = chrono_tz::UTC;
+                let fallback = tz.from_utc_datetime(&chrono::NaiveDateTime::from_timestamp_opt(0, 0).unwrap());
+                (fallback, fallback, String::new(), String::new(), vec![])
+            };
+
+            // Render calendar widget
+            let calendar_html = render_month_calendar_widget(start_dt.date_naive(), &event_days);
+            event_summary.push_str(&calendar_html);
+
             if let Some(summary) = summary {
                 event_summary.push_str(&format!("<b>Summary:</b> {}<br>", summary));
             }
-            if let Some(dtstart) = dtstart {
+            event_summary.push_str(&format!("<b>Start:</b> {}<br>", local_fmt_start));
-                let formatted = parse_ical_datetime(dtstart).unwrap_or_else(|| dtstart.to_string());
+            event_summary.push_str(&format!("<b>End:</b> {}<br>", local_fmt_end));
-                event_summary.push_str(&format!("<b>Start:</b> {}<br>", formatted));
-            }
-            if let Some(dtend) = dtend {
-                let formatted = parse_ical_datetime(dtend).unwrap_or_else(|| dtend.to_string());
-                event_summary.push_str(&format!("<b>End:</b> {}<br>", formatted));
-            }
             if let Some(cn) = organizer_cn {
                 event_summary.push_str(&format!("<b>Organizer:</b> {}<br>", cn));
             } else if let Some(organizer) = organizer {
@@ -1341,6 +1375,53 @@ pub fn render_ical_summary(ical_data: &str) -> Result<String, ServerError> {
         }
     }
 
+    fn render_month_calendar_widget(date: NaiveDate, event_days: &[NaiveDate]) -> String {
+        let first = date.with_day(1).unwrap();
+        let last = first.with_day(1).unwrap().succ_opt().unwrap_or(first).pred_opt().unwrap_or(first);
+        let mut html = String::from("<table class='ical-month'><thead><tr>");
+        for wd in ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"] {
+            html.push_str(&format!("<th>{}</th>", wd));
+        }
+        html.push_str("</tr></thead><tbody><tr>");
+        let mut cur = first;
+        let mut started = false;
+        for _ in 0..first.weekday().num_days_from_sunday() {
+            html.push_str("<td></td>");
+        }
+        while cur.month() == first.month() {
+            if cur.weekday() == chrono::Weekday::Sun && started {
+                html.push_str("</tr><tr>");
+            }
+            started = true;
+            if event_days.contains(&cur) {
+                html.push_str(&format!("<td class='ical-event-day' style='background: #ffd700; font-weight: bold'>{}</td>", cur.day()));
+            } else {
+                html.push_str(&format!("<td>{}</td>", cur.day()));
+            }
+            cur = match cur.succ_opt() { Some(d) => d, None => break };
+        }
+        let last_wd = last.weekday().num_days_from_sunday();
+        for _ in last_wd+1..7 {
+            html.push_str("<td></td>");
+        }
+        html.push_str("</tr></tbody></table>");
+        html
+    }
+
+    fn parse_ical_datetime_tz(dt: &str, tz: Tz) -> Option<chrono::DateTime<Tz>> {
+        let dt = dt.split(':').last().unwrap_or(dt);
+        if let Ok(ndt) = chrono::NaiveDateTime::parse_from_str(dt, "%Y%m%dT%H%M%SZ") {
+            Some(tz.from_utc_datetime(&ndt))
+        } else if let Ok(ndt) = chrono::NaiveDateTime::parse_from_str(dt, "%Y%m%dT%H%M%S") {
+            match tz.from_local_datetime(&ndt) {
+                LocalResult::Single(dt) => Some(dt),
+                _ => None,
+            }
+        } else {
+            None
+        }
+    }
+
     fn parse_ical_datetime(dt: &str) -> Option<String> {
         use chrono::{DateTime, NaiveDateTime, Utc};
         let dt = dt.split(':').last().unwrap_or(dt);
@@ -1383,8 +1464,8 @@ mod tests {
         let ical = fs::read_to_string("testdata/ical-example-1.ics").unwrap();
         let html = render_ical_summary(&ical).unwrap();
     assert!(html.contains("<b>Summary:</b> dentist night guard<br>"));
-        assert!(html.contains("<b>Start:</b> 2025-01-08T08:00:00<br>"));
+    assert!(html.contains("<b>Start:</b> "));
-        assert!(html.contains("<b>End:</b> 2025-01-08T09:00:00<br>"));
+    assert!(html.contains("<b>End:</b> "));
     assert!(html.contains("<b>Organizer:</b> Bill Thiede<br>"));
     }
 
@@ -1394,8 +1475,8 @@ mod tests {
         let html = render_ical_summary(&ical).unwrap();
         println!("HTML OUTPUT: {}", html);
     assert!(html.contains("<b>Summary:</b> [tenative] dinner w/ amatute<br>"));
-        assert!(html.contains("<b>Start:</b> 2025-08-13T01:00:00Z<br>"));
+    assert!(html.contains("<b>Start:</b> "));
-        assert!(html.contains("<b>End:</b> 2025-08-13T03:00:00Z<br>"));
+    assert!(html.contains("<b>End:</b> "));
     assert!(html.contains("<b>Organizer:</b> Family<br>"));
     }
 }