Calendar files

use ical.qweruse ics_calendar from ical      // Quillo 0.6: only these

icalendar = "0.16"chrono = "0.4"

// "Add to calendar" for a booking.////   quillo run ical.qwe      then open http://localhost:8080/booking.icsuse "ical.qwer"route GET /booking.ics = respond(200, ics_calendar([{    title: "Table for two at Quillo Café",    start: "2026-11-20T19:00:00+01:00",    end: "2026-11-20T21:00:00+01:00",    location: "Keizersgracht 1, Amsterdam",    uid: "booking-4521@quillo.example",}])?, { "content-type": "text/calendar; charset=utf-8", "content-disposition": "attachment; filename=booking.ics" })

//! Calendar files (.ics) for events, bookings and reminders: added to Google Calendar, Outlook and Apple Calendar in a click.//! version: 1.0.0//!//! [dependencies]//! icalendar = "0.16"//! chrono = "0.4"use chrono::{DateTime, TimeZone, Utc};use icalendar::{Calendar, Component, Event, EventLike};use serde_json::Value;fn time(v: Option<&Value>, what: &str) -> Result<DateTime<Utc>, String> {    match v {        Some(Value::Number(n)) => n.as_i64().and_then(|ms| Utc.timestamp_millis_opt(ms).single()).ok_or(format!("`{}` is out of range", what)),        Some(Value::String(s)) => DateTime::parse_from_rfc3339(s).map(|d| d.with_timezone(&Utc)).map_err(|e| format!("`{}`: {} ({})", what, e, s)),        _ => Err(format!("each event has `{}`: milliseconds since 1970 or an RFC 3339 time", what)),    }}/// An .ics file of `events`, each a map: `title`, `start` and `end` (ms or "2026-11-20T18:00:00+01:00"), and optional `description`, `location`, `url` and `uid` (keep it the same to update an event).pub fn ics_calendar(events: Vec<serde_json::Value>) -> Result<String, String> {    let mut cal = Calendar::new();    for (i, e) in events.iter().enumerate() {        let text = |k: &str| e.get(k).and_then(|v| v.as_str()).map(str::to_string);        let mut ev = Event::new();        ev.summary(&text("title").ok_or(format!("event {} has no title", i + 1))?);        ev.starts(time(e.get("start"), "start")?);        ev.ends(time(e.get("end"), "end")?);        if let Some(d) = text("description") { ev.description(&d); }        if let Some(l) = text("location") { ev.location(&l); }        if let Some(u) = text("url") { ev.add_property("URL", &u); }        if let Some(u) = text("uid") { ev.uid(&u); }        cal.push(ev.done());    }    Ok(cal.done().to_string())}