huskies: merge 615_story_extract_timer_service

server/src/service/timer/parse.rs

@@ -0,0 +1,179 @@
+//! Pure parsing logic for timer bot-commands and time display formatting.
+//!
+//! No side effects: no filesystem access, no clock reads.
+
+use chrono::{DateTime, Local, Utc};
+use chrono_tz::Tz;
+
+use crate::chat::util::strip_bot_mention;
+
+// ── Command types ──────────────────────────────────────────────────────────
+
+/// A parsed `timer` command.
+#[derive(Debug, PartialEq)]
+pub enum TimerCommand {
+    /// `timer <story_id_or_number> <HH:MM>` — schedule a deferred start.
+    Schedule {
+        story_number_or_id: String,
+        hhmm: String,
+    },
+    /// `timer list` — list all pending timers.
+    List,
+    /// `timer cancel <story_id_or_number>` — remove a pending timer.
+    Cancel { story_number_or_id: String },
+    /// Malformed arguments.
+    BadArgs,
+}
+
+// ── Command extraction ─────────────────────────────────────────────────────
+
+/// Parse a `timer` command from a raw message body.
+///
+/// Strips the bot mention prefix and matches the `timer` keyword.
+/// Returns `None` when the message is not a timer command at all.
+pub fn extract_timer_command(
+    message: &str,
+    bot_name: &str,
+    bot_user_id: &str,
+) -> Option<TimerCommand> {
+    let stripped = strip_bot_mention(message, bot_name, bot_user_id);
+    let trimmed = stripped
+        .trim()
+        .trim_start_matches(|c: char| !c.is_alphanumeric());
+
+    let (cmd, args) = match trimmed.split_once(char::is_whitespace) {
+        Some((c, a)) => (c, a.trim()),
+        None => (trimmed, ""),
+    };
+
+    if !cmd.eq_ignore_ascii_case("timer") {
+        return None;
+    }
+
+    // `timer` with no args or `timer list`
+    if args.is_empty() || args.eq_ignore_ascii_case("list") {
+        return Some(TimerCommand::List);
+    }
+
+    let (sub, rest) = match args.split_once(char::is_whitespace) {
+        Some((s, r)) => (s, r.trim()),
+        None => (args, ""),
+    };
+
+    // `timer cancel <id>`
+    if sub.eq_ignore_ascii_case("cancel") {
+        if rest.is_empty() {
+            return Some(TimerCommand::BadArgs);
+        }
+        return Some(TimerCommand::Cancel {
+            story_number_or_id: rest.to_string(),
+        });
+    }
+
+    // `timer <id> <HH:MM>`
+    if rest.is_empty() {
+        return Some(TimerCommand::BadArgs);
+    }
+
+    Some(TimerCommand::Schedule {
+        story_number_or_id: sub.to_string(),
+        hhmm: rest.to_string(),
+    })
+}
+
+// ── Display helpers ────────────────────────────────────────────────────────
+
+/// Format a UTC instant for display in the given timezone (or local time when
+/// `timezone` is `None`).  Returns `(formatted_string, label)` where `label`
+/// is either the IANA timezone name or `"server local time"`.
+pub(super) fn format_in_timezone(dt: DateTime<Utc>, timezone: Option<&str>) -> (String, String) {
+    match timezone.and_then(|s| s.parse::<Tz>().ok()) {
+        Some(tz) => {
+            let tz_time = dt.with_timezone(&tz);
+            (tz_time.format("%Y-%m-%d %H:%M").to_string(), tz.to_string())
+        }
+        None => {
+            let local_time = dt.with_timezone(&Local);
+            (
+                local_time.format("%Y-%m-%d %H:%M").to_string(),
+                "server local time".to_string(),
+            )
+        }
+    }
+}
+
+// ── Tests ──────────────────────────────────────────────────────────────────
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn non_timer_command_returns_none() {
+        assert!(extract_timer_command("Timmy help", "Timmy", "@bot:home").is_none());
+    }
+
+    #[test]
+    fn timer_list_no_args() {
+        assert_eq!(
+            extract_timer_command("Timmy timer", "Timmy", "@bot:home"),
+            Some(TimerCommand::List)
+        );
+    }
+
+    #[test]
+    fn timer_list_explicit() {
+        assert_eq!(
+            extract_timer_command("Timmy timer list", "Timmy", "@bot:home"),
+            Some(TimerCommand::List)
+        );
+    }
+
+    #[test]
+    fn timer_cancel_story_id() {
+        assert_eq!(
+            extract_timer_command("Timmy timer cancel 421_story_foo", "Timmy", "@bot:home"),
+            Some(TimerCommand::Cancel {
+                story_number_or_id: "421_story_foo".to_string()
+            })
+        );
+    }
+
+    #[test]
+    fn timer_cancel_no_arg_is_bad_args() {
+        assert_eq!(
+            extract_timer_command("Timmy timer cancel", "Timmy", "@bot:home"),
+            Some(TimerCommand::BadArgs)
+        );
+    }
+
+    #[test]
+    fn timer_schedule_with_story_id() {
+        assert_eq!(
+            extract_timer_command("Timmy timer 421_story_foo 14:30", "Timmy", "@bot:home"),
+            Some(TimerCommand::Schedule {
+                story_number_or_id: "421_story_foo".to_string(),
+                hhmm: "14:30".to_string(),
+            })
+        );
+    }
+
+    #[test]
+    fn timer_schedule_with_number() {
+        assert_eq!(
+            extract_timer_command("Timmy timer 421 14:30", "Timmy", "@bot:home"),
+            Some(TimerCommand::Schedule {
+                story_number_or_id: "421".to_string(),
+                hhmm: "14:30".to_string(),
+            })
+        );
+    }
+
+    #[test]
+    fn timer_schedule_missing_time_is_bad_args() {
+        assert_eq!(
+            extract_timer_command("Timmy timer 421_story_foo", "Timmy", "@bot:home"),
+            Some(TimerCommand::BadArgs)
+        );
+    }
+}