feat: forced tool tips (#8752)

Force an announcement tooltip in the CLI. This query the gh repo on this
[file](https://raw.githubusercontent.com/openai/codex/main/announcement_tip.toml)
which contains announcements in TOML looking like this:
```
# Example announcement tips for Codex TUI.
# Each [[announcements]] entry is evaluated in order; the last matching one is shown.
# Dates are UTC, formatted as YYYY-MM-DD. The from_date is inclusive and the to_date is exclusive.
# version_regex matches against the CLI version (env!("CARGO_PKG_VERSION")); omit to apply to all versions.
# target_app specify which app should display the announcement (cli, vsce, ...).

[[announcements]]
content = "Welcome to Codex! Check out the new onboarding flow."
from_date = "2024-10-01"
to_date = "2024-10-15"
version_regex = "^0\\.0\\.0$"
target_app = "cli"
``` 

To make this efficient, the announcement is queried on a best effort
basis at the launch of the CLI (no refresh made after this).
This is done in an async way and we display the announcement (with 100%
probability) iff the announcement is available, the cache is correctly
warmed and there is a matching announcement (matching is recomputed for
each new session).

codex-rs/tui/src/tooltips.rs

@@ -2,15 +2,10 @@ use codex_core::features::FEATURES;
 use lazy_static::lazy_static;
 use rand::Rng;
 
+const ANNOUNCEMENT_TIP_URL: &str =
+    "https://raw.githubusercontent.com/openai/codex/main/announcement_tip.toml";
 const RAW_TOOLTIPS: &str = include_str!("../tooltips.txt");
 
-fn beta_tooltips() -> Vec<&'static str> {
-    FEATURES
-        .iter()
-        .filter_map(|spec| spec.stage.beta_announcement())
-        .collect()
-}
-
 lazy_static! {
     static ref TOOLTIPS: Vec<&'static str> = RAW_TOOLTIPS
         .lines()
@@ -25,9 +20,20 @@ lazy_static! {
     };
 }
 
-pub(crate) fn random_tooltip() -> Option<&'static str> {
+fn beta_tooltips() -> Vec<&'static str> {
+    FEATURES
+        .iter()
+        .filter_map(|spec| spec.stage.beta_announcement())
+        .collect()
+}
+
+/// Pick a random tooltip to show to the user when starting Codex.
+pub(crate) fn random_tooltip() -> Option<String> {
+    if let Some(announcement) = announcement::fetch_announcement_tip() {
+        return Some(announcement);
+    }
     let mut rng = rand::rng();
-    pick_tooltip(&mut rng)
+    pick_tooltip(&mut rng).map(str::to_string)
 }
 
 fn pick_tooltip<R: Rng + ?Sized>(rng: &mut R) -> Option<&'static str> {
@@ -40,9 +46,149 @@ fn pick_tooltip<R: Rng + ?Sized>(rng: &mut R) -> Option<&'static str> {
     }
 }
 
+pub(crate) mod announcement {
+    use crate::tooltips::ANNOUNCEMENT_TIP_URL;
+    use crate::version::CODEX_CLI_VERSION;
+    use chrono::NaiveDate;
+    use chrono::Utc;
+    use regex_lite::Regex;
+    use serde::Deserialize;
+    use std::sync::OnceLock;
+    use std::thread;
+    use std::time::Duration;
+
+    static ANNOUNCEMENT_TIP: OnceLock<Option<String>> = OnceLock::new();
+
+    /// Prewarm the cache of the announcement tip.
+    pub(crate) fn prewarm() {
+        let _ = thread::spawn(|| ANNOUNCEMENT_TIP.get_or_init(init_announcement_tip_in_thread));
+    }
+
+    /// Fetch the announcement tip, return None if the prewarm is not done yet.
+    pub(crate) fn fetch_announcement_tip() -> Option<String> {
+        ANNOUNCEMENT_TIP
+            .get()
+            .cloned()
+            .flatten()
+            .and_then(|raw| parse_announcement_tip_toml(&raw))
+    }
+
+    #[derive(Debug, Deserialize)]
+    struct AnnouncementTipRaw {
+        content: String,
+        from_date: Option<String>,
+        to_date: Option<String>,
+        version_regex: Option<String>,
+        target_app: Option<String>,
+    }
+
+    #[derive(Debug, Deserialize)]
+    struct AnnouncementTipDocument {
+        announcements: Vec<AnnouncementTipRaw>,
+    }
+
+    #[derive(Debug)]
+    struct AnnouncementTip {
+        content: String,
+        from_date: Option<NaiveDate>,
+        to_date: Option<NaiveDate>,
+        version_regex: Option<Regex>,
+        target_app: String,
+    }
+
+    fn init_announcement_tip_in_thread() -> Option<String> {
+        thread::spawn(blocking_init_announcement_tip)
+            .join()
+            .ok()
+            .flatten()
+    }
+
+    fn blocking_init_announcement_tip() -> Option<String> {
+        let response = reqwest::blocking::Client::new()
+            .get(ANNOUNCEMENT_TIP_URL)
+            .timeout(Duration::from_millis(2000))
+            .send()
+            .ok()?;
+        response.error_for_status().ok()?.text().ok()
+    }
+
+    pub(crate) fn parse_announcement_tip_toml(text: &str) -> Option<String> {
+        let announcements = toml::from_str::<AnnouncementTipDocument>(text)
+            .map(|doc| doc.announcements)
+            .or_else(|_| toml::from_str::<Vec<AnnouncementTipRaw>>(text))
+            .ok()?;
+
+        let mut latest_match = None;
+        let today = Utc::now().date_naive();
+        for raw in announcements {
+            let Some(tip) = AnnouncementTip::from_raw(raw) else {
+                continue;
+            };
+            if tip.version_matches(CODEX_CLI_VERSION)
+                && tip.date_matches(today)
+                && tip.target_app == "cli"
+            {
+                latest_match = Some(tip.content);
+            }
+        }
+        latest_match
+    }
+
+    impl AnnouncementTip {
+        fn from_raw(raw: AnnouncementTipRaw) -> Option<Self> {
+            let content = raw.content.trim();
+            if content.is_empty() {
+                return None;
+            }
+
+            let from_date = match raw.from_date {
+                Some(date) => Some(NaiveDate::parse_from_str(&date, "%Y-%m-%d").ok()?),
+                None => None,
+            };
+            let to_date = match raw.to_date {
+                Some(date) => Some(NaiveDate::parse_from_str(&date, "%Y-%m-%d").ok()?),
+                None => None,
+            };
+            let version_regex = match raw.version_regex {
+                Some(pattern) => Some(Regex::new(&pattern).ok()?),
+                None => None,
+            };
+
+            Some(Self {
+                content: content.to_string(),
+                from_date,
+                to_date,
+                version_regex,
+                target_app: raw.target_app.unwrap_or("cli".to_string()).to_lowercase(),
+            })
+        }
+
+        fn version_matches(&self, version: &str) -> bool {
+            self.version_regex
+                .as_ref()
+                .is_none_or(|regex| regex.is_match(version))
+        }
+
+        fn date_matches(&self, today: NaiveDate) -> bool {
+            if let Some(from) = self.from_date
+                && today < from
+            {
+                return false;
+            }
+            if let Some(to) = self.to_date
+                && today >= to
+            {
+                return false;
+            }
+            true
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::tooltips::announcement::parse_announcement_tip_toml;
     use rand::SeedableRng;
     use rand::rngs::StdRng;
 
@@ -62,4 +208,104 @@ mod tests {
         let mut rng = StdRng::seed_from_u64(7);
         assert_eq!(expected, pick_tooltip(&mut rng));
     }
+
+    #[test]
+    fn announcement_tip_toml_picks_last_matching() {
+        let toml = r#"
+[[announcements]]
+content = "first"
+from_date = "2000-01-01"
+
+[[announcements]]
+content = "latest match"
+version_regex = ".*"
+target_app = "cli"
+
+[[announcements]]
+content = "should not match"
+to_date = "2000-01-01"
+        "#;
+
+        assert_eq!(
+            Some("latest match".to_string()),
+            parse_announcement_tip_toml(toml)
+        );
+
+        let toml = r#"
+[[announcements]]
+content = "first"
+from_date = "2000-01-01"
+target_app = "cli"
+
+[[announcements]]
+content = "latest match"
+version_regex = ".*"
+
+[[announcements]]
+content = "should not match"
+to_date = "2000-01-01"
+        "#;
+
+        assert_eq!(
+            Some("latest match".to_string()),
+            parse_announcement_tip_toml(toml)
+        );
+    }
+
+    #[test]
+    fn announcement_tip_toml_picks_no_match() {
+        let toml = r#"
+[[announcements]]
+content = "first"
+from_date = "2000-01-01"
+to_date = "2000-01-05"
+
+[[announcements]]
+content = "latest match"
+version_regex = "invalid_version_name"
+
+[[announcements]]
+content = "should not match either "
+target_app = "vsce"
+        "#;
+
+        assert_eq!(None, parse_announcement_tip_toml(toml));
+    }
+
+    #[test]
+    fn announcement_tip_toml_bad_deserialization() {
+        let toml = r#"
+[[announcements]]
+content = 123
+from_date = "2000-01-01"
+        "#;
+
+        assert_eq!(None, parse_announcement_tip_toml(toml));
+    }
+
+    #[test]
+    fn announcement_tip_toml_parse_comments() {
+        let toml = r#"
+# Example announcement tips for Codex TUI.
+# Each [[announcements]] entry is evaluated in order; the last matching one is shown.
+# Dates are UTC, formatted as YYYY-MM-DD. The from_date is inclusive and the to_date is exclusive.
+# version_regex matches against the CLI version (env!("CARGO_PKG_VERSION")); omit to apply to all versions.
+# target_app specify which app should display the announcement (cli, vsce, ...).
+
+[[announcements]]
+content = "Welcome to Codex! Check out the new onboarding flow."
+from_date = "2024-10-01"
+to_date = "2024-10-15"
+target_app = "cli"
+version_regex = "^0\\.0\\.0$"
+
+[[announcements]]
+content = "This is a test announcement"
+        "#;
+
+        assert_eq!(
+            Some("This is a test announcement".to_string()),
+            parse_announcement_tip_toml(toml)
+        );
+    }
 }