add discord guild icon updating by event schedule

src/discordbot/guild_icon.rs

@@ -0,0 +1,142 @@
+use chrono::{Datelike, Duration, Local, TimeZone, Utc};
+use chrono_tz::Europe::Warsaw;
+use serenity::all::{Context, CreateAttachment, EditGuild, Guild, GuildId};
+use std::time::Duration as StdDuration;
+use tracing::{error, info, warn};
+
+const MAIN_GUILD_ID: GuildId = GuildId::new(447075692664979466);
+
+enum Event {
+    Normal,
+    PolskaGórą,
+    PrideMonth,
+    ValentineDay,
+    Rogaliki,
+    Halloween,
+    Christmas,
+    NewYears,
+    AnniversaryGractwo,
+    AnniversaryTF2,
+    AnniversaryMinecraft,
+    StarWarsDay,
+}
+
+impl Event {
+    fn icon(&self) -> &str {
+        use Event as E;
+        match self {
+            E::PolskaGórą => "./assets/logo-x512-polish.png",
+            E::PrideMonth => "./assets/logo-x512-lgbtflag.png",
+            E::StarWarsDay => "./assets/logo-x512-starwars.png",
+            _ => "./assets/logo-x512.png",
+        }
+    }
+}
+
+fn get_current_event() -> Event {
+    let today = Local::now();
+    let (month, day) = (today.month(), today.day());
+
+    match (day, month) {
+        (1, 1) => Event::NewYears,
+        (2..=6, 1) => Event::Christmas,
+        (14, 2) => Event::ValentineDay,
+        (1..=3, 5) => Event::PolskaGórą,
+        (4, 5) => Event::StarWarsDay,
+        (17, 5) => Event::AnniversaryMinecraft,
+        (7, 6) => Event::AnniversaryGractwo,
+        (_, 6) => Event::PrideMonth,
+        (24, 8) => Event::AnniversaryTF2,
+        (10, 10) => Event::AnniversaryTF2,
+        (31, 10) => Event::Halloween,
+        (11, 11) => Event::Rogaliki,
+        (24..=30, 12) => Event::Christmas,
+        (31, 12) => Event::NewYears,
+        _ => Event::Normal,
+    }
+}
+
+pub fn init_service(ctx: &Context, guild_id: &GuildId) {
+    let (ctx, guild_id) = (ctx.clone(), guild_id.clone());
+    info!("Initialising guild name/icon automation service...");
+
+    if guild_id != MAIN_GUILD_ID {
+        info!("Guild name/icon automation service not initialised; Bot not running on main guild.");
+        return;
+    }
+
+    tokio::spawn(async move {
+        run_icon_service(ctx, guild_id).await;
+    });
+}
+
+pub async fn run_icon_service(ctx: Context, guild_id: GuildId) {
+    loop {
+        update_icon(&ctx, guild_id).await.ok();
+        sleep_until_next_midnight().await;
+    }
+}
+
+async fn update_icon(ctx: &Context, guild_id: GuildId) -> Result<(), String> {
+    let mut guild = match Guild::get(&ctx.http, guild_id).await {
+        Ok(g) => g,
+        Err(e) => {
+            error!("Could not get guild info...");
+            return Err("Could not get guild info: {e}".to_string());
+        }
+    };
+    let event = get_current_event();
+
+    let icon = match CreateAttachment::path(event.icon()).await {
+        Ok(i) => i,
+        Err(e) => {
+            error!("Could not create icon attachment...");
+            return Err("Could not create icon attachment: {e}".to_string());
+        }
+    };
+    match guild
+        .edit(&ctx.http, EditGuild::new().icon(Some(&icon)))
+        .await
+    {
+        Ok(_) => info!("Guild icon updated."),
+        Err(e) => {
+            error!("Could not update guild icon...");
+            return Err("Could not update guild icon: {e}".to_string());
+        }
+    };
+
+    Ok(())
+}
+
+async fn sleep_until_next_midnight() {
+    let now = Utc::now().with_timezone(&Warsaw);
+    let tomorrow = now.date_naive() + chrono::Duration::days(1);
+
+    let next_midnight = match Warsaw
+        .with_ymd_and_hms(
+            tomorrow.year_ce().1 as i32,
+            tomorrow.month(),
+            tomorrow.day(),
+            0,
+            0,
+            0,
+        )
+        .earliest()
+    {
+        Some(nm) => nm,
+        None => Utc::now().with_timezone(&Warsaw) + Duration::minutes(61),
+        // e.g. jumps in time occur at 2AM/3AM, Midnight shouldn't be affected
+        // but even if it was, returning None, a gap shouldn't last more than an hour.
+    };
+
+    let sleeptime = match next_midnight.signed_duration_since(now).to_std() {
+        Ok(t) => t,
+        Err(_) => {
+            warn!("The next midnight is, supposedly, not in the future.");
+            warn!("Sleeping an hour instead...");
+            StdDuration::from_secs(1 * 60 * 60)
+        }
+    };
+
+    tokio::time::sleep(sleeptime).await;
+}

src/discordbot/mod.rs

@@ -11,6 +11,7 @@ const GUILD_ID: &str = "DISCORD_SERVER_ID";
 struct Handler;
 
 mod commands;
+mod guild_icon;
 
 #[async_trait]
 impl EventHandler for Handler {
@@ -31,6 +32,8 @@ impl EventHandler for Handler {
             Ok(_) => info!("Successfully registered commands on the guild.",),
             Err(why) => info!("Failed to register commands on the guild: {why:?}"),
         };
+
+        guild_icon::init_service(&ctx, &guild_id);
     }
 
     async fn interaction_create(&self, ctx: Context, interaction: Interaction) {