Score diffs

Signed-off-by: prescientmoon <git@moonythm.dev>

src/arcaea/play.rs

@@ -255,7 +255,7 @@ impl Play {
 		author: Option<&poise::serenity_prelude::User>,
 	) -> Result<(CreateEmbed, Option<CreateAttachment>), Error> {
 		// {{{ Get previously best score
-		let previously_best = query_as!(
+		let prev_play = query_as!(
 			DbPlay,
 			"
         SELECT * FROM plays
@@ -277,6 +277,8 @@ impl Play {
 			)
 		})?
 		.map(|p| p.to_play());
+		let prev_score = prev_play.as_ref().map(|p| p.score);
+		let prev_zeta_score = prev_play.as_ref().map(|p| p.zeta_score);
 		// }}}
 
 		let attachement_name = format!("{:?}-{:?}-{:?}.png", song.id, self.score.0, index);
@@ -290,43 +292,23 @@ impl Play {
 				"{} [{:?} {}]",
 				&song.title, chart.difficulty, chart.level
 			))
-			.field("Score", format!("{} (+?)", self.score), true)
+			.field("Score", self.score.display_with_diff(prev_score)?, true)
 			.field(
 				"Rating",
-				format!(
-					"{:.2} (+?)",
-					self.score.play_rating_f32(chart.chart_constant)
-				),
+				self.score.display_play_rating(prev_score, chart)?,
 				true,
 			)
 			.field("Grade", format!("{}", self.score.grade()), true)
-			.field("ξ-Score", format!("{} (+?)", self.zeta_score), true)
+			.field(
+				"ξ-Score",
+				self.zeta_score.display_with_diff(prev_zeta_score)?,
+				true,
+			)
 			// {{{ ξ-Rating
 			.field(
 				"ξ-Rating",
-				{
-					let play_rating = self.zeta_score.play_rating_f32(chart.chart_constant);
-					if let Some(previous) = previously_best {
-						let previous_play_rating =
-							previous.zeta_score.play_rating_f32(chart.chart_constant);
-
-						if play_rating >= previous_play_rating {
-							format!(
-								"{:.2} (+{})",
-								play_rating,
-								play_rating - previous_play_rating
-							)
-						} else {
-							format!(
-								"{:.2} (-{})",
-								play_rating,
-								play_rating - previous_play_rating
-							)
-						}
-					} else {
-						format!("{:.2}", play_rating)
-					}
-				},
+				self.zeta_score
+					.display_play_rating(prev_zeta_score, chart)?,
 				true,
 			)
 			// }}}

src/arcaea/score.rs

@@ -1,9 +1,11 @@
-use std::fmt::Display;
+use std::fmt::{Display, Write};
 
 use num::Rational64;
 
 use crate::context::Error;
 
+use super::chart::Chart;
+
 // {{{ Grade
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 pub enum Grade {
@@ -125,6 +127,25 @@ impl Score {
 	pub fn play_rating_f32(self, chart_constant: u32) -> f32 {
 		(self.play_rating(chart_constant)) as f32 / 100.0
 	}
+
+	pub fn display_play_rating(self, prev: Option<Self>, chart: &Chart) -> Result<String, Error> {
+		let mut buffer = String::with_capacity(14);
+
+		let play_rating = self.play_rating_f32(chart.chart_constant);
+		write!(buffer, "{:.2}", play_rating)?;
+
+		if let Some(prev) = prev {
+			let prev_play_rating = prev.play_rating_f32(chart.chart_constant);
+
+			if play_rating >= prev_play_rating {
+				write!(buffer, " (+{:.2})", play_rating - prev_play_rating)?;
+			} else {
+				write!(buffer, " (-{:.2})", play_rating - prev_play_rating)?;
+			}
+		}
+
+		Ok(buffer)
+	}
 	// }}}
 	// {{{ Score => grade
 	#[inline]
@@ -307,6 +328,41 @@ impl Score {
 		}
 	}
 	// }}}
+	// {{{ Display self with diff
+	/// Similar to the display implementation, but without the padding
+	/// to at least 7 digits.
+	fn display_mini_into(self, buffer: &mut String) -> Result<(), Error> {
+		let score = self.0;
+		if self.0 < 1_000 {
+			write!(buffer, "{}", score)?;
+		} else if self.0 < 1_000_000 {
+			write!(buffer, "{}'{:0>3}", (score / 1000), score % 1000)?;
+		} else {
+			write!(buffer, "{}", self)?;
+		}
+
+		Ok(())
+	}
+
+	pub fn display_with_diff(self, prev: Option<Self>) -> Result<String, Error> {
+		let mut buffer = String::with_capacity(24);
+		write!(buffer, "{}", self)?;
+
+		if let Some(prev) = prev {
+			write!(buffer, " (")?;
+			if self >= prev {
+				write!(buffer, "+")?;
+				Score(self.0 - prev.0).display_mini_into(&mut buffer)?;
+			} else {
+				write!(buffer, "-")?;
+				Score(prev.0 - self.0).display_mini_into(&mut buffer)?;
+			}
+			write!(buffer, ")")?;
+		}
+
+		Ok(buffer)
+	}
+	// }}}
 }
 
 impl Display for Score {

src/assets.rs

@@ -1,4 +1,3 @@
-#![allow(dead_code)]
 use std::{cell::RefCell, env::var, path::PathBuf, str::FromStr, sync::OnceLock};
 
 use freetype::{Face, Library};