Implement setter functions for symbol selection

crates/save/src/lib.rs

@@ -46,6 +46,9 @@ pub enum Error {
     #[error("Failed to serialize savefile")]
     SerializationFailed(binrw::Error),
 
+    #[error("Symbol id is out of range")]
+    SymbolIdOutOfRange,
+
     #[error("Failed to read file")]
     FileReadingFailed(io::Error),
 }

crates/save/src/symbol.rs

@@ -3,7 +3,10 @@ use core::fmt;
 use binrw::{BinRead, BinWrite};
 use substring::Substring;
 
+use crate::{Error, Result};
 
+
+const MAX_SYMBOL_ID: u32 = 20;
 const SYMBOL_PARTS: &str = include_str!("symbol_parts.txt");
 const SYMBOL_PART_WIDTH: usize = 6;
 const SYMBOL_PART_HEIGTH: usize = 3;
@@ -11,7 +14,42 @@ const SYMBOL_PART_HEIGTH: usize = 3;
 
 #[derive(Debug, Clone, Copy, BinRead, BinWrite)]
 pub struct Symbol {
-    pub id: u32,
+    #[br(assert(id < MAX_SYMBOL_ID))]
+    id: u32,
+}
+
+impl Symbol {
+    pub fn set_by_id(&mut self, id: u32) -> Result<()> {
+        if id > MAX_SYMBOL_ID {
+            return Err(Error::SymbolIdOutOfRange);
+        }
+
+        self.id = id;
+
+        Ok(())
+    }
+
+    pub fn wrapping_next(&self) -> Self {
+        let id = self.id + 1;
+        if id > MAX_SYMBOL_ID {
+            Self { id: 0 }
+        } else {
+            Self { id }
+        }
+    }
+
+    pub fn wrapping_previous(&self) -> Self {
+        match self.id.checked_sub(1) {
+            Some(id) => Self { id },
+            None => Self { id: MAX_SYMBOL_ID },
+        }
+    }
+}
+
+impl AsRef<u32> for Symbol {
+    fn as_ref(&self) -> &u32 {
+        &self.id
+    }
 }
 
 impl fmt::Display for Symbol {

crates/save/src/test.rs

@@ -16,7 +16,7 @@ fn general_info() {
     assert_eq!(savefile.robe_color(), RobeColor::Red);
     assert_eq!(savefile.robe_tier(), 4);
 
-    assert_eq!(savefile.symbol.id, 7);
+    assert_eq!(savefile.symbol.as_ref(), &7);
     assert_eq!(savefile.scarf_length, 27);
     assert_eq!(savefile.current_level, 1);
     assert_eq!(savefile.total_collected_symbols, 107);

crates/wayfarer/src/edit.rs

@@ -63,7 +63,7 @@ fn edit_file(cur_savefile: &Savefile, args: &Args) -> Result<Savefile> {
     }
 
     if let Some(val) = args.symbol {
-        savefile.symbol.id = val;
+        savefile.symbol.set_by_id(val)?;
     }
 
     if let Some(color) = &args.robe_color {

crates/wayfarer/src/tui/state.rs

@@ -187,15 +187,7 @@ impl State {
 
                 savefile.scarf_length = new_length;
             }
-            6 => {
-                let next_symbol_id = value.parse()?;
-
-                if next_symbol_id > 20 {
-                    bail!("Symbol id out of range");
-                }
-
-                savefile.symbol.id = next_symbol_id;
-            }
+            6 => savefile.symbol.set_by_id(value.parse()?)?,
             7 => {
                 let new_color = match value {
                     "Red" | "red" => RobeColor::Red,
@@ -244,14 +236,7 @@ impl State {
                     savefile.scarf_length += 1;
                 }
             }
-            6 => {
-                let next_symbol = savefile.symbol.id + 1;
-                savefile.symbol.id = if next_symbol > 20 {
-                    0
-                } else {
-                    savefile.symbol.id + 1
-                };
-            }
+            6 => savefile.symbol = savefile.symbol.wrapping_next(),
             7 => {
                 savefile.set_robe_color(match savefile.robe_color() {
                     RobeColor::Red => RobeColor::White,
@@ -304,14 +289,7 @@ impl State {
                     savefile.scarf_length = savefile.scarf_length.saturating_sub(1);
                 }
             }
-            6 => {
-                let next_symbol = savefile.symbol.id as i32 - 1;
-                savefile.symbol.id = if next_symbol < 0 {
-                    20
-                } else {
-                    next_symbol as u32
-                };
-            }
+            6 => savefile.symbol = savefile.symbol.wrapping_previous(),
             7 => {
                 savefile.set_robe_color(match savefile.robe_color() {
                     RobeColor::Red => RobeColor::White,

crates/wayfarer/src/tui/view/info/stats.rs

@@ -55,7 +55,7 @@ pub(super) fn render<'a>(state: &mut State, frame: &mut Frame, area: Rect) {
         ("Current Level", savefile.current_level_name().to_string()),
         ("Companions Met", savefile.companions_met.to_string()),
         ("Scarf Length", savefile.scarf_length.to_string()),
-        ("Symbol Number", savefile.symbol.id.to_string()),
+        ("Symbol Number", savefile.symbol.as_ref().to_string()),
         ("Robe Color", savefile.robe_color().to_string()),
         ("Robe Tier", savefile.robe_tier().to_string()),
         ("Last Played", savefile.last_played.to_string()),