Implement dummy chess solver

It chooses a random available move ¯\_(ツ)_/¯

rs/src/ui.rs

@@ -182,10 +182,9 @@ impl Ui {
                     let error = format!("No moves possible from {}", position);
                     Err(error)
                 }
-                Ok(positions) => Ok(positions
-                    .iter()
-                    .map(|pos| format!("{}", pos))
-                    .collect()),
+                Ok(positions) => {
+                    Ok(positions.map(|pos| format!("{}", pos)).collect())
+                }
             }
         } else {
             Err("get_moves takes 1 arg".to_owned())
@@ -208,6 +207,29 @@ impl Ui {
             Err("make_move takes 2 args".to_owned())
         }
     }
+    fn choose_move(&self, args: &[&str]) -> Result<String, String> {
+        if let [color_str] = args {
+            if let [color_char] = color_str.chars().collect::<Vec<char>>()[..]
+            {
+                match self.engine.choose_move(
+                    &board::Color::parse(color_char).map_err(|_| {
+                        format!("Couldn't parse color code {}", color_char)
+                    })?,
+                ) {
+                    Some((source, target)) => {
+                        Ok(format!("{},{}", source, target))
+                    }
+                    None => {
+                        Err(format!("No move possible for {}", color_char))
+                    }
+                }
+            } else {
+                Err(format!("Invalid color string {}", color_str))
+            }
+        } else {
+            Err("choose_move takes 1 arg".to_owned())
+        }
+    }
     fn handle_command(&mut self, s: &str) -> Result<String, String> {
         let mut cmd = s.split(',');
         // There will be at least an empty string => otherwise panic
@@ -218,6 +240,7 @@ impl Ui {
             "get_moves" => self.get_moves(&args),
             "make_move" => self.make_move(&args),
             "set_state" => self.set_state(&args),
+            "choose_move" => self.choose_move(&args),
             "" => Err("No command given".to_owned()),
             _ => Err("Invalid command".to_owned()),
         }