get_good_move function

klondike-cli/src/main.rs

@@ -195,32 +195,7 @@ fn find_valid_instruction(
 		.then_some(instruction)
 }
 
-fn main() -> Result<(), std::io::Error> {
-	let mut session = Session::new(Klondike::new_random_default());
-	let mut input = String::new();
-	loop {
-		// display game
-		println!("{}", Displayed(session.state()));
-
-		// parse input
-		input.clear();
-		std::io::stdin().read_line(&mut input)?;
-		let Ok(instruction) = input.trim().parse() else {
-			println!("Invalid instruction.");
-			continue;
-		};
-
-		// run game
-		match instruction {
-			SessionInstruction::New => session = Session::new(Klondike::new_random_default()),
-			SessionInstruction::Undo => session.undo(),
-			SessionInstruction::Exit => break Ok(()),
-			SessionInstruction::Hint => {
-				for instruction in session.possible_instructions() {
-					println!("{instruction:?}");
-				}
-			}
-			SessionInstruction::Auto => {
+fn get_good_move(state: &Klondike) -> Option<KlondikeInstruction> {
 	fn useless_moves(instruction: &KlondikeInstruction) -> bool {
 		!matches!(
 			instruction,
@@ -231,10 +206,7 @@ fn main() -> Result<(), std::io::Error> {
 			})
 		)
 	}
-				fn instruction_priority(
-					state: &Klondike,
-					instruction: &KlondikeInstruction,
-				) -> usize {
+	fn instruction_priority(state: &Klondike, instruction: &KlondikeInstruction) -> usize {
 		// 1 Move into foundation
 		// 2 T->T Move to reveal new card (moving a non-king to reveal empty tableau also counts)
 		// 3 Move from stock
@@ -261,11 +233,39 @@ fn main() -> Result<(), std::io::Error> {
 			KlondikeInstruction::RotateStock => 4,
 		}
 	}
-				if let Some(instruction) = session
+	state
 		.possible_instructions()
 		.filter(useless_moves)
-					.min_by_key(|ins| instruction_priority(session.state(), ins))
-				{
+		.min_by_key(|ins| instruction_priority(state, ins))
+}
+
+fn main() -> Result<(), std::io::Error> {
+	let mut session = Session::new(Klondike::new_random_default());
+	let mut input = String::new();
+	loop {
+		// display game
+		println!("{}", Displayed(session.state()));
+
+		// parse input
+		input.clear();
+		std::io::stdin().read_line(&mut input)?;
+		let Ok(instruction) = input.trim().parse() else {
+			println!("Invalid instruction.");
+			continue;
+		};
+
+		// run game
+		match instruction {
+			SessionInstruction::New => session = Session::new(Klondike::new_random_default()),
+			SessionInstruction::Undo => session.undo(),
+			SessionInstruction::Exit => break Ok(()),
+			SessionInstruction::Hint => {
+				for instruction in session.possible_instructions() {
+					println!("{instruction:?}");
+				}
+			}
+			SessionInstruction::Auto => {
+				if let Some(instruction) = get_good_move(session.state()) {
 					session.process_instruction(instruction);
 				} else {
 					println!("No valid moves!");