refactor(commands): separate commands definitions and other code into modules

crates/commands/src/tree.rs

@@ -0,0 +1,57 @@
+use crate::{commands::Command, Token};
+use std::{cmp::Ordering, collections::HashMap};
+
+#[derive(Debug, Clone)]
+pub struct TreeBranch {
+    pub current_command_key: Option<String>,
+    /// branches.keys(), but sorted by specificity
+    pub possible_tokens: Vec<Token>,
+    pub branches: HashMap<Token, TreeBranch>,
+}
+
+impl TreeBranch {
+    pub fn register_command(&mut self, command: Command) {
+        let mut current_branch = self;
+        // iterate over tokens in command
+        for token in command.tokens {
+            // recursively get or create a sub-branch for each token
+            current_branch = current_branch.branches.entry(token).or_insert(TreeBranch {
+                current_command_key: None,
+                possible_tokens: vec![],
+                branches: HashMap::new(),
+            })
+        }
+        // when we're out of tokens, add an Empty branch with the callback and no sub-branches
+        current_branch.branches.insert(
+            Token::Empty,
+            TreeBranch {
+                current_command_key: Some(command.cb),
+                possible_tokens: vec![],
+                branches: HashMap::new(),
+            },
+        );
+    }
+
+    pub fn sort_tokens(&mut self) {
+        for branch in self.branches.values_mut() {
+            branch.sort_tokens();
+        }
+
+        // put Value tokens at the end
+        // i forget exactly how this works
+        // todo!: document this before PR mergs
+        self.possible_tokens = self
+            .branches
+            .keys()
+            .into_iter()
+            .map(|v| v.clone())
+            .collect();
+        self.possible_tokens.sort_by(|v, _| {
+            if matches!(v, Token::Value(_)) {
+                Ordering::Greater
+            } else {
+                Ordering::Less
+            }
+        });
+    }
+}