add some more stuff from brigadier

25 files changed, 902 insertions, 10 deletions

diff --git a/.gitignore b/.gitignore
index ea8c4bf7..f97818c7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 /target
+/doc
\ No newline at end of file
diff --git a/Cargo.lock b/Cargo.lock
index 67259fef..0eeb6520 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -70,6 +70,9 @@ dependencies = [
 [[package]]
 name = "azalea-brigadier"
 version = "0.1.0"
+dependencies = [
+ "lazy_static",
+]
 
 [[package]]
 name = "azalea-chat"
diff --git a/azalea-brigadier/Cargo.toml b/azalea-brigadier/Cargo.toml
index c617ffb1..3694a4b7 100644
--- a/azalea-brigadier/Cargo.toml
+++ b/azalea-brigadier/Cargo.toml
@@ -1,8 +1,9 @@
 [package]
+edition = "2021"
 name = "azalea-brigadier"
 version = "0.1.0"
-edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+lazy_static = "^1.4"
diff --git a/azalea-brigadier/src/arguments/argument_type.rs b/azalea-brigadier/src/arguments/argument_type.rs
index 4c48d6bb..34d57285 100644
--- a/azalea-brigadier/src/arguments/argument_type.rs
+++ b/azalea-brigadier/src/arguments/argument_type.rs
@@ -5,7 +5,7 @@ use crate::{
     suggestion::{suggestions::Suggestions, suggestions_builder::SuggestionsBuilder},
 };
 
-pub trait ArgumentType<T> {
+pub trait ArgumentType {
     // T parse(StringReader reader) throws CommandSyntaxException;
 
     // default <S> CompletableFuture<Suggestions> listSuggestions(final CommandContext<S> context, final SuggestionsBuilder builder) {
@@ -16,7 +16,7 @@ pub trait ArgumentType<T> {
     //     return Collections.emptyList();
     // }
 
-    fn parse(reader: &mut StringReader) -> Result<T, CommandSyntaxException>;
+    fn parse<T>(reader: &mut StringReader) -> Result<T, CommandSyntaxException>;
 
     fn list_suggestions<S>(
         context: &CommandContext<S>,
diff --git a/azalea-brigadier/src/arguments/bool_argument_type.rs b/azalea-brigadier/src/arguments/bool_argument_type.rs
index d4a33517..f4c03373 100644
--- a/azalea-brigadier/src/arguments/bool_argument_type.rs
+++ b/azalea-brigadier/src/arguments/bool_argument_type.rs
@@ -1,8 +1,19 @@
-struct BoolArgumentType {
-	// private static final Collection<String> EXAMPLES = Arrays.asList("true", "false");
-	const EXAMPLES: &'static [&'static str] = &["true", "false"];
-}
+use crate::context::command_context::CommandContext;
+
+use super::argument_type::ArgumentType;
+
+struct BoolArgumentType {}
+
+impl ArgumentType for BoolArgumentType {}
 
-impl ArgumentType for BoolArgumentType {
-	
-}
\ No newline at end of file
+impl BoolArgumentType {
+    const EXAMPLES: &'static [&'static str] = &["true", "false"];
+
+    fn bool() -> Self {
+        Self {}
+    }
+
+    fn get_bool<S>(context: CommandContext<S>, name: String) {
+        context.get_argument::<bool>(name)
+    }
+}
diff --git a/azalea-brigadier/src/arguments/mod.rs b/azalea-brigadier/src/arguments/mod.rs
index 50b0f09b..487c5db7 100644
--- a/azalea-brigadier/src/arguments/mod.rs
+++ b/azalea-brigadier/src/arguments/mod.rs
@@ -1 +1,7 @@
 pub mod argument_type;
+pub mod bool_argument_type;
+pub mod double_argument_type;
+pub mod float_argument_type;
+pub mod integer_argument_type;
+pub mod long_argument_type;
+pub mod string_argument_type;
diff --git a/azalea-brigadier/src/builder/argument_builder.rs b/azalea-brigadier/src/builder/argument_builder.rs
index e69de29b..8a64a9e4 100644
--- a/azalea-brigadier/src/builder/argument_builder.rs
+++ b/azalea-brigadier/src/builder/argument_builder.rs
@@ -0,0 +1,106 @@
+use crate::{
+    command::Command,
+    redirect_modifier::RedirectModifier,
+    single_redirect_modifier::SingleRedirectModifier,
+    tree::{command_node::CommandNode, root_command_node::RootCommandNode},
+};
+
+pub struct BaseArgumentBuilder<S, T>
+where
+    T: ArgumentBuilder<S, T>,
+{
+    arguments: RootCommandNode<S>,
+    command: dyn Command<S>,
+    requirement: dyn Fn(&S) -> bool,
+    target: Option<dyn CommandNode<S>>,
+    modifier: Option<dyn RedirectModifier<S>>,
+    forks: bool,
+}
+
+pub trait ArgumentBuilder<S, T> {
+    fn this() -> T;
+    fn build(self) -> dyn CommandNode<S>;
+}
+
+impl<S, T> BaseArgumentBuilder<S, T>
+where
+    T: ArgumentBuilder<S, T>,
+{
+    pub fn then(&mut self, command: dyn CommandNode<S>) -> Result<&mut T, String> {
+        if self.target.is_some() {
+            return Err("Cannot add children to a redirected node".to_string());
+        }
+        self.command = command;
+        Ok(self)
+    }
+
+    pub fn arguments(&self) -> &Vec<dyn CommandNode<S>> {
+        &self.arguments.get_children()
+    }
+
+    pub fn executes(&mut self, command: dyn Command<S>) -> &mut T {
+        self.command = command;
+        self
+    }
+
+    pub fn command(&self) -> dyn Command<S> {
+        self.command
+    }
+
+    pub fn requires(&mut self, requirement: dyn Fn(&S) -> bool) -> &mut T {
+        self.requirement = requirement;
+        self
+    }
+
+    pub fn requirement(&self) -> dyn Fn(&S) -> bool {
+        self.requirement
+    }
+
+    pub fn redirect(&mut self, target: dyn CommandNode<S>) -> &mut T {
+        self.forward(target, None, false)
+    }
+
+    pub fn redirect_modifier(
+        &mut self,
+        target: dyn CommandNode<S>,
+        modifier: dyn SingleRedirectModifier<S>,
+    ) -> &mut T {
+        // forward(target, modifier == null ? null : o -> Collections.singleton(modifier.apply(o)), false);
+        self.forward(target, modifier.map(|m| |o| vec![m.apply(o)]), false)
+    }
+
+    pub fn fork(
+        &mut self,
+        target: dyn CommandNode<S>,
+        modifier: dyn RedirectModifier<S>,
+    ) -> &mut T {
+        self.forward(target, Some(modifier), true)
+    }
+
+    pub fn forward(
+        &mut self,
+        target: dyn CommandNode<S>,
+        modifier: Option<dyn RedirectModifier<S>>,
+        fork: bool,
+    ) -> Result<&mut T, String> {
+        if !self.arguments.get_children().is_empty() {
+            return Err("Cannot forward a node with children".to_string());
+        }
+        self.target = Some(target);
+        self.modifier = modifier;
+        self.forks = fork;
+        Ok(self)
+    }
+
+    pub fn redirect(&self) -> Option<&dyn CommandNode<S>> {
+        self.target.as_ref()
+    }
+
+    pub fn redirect_modifier(&self) -> Option<&dyn RedirectModifier<S>> {
+        self.modifier.as_ref()
+    }
+
+    pub fn is_fork(&self) -> bool {
+        self.forks
+    }
+}
diff --git a/azalea-brigadier/src/builder/mod.rs b/azalea-brigadier/src/builder/mod.rs
index e69de29b..26f2f644 100644
--- a/azalea-brigadier/src/builder/mod.rs
+++ b/azalea-brigadier/src/builder/mod.rs
@@ -0,0 +1,3 @@
+pub mod argument_builder;
+pub mod literal_argument_builder;
+pub mod required_argument_builder;
diff --git a/azalea-brigadier/src/command.rs b/azalea-brigadier/src/command.rs
index e69de29b..a76454b7 100644
--- a/azalea-brigadier/src/command.rs
+++ b/azalea-brigadier/src/command.rs
@@ -0,0 +1,10 @@
+use crate::{
+    context::command_context::CommandContext,
+    exceptions::command_syntax_exception::CommandSyntaxException,
+};
+
+pub const SINGLE_SUCCESS: i32 = 1;
+
+pub trait Command<S> {
+    fn run(&self, context: &mut CommandContext<S>) -> Result<i32, CommandSyntaxException>;
+}
diff --git a/azalea-brigadier/src/command_dispatcher.rs b/azalea-brigadier/src/command_dispatcher.rs
index e69de29b..c476a39b 100644
--- a/azalea-brigadier/src/command_dispatcher.rs
+++ b/azalea-brigadier/src/command_dispatcher.rs
@@ -0,0 +1,23 @@
+/// The core command dispatcher, for registering, parsing, and executing commands.
+/// The `S` generic is a custom "source" type, such as a user or originator of a command
+pub struct CommandDispatcher<S> {
+    root: RootCommandNode<S>,
+}
+
+impl<S> CommandDispatcher<S> {
+    /// The string required to separate individual arguments in an input string
+    ///
+    /// See: [`ARGUMENT_SEPARATOR_CHAR`]
+    const ARGUMENT_SEPARATOR: &'static str = " ";
+
+    /// The char required to separate individual arguments in an input string
+    ///
+    /// See: [`ARGUMENT_SEPARATOR`]
+    const ARGUMENT_SEPARATOR_CHAR: char = ' ';
+
+    const USAGE_OPTIONAL_OPEN: &'static str = "[";
+    const USAGE_OPTIONAL_CLOSE: &'static str = "]";
+    const USAGE_REQUIRED_OPEN: &'static str = "(";
+    const USAGE_REQUIRED_CLOSE: &'static str = ")";
+    const USAGE_OR: &'static str = "|";
+}
diff --git a/azalea-brigadier/src/context/command_context.rs b/azalea-brigadier/src/context/command_context.rs
index ddbb447e..c6210a88 100644
--- a/azalea-brigadier/src/context/command_context.rs
+++ b/azalea-brigadier/src/context/command_context.rs
@@ -1,3 +1,90 @@
+use super::{
+    parsed_argument::ParsedArgument, parsed_command_node::ParsedCommandNode,
+    string_range::StringRange,
+};
+use crate::{
+    arguments::argument_type::ArgumentType, command::Command, redirect_modifier::RedirectModifier,
+    tree::command_node::CommandNode,
+};
+use std::collections::HashMap;
+
 pub struct CommandContext<S> {
     source: S,
+    input: String,
+    command: dyn Command<S>,
+    arguments: HashMap<String, ParsedArgument<S, dyn ArgumentType>>,
+    root_node: dyn CommandNode<S>,
+    nodes: Vec<ParsedCommandNode<S>>,
+    range: StringRange,
+    child: Option<CommandContext<S>>,
+    modifier: Option<dyn RedirectModifier<S>>,
+    forks: bool,
+}
+
+impl<S> CommandContext<S> {
+    pub fn clone_for(&self, source: S) -> Self {
+        if self.source == source {
+            return self.clone();
+        }
+        Self {
+            source,
+            input: self.input.clone(),
+            command: self.command.clone(),
+            arguments: self.arguments.clone(),
+            root_node: self.root_node.clone(),
+            nodes: self.nodes.clone(),
+            range: self.range.clone(),
+            child: self.child.clone(),
+            modifier: self.modifier.clone(),
+            forks: self.forks,
+        }
+    }
+
+    fn child(&self) -> &Option<CommandContext<S>> {
+        &self.child
+    }
+
+    fn last_child(&self) -> &CommandContext<S> {
+        let mut result = self;
+        while result.child.is_some() {
+            result = result.child.as_ref().unwrap();
+        }
+        result
+    }
+
+    fn command(&self) -> &dyn Command<S> {
+        &self.command
+    }
+
+    fn source(&self) -> &S {
+        &self.source
+    }
+
+    // public <V> V getArgument(final String name, final Class<V> clazz) {
+    //     final ParsedArgument<S, ?> argument = arguments.get(name);
+
+    //     if (argument == null) {
+    //         throw new IllegalArgumentException("No such argument '" + name + "' exists on this command");
+    //     }
+
+    //     final Object result = argument.getResult();
+    //     if (PRIMITIVE_TO_WRAPPER.getOrDefault(clazz, clazz).isAssignableFrom(result.getClass())) {
+    //         return (V) result;
+    //     } else {
+    //         throw new IllegalArgumentException("Argument '" + name + "' is defined as " + result.getClass().getSimpleName() + ", not " + clazz);
+    //     }
+    // }
+    fn get_argument<V>(&self, name: &str) -> Result<V, String> {
+        let argument = self.arguments.get(name);
+
+        if argument.is_none() {
+            return Err(format!(
+                "No such argument '{}' exists on this command",
+                name
+            ));
+        }
+
+        let result = argument.unwrap().result();
+        Ok(result)
+    }
 }
diff --git a/azalea-brigadier/src/context/command_context_builder.rs b/azalea-brigadier/src/context/command_context_builder.rs
index e69de29b..e74b5b1c 100644
--- a/azalea-brigadier/src/context/command_context_builder.rs
+++ b/azalea-brigadier/src/context/command_context_builder.rs
@@ -0,0 +1,180 @@
+use std::collections::HashMap;
+
+use crate::{
+    arguments::argument_type::ArgumentType, command::Command,
+    command_dispatcher::CommandDispatcher, redirect_modifier::RedirectModifier,
+    tree::command_node::CommandNode,
+};
+
+use super::{
+    command_context::CommandContext, parsed_argument::ParsedArgument,
+    parsed_command_node::ParsedCommandNode, string_range::StringRange,
+    suggestion_context::SuggestionContext,
+};
+
+// public class CommandContextBuilder<S> {
+//     private final Map<String, ParsedArgument<S, ?>> arguments = new LinkedHashMap<>();
+//     private final CommandNode<S> rootNode;
+//     private final List<ParsedCommandNode<S>> nodes = new ArrayList<>();
+//     private final CommandDispatcher<S> dispatcher;
+//     private S source;
+//     private Command<S> command;
+//     private CommandContextBuilder<S> child;
+//     private StringRange range;
+//     private RedirectModifier<S> modifier = null;
+//     private boolean forks;
+
+#[derive(Clone)]
+pub struct CommandContextBuilder<S> {
+    arguments: HashMap<String, ParsedArgument<S, dyn ArgumentType>>,
+    root_node: dyn CommandNode<S>,
+    nodes: Vec<ParsedCommandNode<S>>,
+    dispatcher: CommandDispatcher<S>,
+    source: S,
+    command: Box<dyn Command<S>>,
+    child: Option<CommandContextBuilder<S>>,
+    range: StringRange,
+    modifier: Option<Box<dyn RedirectModifier<S>>>,
+    forks: bool,
+}
+
+// public CommandContextBuilder(final CommandDispatcher<S> dispatcher, final S source, final CommandNode<S> rootNode, final int start) {
+// 	this.rootNode = rootNode;
+// 	this.dispatcher = dispatcher;
+// 	this.source = source;
+// 	this.range = StringRange.at(start);
+// }
+
+impl<S> CommandContextBuilder<S> {
+    pub fn new(
+        dispatcher: CommandDispatcher<S>,
+        source: S,
+        root_node: dyn CommandNode<S>,
+        start: usize,
+    ) -> Self {
+        Self {
+            root_node,
+            dispatcher,
+            source,
+            range: StringRange::at(start),
+            ..Default::default()
+        }
+    }
+
+    pub fn with_source(mut self, source: S) -> Self {
+        self.source = source;
+        self
+    }
+
+    pub fn source(&self) -> &S {
+        &self.source
+    }
+
+    pub fn root_node(&self) -> &dyn CommandNode<S> {
+        &self.root_node
+    }
+
+    pub fn with_argument(
+        mut self,
+        name: String,
+        argument: ParsedArgument<S, dyn ArgumentType>,
+    ) -> Self {
+        self.arguments.insert(name, argument);
+        self
+    }
+
+    pub fn arguments(&self) -> &HashMap<String, ParsedArgument<S, dyn ArgumentType>> {
+        &self.arguments
+    }
+
+    pub fn with_command(mut self, command: Box<dyn Command<S>>) -> Self {
+        self.command = command;
+        self
+    }
+
+    pub fn with_node(mut self, node: dyn CommandNode<S>, range: StringRange) -> Self {
+        self.nodes.push(ParsedCommandNode::new(node, range));
+        self.range = StringRange::encompassing(&self.range, &range);
+        self.modifier = node.redirect_modifier();
+        self.forks = node.is_fork();
+        self
+    }
+
+    pub fn with_child(mut self, child: CommandContextBuilder<S>) -> Self {
+        self.child = Some(child);
+        self
+    }
+
+    pub fn child(&self) -> Option<&CommandContextBuilder<S>> {
+        self.child.as_ref()
+    }
+
+    pub fn last_child(&self) -> Option<&CommandContextBuilder<S>> {
+        let mut result = self;
+        while let Some(child) = result.child() {
+            result = child;
+        }
+        Some(result)
+    }
+
+    pub fn command(&self) -> &dyn Command<S> {
+        &*self.command
+    }
+
+    pub fn nodes(&self) -> &Vec<ParsedCommandNode<S>> {
+        &self.nodes
+    }
+
+    pub fn build(self, input: &str) -> CommandContext<S> {
+        CommandContext {
+            source: self.source,
+            input,
+            arguments: self.arguments,
+            command: self.command,
+            root_node: self.root_node,
+            nodes: self.nodes,
+            range: self.range,
+            child: self.child.map(|child| child.build(input)),
+            modifier: self.modifier,
+            forks: self.forks,
+        }
+    }
+
+    pub fn dispatcher(&self) -> &CommandDispatcher<S> {
+        &self.dispatcher
+    }
+
+    pub fn range(&self) -> &StringRange {
+        &self.range
+    }
+
+    pub fn find_suggestion_context(&self, cursor: i32) -> Result<SuggestionContext<S>, String> {
+        if self.range.start() <= cursor {
+            if self.range.end() < cursor {
+                if let Some(child) = self.child() {
+                    child.find_suggestion_context(cursor);
+                } else if !self.nodes.is_empty() {
+                    let last = self.nodes.last().unwrap();
+                    let end = last.range().end() + 1;
+                    return SuggestionContext::new(last.node(), end);
+                } else {
+                    return SuggestionContext::new(self.root_node, self.range.start());
+                }
+            } else {
+                let prev = self.root_node;
+                for node in &self.nodes {
+                    let node_range = node.range();
+                    if node_range.start() <= cursor && cursor <= node_range.end() {
+                        return SuggestionContext::new(prev, node_range.start());
+                    }
+                    prev = node.node();
+                }
+                if prev.is_none() {
+                    return Err(String::from("Can't find node before cursor"));
+                }
+                return SuggestionContext::new(prev.unwrap(), self.range.start());
+            }
+        }
+        Err(String::from("Can't find node before cursor"))
+    }
+}
diff --git a/azalea-brigadier/src/context/parsed_argument.rs b/azalea-brigadier/src/context/parsed_argument.rs
index e69de29b..5f9c2cdb 100644
--- a/azalea-brigadier/src/context/parsed_argument.rs
+++ b/azalea-brigadier/src/context/parsed_argument.rs
@@ -0,0 +1,24 @@
+use super::string_range::StringRange;
+
+#[derive(PartialEq, Eq, Hash)]
+pub struct ParsedArgument<S, T> {
+    range: StringRange,
+    result: T,
+}
+
+impl<S, T> ParsedArgument<S, T> {
+    fn new(start: usize, end: usize, result: T) -> Self {
+        Self {
+            range: StringRange::between(start, end),
+            result,
+        }
+    }
+
+    fn range(&self) -> &StringRange {
+        &self.range
+    }
+
+    fn result(&self) -> &T {
+        &self.result
+    }
+}
diff --git a/azalea-brigadier/src/context/parsed_command_node.rs b/azalea-brigadier/src/context/parsed_command_node.rs
index e69de29b..98e99959 100644
--- a/azalea-brigadier/src/context/parsed_command_node.rs
+++ b/azalea-brigadier/src/context/parsed_command_node.rs
@@ -0,0 +1,22 @@
+use super::string_range::StringRange;
+use crate::tree::command_node::CommandNode;
+
+#[derive(Hash, PartialEq, Eq, Debug, Clone)]
+pub struct ParsedCommandNode<S> {
+    node: dyn CommandNode<S>,
+    range: StringRange,
+}
+
+impl<S> ParsedCommandNode<S> {
+    fn new(node: dyn CommandNode<S>, range: StringRange) -> Self {
+        Self { node, range }
+    }
+
+    fn node(&self) -> &dyn CommandNode<S> {
+        &self.node
+    }
+
+    fn range(&self) -> &StringRange {
+        &self.range
+    }
+}
diff --git a/azalea-brigadier/src/context/string_range.rs b/azalea-brigadier/src/context/string_range.rs
index e69de29b..d775ab68 100644
--- a/azalea-brigadier/src/context/string_range.rs
+++ b/azalea-brigadier/src/context/string_range.rs
@@ -0,0 +1,45 @@
+use std::cmp;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct StringRange {
+    start: usize,
+    end: usize,
+}
+
+impl StringRange {
+    pub fn new(start: usize, end: usize) -> Self {
+        Self { start, end }
+    }
+
+    pub fn at(pos: usize) -> Self {
+        Self::new(pos, pos)
+    }
+
+    pub fn between(start: usize, end: usize) -> Self {
+        Self::new(start, end)
+    }
+
+    pub fn encompassing(a: &Self, b: &Self) -> Self {
+        Self::new(cmp::min(a.start, b.start), cmp::max(a.end, b.end))
+    }
+
+    pub fn start(&self) -> usize {
+        self.start
+    }
+
+    pub fn end(&self) -> usize {
+        self.end
+    }
+
+    pub fn get(&self, reader: &str) -> &str {
+        &reader[self.start..self.end]
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.start == self.end
+    }
+
+    pub fn length(&self) -> usize {
+        self.end - self.start
+    }
+}
diff --git a/azalea-brigadier/src/context/suggestion_context.rs b/azalea-brigadier/src/context/suggestion_context.rs
index e69de29b..540a5f23 100644
--- a/azalea-brigadier/src/context/suggestion_context.rs
+++ b/azalea-brigadier/src/context/suggestion_context.rs
@@ -0,0 +1,6 @@
+use crate::tree::command_node::CommandNode;
+
+pub struct SuggestionContext<S> {
+    parent: dyn CommandNode<S>,
+    start_pos: usize,
+}
diff --git a/azalea-brigadier/src/lib.rs b/azalea-brigadier/src/lib.rs
index d0966de3..b2345abb 100644
--- a/azalea-brigadier/src/lib.rs
+++ b/azalea-brigadier/src/lib.rs
@@ -1,3 +1,6 @@
+#[macro_use]
+extern crate lazy_static;
+
 mod ambiguity_consumer;
 mod arguments;
 mod builder;
diff --git a/azalea-brigadier/src/redirect_modifier.rs b/azalea-brigadier/src/redirect_modifier.rs
index e69de29b..cfefd120 100644
--- a/azalea-brigadier/src/redirect_modifier.rs
+++ b/azalea-brigadier/src/redirect_modifier.rs
@@ -0,0 +1,8 @@
+use crate::{
+    context::command_context::CommandContext,
+    exceptions::command_syntax_exception::CommandSyntaxException,
+};
+
+pub trait RedirectModifier<S> {
+    fn apply(&self, context: CommandContext<S>) -> Result<Vec<S>, CommandSyntaxException>;
+}
diff --git a/azalea-brigadier/src/single_redirect_modifier.rs b/azalea-brigadier/src/single_redirect_modifier.rs
index e69de29b..dd63244d 100644
--- a/azalea-brigadier/src/single_redirect_modifier.rs
+++ b/azalea-brigadier/src/single_redirect_modifier.rs
@@ -0,0 +1,8 @@
+use crate::{
+    context::command_context::CommandContext,
+    exceptions::command_syntax_exception::CommandSyntaxException,
+};
+
+pub trait SingleRedirectModifier<S> {
+    fn apply(&self, context: CommandContext<S>) -> Result<S, CommandSyntaxException>;
+}
diff --git a/azalea-brigadier/src/suggestion/suggestion_provider.rs b/azalea-brigadier/src/suggestion/suggestion_provider.rs
index e69de29b..3027d460 100644
--- a/azalea-brigadier/src/suggestion/suggestion_provider.rs
+++ b/azalea-brigadier/src/suggestion/suggestion_provider.rs
@@ -0,0 +1,14 @@
+use crate::{
+    context::command_context::CommandContext,
+    exceptions::command_syntax_exception::CommandSyntaxException,
+};
+
+use super::{suggestions::Suggestions, suggestions_builder::SuggestionsBuilder};
+
+pub trait SuggestionProvider<S> {
+    fn suggestions(
+        &self,
+        context: &CommandContext<S>,
+        builder: &SuggestionsBuilder,
+    ) -> Result<Suggestions, CommandSyntaxException>;
+}
diff --git a/azalea-brigadier/src/tree/argument_command_node.rs b/azalea-brigadier/src/tree/argument_command_node.rs
index e69de29b..df7d3f5c 100644
--- a/azalea-brigadier/src/tree/argument_command_node.rs
+++ b/azalea-brigadier/src/tree/argument_command_node.rs
@@ -0,0 +1,118 @@
+use std::fmt::{Display, Formatter};
+
+use crate::{
+    arguments::argument_type::ArgumentType,
+    context::{
+        command_context::CommandContext, command_context_builder::CommandContextBuilder,
+        parsed_argument::ParsedArgument,
+    },
+    exceptions::command_syntax_exception::CommandSyntaxException,
+    string_reader::StringReader,
+    suggestion::{
+        suggestion_provider::SuggestionProvider, suggestions::Suggestions,
+        suggestions_builder::SuggestionsBuilder,
+    },
+};
+
+use super::command_node::{BaseCommandNode, CommandNode};
+
+const USAGE_ARGUMENT_OPEN: &str = "<";
+const USAGE_ARGUMENT_CLOSE: &str = ">";
+
+#[derive(Hash, PartialEq, Eq, Debug, Clone)]
+pub struct ArgumentCommandNode<S, T> {
+    name: String,
+    type_: dyn ArgumentType,
+    custom_suggestions: dyn SuggestionProvider<S>,
+    // Since Rust doesn't have extending, we put the struct this is extending as the "base" field
+    pub base: BaseCommandNode<S>,
+}
+
+impl<S, T> ArgumentCommandNode<S, T> {
+    fn get_type(&self) -> &dyn ArgumentType {
+        &self.type_
+    }
+
+    fn custom_suggestions(&self) -> &dyn SuggestionProvider<S> {
+        &self.custom_suggestions
+    }
+}
+
+impl<S, T> CommandNode<S> for ArgumentCommandNode<S, T> {
+    fn name(&self) -> &str {
+        &self.name
+    }
+
+    fn parse(
+        &self,
+        reader: StringReader,
+        context_builder: CommandContextBuilder<S>,
+    ) -> Result<(), CommandSyntaxException> {
+        // final int start = reader.getCursor();
+        // final T result = type.parse(reader);
+        // final ParsedArgument<S, T> parsed = new ParsedArgument<>(start, reader.getCursor(), result);
+
+        // contextBuilder.withArgument(name, parsed);
+        // contextBuilder.withNode(this, parsed.getRange());
+
+        let start = reader.get_cursor();
+        let result = self.get_type().parse(reader)?;
+        let parsed = ParsedArgument::new(start, reader.get_cursor(), result);
+
+        context_builder.with_argument(&self.name, parsed);
+        context_builder.with_node(self, parsed.get_range());
+
+        Ok(())
+    }
+
+    fn list_suggestions(
+        &self,
+        context: CommandContext<S>,
+        builder: SuggestionsBuilder,
+    ) -> Result<Suggestions, CommandSyntaxException> {
+        if self.custom_suggestions.is_none() {
+            self.get_type().list_suggestions(context, builder)
+        } else {
+            self.custom_suggestions.get_suggestions(context, builder)
+        }
+    }
+
+    fn is_valid_input(&self, input: &str) -> bool {
+        let reader = StringReader::new(input);
+        let result = self.get_type().parse(reader);
+        if result.is_ok() {
+            return !reader.can_read() || reader.peek() == ' ';
+        } else {
+            return false;
+        }
+    }
+
+    fn usage_text(&self) -> &str {
+        USAGE_ARGUMENT_OPEN + self.name + USAGE_ARGUMENT_CLOSE
+    }
+
+    fn create_builder(&self) -> RequiredArgumentBuilder<S, T> {
+        let builder = RequiredArgumentBuilder::argument(&self.name, &self.type_);
+        builder.requires(self.base.get_requirement());
+        builder.forward(
+            self.base.get_redirect(),
+            self.base.get_redirect_modifier(),
+            self.base.is_fork(),
+        );
+        builder.suggests(self.custom_suggestions());
+        if self.base.get_command() != None {
+            builder.executes(self.base.get_command().unwrap());
+        }
+        builder
+    }
+
+    fn get_examples(&self) -> Vec<String> {
+        self.type_.get_examples()
+    }
+}
+
+impl Display for ArgumentCommandNode<String, String> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "<argument {}: {}>", self.name, self.type_)
+    }
+}
diff --git a/azalea-brigadier/src/tree/command_node.rs b/azalea-brigadier/src/tree/command_node.rs
index e69de29b..286820b9 100644
--- a/azalea-brigadier/src/tree/command_node.rs
+++ b/azalea-brigadier/src/tree/command_node.rs
@@ -0,0 +1,52 @@
+use std::collections::HashMap;
+
+use crate::{
+    builder::argument_builder::ArgumentBuilder,
+    command::Command,
+    context::{command_context::CommandContext, command_context_builder::CommandContextBuilder},
+    exceptions::command_syntax_exception::CommandSyntaxException,
+    redirect_modifier::RedirectModifier,
+    string_reader::StringReader,
+    suggestion::{suggestions::Suggestions, suggestions_builder::SuggestionsBuilder},
+};
+
+use super::{argument_command_node::ArgumentCommandNode, literal_command_node::LiteralCommandNode};
+
+pub struct BaseCommandNode<S> {
+    // private final Map<String, CommandNode<S>> children = new LinkedHashMap<>();
+    // private final Map<String, LiteralCommandNode<S>> literals = new LinkedHashMap<>();
+    // private final Map<String, ArgumentCommandNode<S, ?>> arguments = new LinkedHashMap<>();
+    // private final Predicate<S> requirement;
+    // private final CommandNode<S> redirect;
+    // private final RedirectModifier<S> modifier;
+    // private final boolean forks;
+    // private Command<S> command;
+    children: HashMap<String, dyn CommandNode<S>>,
+    literals: HashMap<String, LiteralCommandNode<S>>,
+    arguments: HashMap<String, ArgumentCommandNode<S, _>>,
+    requirement: Option<dyn Fn(&S) -> bool>,
+    redirect: Option<dyn CommandNode<S>>,
+    modifier: Option<dyn RedirectModifier<S>>,
+    forks: bool,
+    command: Option<dyn Command<S>>,
+}
+
+impl<S> BaseCommandNode<S> {}
+
+pub trait CommandNode<S> {
+    fn name(&self) -> &str;
+    fn usage_text(&self) -> &str;
+    fn parse(
+        &self,
+        reader: StringReader,
+        context_builder: CommandContextBuilder<S>,
+    ) -> Result<(), CommandSyntaxException>;
+    fn list_suggestions(
+        &self,
+        context: CommandContext<S>,
+        builder: SuggestionsBuilder,
+    ) -> Result<Suggestions, CommandSyntaxException>;
+    fn is_valid_input(&self, input: &str) -> bool;
+    fn create_builder<T>(&self) -> dyn ArgumentBuilder<S, T>;
+    fn get_examples(&self) -> Vec<String>;
+}
diff --git a/azalea-brigadier/src/tree/literal_command_node.rs b/azalea-brigadier/src/tree/literal_command_node.rs
index e69de29b..bb0e613c 100644
--- a/azalea-brigadier/src/tree/literal_command_node.rs
+++ b/azalea-brigadier/src/tree/literal_command_node.rs
@@ -0,0 +1,96 @@
+use crate::{
+    context::{command_context::CommandContext, command_context_builder::CommandContextBuilder},
+    exceptions::{
+        builtin_exceptions::BuiltInExceptions, command_syntax_exception::CommandSyntaxException,
+    },
+    string_reader::StringReader,
+    suggestion::{suggestions::Suggestions, suggestions_builder::SuggestionsBuilder},
+};
+
+use super::command_node::{BaseCommandNode, CommandNode};
+
+#[derive(Hash, PartialEq, Eq, Debug, Clone)]
+pub struct LiteralCommandNode<S> {
+    literal: String,
+    literal_lowercase: String,
+    // Since Rust doesn't have extending, we put the struct this is extending as the "base" field
+    pub base: BaseCommandNode<S>,
+}
+
+impl<S> LiteralCommandNode<S> {
+    pub fn literal(&self) -> &String {
+        &self.literal
+    }
+
+    pub fn parse(&self, reader: StringReader) -> i32 {
+        let start = reader.get_cursor();
+        if reader.can_read(self.literal.len()) {
+            let end = start + self.literal.len();
+            if reader.get_string()[start..end].eq(&self.literal) {
+                reader.set_cursor(end);
+                if !reader.can_read() || reader.peek() == ' ' {
+                    return end as i32;
+                } else {
+                    reader.set_cursor(start);
+                }
+            }
+        }
+        -1
+    }
+}
+
+impl<S> CommandNode<S> for LiteralCommandNode<S> {
+    fn name(&self) -> &str {
+        &self.literal
+    }
+
+    fn parse(
+        &self,
+        reader: StringReader,
+        context_builder: CommandContextBuilder<S>,
+    ) -> Result<(), CommandSyntaxException> {
+        let start = reader.get_cursor();
+        let end = self.parse(reader);
+        if end > -1 {
+            return Ok(());
+        }
+
+        Err(BuiltInExceptions::LiteralIncorrect {
+            expected: self.literal(),
+        }
+        .create_with_context(reader))
+    }
+
+    fn list_suggestions(
+        &self,
+        context: CommandContext<S>,
+        builder: SuggestionsBuilder,
+    ) -> Result<Suggestions, CommandSyntaxException> {
+        if self
+            .literal_lowercase
+            .starts_with(&builder.remaining_lowercase())
+        {
+            builder.suggest(self.literal())
+        } else {
+            Suggestions::empty()
+        }
+    }
+
+    fn is_valid_input(&self, input: &str) -> bool {
+        self.parse(StringReader::from(input)) > -1
+    }
+
+    fn usage_text(&self) -> &str {
+        self.literal
+    }
+
+    fn create_builder(&self) -> LiteralArgumentBuilder<S> {
+        let builder = LiteralArgumentBuilder::literal(self.literal());
+        builder.requires(self.requirement());
+        builder.forward(self.redirect(), self.redirect_modifier(), self.is_fork());
+        if self.command().is_some() {
+            builder.executes(self.command().unwrap());
+        }
+        builder
+    }
+}
diff --git a/azalea-brigadier/src/tree/mod.rs b/azalea-brigadier/src/tree/mod.rs
index e69de29b..3dc22583 100644
--- a/azalea-brigadier/src/tree/mod.rs
+++ b/azalea-brigadier/src/tree/mod.rs
@@ -0,0 +1,4 @@
+pub mod argument_command_node;
+pub mod command_node;
+pub mod literal_command_node;
+pub mod root_command_node;
diff --git a/azalea-brigadier/src/tree/root_command_node.rs b/azalea-brigadier/src/tree/root_command_node.rs
index e69de29b..004ab6a8 100644
--- a/azalea-brigadier/src/tree/root_command_node.rs
+++ b/azalea-brigadier/src/tree/root_command_node.rs
@@ -0,0 +1,61 @@
+use std::fmt::{Display, Formatter};
+
+use crate::{
+    context::{command_context::CommandContext, command_context_builder::CommandContextBuilder},
+    exceptions::{
+        builtin_exceptions::BuiltInExceptions, command_syntax_exception::CommandSyntaxException,
+    },
+    string_reader::StringReader,
+    suggestion::{suggestions::Suggestions, suggestions_builder::SuggestionsBuilder},
+};
+
+use super::command_node::{BaseCommandNode, CommandNode};
+
+#[derive(Hash, PartialEq, Eq, Debug, Clone)]
+pub struct RootCommandNode<S> {
+    // Since Rust doesn't have extending, we put the struct this is extending as the "base" field
+    pub base: BaseCommandNode<S>,
+}
+
+impl<S> CommandNode<S> for RootCommandNode<S> {
+    fn name(&self) -> &str {
+        ""
+    }
+
+    fn parse(
+        &self,
+        reader: StringReader,
+        context_builder: CommandContextBuilder<S>,
+    ) -> Result<(), CommandSyntaxException> {
+    }
+
+    fn list_suggestions(
+        &self,
+        context: CommandContext<S>,
+        builder: SuggestionsBuilder,
+    ) -> Result<Suggestions, CommandSyntaxException> {
+        Suggestions::empty()
+    }
+
+    fn is_valid_input(&self, input: &str) -> bool {
+        false
+    }
+
+    fn usage_text(&self) -> &str {
+        ""
+    }
+
+    fn create_builder(&self) -> () {
+        panic!("Cannot convert root into a builder");
+    }
+
+    fn get_examples(&self) -> Vec<String> {
+        vec![]
+    }
+}
+
+impl Display for RootCommandNode<()> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        write!(f, "<root>")
+    }
+}