brigadier suggestions

closes #109

3 files changed, 50 insertions, 1 deletions

diff --git a/azalea-brigadier/src/context/command_context_builder.rs b/azalea-brigadier/src/context/command_context_builder.rs
index 99c40dac..75295825 100755
--- a/azalea-brigadier/src/context/command_context_builder.rs
+++ b/azalea-brigadier/src/context/command_context_builder.rs
@@ -2,7 +2,7 @@ use parking_lot::RwLock;
 
 use super::{
     command_context::CommandContext, parsed_command_node::ParsedCommandNode,
-    string_range::StringRange, ParsedArgument,
+    string_range::StringRange, suggestion_context::SuggestionContext, ParsedArgument,
 };
 use crate::{
     command_dispatcher::CommandDispatcher,
@@ -99,6 +99,43 @@ impl<'a, S> CommandContextBuilder<'a, S> {
             input: input.to_string(),
         }
     }
+
+    pub fn find_suggestion_context(&self, cursor: usize) -> SuggestionContext<S> {
+        if self.range.start() > cursor {
+            panic!("Can't find node before cursor");
+        }
+
+        if self.range.end() < cursor {
+            if let Some(child) = &self.child {
+                child.find_suggestion_context(cursor)
+            } else if let Some(last) = self.nodes.last() {
+                SuggestionContext {
+                    parent: Arc::clone(&last.node),
+                    start_pos: last.range.end() + 1,
+                }
+            } else {
+                SuggestionContext {
+                    parent: Arc::clone(&self.root),
+                    start_pos: self.range.start(),
+                }
+            }
+        } else {
+            let mut prev = &self.root;
+            for node in &self.nodes {
+                if node.range.start() <= cursor && cursor <= node.range.end() {
+                    return SuggestionContext {
+                        parent: Arc::clone(prev),
+                        start_pos: node.range.start(),
+                    };
+                }
+                prev = &node.node;
+            }
+            SuggestionContext {
+                parent: Arc::clone(prev),
+                start_pos: self.range.start(),
+            }
+        }
+    }
 }
 
 impl<S> Debug for CommandContextBuilder<'_, S> {
diff --git a/azalea-brigadier/src/context/mod.rs b/azalea-brigadier/src/context/mod.rs
index d535602a..28e1a12e 100755
--- a/azalea-brigadier/src/context/mod.rs
+++ b/azalea-brigadier/src/context/mod.rs
@@ -3,6 +3,7 @@ mod command_context_builder;
 mod parsed_argument;
 mod parsed_command_node;
 mod string_range;
+pub mod suggestion_context;
 
 pub use command_context::CommandContext;
 pub use command_context_builder::CommandContextBuilder;
diff --git a/azalea-brigadier/src/context/suggestion_context.rs b/azalea-brigadier/src/context/suggestion_context.rs
new file mode 100644
index 00000000..58a73fdb
--- /dev/null
+++ b/azalea-brigadier/src/context/suggestion_context.rs
@@ -0,0 +1,11 @@
+use std::sync::Arc;
+
+use parking_lot::RwLock;
+
+use crate::tree::CommandNode;
+
+#[derive(Debug)]
+pub struct SuggestionContext<S> {
+    pub parent: Arc<RwLock<CommandNode<S>>>,
+    pub start_pos: usize,
+}