feat(core): add relevant snippets in completion request. (TabbyML#1742)

* feat(api): add relevant snippets in completion request.

* fix: define Declaration instead of using Snippets.

* Apply suggestions from code review

Co-authored-by: Meng Zhang <meng@tabbyml.com>

---------

Co-authored-by: Meng Zhang <meng@tabbyml.com>

Author: icycodes

crates/tabby/src/serve.rs

@@ -55,6 +55,7 @@ Install following IDE / Editor extensions to get started with [Tabby](https://gi
         completion::CompletionRequest,
         completion::CompletionResponse,
         completion::Segments,
+        completion::Declaration,
         completion::Choice,
         completion::Snippet,
         completion::DebugOptions,

crates/tabby/src/services/completion.rs

@@ -109,19 +109,37 @@ pub struct Segments {
     suffix: Option<String>,
 
     /// The relative path of the file that is being edited.
-    /// When git_url is set, this is the path of the file in the git repository.
-    /// When git_url is empty, this is the path of the file in the workspace.
+    /// - When `git_url` is set, this is the path of the file in the git repository.
+    /// - When `git_url` is empty, this is the path of the file in the workspace.
     filepath: Option<String>,
 
     /// The remote URL of the current git repository.
     /// Leave this empty if the file is not in a git repository,
     /// or the git repository does not have a remote URL.
     git_url: Option<String>,
 
+    /// The relevant declaration code snippets provided by editor.
+    /// It'll contains declarations extracted from `prefix` segments using LSP.
+    declarations: Option<Vec<Declaration>>,
+
     /// Clipboard content when requesting code completion.
     clipboard: Option<String>,
 }
 
+/// A snippet of declaration code that is relevant to the current completion request.
+#[derive(Serialize, Deserialize, ToSchema, Clone, Debug)]
+pub struct Declaration {
+    /// Filepath of the file where the snippet is from.
+    /// - When the file belongs to the same workspace as the current file,
+    ///   this is a relative filepath, that has the same root as the current file.
+    /// - When the file located outside the workspace, such as in a dependency package,
+    ///   this is a file URI with an absolute filepath.
+    filepath: String,
+
+    /// Body of the snippet.
+    body: String,
+}
+
 impl From<Segments> for api::event::Segments {
     fn from(val: Segments) -> Self {
         Self {

crates/tabby/src/services/completion/completion_prompt.rs

@@ -195,6 +195,7 @@ mod tests {
             suffix,
             filepath: None,
             git_url: None,
+            declarations: None,
             clipboard: None,
         }
     }