Replace gix with configurable libgit2 diffs

src/app/preferences.rs

@@ -12,6 +12,12 @@ pub(super) struct PreferenceDraft {
     pub(super) endpoint_cors: bool,
     pub(super) dev_brain_enabled: bool,
     pub(super) dev_brain_vault_path: String,
+    pub(super) git_diff_algorithm: GitDiffAlgorithm,
+    pub(super) git_context_lines: String,
+    pub(super) git_interhunk_lines: String,
+    pub(super) git_indent_heuristic: bool,
+    pub(super) git_whitespace: GitDiffWhitespace,
+    pub(super) git_ignore_blank_lines: bool,
     pub(super) context_tokens: String,
     pub(super) max_generated_tokens: String,
     pub(super) system_prompt: text_editor::Content,
@@ -64,6 +70,12 @@ impl PreferenceDraft {
             endpoint_cors: config.endpoint.cors,
             dev_brain_enabled: config.dev_brain.enabled,
             dev_brain_vault_path: config.dev_brain.vault_path.clone().unwrap_or_default(),
+            git_diff_algorithm: config.git.diff_algorithm,
+            git_context_lines: config.git.context_lines.to_string(),
+            git_interhunk_lines: config.git.interhunk_lines.to_string(),
+            git_indent_heuristic: config.git.indent_heuristic,
+            git_whitespace: config.git.whitespace,
+            git_ignore_blank_lines: config.git.ignore_blank_lines,
             context_tokens: generation.context_tokens.to_string(),
             max_generated_tokens: generation.max_generated_tokens.to_string(),
             system_prompt: text_editor::Content::with_text(&generation.system_prompt),
@@ -126,6 +138,17 @@ impl PreferenceDraft {
         Ok(preferences)
     }
 
+    pub(super) fn git(&self) -> Result<GitConfig, String> {
+        Ok(GitConfig {
+            diff_algorithm: self.git_diff_algorithm,
+            context_lines: parse_u32("Git diff context lines", &self.git_context_lines)?,
+            interhunk_lines: parse_u32("Git diff interhunk lines", &self.git_interhunk_lines)?,
+            indent_heuristic: self.git_indent_heuristic,
+            whitespace: self.git_whitespace,
+            ignore_blank_lines: self.git_ignore_blank_lines,
+        })
+    }
+
     pub(super) fn reset(&mut self) {
         *self = Self::from_saved(&Config::default());
     }
@@ -248,6 +271,13 @@ fn parse_optional_u32(name: &str, value: &str) -> Result<Option<u32>, String> {
     parse_optional_number(name, value)
 }
 
+fn parse_u32(name: &str, value: &str) -> Result<u32, String> {
+    value
+        .trim()
+        .parse()
+        .map_err(|_| format!("{name} must be a non-negative whole number."))
+}
+
 fn parse_optional_u8(name: &str, value: &str) -> Result<Option<u8>, String> {
     parse_optional_number(name, value)
 }
@@ -363,6 +393,13 @@ impl App {
                 return;
             }
         };
+        let git = match self.preference_draft.git() {
+            Ok(git) => git,
+            Err(error) => {
+                self.preference_error = Some(error);
+                return;
+            }
+        };
         let config = Config {
             model: self.preference_draft.model,
             idle_timeout_minutes,
@@ -378,6 +415,7 @@ impl App {
             },
             generation,
             runtime,
+            git,
             interface: self.config.interface.clone(),
         };
         if let Err(error) = config.validate() {