✨ Add automatic commit style detection for default mode

Introduce local style detection that analyzes recent git history to
automatically mirror the repository's commit format (gitmoji,
conventional commits, or plain) when no explicit style is configured.

Key changes:
- Add gitmoji_override field to Config to track explicit CLI overrides
- Skip style injection in default mode when no override is set
- Update commit.toml prompt with style detection instructions
- Agent now calls git_log to detect format patterns rather than
  defaulting to a specific style

This ensures Git-Iris respects each project's established conventions
while still producing high-quality, descriptive commit messages.

Author: hyperb1iss

src/agents/capabilities/commit.toml

@@ -21,11 +21,12 @@ Do not skip this step.
 
 ## Workflow — Progressive Analysis
 1. **FIRST**: Call `project_docs(doc_type="context")` — understand the project's conventions
-2. Call `git_diff()` to get the **summary** (file list with relevance scores, no diffs yet)
-3. Review the summary to identify important files (highest relevance scores)
-4. Call `git_diff(detail="standard", files=["important-file1.rs", "important-file2.rs"])` for full diffs of key files
-5. Repeat step 4 for additional files if needed (stay focused on top 5-7 files max)
-6. Generate the commit message based on your progressive analysis
+2. **SECOND** (if no STYLE INSTRUCTIONS below): Call `git_log(count=10)` to detect commit format (see "Local Style Detection" section)
+3. Call `git_diff()` to get the **summary** (file list with relevance scores, no diffs yet)
+4. Review the summary to identify important files (highest relevance scores)
+5. Call `git_diff(detail="standard", files=["important-file1.rs", "important-file2.rs"])` for full diffs of key files
+6. Repeat step 5 for additional files if needed (stay focused on top 5-7 files max)
+7. Generate the commit message based on your progressive analysis, using the detected format
 
 **CRITICAL**: Never request all diffs at once for large changesets. Always start with summary, then selectively drill into important files.
 
@@ -62,6 +63,49 @@ When the context indicates **amend mode** (you'll see `"mode": "amend"` with an
 ## Style Adaptation
 If STYLE INSTRUCTIONS are provided below, **prioritize that style** in your word choice, tone, and descriptions. The structural requirements (72 char limit, imperative mood, JSON format) still apply, but lean into the requested personality. A cosmic preset means cosmic language. A playful preset means playful vibes. Express the style!
 
+## Local Style Detection (Default Mode)
+If NO "STYLE INSTRUCTIONS" or "GITMOJI INSTRUCTIONS" section appears below, you MUST detect and mirror the repository's commit **format**:
+
+1. Call `git_log(count=10)` to analyze recent commits
+2. **Observe the actual patterns** — look for:
+   - Prefix patterns (type:, [TAG], (scope), MODULE:, etc.)
+   - Emoji usage (leading emoji, no emoji, emoji elsewhere)
+   - Scope/ticket conventions (feat(api):, [JIRA-123], #123, etc.)
+   - Capitalization style (lowercase, Sentence case, UPPERCASE)
+   - Any other consistent formatting the team uses
+
+3. **Common formats for reference:**
+
+   **Conventional Commits** — `type(scope): message`
+   - `feat: add user authentication`
+   - `fix(api): resolve null pointer`
+   → Set `emoji` to `null`. NO EMOJIS.
+
+   **Gitmoji** — emoji prefix
+   - `✨ Add user authentication`
+   - `🐛 Fix null pointer`
+   → Set `emoji` field appropriately.
+
+   **Ticket/Issue prefixes** — `[TAG-123] message` or `TAG-123: message`
+   - `[ENG-1234] Add user authentication`
+   - `PROJ-456: Fix null pointer`
+   → Mirror the exact bracket/format style. Set `emoji` to `null` unless repo mixes with emoji.
+
+   **Custom patterns** — mirror whatever you see
+   - `(auth) Add user authentication` → use `(scope) message` format
+   - `AUTH: Add user login` → use `MODULE: message` format
+   - `[feature] Add auth` → use `[type] message` format
+
+4. **CRITICAL rules:**
+   - If NO emojis in recent commits → set `emoji` to `null`, don't add any
+   - If conventional commits detected → use type prefix, NO emojis
+   - Mirror the EXACT prefix style (brackets, parens, colons, spacing)
+   - Match capitalization patterns
+
+**Mirror format, NOT quality.** Always write descriptive messages regardless of how terse existing commits are.
+
+**This detection is MANDATORY when no style instructions appear below.**
+
 ## JSON Output
 Return a `GeneratedMessage` with:
 - `emoji` (string or null)

src/agents/iris.rs

@@ -627,10 +627,17 @@ Guidelines:
 
         let preset_name = config.get_effective_preset_name();
         let is_conventional = preset_name == "conventional";
-        let gitmoji_enabled = config.use_gitmoji && !is_conventional;
+        let is_default_mode = preset_name == "default" || preset_name.is_empty();
 
-        // Inject instruction preset if configured
-        if !preset_name.is_empty() && preset_name != "default" {
+        // For commits in default mode with no explicit gitmoji override, use style detection
+        // (don't inject any style instructions - let the agent detect from git_log)
+        let use_style_detection =
+            capability == "commit" && is_default_mode && config.gitmoji_override.is_none();
+
+        let gitmoji_enabled = config.use_gitmoji && !is_conventional && !use_style_detection;
+
+        // Inject instruction preset if configured (skip for default mode)
+        if !preset_name.is_empty() && !is_default_mode {
             let library = crate::instruction_presets::get_instruction_preset_library();
             if let Some(preset) = library.get_preset(preset_name) {
                 tracing::info!("📋 Injecting '{}' preset style instructions", preset_name);
@@ -644,7 +651,11 @@ Guidelines:
 
         // Handle commit-specific styling (structured JSON output with emoji field)
         if capability == "commit" {
-            if gitmoji_enabled {
+            if use_style_detection {
+                // In default mode, let the agent detect style from git_log
+                // The commit.toml prompt has instructions for this
+                tracing::info!("🔍 Using local commit style detection (default mode)");
+            } else if gitmoji_enabled {
                 system_prompt.push_str("\n\n=== GITMOJI INSTRUCTIONS ===\n");
                 system_prompt.push_str("Set the 'emoji' field to a single relevant gitmoji. ");
                 system_prompt.push_str(

src/commands.rs

@@ -317,6 +317,7 @@ pub fn handle_project_config_command(
         temp_instructions: None,
         temp_preset: None,
         is_project_config: true,
+        gitmoji_override: None,
     });
 
     let mut changes_made = false;

src/common.rs

@@ -92,11 +92,13 @@ impl CommonParams {
             config.set_temp_preset(Some(preset.clone()));
         }
 
-        if let Some(use_gitmoji) = self.resolved_gitmoji()
-            && config.use_gitmoji != use_gitmoji
-        {
-            config.use_gitmoji = use_gitmoji;
-            changes_made = true;
+        // Track whether gitmoji was explicitly set via CLI (for style detection)
+        if let Some(use_gitmoji) = self.resolved_gitmoji() {
+            config.gitmoji_override = Some(use_gitmoji);
+            if config.use_gitmoji != use_gitmoji {
+                config.use_gitmoji = use_gitmoji;
+                changes_made = true;
+            }
         }
 
         Ok(changes_made)

src/config.rs

@@ -51,6 +51,9 @@ pub struct Config {
     /// Runtime-only: flag if loaded from project config
     #[serde(skip)]
     pub is_project_config: bool,
+    /// Runtime-only: whether gitmoji was explicitly set via CLI (None = use style detection)
+    #[serde(skip)]
+    pub gitmoji_override: Option<bool>,
 }
 
 fn default_true() -> bool {
@@ -86,6 +89,7 @@ impl Default for Config {
             temp_instructions: None,
             temp_preset: None,
             is_project_config: false,
+            gitmoji_override: None,
         }
     }
 }