# Git Commit Prefix Generator

A Rust CLI tool that automatically generates conventional git commit message prefixes by analyzing git diffs. It suggests commit types (feat, fix, docs, style, refactor, test, chore) and auto-detects scopes based on changed file paths, helping developers maintain consistent commit conventions without external dependencies.

## Features

- **Automatic commit type detection** - Maps changed files to conventional commit types
- **Scope auto-detection** - Extracts scope names from file paths (e.g., 'auth' from `src/auth/login.rs`)
- **Multiple output formats** - Short, verbose, compact, and JSON for scripting
- **Interactive mode** - Prompts for confirming/selecting types and scopes
- **Configuration support** - Load custom conventions from `.commitlintrc` or custom config files
- **Staged changes support** - Analyze both working directory and staged changes

## Installation

```bash
cargo install git-commit-prefix-gen
```

Or build from source:

```bash
git clone https://github.com/user/git-commit-prefix-gen
cd git-commit-prefix-gen
cargo build --release
```

## Usage

### Basic usage

```bash
git-commit-prefix-gen
```

### Specify output format

```bash
git-commit-prefix-gen --format short      # Default: feat(auth): add login
git-commit-prefix-gen --format verbose    # Detailed output with file list
git-commit-prefix-gen --format compact    # No spaces: feat(auth):add login
git-commit-prefix-gen --format json       # JSON for scripting
```

### Override detected type/scope

```bash
git-commit-prefix-gen --type feat --scope api
```

### Analyze staged changes

```bash
git-commit-prefix-gen --staged
```

### Interactive mode

```bash
git-commit-prefix-gen --interactive
```

### Use custom config file

```bash
git-commit-prefix-gen --config .commitlintrc.json
```

### Dry run (no changes)

```bash
git-commit-prefix-gen --dry-run
```

## Supported Commit Types

| Type | Description |
|------|-------------|
| `feat` | A new feature |
| `fix` | A bug fix |
| `docs` | Documentation only changes |
| `style` | Changes that do not affect the meaning of the code (white-space, formatting, etc) |
| `refactor` | A code change that neither fixes a bug nor adds a feature |
| `test` | Adding missing tests or correcting existing tests |
| `chore` | Changes to the build process or auxiliary tools |
| `build` | Changes to the build system |
| `ci` | Changes to CI configuration |
| `perf` | A code change that improves performance |
| `revert` | Reverts a previous commit |

## Configuration

The tool supports custom configuration files. By default, it searches for:

- `.commitlintrc.js`
- `.commitlintrc.json`
- `.commitlintrc.yaml`
- `.commitlintrc.yml`
- `commitlint.config.js`
- `.git-commit-prefix-gen.yaml`
- `.git-commit-prefix-gen.json`

### Example Configuration

```yaml
type_mapping:
  - pattern: "src/**/*.rs"
    type: "feat"
  - pattern: "tests/**/*.rs"
    type: "test"
  - pattern: "docs/**/*.md"
    type: "docs"

scope_patterns:
  - pattern: "^src/([^/]+)/"
    base: "src"
  - pattern: "^lib/([^/]+)/"
    base: "lib"

ignored_patterns:
  - "^target/"
  - "^node_modules/"
  - "^\\.git/"
```

## Exit Codes

| Code | Description |
|------|-------------|
| 0 | Success |
| 1 | No changes detected or error |
| 128 | Not in a git repository |

## Library Usage

```rust
use git_commit_prefix_gen::{Analyzer, CommitConvention};

fn main() {
    let convention = CommitConvention::default();
    let analyzer = Analyzer::with_convention(convention);

    let changes = analyzer.analyze(&std::env::current_dir().unwrap()).unwrap();
    let suggestions = analyzer.generate_suggestions(&changes);

    for suggestion in &suggestions {
        println!("{}", suggestion);
    }
}
```

## Development

```bash
# Run tests
cargo test

# Run tests with verbose output
cargo test -- --nocapture

# Build
cargo build

# Build release
cargo build --release

# Run examples
cargo run --example basic_usage
cargo run --example custom_config
```

## Dependencies

- git2 - Git bindings
- clap - CLI argument parsing
- serde - Serialization
- regex - Pattern matching
- anyhow - Error handling
- dialoguer - Interactive prompts