# AGENTS.md - SCL Language Server (Unified)

This is a unified Neovim/LazyVim plugin for Siemens SCL language support.

## Project Overview

The unified `scl_lsp` project provides:
- **LSP Server** - Language Server Protocol implementation
- **Linter** - Diagnostics and code validation
- **Formatter** - Document formatting
- **Syntax Highlighting** - Tree-sitter based
- **Auto-completion** - blink.cmp integration
- **Auto-prefix** - Automatic `#` prefixing for variables

## Project Structure

```
scl_lsp/
├── src/                        # LSP server implementation
│   ├── main.lua               # Entry point, protocol handling
│   ├── parser.lua             # Regex-based SCL parser
│   ├── treesitter.lua        # Tree-sitter integration
│   ├── diagnostics.lua       # Linter diagnostics
│   ├── formatter.lua         # Document formatter
│   ├── json.lua              # JSON encoder/decoder
│   └── plc_json.lua          # External UDT loading
├── lua/
│   ├── scl/                  # Neovim plugin modules (from scl_syntax_nvim)
│   │   ├── init.lua
│   │   ├── auto_prefix.lua
│   │   ├── blink_cmp_source.lua
│   │   ├── fb_parser.lua
│   │   ├── udt_parser.lua
│   │   ├── variables.lua
│   │   └── workspace_types.lua
│   └── scl_lsp/
│       ├── init.lua          # Unified plugin setup
│       └── plugins/
│           └── scl.lua       # LazyVim plugin spec
├── queries/                  # Tree-sitter queries
│   ├── highlights.scm
│   ├── indents.scm
│   ├── folds.scm
│   ├── locals.scm
│   └── tags.scm
├── grammar.js                # Tree-sitter grammar
└── tree-sitter.json         # Parser config
```

## Development

### Running the LSP Server

```bash
# Direct execution
lua src/main.lua

# Via shell script
./scl_lsp.sh

# With test mode
lua src/main.lua --test
```

### Testing

```bash
# Tree-sitter parser
npm test
tree-sitter generate

# Test file parsing
tree-sitter parse corpus/test/main_org_block.scl
```

### Key Patterns

- **LSP Protocol**: JSON-RPC over stdin/stdout in `src/main.lua`
- **Diagnostics**: `src/diagnostics.lua` - validates SCL code
- **Formatter**: `src/formatter.lua` - formats SCL documents
- **Syntax**: Tree-sitter queries in `queries/`
- **Plugin Setup**: `lua/scl_lsp/init.lua` - LazyVim integration

## Configuration

See `README.md` for configuration options and usage.