# Lua game package format

A game package is a manifest plus Lua scripts and optional assets.

Typical structure:

```text
assets/games/<gameId>/
  manifest.json
  scripts/
    main.lua
    state.lua
    ui.lua
    runtime_defs.lua
  assets/
    image.png
  audio/
    click.wav
```

## Manifest modules

Lua modules must be declared in `manifest.json`.

```json
{
  "id": "template",
  "version": "0.1.0",
  "entry": "main",
  "modules": {
    "main": "scripts/main.lua",
    "state": "scripts/state.lua",
    "ui": "scripts/ui.lua",
    "runtime_ui": "runtime:runtime_ui.lua",
    "runtime_widgets": "runtime:runtime_widgets.lua",
    "runtime_commands": "runtime:runtime_commands.lua",
    "layout": "runtime:layout.lua"
  }
}
```

Lua imports by module name:

```lua
local ui = runtime.import("ui")
local widgets = runtime.import("runtime_widgets")
```

Do not use `require`, `package`, `dofile`, `loadfile`, or `os`.

## Path rules

Package-local module paths:

```text
scripts/*.lua
```

Runtime shared module paths:

```text
runtime:*.lua
```

`runtime:` paths must not contain `/`, `..`, or an empty filename.

## Entry module

The manifest `entry` module should expose lifecycle/event functions expected by the script engine. Keep game-specific state in Lua modules and return runtime diffs/commands through the approved protocol.

## Runtime helper modules

Shared helpers are provided by the runtime package:

```text
assets/runtime/lua/runtime_ui.lua
assets/runtime/lua/runtime_widgets.lua
assets/runtime/lua/runtime_commands.lua
assets/runtime/lua/layout.lua
```

Use helpers for authoring convenience, but remember helpers must normalize into supported Runtime protocol nodes/commands before Dart validation.

## Generated Lua definitions

`runtime_defs.lua` files are generated from common definitions. After changing helper APIs, run:

```bash
dart run tool/generate_lua_runtime_defs.dart
```

Check without rewriting:

```bash
dart run tool/generate_lua_runtime_defs.dart --check
```

## Package validation

A host repository can validate a game package with:

```bash
dart run tool/check_runtime_package.dart assets/games/template packages/flame_lua_runtime/assets/runtime/lua
```

Within this package repo, example game packages live under:

```text
example/assets/games/
```