# arma-rs

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The best way to make Arma 3 Extensions.

## Usage

```toml
[dependencies]
arma-rs = "1.11.10"

[lib]
name = "my_extension"
crate-type = ["cdylib"]
```

### Hello World

```rust
use arma_rs::{arma, Extension};

#[arma]
fn init() -> Extension {
    Extension::build()
        .command("hello", hello)
        .command("welcome", welcome)
        .finish()
}

pub fn hello() -> &'static str {
    "Hello"
}

pub fn welcome(name: String) -> String {
    format!("Welcome {}", name)
}
```

```sqf
"my_extension" callExtension ["hello", []]; // Returns ["Hello", 0, 0]
"my_extension" callExtension ["welcome", ["John"]]; // Returns ["Welcome John", 0, 0]
```

## Command Groups

Commands can be grouped together, making your large projects much easier to manage.

```rust
use arma_rs::{arma, Extension, Group};

#[arma]
fn init() -> Extension {
    Extension::build()
        .group("hello",
            Group::new()
                .command("english", hello::english)
                .group("english",
                    Group::new()
                        .command("casual", hello::english_casual)
                )
                .command("french", hello::french),
        )
        .group("welcome",
            Group::new()
                .command("english", welcome::english)
                .command("french", welcome::french),
        )
        .finish()
}

mod hello {
    pub fn english() -> &'static str {
        "Hello"
    }
    pub fn english_casual() -> &'static str {
        "Hey"
    }
    pub fn french() -> &'static str {
        "Bonjour"
    }
}

mod welcome {
    pub fn english(name: String) -> String {
        format!("Welcome {}", name)
    }
    pub fn french(name: String) -> String {
        format!("Bienvenue {}", name)
    }
}
```

Commands groups are called by using the format `group:command`. You can nest groups as much as you want.

```sqf
"my_extension" callExtension ["hello:english", []]; // Returns ["Hello", 0, 0]
"my_extension" callExtension ["hello:english:casual", []]; // Returns ["Hey", 0, 0]
"my_extension" callExtension ["hello:french", []]; // Returns ["Bonjour", 0, 0]
```

## Callbacks

Extension callbacks can be invoked anywhere in the extension by adding a variable of type `Context` to the start of a handler.

```rust
use arma_rs::Context;

pub fn sleep(ctx: Context, duration: u64, id: String) {
    std::thread::spawn(move || {
        std::thread::sleep(std::time::Duration::from_secs(duration));
        ctx.callback_data("example_timer", "done", Some(id));
    });
}

pub fn group() -> arma_rs::Group {
    arma_rs::Group::new().command("sleep", sleep)
}
```

## Call Context

Since Arma v2.11 additional context is provided each time the extension is called. This context can be accessed through the optional `ArmaCallContext` argument.

Since Arma v2.18 the context is only requested from Arma when the functionh has `ArmaCallContext` as an argument.

```rust
use arma_rs::{CallContext, CallContextStackTrace};

pub fn call_context(call_context: CallContext) -> String {
    format!(
        "{:?},{:?},{:?},{:?},{:?}",
        call_context.caller(),
        call_context.source(),
        call_context.mission(),
        call_context.server(),
        call_context.remote_exec_owner(),
    )
}

pub fn stack_trace(call_context: CallContextStackTrace) -> String {
    format!(
        "{:?}\n{:?}",
        call_context.source(),
        call_context.stack_trace()
    )
}

pub fn group() -> arma_rs::Group {
    arma_rs::Group::new()
        .command("call_context", call_context)
        .command("stack_trace", stack_trace)
}
```

## Persistent State

Both the extension and command groups allow for type based persistent state values with at most one instance per type. These state values can then be accessed through the optional `Context` argument.

### Global State

Extension state is accessible from any command handler.

```rust
use arma_rs::{arma, Context, ContextState, Extension};

use std::sync::atomic::{AtomicU32, Ordering};

#[arma]
fn init() -> Extension {
    Extension::build()
        .command("counter_increment", increment)
        .state(AtomicU32::new(0))
        .finish()
}

pub fn increment(ctx: Context) -> Result<(), ()> {
    let Some(counter) = ctx.global().get::<AtomicU32>() else {
        return Err(());
    };
    counter.fetch_add(1, Ordering::SeqCst);
    Ok(())
}
```

### Group State

Command group state is only accessible from command handlers within the same group.

```rust
use arma_rs::{Context, ContextState, Extension};

use std::sync::atomic::{AtomicU32, Ordering};

pub fn increment(ctx: Context) -> Result<(), ()> {
    let Some(counter) = ctx.group().get::<AtomicU32>() else {
        return Err(());
    };
    counter.fetch_add(1, Ordering::SeqCst);
    Ok(())
}

pub fn group() -> arma_rs::Group {
    arma_rs::Group::new()
        .command("increment", increment)
        .state(AtomicU32::new(0))
}
```

## Custom Types

If you're bringing your existing Rust library with your own types, you can easily define how they are converted to and from Arma.

```rust
use arma_rs::{FromArma, IntoArma, Value, FromArmaError};

pub struct MemoryReport {
    total: u64,
    free: u64,
    avail: u64,
}

impl FromArma for MemoryReport {
    fn from_arma(s: String) -> Result<Self, FromArmaError> {
        let (total, free, avail) = <(u64, u64, u64)>::from_arma(s)?;
        Ok(Self { total, free, avail })
    }
}

impl IntoArma for MemoryReport {
    fn to_arma(&self) -> Value {
        Value::Array(
            vec![self.total, self.free, self.avail]
                .into_iter()
                .map(|v| v.to_string().to_arma())
                .collect(),
        )
    }
}
```

### Derive

Alternatively you can derive these traits. Note that the derive and manual implementation examples slightly differ, as when deriving map like structs its represented as an hashmap rather than an array. For more information on data representation and attributes see: [FromArma](https://docs.rs/arma-rs/latest/arma_rs/derive.FromArma.html) and [IntoArma](https://docs.rs/arma-rs/latest/arma_rs/derive.IntoArma.html).

```rust
use arma_rs::{FromArma, IntoArma};

#[derive(FromArma, IntoArma)]
struct MemoryReport {
    #[arma(to_string)]
    total: u64,
    #[arma(to_string)]
    free: u64,
    #[arma(to_string)]
    avail: u64,
}
```

Deriving is currently only supported for structs, this might change in the future.

## Error Codes

By default arma-rs will only allow commands via `RvExtensionArgs`. Using `callExtension` with only a function name will return an empty string.

```sqf
"my_extension" callExtension "hello:english" // returns ""
"my_extension" callExtension ["hello:english", []] // returns ["Hello", 0, 0]
```

This behaviour can be changed by calling `.allow_no_args()` when building the extension. It is recommended not to use this, and to implement error handling instead.

| Code | Description                                       |
|------|---------------------------------------------------|
|  0   | Success                                           |
|  1   | Command not found                                 |
|  2x  | Invalid argument count, x is received count       |
|  3x  | Invalid argument type, x is argument position     |
|  4   | Attempted to write a value larger than the buffer |
|  9   | Application error, from using a Result            |

### Error Examples

```rust
use arma_rs::Context;

pub fn add(a: i32, b: i32) -> i32 {
    a + b
}

pub fn overflow(ctx: Context) -> String {
    "X".repeat(ctx.buffer_len() + 1)
}

pub fn should_error(error: bool) -> Result<String, String> {
  if error {
    Err(String::from("told to error"))
  } else {
    Ok(String::from("told to succeed"))
  }
}
```

```sqf
"my_extension" callExtension ["add", [1, 2]]; // Returns ["3", 0, 0]
"my_extension" callExtension ["sub", [1, 2]]; // Returns ["", 1, 0]
"my_extension" callExtension ["add", [1, 2, 3]]; // Returns ["", 23, 0], didn't expect 3 elements
"my_extension" callExtension ["add", [1, "two"]]; // Returns ["", 31, 0], unable to parse the second argument
"my_extension" callExtension ["overflow", []]; // Returns ["", 4, 0], the return size was larger than the buffer
"my_extension" callExtension ["should_error", [true]]; // Returns ["told to error", 9, 0]
"my_extension" callExtension ["should_error", [false]]; // Returns ["told to succeed", 0, 0]
```

## Testing

Tests can be created utilizing the `extension.call()` method.

```rust,ignore
mod tests {
    #[test]
    fn hello() {
        let extension = init().testing();
        let (output, _) = extension.call("hello:english", None);
        assert_eq!(output, "hello");
    }

    #[test]
    fn welcome() {
        let extension = init().testing();
        let (output, _) =
            extension.call("welcome:english", Some(vec!["John".to_string()]));
        assert_eq!(output, "Welcome John");
    }

    #[test]
    fn sleep_1sec() {
        let extension = Extension::build()
            .group("timer", super::group())
            .finish()
            .testing();
        let (_, code) = extension.call(
            "timer:sleep",
            Some(vec!["1".to_string(), "test".to_string()]),
        );
        assert_eq!(code, 0);
        let result = extension.callback_handler(
            |name, func, data| {
                assert_eq!(name, "timer:sleep");
                assert_eq!(func, "done");
                if let Some(Value::String(s)) = data {
                    Result::Ok(s)
                } else {
                    Result::Err("Data was not a string".to_string())
                }
            },
            Duration::from_secs(2),
        );
        assert_eq!(Result::Ok("test".to_string()), result);
    }
}
```

## Unit Loadout Array

arma-rs includes a [loadout module](https://docs.rs/arma-rs/latest/arma_rs/loadout/index.html) to assist with the handling of [Arma's Unit Loadout Array](https://community.bistudio.com/wiki/Unit_Loadout_Array).

```rust
use arma_rs::{FromArma, loadout::{Loadout, InventoryItem, Weapon, Magazine}};

let l = r#"[[],[],[],["U_Marshal",[]],[],[],"H_Cap_headphones","G_Aviator",[],["ItemMap","ItemGPS","","ItemCompass","ItemWatch",""]]"#;
let mut loadout = Loadout::from_arma(l.to_string()).unwrap();
loadout.set_secondary({
    let mut weapon = Weapon::new("launch_B_Titan_short_F".to_string());
    weapon.set_primary_magazine(Magazine::new("Titan_AT".to_string(), 1));
    weapon
});
loadout.set_primary({
    let mut weapon = Weapon::new("arifle_MXC_F".to_string());
    weapon.set_optic("optic_Holosight".to_string());
    weapon
});
let uniform = loadout.uniform_mut();
uniform.set_class("U_B_CombatUniform_mcam".to_string());
let uniform_items = uniform.items_mut().unwrap();
uniform_items.push(InventoryItem::new_item("FirstAidKit".to_string(), 3));
uniform_items.push(InventoryItem::new_magazine("30Rnd_65x39_caseless_mag".to_string(), 5, 30));
```

## Common Rust Libraries

arma-rs supports some common Rust libraries.
You can enable their support by adding their name to the features of arma-rs.

```toml
arma-rs = { version = "1.8.0", features = ["chrono"] }
```

Please create an issue first if you would like to add support for a new library.

### chrono

[`crates.io`](https://crates.io/crates/chrono)

#### chrono - Convert to Arma

[`NaiveDateTime`](https://docs.rs/chrono/latest/chrono/naive/struct.NaiveDateTime.html) and [`DateTime<TimeZone>`](https://docs.rs/chrono/latest/chrono/struct.DateTime.html) will be converted to [Arma's date array](https://community.bistudio.com/wiki/systemTimeUTC).
The timezone will always be converted to UTC.

#### chrono - Convert From Arma

[Arma's date array](https://community.bistudio.com/wiki/systemTimeUTC) can be converted to [`NaiveDateTime`](https://docs.rs/chrono/latest/chrono/naive/struct.NaiveDateTime.html).

### uuid

[`crates.io`](https://crates.io/crates/uuid)

#### uuid - Convert To Arma

[`Uuid`](https://docs.rs/uuid/latest/uuid/struct.Uuid.html) will be converted to a string.

### serde_json

[`crates.io`](https://crates.io/crates/serde_json)

#### serde_json - Convert To Arma

Any variant of [`serde_json::Value`](https://docs.serde.rs/serde_json/enum.Value.html) will be converted to the appropriate Arma type.

## Building for x86 (32 Bit)

```sh
rustup toolchain install stable-i686-pc-windows-msvc
cargo +stable-i686-pc-windows-msvc build
```

## Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.