discord-rpc-client/src/java.rs

#![allow(clippy::await_holding_lock)]

use std::sync::MutexGuard;

use anyhow::Result;
use jni::objects::{JClass, JObject, JString, JValue};
use jni::signature::{JavaType, Primitive};
use jni::JNIEnv;

pub use jni;

use crate as drpc;

mod jvm_types {
    pub const BOOLEAN: &str = "java/lang/Boolean";
    pub const INTEGER: &str = "java/lang/Integer";
    pub const LONG: &str = "java/lang/Long";
    pub const STRING: &str = "java/lang/String";
}

macro_rules! signature {
    (bool) => {
        "Z"
    };
    (i32) => {
        "I"
    };
    (i64) => {
        "J"
    };
    (class $path:expr) => {
        const_format::formatcp!("L{};", $path)
    };
}

const PATH_DISCORD_RPC: &str = "com/discord/rpc/DiscordRPC";

lazy_static::lazy_static! {
    static ref RUNTIME: tokio::runtime::Runtime = tokio::runtime::Runtime::new().expect("unable to create tokio runtime");
}

fn is_null<'b, O>(env: JNIEnv, ref1: O) -> jni::errors::Result<bool>
where
    O: Into<JObject<'b>>,
{
    env.is_same_object(ref1, JObject::null())
}

// taking the [`JNIEnv`] as a reference is needed to satisfy the lifetime checker.
fn get_client<'a>(env: &'a JNIEnv<'a>, obj: JObject<'a>) -> Result<MutexGuard<'a, drpc::Client>> {
    if !env.is_instance_of(obj, PATH_DISCORD_RPC)? {
        bail!("not an instance of DiscordRPC");
    }

    let client = env.get_rust_field::<_, _, drpc::Client>(obj, "handle")?;
    Ok(client)
}

// TODO: method to destory afterwards.
#[inline(always)]
pub fn jni_create<'a>(env: JNIEnv<'a>, _class: JClass) -> Result<JObject<'a>> {
    let client = drpc::Client::default();

    let jobj = env.alloc_object(PATH_DISCORD_RPC)?;
    env.set_rust_field(jobj, "handle", client)?;
    Ok(jobj)
}

#[inline(always)]
pub fn jni_connect(env: JNIEnv, obj: JObject, client_id: JString) -> Result<()> {
    let client = get_client(&env, obj)?;

    let client_id = env.get_string(client_id)?.to_str()?.parse::<u64>()?;

    if let Some(current_client_id) = client.client_id() {
        if current_client_id != client_id {
            RUNTIME.block_on(async { client.disconnect().await });
        }
    }

    RUNTIME.block_on(async { client.connect(client_id).await })?;
    Ok(())
}

#[inline(always)]
pub fn jni_disconnect(env: JNIEnv, obj: JObject) -> Result<()> {
    let client = get_client(&env, obj)?;

    RUNTIME.block_on(async { client.disconnect().await });
    Ok(())
}

#[inline(always)]
pub fn jni_set_activity(env: JNIEnv, obj: JObject, j_activity: JObject) -> Result<()> {
    let client = get_client(&env, obj)?;

    let activity = jobject_to_activity(env, j_activity)?;
    RUNTIME.block_on(async { client.set_activity(activity).await })?;
    Ok(())
}

#[inline(always)]
pub fn jni_clear_activity(env: JNIEnv, obj: JObject) -> Result<()> {
    let client = get_client(&env, obj)?;

    RUNTIME.block_on(async { client.clear_activity().await })?;
    Ok(())
}

fn jobject_to_activity(env: JNIEnv, jobject: JObject) -> Result<drpc::models::Activity> {
    let j_state = env.get_field(jobject, "state", signature!(class jvm_types::STRING))?;
    let j_details = env.get_field(jobject, "details", signature!(class jvm_types::STRING))?;
    let j_instance = env.get_field(jobject, "instance", signature!(bool))?;
    let j_timestamps = env.get_field(
        jobject,
        "timestamps",
        signature!(class "com/discord/rpc/ActivityTimestamps"),
    )?;
    let j_assets = env.get_field(jobject, "assets", signature!(class "com/discord/rpc/ActivityAssets"))?;
    let j_party = env.get_field(jobject, "party", signature!(class "com/discord/rpc/ActivityParty"))?;
    let j_secrets = env.get_field(jobject, "secrets", signature!(class "com/discord/rpc/ActivitySecrets"))?;

    let mut activity = drpc::models::Activity::new();
    if let JValue::Object(obj) = j_state {
        if !is_null(env, obj)? {
            activity = activity.state(env.get_string(obj.into())?);
        }
    }
    if let JValue::Object(obj) = j_details {
        if !is_null(env, obj)? {
            activity = activity.details(env.get_string(obj.into())?);
        }
    }
    if let JValue::Bool(b) = j_instance {
        if b != 0 {
            activity = activity.instance(true);
        }
    }
    if let JValue::Object(obj) = j_timestamps {
        if !is_null(env, obj)? {
            let timestamps = jobject_to_activity_timestamps(env, obj)?;
            activity = activity.timestamps(|_| timestamps);
        }
    }
    if let JValue::Object(obj) = j_assets {
        if !is_null(env, obj)? {
            let assets = jobject_to_activity_assets(env, obj)?;
            activity = activity.assets(|_| assets);
        }
    }
    if let JValue::Object(obj) = j_party {
        if !is_null(env, obj)? {
            let party = jobject_to_activity_party(env, obj)?;
            activity = activity.party(|_| party);
        }
    }
    if let JValue::Object(obj) = j_secrets {
        if !is_null(env, obj)? {
            let secrets = jobject_to_activity_secrets(env, obj)?;
            activity = activity.secrets(|_| secrets);
        }
    }

    Ok(activity)
}

fn jobject_to_activity_timestamps(
    env: JNIEnv,
    jobject: JObject,
) -> Result<drpc::models::ActivityTimestamps> {
    let j_start = env.get_field(jobject, "start", signature!(class jvm_types::LONG))?;
    let j_end = env.get_field(jobject, "end", signature!(class jvm_types::LONG))?;

    let mut timestamps = drpc::models::ActivityTimestamps::new();
    if let JValue::Object(obj) = j_start {
        if !is_null(env, obj)? {
            if let JValue::Long(l) = env.call_method_unchecked(
                obj,
                (obj, "longValue", "()J"),
                JavaType::Primitive(Primitive::Long),
                &[],
            )? {
                timestamps = timestamps.start(l as u64);
            }
        }
    }
    if let JValue::Object(obj) = j_end {
        if !is_null(env, obj)? {
            if let JValue::Long(l) = env.call_method_unchecked(
                obj,
                (obj, "longValue", "()J"),
                JavaType::Primitive(Primitive::Long),
                &[],
            )? {
                timestamps = timestamps.end(l as u64);
            }
        }
    }

    Ok(timestamps)
}

fn jobject_to_activity_assets(
    env: JNIEnv,
    jobject: JObject,
) -> Result<drpc::models::ActivityAssets> {
    let j_lrg_img = env.get_field(jobject, "largeImage", signature!(class jvm_types::STRING))?;
    let j_lrg_txt = env.get_field(jobject, "largeText", signature!(class jvm_types::STRING))?;
    let j_sml_img = env.get_field(jobject, "smallImage", signature!(class jvm_types::STRING))?;
    let j_sml_txt = env.get_field(jobject, "smallText", signature!(class jvm_types::STRING))?;

    let mut assets = drpc::models::ActivityAssets::new();
    if let JValue::Object(obj) = j_lrg_img {
        if !is_null(env, obj)? {
            assets = assets.large_image(env.get_string(obj.into())?);
        }
    }
    if let JValue::Object(obj) = j_lrg_txt {
        if !is_null(env, obj)? {
            assets = assets.large_text(env.get_string(obj.into())?);
        }
    }
    if let JValue::Object(obj) = j_sml_img {
        if !is_null(env, obj)? {
            assets = assets.small_image(env.get_string(obj.into())?);
        }
    }
    if let JValue::Object(obj) = j_sml_txt {
        if !is_null(env, obj)? {
            assets = assets.small_text(env.get_string(obj.into())?);
        }
    }

    Ok(assets)
}

fn jobject_to_activity_party(env: JNIEnv, jobject: JObject) -> Result<drpc::models::ActivityParty> {
    let j_id = env.get_field(jobject, "id", signature!(i32))?;
    let j_min_size = env.get_field(jobject, "minSize", signature!(i32))?;
    let j_max_size = env.get_field(jobject, "maxSize", signature!(i32))?;

    let mut party = drpc::models::ActivityParty::new();
    if let JValue::Int(l) = j_id {
        party = party.id(l as u32);
    }
    if let (JValue::Int(l1), JValue::Int(l2)) = (j_min_size, j_max_size) {
        party = party.size((l1 as u32, l2 as u32));
    }

    Ok(party)
}

fn jobject_to_activity_secrets(
    env: JNIEnv,
    jobject: JObject,
) -> Result<drpc::models::ActivitySecrets> {
    let j_join = env.get_field(jobject, "join", signature!(class jvm_types::STRING))?;
    let j_spectate = env.get_field(jobject, "spectate", signature!(class jvm_types::STRING))?;
    let j_game = env.get_field(jobject, "game", signature!(class jvm_types::STRING))?;

    let mut secrets = drpc::models::ActivitySecrets::new();
    if let JValue::Object(obj) = j_join {
        if !is_null(env, obj)? {
            secrets = secrets.join(env.get_string(obj.into())?);
        }
    }
    if let JValue::Object(obj) = j_spectate {
        if !is_null(env, obj)? {
            secrets = secrets.spectate(env.get_string(obj.into())?);
        }
    }
    if let JValue::Object(obj) = j_game {
        if !is_null(env, obj)? {
            secrets = secrets.game(env.get_string(obj.into())?);
        }
    }

    Ok(secrets)
}