/*
 * Copyright 2022 Fluence Labs Limited
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

use crate::test_runner::AirRunner;

use avm_server::avm_runner::*;
use fluence_keypair::KeyPair;
use once_cell::sync::OnceCell;

use std::path::PathBuf;

// 10 Mb
const AVM_MAX_HEAP_SIZE: u64 = 10 * 1024 * 1024;
const AIR_WASM_PATH: &str = "../target/wasm32-wasi/debug/air_interpreter_server.wasm";
const RELEASE_AIR_WASM_PATH: &str = "../target/wasm32-wasi/release/air_interpreter_server.wasm";

pub struct WasmAirRunner {
    current_peer_id: String,
    runner: object_pool::Reusable<'static, AVMRunner>,
}

fn make_pooled_avm_runner() -> AVMRunner {
    let logging_mask = i32::MAX;

    AVMRunner::new(
        PathBuf::from(AIR_WASM_PATH),
        Some(AVM_MAX_HEAP_SIZE),
        logging_mask,
    )
    .expect("vm should be created")
}

impl AirRunner for WasmAirRunner {
    fn new(current_peer_id: impl Into<String>) -> Self {
        static POOL_CELL: OnceCell<object_pool::Pool<AVMRunner>> = OnceCell::new();

        let pool = POOL_CELL.get_or_init(|| {
            object_pool::Pool::new(
                // we create an empty pool and let it fill on demand
                0,
                || unreachable!(),
            )
        });

        let runner = pool.pull(make_pooled_avm_runner);

        Self {
            current_peer_id: current_peer_id.into(),
            runner,
        }
    }

    fn call(
        &mut self,
        air: impl Into<String>,
        prev_data: impl Into<Vec<u8>>,
        data: impl Into<Vec<u8>>,
        init_peer_id: impl Into<String>,
        timestamp: u64,
        ttl: u32,
        override_current_peer_id: Option<String>,
        call_results: avm_server::CallResults,
        keypair: &KeyPair,
        particle_id: String,
    ) -> Result<RawAVMOutcome, Box<dyn std::error::Error>> {
        let current_peer_id =
            override_current_peer_id.unwrap_or_else(|| self.current_peer_id.clone());

        Ok(self.runner.call(
            air,
            prev_data,
            data,
            init_peer_id,
            timestamp,
            ttl,
            current_peer_id,
            call_results,
            keypair,
            particle_id,
        )?)
    }
}

/// WASM runner that runs release build form benchmarking.
pub struct ReleaseWasmAirRunner {
    current_peer_id: String,
    // these instances are not cached, as benches create relatively small number of instances
    runner: AVMRunner,
}

impl AirRunner for ReleaseWasmAirRunner {
    fn new(current_peer_id: impl Into<String>) -> Self {
        let logging_mask = i32::MAX;

        let runner = AVMRunner::new(
            PathBuf::from(RELEASE_AIR_WASM_PATH),
            Some(AVM_MAX_HEAP_SIZE),
            logging_mask,
        )
        .expect("vm should be created");

        Self {
            current_peer_id: current_peer_id.into(),
            runner,
        }
    }

    fn call(
        &mut self,
        air: impl Into<String>,
        prev_data: impl Into<Vec<u8>>,
        data: impl Into<Vec<u8>>,
        init_peer_id: impl Into<String>,
        timestamp: u64,
        ttl: u32,
        override_current_peer_id: Option<String>,
        call_results: avm_server::CallResults,
        keypair: &KeyPair,
        particle_id: String,
    ) -> Result<RawAVMOutcome, Box<dyn std::error::Error>> {
        let current_peer_id =
            override_current_peer_id.unwrap_or_else(|| self.current_peer_id.clone());

        Ok(self.runner.call(
            air,
            prev_data,
            data,
            init_peer_id,
            timestamp,
            ttl,
            current_peer_id,
            call_results,
            keypair,
            particle_id,
        )?)
    }
}