use std::sync::{atomic::Ordering, Arc};
use std::thread;
use std::time::{Duration, Instant};

use ::glommio::LocalExecutorBuilder;
use rand::prelude::*;
use rand_distr::Gamma;

mod common;
mod config;
mod network;
mod utils;

use common::*;
use config::*;
use network::*;

#[global_allocator]
static GLOBAL: mimalloc::MiMalloc = mimalloc::MiMalloc;

/// Multiply bytes during a second with this to get Mbit/s
const MBITS_FACTOR: f64 = 1.0 / ((1024.0 * 1024.0) / 8.0);

pub fn main() {
    aquatic_common::cli::run_app_with_cli_and_config::<Config>(
        "aquatic_http_load_test: BitTorrent load tester",
        env!("CARGO_PKG_VERSION"),
        run,
        None,
    )
}

fn run(config: Config) -> ::anyhow::Result<()> {
    if config.torrents.weight_announce + config.torrents.weight_scrape == 0 {
        panic!("Error: at least one weight must be larger than zero.");
    }

    println!("Starting client with config: {:#?}", config);

    let mut info_hashes = Vec::with_capacity(config.torrents.number_of_torrents);

    let mut rng = SmallRng::from_entropy();

    for _ in 0..config.torrents.number_of_torrents {
        info_hashes.push(InfoHash(rng.gen()));
    }

    let gamma = Gamma::new(
        config.torrents.torrent_gamma_shape,
        config.torrents.torrent_gamma_scale,
    )
    .unwrap();

    let state = LoadTestState {
        info_hashes: Arc::new(info_hashes),
        statistics: Arc::new(Statistics::default()),
        gamma: Arc::new(gamma),
    };

    let opt_tls_config = if config.enable_tls {
        Some(create_tls_config().unwrap())
    } else {
        None
    };

    for _ in 0..config.num_workers {
        let config = config.clone();
        let opt_tls_config = opt_tls_config.clone();
        let state = state.clone();

        LocalExecutorBuilder::default()
            .name("load-test")
            .spawn(move || async move {
                run_socket_thread(config, opt_tls_config, state)
                    .await
                    .unwrap();
            })
            .unwrap();
    }

    monitor_statistics(state, &config);

    Ok(())
}

fn monitor_statistics(state: LoadTestState, config: &Config) {
    let start_time = Instant::now();
    let mut report_avg_response_vec: Vec<f64> = Vec::new();

    let interval = 5;
    let interval_f64 = interval as f64;

    loop {
        thread::sleep(Duration::from_secs(interval));

        let statistics = state.statistics.as_ref();

        let responses_announce = statistics
            .responses_announce
            .fetch_and(0, Ordering::Relaxed) as f64;
        // let response_peers = statistics.response_peers
        //     .fetch_and(0, Ordering::SeqCst) as f64;

        let requests_per_second =
            statistics.requests.fetch_and(0, Ordering::Relaxed) as f64 / interval_f64;
        let responses_scrape_per_second =
            statistics.responses_scrape.fetch_and(0, Ordering::Relaxed) as f64 / interval_f64;
        let responses_failure_per_second =
            statistics.responses_failure.fetch_and(0, Ordering::Relaxed) as f64 / interval_f64;

        let bytes_sent_per_second =
            statistics.bytes_sent.fetch_and(0, Ordering::Relaxed) as f64 / interval_f64;
        let bytes_received_per_second =
            statistics.bytes_received.fetch_and(0, Ordering::Relaxed) as f64 / interval_f64;

        let responses_announce_per_second = responses_announce / interval_f64;

        let responses_per_second = responses_announce_per_second
            + responses_scrape_per_second
            + responses_failure_per_second;

        report_avg_response_vec.push(responses_per_second);

        println!();
        println!("Requests out: {:.2}/second", requests_per_second);
        println!("Responses in: {:.2}/second", responses_per_second);
        println!(
            "  - Announce responses: {:.2}",
            responses_announce_per_second
        );
        println!("  - Scrape responses:   {:.2}", responses_scrape_per_second);
        println!(
            "  - Failure responses:  {:.2}",
            responses_failure_per_second
        );
        //println!("Peers per announce response: {:.2}", response_peers / responses_announce);
        println!(
            "Bandwidth out: {:.2}Mbit/s",
            bytes_sent_per_second * MBITS_FACTOR
        );
        println!(
            "Bandwidth in:  {:.2}Mbit/s",
            bytes_received_per_second * MBITS_FACTOR
        );

        let time_elapsed = start_time.elapsed();
        let duration = Duration::from_secs(config.duration as u64);

        if config.duration != 0 && time_elapsed >= duration {
            let report_len = report_avg_response_vec.len() as f64;
            let report_sum: f64 = report_avg_response_vec.into_iter().sum();
            let report_avg: f64 = report_sum / report_len;

            println!(
                concat!(
                    "\n# aquatic load test report\n\n",
                    "Test ran for {} seconds.\n",
                    "Average responses per second: {:.2}\n\nConfig: {:#?}\n"
                ),
                time_elapsed.as_secs(),
                report_avg,
                config
            );

            break;
        }
    }
}

#[derive(Debug)]
struct FakeCertificateVerifier;

impl rustls::client::danger::ServerCertVerifier for FakeCertificateVerifier {
    fn verify_server_cert(
        &self,
        _end_entity: &rustls::pki_types::CertificateDer<'_>,
        _intermediates: &[rustls::pki_types::CertificateDer<'_>],
        _server_name: &rustls::pki_types::ServerName<'_>,
        _ocsp_response: &[u8],
        _now: rustls::pki_types::UnixTime,
    ) -> Result<rustls::client::danger::ServerCertVerified, rustls::Error> {
        Ok(rustls::client::danger::ServerCertVerified::assertion())
    }

    fn verify_tls12_signature(
        &self,
        _message: &[u8],
        _cert: &rustls::pki_types::CertificateDer<'_>,
        _dss: &rustls::DigitallySignedStruct,
    ) -> Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error> {
        Ok(rustls::client::danger::HandshakeSignatureValid::assertion())
    }

    fn verify_tls13_signature(
        &self,
        _message: &[u8],
        _cert: &rustls::pki_types::CertificateDer<'_>,
        _dss: &rustls::DigitallySignedStruct,
    ) -> Result<rustls::client::danger::HandshakeSignatureValid, rustls::Error> {
        Ok(rustls::client::danger::HandshakeSignatureValid::assertion())
    }

    fn supported_verify_schemes(&self) -> Vec<rustls::SignatureScheme> {
        vec![
            rustls::SignatureScheme::ECDSA_NISTP384_SHA384,
            rustls::SignatureScheme::ECDSA_NISTP256_SHA256,
            rustls::SignatureScheme::RSA_PSS_SHA512,
            rustls::SignatureScheme::RSA_PSS_SHA384,
            rustls::SignatureScheme::RSA_PSS_SHA256,
            rustls::SignatureScheme::ED25519,
        ]
    }
}

fn create_tls_config() -> anyhow::Result<Arc<rustls::ClientConfig>> {
    let mut config = rustls::ClientConfig::builder()
        .with_root_certificates(rustls::RootCertStore::empty())
        .with_no_client_auth();

    config
        .dangerous()
        .set_certificate_verifier(Arc::new(FakeCertificateVerifier));

    Ok(Arc::new(config))
}