pub mod config;
pub mod container;
pub mod data;
pub mod global;
pub mod grpc;
pub mod utils;

use anyhow::anyhow;
use anyhow::Result;
use data::App;
use detee_shared::app_proto::{
    brain_message_app, AppContract, AppNodeResources, BrainMessageApp, DaemonMessageApp,
    MappedPort, NewAppRes,
};
use detee_shared::sgx::types::brain::AppDeployConfig;
use global::PUBLIC_KEY;
use log::info;
use log::warn;
use std::collections::HashSet;
use std::fs::File;
use std::path::Path;
use std::time::Duration;
use tokio::sync::mpsc::Receiver;
use tokio::sync::mpsc::Sender;
use tokio::time::sleep;

use utils::cleanup_enclave_disk_and_package;

pub use crate::config::HostConfig;
pub use crate::data::HostResources;

use global::DAEMON_CONFIG_PATH;
use global::DEPLOYED_APPS_CONFIG_DIR;

#[derive(Debug)]
pub struct AppHandler {
    pub receiver: Receiver<BrainMessageApp>,
    pub sender: Sender<DaemonMessageApp>,
    pub host_config: HostConfig,
    pub host_resource: HostResources,
}

impl AppHandler {
    pub fn new(receiver: Receiver<BrainMessageApp>, sender: Sender<DaemonMessageApp>) -> Self {
        // TODO: load from config and resources from file,
        //       if not found use default and save host resources to file

        let host_config = match HostConfig::load_from_disk(&DAEMON_CONFIG_PATH) {
            Ok(config) => config,
            Err(e) => panic!("Could not load config: {e:?}"),
        };
        let host_resource = match HostResources::load_from_disk() {
            Ok(res) => res,
            Err(e) => {
                warn!("Could not load resources from disk: {e:?}");
                info!("Creating new resource calculator.");
                HostResources::new()
            }
        };

        Self {
            receiver,
            sender,
            host_config,
            host_resource,
        }
    }

    async fn handle_contracts(&mut self, contracts: Vec<AppContract>) {
        let apps_in_host = self.host_resource.existing_apps.clone();
        let apps_in_brain: HashSet<String> = contracts
            .iter()
            .map(|contact| contact.uuid.clone())
            .collect();

        let deleted_apps: HashSet<String> =
            apps_in_host.difference(&apps_in_brain).cloned().collect();

        for uuid in deleted_apps {
            if let Err(e) = self.handle_del_app_req(uuid.clone()).await {
                log::error!("Failed to delete app: {e}");
            }
        }
    }

    async fn run(mut self) {
        sleep(Duration::from_millis(500)).await;
        self.send_node_resources().await;
        while let Some(brain_msg) = self.receiver.recv().await {
            match brain_msg.msg {
                Some(brain_message_app::Msg::NewAppReq(msg)) => {
                    self.handle_new_app_req(msg.into()).await;
                }
                Some(brain_message_app::Msg::DeleteAppReq(msg)) => {
                    if let Err(er) = self.handle_del_app_req(msg.uuid).await {
                        log::error!("Failed to delete app: {er}");
                    }

                    self.send_node_resources().await;
                }
                None => {
                    log::error!("Brain disconnected");
                    break;
                }
            }
        }
    }

    async fn handle_new_app_req(&mut self, new_app_req: AppDeployConfig) {
        let uuid = new_app_req.uuid.clone();
        let app_result = App::new(new_app_req, &self.host_config, &mut self.host_resource).await;

        match app_result {
            Ok(app) => {
                self.send_node_resources().await;

                info!("Succesfully started App {uuid}");
                let res = NewAppRes {
                    uuid,
                    status: "success".to_string(),
                    error: "".to_string(),
                    mapped_ports: app.mapped_ports.into_iter().map(MappedPort::from).collect(),
                    ip_address: self.host_config.host_ip_address.clone(),
                };
                let _ = self.sender.send(res.into()).await;
            }
            Err(e) => {
                let res = NewAppRes {
                    uuid,
                    status: "failed".to_string(),
                    error: e.to_string(),
                    ..Default::default()
                };

                log::error!("sending response {:?}", res);
                let _ = self.sender.send(res.into()).await;
            }
        };
    }

    async fn handle_del_app_req(&mut self, uuid: String) -> Result<()> {
        let app_handle_file_name = format!("{}/{}.yaml", *DEPLOYED_APPS_CONFIG_DIR, &uuid);
        let content = std::fs::read_to_string(&app_handle_file_name)?;
        let app_instance: App = serde_yml::from_str(&content)?;

        app_instance.delete_app(&mut self.host_resource).await?;
        std::fs::remove_file(&app_handle_file_name)?;

        if let Err(er) = cleanup_enclave_disk_and_package(uuid).await {
            log::error!("Failed to cleanup disk:\n{er}");
        };

        Ok(())
    }

    async fn send_node_resources(&mut self) {
        let host_config = self.host_config.clone();
        let host_resource = self.host_resource.clone();

        let node_pubkey = PUBLIC_KEY.to_string();
        let avail_no_of_port =
            (host_config.public_port_range.len() - host_resource.reserved_host_ports.len()) as u32;

        let avail_vcpus = host_config.max_vcpu_reservation - host_resource.reserved_vcpus;
        let avail_memory_mb = host_config.max_mem_reservation_mb - host_resource.reserved_memory_mb;
        let avail_storage_mb = host_config.max_disk_reservation_mb - host_resource.reserved_disk_mb;
        let max_ports_per_app = host_config.max_ports_per_app;

        let resource_update = AppNodeResources {
            node_pubkey,
            avail_no_of_port,
            avail_vcpus,
            avail_memory_mb,
            avail_storage_mb,
            max_ports_per_app,
        };

        log::debug!("sending node resources on brain: {resource_update:?}");
        let _ = self.sender.send(resource_update.into()).await;
    }
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    set_logging();
    log::info!("Detee daemon running");

    loop {
        if std::env::var("DAEMON_AUTO_UPGRADE") != Ok("OFF".to_string()) {
            // This upgrade procedure will get replaced in prod. We need this for the testnet.
            if let Err(e) = download_and_replace_binary().await {
                log::error!("Failed to upgrade detee-sgx-daemon to newer version: {e}");
            }
        }

        let (brain_msg_tx, brain_msg_rx) = tokio::sync::mpsc::channel(6);
        let (daemon_msg_tx, daemon_msg_rx) = tokio::sync::mpsc::channel(6);

        let mut app_handler = AppHandler::new(brain_msg_rx, daemon_msg_tx.clone());
        let network = app_handler.host_config.network.clone();

        let mut contracts = vec![];
        match grpc::register_node(&app_handler.host_config).await {
            Ok(app_contracts) => {
                contracts.append(&mut app_contracts.iter().map(|c| c.uuid.clone()).collect());
                app_handler.handle_contracts(app_contracts).await
            }

            Err(e) => log::error!("Failed to connect to brain: {e}"),
        }

        tokio::spawn(async move {
            app_handler.run().await;
        });

        log::info!("Connecting to brain...");
        if let Err(e) = grpc::connect_and_run(grpc::ConnectionData {
            network,
            brain_msg_tx,
            daemon_msg_rx,
            daemon_msg_tx,
            app_contracts_uuid: contracts,
        })
        .await
        {
            log::error!("The connection broke: {e}");
        }
        sleep(Duration::from_secs(3)).await;
    }
}

fn set_logging() {
    let log_level = match std::env::var("LOG_LEVEL") {
        Ok(val) => match val.as_str() {
            "DEBUG" => log::LevelFilter::Debug,
            "INFO" => log::LevelFilter::Info,
            _ => log::LevelFilter::Error,
        },
        _ => log::LevelFilter::Warn,
    };
    env_logger::builder()
        .filter_level(log_level)
        .format_timestamp(None)
        .init();
}

async fn download_and_replace_binary() -> Result<()> {
    use reqwest::get;
    use std::os::unix::fs::PermissionsExt;
    const TMP_DAEMON: &str = "/usr/local/bin/detee/new-daemon";
    const BINARY: &str = "/usr/local/bin/detee-sgx-daemon";
    let response = get("https://registry.detee.ltd/sgx/daemon/detee-sgx-daemon").await?;
    if !response.status().is_success() {
        return Err(anyhow!("Failed to download file: {}", response.status()));
    }
    let mut tmp_file = File::create(Path::new(&TMP_DAEMON))?;
    std::io::copy(&mut response.bytes().await?.as_ref(), &mut tmp_file)?;
    let new_hash = crate::global::compute_sha256(TMP_DAEMON)?;
    let old_hash = crate::global::compute_sha256(BINARY)?;
    log::debug!("Old binary hash: {old_hash}. New binary hash: {new_hash}");
    if new_hash != old_hash {
        std::fs::rename(BINARY, BINARY.to_string() + "_BACKUP")?;
        std::fs::rename(TMP_DAEMON, BINARY)?;
        std::fs::set_permissions(BINARY, std::fs::Permissions::from_mode(0o775))?;
        std::process::exit(0);
    }
    Ok(())
}