#![allow(dead_code)]

// SPDX-License-Identifier: Apache-2.0

use crate::constants::{ACCOUNT, DEFAULT_ENDPOINT, NEW_VM_REQ, UPDATE_VM_REQ, VM_NODE};
use crate::db::prelude as db;
use crate::grpc::{check_sig_from_parts, check_sig_from_req};
use detee_shared::common_proto::Empty;
use detee_shared::vm_proto::brain_vm_cli_server::BrainVmCli;
use detee_shared::vm_proto::brain_vm_daemon_server::BrainVmDaemon;
use detee_shared::vm_proto::{ListVmContractsReq, *};
use surrealdb::engine::remote::ws::Client;
use surrealdb::Surreal;

use log::info;
use std::pin::Pin;
use std::sync::Arc;
use tokio::sync::mpsc;
use tokio_stream::wrappers::ReceiverStream;
use tokio_stream::{Stream, StreamExt};
use tonic::{Request, Response, Status, Streaming};

pub struct VmDaemonServer {
    pub db: Arc<Surreal<Client>>,
}

impl VmDaemonServer {
    pub fn new(db: Arc<Surreal<Client>>) -> Self {
        Self { db }
    }
}

#[tonic::async_trait]
impl BrainVmDaemon for VmDaemonServer {
    type BrainMessagesStream = Pin<Box<dyn Stream<Item = Result<BrainVmMessage, Status>> + Send>>;
    type RegisterVmNodeStream = Pin<Box<dyn Stream<Item = Result<DeleteVmReq, Status>> + Send>>;

    async fn register_vm_node(
        &self,
        req: Request<RegisterVmNodeReq>,
    ) -> Result<Response<Self::RegisterVmNodeStream>, Status> {
        let req = check_sig_from_req(req)?;
        info!("Starting registration process for {:?}", req);
        db::VmNode {
            id: surrealdb::RecordId::from((VM_NODE, req.node_pubkey.clone())),
            operator: surrealdb::RecordId::from((ACCOUNT, req.operator_wallet)),
            pub_sub_node: std::env::var("BRAIN_PUBLIC_ENDPOINT")
                .unwrap_or(DEFAULT_ENDPOINT.to_string()),
            country: req.country,
            region: req.region,
            city: req.city,
            ip: req.main_ip,
            price: req.price,
            avail_mem_mb: 0,
            avail_vcpus: 0,
            avail_storage_gbs: 0,
            avail_ipv4: 0,
            avail_ipv6: 0,
            avail_ports: 0,
            max_ports_per_vm: 0,
            disconnected_at: surrealdb::sql::Datetime::default(),
            connected_at: surrealdb::sql::Datetime::default(),
        }
        .register(&self.db)
        .await?;

        info!("Sending deleted contracts to {}", req.node_pubkey);
        let deleted_vms = db::DeletedVm::list_by_node(&self.db, &req.node_pubkey).await?;
        let (tx, rx) = mpsc::channel(6);
        tokio::spawn(async move {
            for deleted_vm in deleted_vms {
                let _ = tx.send(Ok(deleted_vm.into())).await;
            }
        });
        let output_stream = ReceiverStream::new(rx);
        Ok(Response::new(Box::pin(output_stream) as Self::RegisterVmNodeStream))
    }

    async fn brain_messages(
        &self,
        req: Request<DaemonStreamAuth>,
    ) -> Result<Response<Self::BrainMessagesStream>, Status> {
        let auth = req.into_inner();
        let pubkey = auth.pubkey.clone();
        check_sig_from_parts(
            &pubkey,
            &auth.timestamp,
            &format!("{:?}", auth.contracts),
            &auth.signature,
        )?;
        info!("Daemon {} connected to receive brain messages", pubkey);
        let _ = db::VmNode::set_online(&self.db, &pubkey).await;

        let (tx, rx) = mpsc::channel(6);
        {
            let db = self.db.clone();
            let pubkey = pubkey.clone();
            let tx = tx.clone();
            tokio::spawn(async move {
                match db::live_vmnode_msgs::<db::DeletedVm>(&db, &pubkey, tx).await {
                    Ok(()) => log::info!("live_vmnode_msgs ended for {pubkey}"),
                    Err(e) => {
                        log::warn!("live_vmnode_msgs errored for {pubkey}: {e}")
                    }
                };
            });
        }
        {
            let db = self.db.clone();
            let pubkey = pubkey.clone();
            let tx = tx.clone();
            tokio::spawn(async move {
                let _ = db::live_vmnode_msgs::<db::NewVmReq>(&db, &pubkey, tx.clone()).await;
            });
        }
        {
            let db = self.db.clone();
            let pubkey = pubkey.clone();
            let tx = tx.clone();
            tokio::spawn(async move {
                let _ = db::live_vmnode_msgs::<db::UpdateVmReq>(&db, &pubkey, tx.clone()).await;
            });
        }

        let output_stream = ReceiverStream::new(rx).map(|msg| Ok(msg.into()));
        Ok(Response::new(Box::pin(output_stream) as Self::BrainMessagesStream))
    }

    async fn daemon_messages(
        &self,
        req: Request<Streaming<VmDaemonMessage>>,
    ) -> Result<Response<Empty>, Status> {
        let mut req_stream = req.into_inner();
        let pubkey: String;
        if let Some(Ok(msg)) = req_stream.next().await {
            log::debug!("demon_messages received the following auth message: {:?}", msg.msg);
            if let Some(vm_daemon_message::Msg::Auth(auth)) = msg.msg {
                pubkey = auth.pubkey.clone();
                check_sig_from_parts(
                    &pubkey,
                    &auth.timestamp,
                    &format!("{:?}", auth.contracts),
                    &auth.signature,
                )?;
            } else {
                return Err(Status::unauthenticated(
                    "Could not authenticate the daemon: could not extract auth signature",
                ));
            }
        } else {
            return Err(Status::unauthenticated("Could not authenticate the daemon"));
        }

        while let Some(daemon_message) = req_stream.next().await {
            match daemon_message {
                Ok(msg) => match msg.msg {
                    Some(vm_daemon_message::Msg::NewVmResp(new_vm_resp)) => {
                        if !new_vm_resp.error.is_empty() {
                            db::NewVmReq::submit_error(
                                &self.db,
                                &new_vm_resp.uuid,
                                new_vm_resp.error,
                            )
                            .await?;
                        } else {
                            db::upsert_record(
                                &self.db,
                                "measurement_args",
                                &new_vm_resp.uuid,
                                new_vm_resp.args.clone(),
                            )
                            .await?;
                            if let Some(args) = new_vm_resp.args {
                                db::ActiveVm::activate(&self.db, &new_vm_resp.uuid, args).await?;
                            }
                        }
                    }
                    Some(vm_daemon_message::Msg::UpdateVmResp(update_vm_resp)) => {
                        if !update_vm_resp.error.is_empty() {
                            db::UpdateVmReq::submit_error(
                                &self.db,
                                &update_vm_resp.uuid,
                                update_vm_resp.error,
                            )
                            .await?;
                        } else {
                            db::upsert_record(
                                &self.db,
                                "measurement_args",
                                &update_vm_resp.uuid,
                                update_vm_resp.args.clone(),
                            )
                            .await?;
                            db::ActiveVm::update(&self.db, &update_vm_resp.uuid).await?;
                        }
                    }
                    Some(vm_daemon_message::Msg::VmNodeResources(node_resources)) => {
                        let node_resources: db::VmNodeResources = node_resources.into();
                        node_resources.merge(&self.db, &pubkey).await?;
                    }
                    _ => {}
                },
                Err(e) => {
                    log::warn!("Daemon disconnected for {pubkey}: {e:?}");
                    let _ = db::VmNode::set_offline(&self.db, &pubkey).await;
                }
            }
        }
        Ok(Response::new(Empty {}))
    }
}

pub struct VmCliServer {
    pub db: Arc<Surreal<Client>>,
}

impl VmCliServer {
    pub fn new(db: Arc<Surreal<Client>>) -> Self {
        Self { db }
    }
}

#[tonic::async_trait]
impl BrainVmCli for VmCliServer {
    type ListVmContractsStream = Pin<Box<dyn Stream<Item = Result<VmContract, Status>> + Send>>;
    type ListVmNodesStream = Pin<Box<dyn Stream<Item = Result<VmNodeListResp, Status>> + Send>>;

    async fn new_vm(&self, req: Request<NewVmReq>) -> Result<Response<NewVmResp>, Status> {
        let req = check_sig_from_req(req)?;
        let id = surrealdb::RecordId::from((VM_NODE, req.node_pubkey.clone()));
        if let Some(redirect) = db::check_pubsub_node(&self.db, id).await? {
            log::info!("redirect: {redirect}");
            return Err(redirect);
        }

        // TODO: make it atleast 1 hour
        if req.locked_nano < 100 {
            log::error!("locking lessthan 100 nano lps: {}", req.locked_nano);
            return Err(Status::unknown("lock atleaset 100 nano lps"));
        }
        info!("New VM requested via CLI: {req:?}");
        if db::Account::is_banned_by_node(&self.db, &req.admin_pubkey, &req.node_pubkey).await? {
            return Err(Status::permission_denied("This operator banned you. What did you do?"));
        }

        let db_req: db::NewVmReq = req.into();
        let id = db_req.id.key().to_string();

        let (oneshot_tx, oneshot_rx) = tokio::sync::oneshot::channel();
        let db = self.db.clone();
        tokio::spawn(async move {
            let _ = oneshot_tx.send(db::WrappedMeasurement::listen(&db, &id, NEW_VM_REQ).await);
        });
        db_req.submit(&self.db).await?;

        match oneshot_rx.await {
            Ok(Err(db::Error::TimeOut(_))) => Err(Status::deadline_exceeded(
                "Network timeout. Please try again later or contact the DeTEE devs team.",
            )),
            Ok(new_vm_resp) => Ok(Response::new(new_vm_resp?.into())),
            Err(e) => {
                log::error!("Something weird happened during CLI NewVmReq. Reached error {e:?}");
                Err(Status::unknown(
                    "Unknown error. Please try again or contact the DeTEE devs team.",
                ))
            }
        }
    }

    async fn update_vm(&self, req: Request<UpdateVmReq>) -> Result<Response<UpdateVmResp>, Status> {
        let req = check_sig_from_req(req)?;
        info!("Update VM requested via CLI: {req:?}");

        let db_req: db::UpdateVmReq = req.clone().into();

        if let Some(redirect) = db::check_pubsub_node(&self.db, db_req.vm_node.clone()).await? {
            log::info!("redirect: {redirect}");
            return Err(redirect);
        }
        let id = db_req.id.key().to_string();

        let mut hostname_changed = false;
        if !req.hostname.is_empty() {
            hostname_changed =
                db::ActiveVm::change_hostname(&self.db, &req.uuid, &req.hostname).await?;
        }

        let hw_change_submitted = db_req.request_hw_update(&self.db).await?;
        if hw_change_submitted.is_none() {
            return Ok(Response::new(UpdateVmResp {
                uuid: req.uuid.clone(),
                error: "VM Contract does not exist.".to_string(),
                args: None,
            }));
        }
        let hw_change_needed = hw_change_submitted.unwrap();

        if !hostname_changed && !hw_change_needed {
            return Ok(Response::new(UpdateVmResp {
                uuid: req.uuid.clone(),
                error: "No modification required".to_string(),
                args: None,
            }));
        }

        // if only the hostname got changed, return a confirmation
        if !hw_change_needed {
            return Ok(Response::new(UpdateVmResp {
                uuid: req.uuid.clone(),
                error: String::new(),
                args: None,
            }));
        }

        // if HW changes got requested, wait for the new args
        let (oneshot_tx, oneshot_rx) = tokio::sync::oneshot::channel();
        let db = self.db.clone();
        tokio::spawn(async move {
            let _ = oneshot_tx.send(db::WrappedMeasurement::listen(&db, &id, UPDATE_VM_REQ).await);
        });

        match oneshot_rx.await {
            Ok(Err(db::Error::TimeOut(_))) => Err(Status::deadline_exceeded(
                "Network timeout. Please try again later or contact the DeTEE devs team.",
            )),
            Ok(new_vm_resp) => Ok(Response::new(new_vm_resp?.into())),
            Err(e) => {
                log::error!("Something weird happened during CLI VM Update. Reached error {e:?}");
                Err(Status::unknown(
                    "Unknown error. Please try again or contact the DeTEE devs team.",
                ))
            }
        }
    }

    async fn extend_vm(&self, req: Request<ExtendVmReq>) -> Result<Response<Empty>, Status> {
        let req = check_sig_from_req(req)?;
        match db::ActiveVm::extend_time(&self.db, &req.uuid, &req.admin_pubkey, req.locked_nano)
            .await
        {
            Ok(()) => Ok(Response::new(Empty {})),
            Err(e)
                if matches!(
                    e,
                    db::Error::ContractNotFound
                        | db::Error::AccessDenied
                        | db::Error::InsufficientFunds
                ) =>
            {
                Err(Status::failed_precondition(e.to_string()))
            }
            Err(e) => {
                log::error!("Error extending VM contract {}: {e}", &req.uuid);
                Err(Status::unknown(format!("Could not extend contract: {e}")))
            }
        }
    }

    async fn delete_vm(&self, req: Request<DeleteVmReq>) -> Result<Response<Empty>, Status> {
        let req = check_sig_from_req(req)?;
        let vm_node = db::ActiveVm::get_by_uuid(&self.db, &req.uuid)
            .await?
            .ok_or(Status::permission_denied("Unauthorized"))?
            .vm_node;

        if let Some(redirect) = db::check_pubsub_node(&self.db, vm_node).await? {
            log::info!("redirect: {redirect}");
            return Err(redirect);
        }
        match db::ActiveVm::delete(&self.db, &req.admin_pubkey, &req.uuid).await {
            Ok(()) => Ok(Response::new(Empty {})),
            Err(db::Error::AccessDenied) => Err(Status::permission_denied("Unauthorized")),
            Err(e) => {
                log::error!("Error deleting VM contract {}: {e}", &req.uuid);
                Err(Status::unknown(
                    "Unknown error. Please try again or contact the DeTEE devs team.",
                ))
            }
        }
    }

    async fn list_vm_contracts(
        &self,
        req: Request<ListVmContractsReq>,
    ) -> Result<Response<Self::ListVmContractsStream>, Status> {
        let req = check_sig_from_req(req)?;
        info!(
            "CLI {} requested ListVMVmContractsStream. As operator: {}",
            req.wallet, req.as_operator
        );
        let mut contracts = Vec::new();
        if !req.uuid.is_empty() {
            if let Some(specific_contract) =
                db::ActiveVmWithNode::get_by_uuid(&self.db, &req.uuid).await?
            {
                if specific_contract.admin.key().to_string() == req.wallet
                    || specific_contract.vm_node.operator.key().to_string() == req.wallet
                {
                    contracts.push(specific_contract);
                }
            }
        } else if req.as_operator {
            contracts
                .append(&mut db::ActiveVmWithNode::list_by_operator(&self.db, &req.wallet).await?);
        } else {
            contracts
                .append(&mut db::ActiveVmWithNode::list_by_admin(&self.db, &req.wallet).await?);
        }
        let (tx, rx) = mpsc::channel(6);
        tokio::spawn(async move {
            for contract in contracts {
                let _ = tx.send(Ok(contract.into())).await;
            }
        });
        let output_stream = ReceiverStream::new(rx);
        Ok(Response::new(Box::pin(output_stream) as Self::ListVmContractsStream))
    }

    async fn list_vm_nodes(
        &self,
        req: Request<VmNodeFilters>,
    ) -> Result<Response<Self::ListVmNodesStream>, tonic::Status> {
        let req = check_sig_from_req(req)?;
        info!("CLI requested ListVmNodesStream: {req:?}");
        let nodes = db::VmNodeWithReports::find_by_filters(&self.db, req).await?;
        let (tx, rx) = mpsc::channel(6);
        tokio::spawn(async move {
            for node in nodes {
                let _ = tx.send(Ok(node.into())).await;
            }
        });
        let output_stream = ReceiverStream::new(rx);
        Ok(Response::new(Box::pin(output_stream) as Self::ListVmNodesStream))
    }

    async fn get_one_vm_node(
        &self,
        req: Request<VmNodeFilters>,
    ) -> Result<Response<VmNodeListResp>, Status> {
        let req = check_sig_from_req(req)?;
        info!("Unknown CLI requested ListVmNodesStream: {req:?}");
        // TODO: optimize this query so that it gets only one node
        let nodes = db::VmNodeWithReports::find_by_filters(&self.db, req).await?;
        if let Some(node) = nodes.into_iter().next() {
            return Ok(Response::new(node.into()));
        }
        Err(Status::not_found("Could not find any node based on your search criteria"))
    }
}