// SPDX-License-Identifier: Apache-2.0

use std::str::FromStr;
use std::time::Duration;

use super::Error;
use crate::constants::{
    ACCOUNT, ACTIVE_VM, DELETED_VM, NEW_VM_REQ, UPDATE_VM_REQ, VM_DAEMON_TIMEOUT, VM_NODE,
    VM_UPDATE_EVENT,
};
use crate::db::{Account, ErrorFromTable, Report};
use detee_shared::vm_proto;
use serde::{Deserialize, Serialize};
use surrealdb::engine::remote::ws::Client;
use surrealdb::sql::Datetime;
use surrealdb::{Notification, RecordId, Surreal};
use tokio_stream::StreamExt as _;

#[derive(Debug, Serialize, Deserialize)]
pub struct VmNode {
    pub id: RecordId,
    pub operator: RecordId,
    pub pub_sub_node: String,
    pub country: String,
    pub region: String,
    pub city: String,
    pub ip: String,
    pub avail_ipv4: u32,
    pub avail_ipv6: u32,
    pub avail_ports: u32,
    pub max_ports_per_vm: u32,
    pub connected_at: Datetime,
    pub disconnected_at: Datetime,
    pub offers: Vec<VmNodeOffer>,
}

impl VmNode {
    pub async fn register(self, db: &Surreal<Client>) -> Result<(), Error> {
        Account::get_or_create(db, &self.operator.key().to_string()).await?;
        let _: Option<VmNode> = db.upsert(self.id.clone()).content(self).await?;
        Ok(())
    }

    pub async fn set_online(db: &Surreal<Client>, vm_node_id: &str) -> Result<(), Error> {
        db.query(format!("UPDATE {VM_NODE}:{vm_node_id} SET connected_at = time::now();")).await?;
        Ok(())
    }

    pub async fn set_offline(db: &Surreal<Client>, vm_node_id: &str) -> Result<(), Error> {
        db.query(format!("UPDATE {VM_NODE}:{vm_node_id} SET disconnected_at = time::now();"))
            .await?;
        Ok(())
    }
}

#[derive(Serialize)]
pub struct VmNodeResources {
    pub avail_ipv4: u32,
    pub avail_ipv6: u32,
    pub avail_ports: u32,
    pub max_ports_per_vm: u32,
    pub offers: Vec<VmNodeOffer>,
}

impl VmNodeResources {
    pub async fn merge(self, db: &Surreal<Client>, node_id: &str) -> Result<(), Error> {
        let _: Option<VmNode> = db.update((VM_NODE, node_id)).merge(self).await?;
        Ok(())
    }
}

#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct VmNodeOffer {
    pub price: u64,
    pub memory_mib: u64,
    pub vcpus: u64,
    pub disk_mib: u64,
}

#[derive(Debug, Serialize, Deserialize)]
pub struct VmNodeWithReports {
    pub id: RecordId,
    pub operator: RecordId,
    pub country: String,
    pub region: String,
    pub city: String,
    pub ip: String,
    pub avail_ipv4: u32,
    pub avail_ipv6: u32,
    pub avail_ports: u32,
    pub max_ports_per_vm: u32,
    pub reports: Vec<Report>,
    pub offers: Vec<VmNodeOffer>,
}

impl VmNodeWithReports {
    pub async fn find_by_filters(
        db: &Surreal<Client>,
        filters: vm_proto::VmNodeFilters,
    ) -> Result<Vec<Self>, Error> {
        let mut query = format!(
            "select *, <-report.* as reports
            from {VM_NODE} where
            avail_ports >= {} &&
            max_ports_per_vm >= {} &&
            avail_ipv4 >= {} &&
            avail_ipv6 >= {} &&
            offers.*.vcpus >= {} &&
            offers.*.memory_mib >= {} &&
            offers.*.disk_mib >= {}\n",
            filters.free_ports,
            filters.free_ports,
            filters.offers_ipv4 as u32,
            filters.offers_ipv6 as u32,
            filters.vcpus,
            filters.memory_mib,
            filters.storage_mib
        );
        if !filters.city.is_empty() {
            query += &format!("&& city = '{}' ", filters.city);
        }
        if !filters.region.is_empty() {
            query += &format!("&& region = '{}' ", filters.region);
        }
        if !filters.country.is_empty() {
            query += &format!("&& country = '{}' ", filters.country);
        }
        if !filters.ip.is_empty() {
            query += &format!("&& ip = '{}' ", filters.ip);
        }
        query += " && connected_at > disconnected_at;";
        let mut result = db.query(query).await?;
        let vm_nodes: Vec<Self> = result.take(0)?;
        Ok(vm_nodes)
    }

    pub async fn find_by_daemon_pubkey(
        db: &Surreal<Client>,
        daemon_key: &str,
    ) -> Result<Option<Self>, Error> {
        let vm_node: Option<VmNodeWithReports> = db
            .query(format!(
                "SELECT *, <-report.* as reports
                FROM {VM_NODE} WHERE id = {VM_NODE}:{daemon_key};"
            ))
            .await?
            .take(0)?;
        Ok(vm_node)
    }
}

pub enum VmDaemonMsg {
    Create(NewVmReq),
    Update(UpdateVmReq),
    Delete(DeletedVm),
}

impl From<NewVmReq> for VmDaemonMsg {
    fn from(value: NewVmReq) -> Self {
        Self::Create(value)
    }
}

impl From<UpdateVmReq> for VmDaemonMsg {
    fn from(value: UpdateVmReq) -> Self {
        Self::Update(value)
    }
}

impl From<DeletedVm> for VmDaemonMsg {
    fn from(value: DeletedVm) -> Self {
        Self::Delete(value)
    }
}

#[derive(Debug, Serialize, Deserialize)]
pub struct NewVmReq {
    pub id: RecordId,
    #[serde(rename = "in")]
    pub admin: RecordId,
    #[serde(rename = "out")]
    pub vm_node: RecordId,
    pub hostname: String,
    pub extra_ports: Vec<u32>,
    pub public_ipv4: bool,
    pub public_ipv6: bool,
    pub disk_size_mib: u32,
    pub vcpus: u32,
    pub memory_mib: u32,
    pub dtrfs_url: String,
    pub dtrfs_sha: String,
    pub kernel_sha: String,
    pub kernel_url: String,
    pub created_at: Datetime,
    pub price_per_unit: u64,
    pub locked_nano: u64,
    pub error: String,
}

impl NewVmReq {
    pub async fn get(db: &Surreal<Client>, id: &str) -> Result<Option<Self>, Error> {
        let new_vm_req: Option<Self> = db.select((NEW_VM_REQ, id)).await?;
        Ok(new_vm_req)
    }

    pub async fn delete(db: &Surreal<Client>, id: &str) -> Result<(), Error> {
        let _: Option<Self> = db.delete((NEW_VM_REQ, id)).await?;
        Ok(())
    }

    pub async fn submit_error(db: &Surreal<Client>, id: &str, error: String) -> Result<(), Error> {
        let tx_query = String::from(
            "
            BEGIN TRANSACTION;

                LET $new_vm_req = $new_vm_req_input;
                LET $error = $error_input;
                LET $record = (select * from $new_vm_req)[0];
                LET $admin = $record.in;

                if $record == None {{
                    THROW 'vm req not exist ' + <string>$new_vm_req
                }};

                UPDATE $new_vm_req SET error = $error;

                UPDATE $admin SET tmp_locked -= $record.locked_nano;
                UPDATE $admin SET balance += $record.locked_nano;

            COMMIT TRANSACTION;",
        );

        log::trace!("submit_new_vm_err query: {tx_query}");

        let mut query_resp = db
            .query(tx_query)
            .bind(("new_vm_req_input", RecordId::from((NEW_VM_REQ, id))))
            .bind(("error_input", error))
            .await?;

        let query_err = query_resp.take_errors();
        if !query_err.is_empty() {
            log::trace!("errors in submit_new_vm_err: {query_err:?}");
            let tx_fail_err_str =
                String::from("The query was not executed due to a failed transaction");

            if query_err.contains_key(&4) && query_err[&4].to_string() != tx_fail_err_str {
                log::error!("vm req not exist: {}", query_err[&4]);
                return Err(Error::ContractNotFound);
            } else {
                log::error!("Unknown error in submit_new_vm_err: {query_err:?}");
                return Err(Error::Unknown("submit_new_vm_req".to_string()));
            }
        }

        Ok(())
    }

    pub async fn submit(self, db: &Surreal<Client>) -> Result<(), Error> {
        let locked_nano = self.locked_nano;
        let tx_query = format!("
            BEGIN TRANSACTION;

                LET $account = $account_input;
                LET $new_vm_req = $new_vm_req_input;
                LET $vm_node = $vm_node_input;
                LET $hostname = $hostname_input;
                LET $dtrfs_url = $dtrfs_url_input;
                LET $dtrfs_sha = $dtrfs_sha_input;
                LET $kernel_url = $kernel_url_input;
                LET $kernel_sha = $kernel_sha_input;

                UPDATE $account SET balance -= {locked_nano};
                IF $account.balance < 0 {{
                    THROW 'Insufficient funds.'
                }};
                UPDATE $account SET tmp_locked += {locked_nano};
                RELATE
                    $account
                    ->$new_vm_req
                    ->$vm_node
                CONTENT {{
                    created_at: time::now(), hostname: $hostname, vcpus: {}, memory_mib: {}, disk_size_mib: {},
                    extra_ports: {:?}, public_ipv4: {}, public_ipv6: {},
                    dtrfs_url: $dtrfs_url, dtrfs_sha: $dtrfs_sha, kernel_url: $kernel_url, kernel_sha: $kernel_sha,
                    price_per_unit: {}, locked_nano: {locked_nano}, error: ''
                }};
            
            COMMIT TRANSACTION;",
            self.vcpus,
            self.memory_mib,
            self.disk_size_mib,
            self.extra_ports,
            self.public_ipv4,
            self.public_ipv6,
            self.price_per_unit
        );

        log::trace!("submit_new_vm_req query: {tx_query}");

        let mut query_resp = db
            .query(tx_query)
            .bind(("account_input", self.admin))
            .bind(("new_vm_req_input", self.id))
            .bind(("vm_node_input", self.vm_node))
            .bind(("hostname_input", self.hostname))
            .bind(("dtrfs_url_input", self.dtrfs_url))
            .bind(("dtrfs_sha_input", self.dtrfs_sha))
            .bind(("kernel_url_input", self.kernel_url))
            .bind(("kernel_sha_input", self.kernel_sha))
            .await?;

        let query_err = query_resp.take_errors();
        if !query_err.is_empty() {
            log::trace!("errors in submit_new_vm_req: {query_err:?}");
            let tx_fail_err_str =
                String::from("The query was not executed due to a failed transaction");

            if query_err.contains_key(&9) && query_err[&9].to_string() != tx_fail_err_str {
                log::error!("Transaction error: {}", query_err[&9]);
                return Err(Error::InsufficientFunds);
            } else {
                log::error!("Unknown error in submit_new_vm_req: {query_err:?}");
                return Err(Error::Unknown("submit_new_vm_req".to_string()));
            }
        }

        Ok(())
    }
}

/// first string is the vm_id
pub enum WrappedMeasurement {
    Args(String, vm_proto::MeasurementArgs),
    Error(String, String),
}

impl WrappedMeasurement {
    /// table must be NEW_VM_REQ or UPDATE_VM_REQ
    /// it will however be enforced if you send anything else
    pub async fn listen(
        db: &Surreal<Client>,
        vm_id: &str,
        table: &str,
    ) -> Result<WrappedMeasurement, Error> {
        let table = match table {
            UPDATE_VM_REQ => UPDATE_VM_REQ,
            _ => NEW_VM_REQ,
        };
        let mut resp = db
            .query(format!("live select error from {table} where id = {table}:{vm_id};"))
            .query(format!(
                "live select * from measurement_args where id = measurement_args:{vm_id};"
            ))
            .await?;
        let mut error_stream = resp.stream::<Notification<ErrorFromTable>>(0)?;
        let mut args_stream = resp.stream::<Notification<vm_proto::MeasurementArgs>>(1)?;

        let mut error =
            db.query(format!("select error from {table} where id = {NEW_VM_REQ}:{vm_id}")).await?;
        if let Some(error_on_newvm_req) = error.take::<Option<ErrorFromTable>>(0)? {
            if !error_on_newvm_req.error.is_empty() {
                return Ok(Self::Error(vm_id.to_string(), error_on_newvm_req.error));
            }
        }

        let args: Option<vm_proto::MeasurementArgs> =
            db.delete(("measurement_args", vm_id)).await?;
        if let Some(args) = args {
            return Ok(Self::Args(vm_id.to_string(), args));
        }
        log::trace!("listening for table: {table}");

        tokio::time::timeout(Duration::from_secs(VM_DAEMON_TIMEOUT), async {
            loop {
                tokio::select! {
                    error_notification = error_stream.next() => {
                        if let Some(err_notif) = error_notification {
                            match err_notif {
                                Ok(err_notif) => {
                                    if err_notif.action == surrealdb::Action::Update
                                    && !err_notif.data.error.is_empty() {
                                        return Ok(Self::Error(vm_id.to_string(), err_notif.data.error));
                                    };
                                },
                                Err(e) => return Err(e.into()),
                            }
                        }
                    }
                    args_notif = args_stream.next() => {
                        if let Some(args_notif) = args_notif {
                            match args_notif {
                                Ok(args_notif) => {
                                    if args_notif.action == surrealdb::Action::Create {
                                        let _: Option<vm_proto::MeasurementArgs> = db.delete(("measurement_args", vm_id)).await?;
                                        return Ok(Self::Args(vm_id.to_string(), args_notif.data));
                                    };
                                },
                                Err(e) => return Err(e.into()),
                            }
                        }
                    }
                }
            }
        })
        .await?
    }
}

#[derive(Clone, Debug, Serialize, Deserialize)]
pub struct ActiveVm {
    pub id: RecordId,
    #[serde(rename = "in")]
    pub admin: RecordId,
    #[serde(rename = "out")]
    pub vm_node: RecordId,
    pub hostname: String,
    pub mapped_ports: Vec<(u32, u32)>,
    pub public_ipv4: String,
    pub public_ipv6: String,
    pub disk_size_mib: u32,
    pub vcpus: u32,
    pub memory_mib: u32,
    pub dtrfs_sha: String,
    pub kernel_sha: String,
    pub created_at: Datetime,
    pub price_per_unit: u64,
    pub locked_nano: u64,
    pub collected_at: Datetime,
}

impl ActiveVm {
    /// total hardware units of this VM
    fn total_units(&self) -> u64 {
        // TODO: Optimize this based on price of hardware.
        // I tried, but this can be done better.
        // Storage cost should also be based on tier
        (self.vcpus as u64 * 10)
            + ((self.memory_mib + 256) as u64 / 200)
            + (self.disk_size_mib as u64 / 10)
            + (!self.public_ipv4.is_empty() as u64 * 10)
    }

    /// Returns price per minute in nanoLP
    pub fn price_per_minute(&self) -> u64 {
        self.total_units() * self.price_per_unit
    }

    pub async fn get_by_id(db: &Surreal<Client>, vm_id: &str) -> Result<Option<Self>, Error> {
        let contract: Option<Self> = db
            .query("select * from $active_vm_id;".to_string())
            .bind(("active_vm_id", RecordId::from((ACTIVE_VM, vm_id))))
            .await?
            .take(0)?;
        Ok(contract)
    }

    pub async fn activate(
        db: &Surreal<Client>,
        id: &str,
        args: vm_proto::MeasurementArgs,
    ) -> Result<(), Error> {
        let new_vm_req = match NewVmReq::get(db, id).await? {
            Some(r) => r,
            None => return Ok(()),
        };

        let mut public_ipv4 = String::new();
        let mut public_ipv6 = String::new();

        for ip in args.ips.iter() {
            if let Ok(ipv4_addr) = std::net::Ipv4Addr::from_str(&ip.address) {
                if !ipv4_addr.is_private() && !ipv4_addr.is_link_local() {
                    public_ipv4 = ipv4_addr.to_string();
                }
                continue;
            }
            if let Ok(ipv6_addr) = std::net::Ipv6Addr::from_str(&ip.address) {
                public_ipv6 = ipv6_addr.to_string();
            }
        }

        let mut mapped_ports = Vec::new();
        let mut guest_ports = vec![22];
        guest_ports.append(&mut new_vm_req.extra_ports.clone());
        let mut i = 0;
        while i < args.exposed_ports.len() && i < guest_ports.len() {
            mapped_ports.push((args.exposed_ports[i], guest_ports[i]));
            i += 1;
        }

        let active_vm = ActiveVm {
            id: RecordId::from((ACTIVE_VM, id)),
            admin: new_vm_req.admin,
            vm_node: new_vm_req.vm_node,
            hostname: new_vm_req.hostname,
            mapped_ports,
            public_ipv4,
            public_ipv6,
            disk_size_mib: new_vm_req.disk_size_mib,
            vcpus: new_vm_req.vcpus,
            memory_mib: new_vm_req.memory_mib,
            dtrfs_sha: new_vm_req.dtrfs_sha,
            kernel_sha: new_vm_req.kernel_sha,
            created_at: new_vm_req.created_at.clone(),
            price_per_unit: new_vm_req.price_per_unit,
            locked_nano: new_vm_req.locked_nano,
            collected_at: new_vm_req.created_at,
        };

        let admin_account = active_vm.admin.key().to_string();
        let locked_nano = active_vm.locked_nano;
        let _: Vec<ActiveVm> = db.insert(()).relation(active_vm).await?;
        NewVmReq::delete(db, id).await?;
        db.query(format!("UPDATE {ACCOUNT}:{admin_account} SET tmp_locked -= {locked_nano};"))
            .await?;
        Ok(())
    }

    pub async fn update(db: &Surreal<Client>, id: &str) -> Result<(), Error> {
        let update_vm_req = match UpdateVmReq::get(db, id).await? {
            Some(r) => r,
            None => return Ok(()),
        };

        let mut active_vm = match Self::get_by_id(db, id).await? {
            Some(vm) => vm,
            None => return Ok(()),
        };

        if update_vm_req.vcpus > 0 {
            active_vm.vcpus = update_vm_req.vcpus;
        }
        if update_vm_req.memory_mib > 0 {
            active_vm.memory_mib = update_vm_req.memory_mib;
        }
        if update_vm_req.disk_size_mib > 0 {
            active_vm.disk_size_mib = update_vm_req.disk_size_mib;
        }
        if !update_vm_req.dtrfs_sha.is_empty() && !update_vm_req.kernel_sha.is_empty() {
            active_vm.dtrfs_sha = update_vm_req.dtrfs_sha;
            active_vm.kernel_sha = update_vm_req.kernel_sha;
        }

        let _: Option<ActiveVm> = db.update(active_vm.id.clone()).content(active_vm).await?;
        UpdateVmReq::delete(db, id).await?;
        Ok(())
    }

    pub async fn change_hostname(
        db: &Surreal<Client>,
        id: &str,
        new_hostname: &str,
    ) -> Result<bool, Error> {
        let contract: Option<Self> = db
            .query(format!(
                "UPDATE {ACTIVE_VM}:{id} SET hostname = '{new_hostname}' RETURN BEFORE;"
            ))
            .await?
            .take(0)?;
        if let Some(contract) = contract {
            if contract.hostname != new_hostname {
                return Ok(true);
            }
        }
        Ok(false)
    }

    pub async fn delete(db: &Surreal<Client>, admin: &str, id: &str) -> Result<(), Error> {
        let mut vm_del_resp = db
            .query(
                "
            BEGIN TRANSACTION;

                LET $active_vm = $vm_id_input;
                LET $admin = $admin_input;

                IF $active_vm.in != $admin {
                    THROW 'Unauthorized'
                };

                return fn::delete_vm($active_vm);

            COMMIT TRANSACTION;
            ",
            )
            .bind(("vm_id_input", RecordId::from((ACTIVE_VM, id))))
            .bind(("admin_input", RecordId::from((ACCOUNT, admin))))
            .await?;

        log::trace!("delete_vm query response: {vm_del_resp:?}");

        let query_err = vm_del_resp.take_errors();
        if !query_err.is_empty() {
            log::trace!("errors in delete_vm: {query_err:?}");
            let tx_fail_err_str =
                String::from("The query was not executed due to a failed transaction");

            if query_err.contains_key(&2) && query_err[&2].to_string() != tx_fail_err_str {
                log::error!("Unauthorized: {}", query_err[&2]);
                return Err(Error::AccessDenied);
            }
        }
        Ok(())
    }

    pub async fn extend_time(
        db: &Surreal<Client>,
        id: &str,
        admin: &str,
        nano_lp: u64,
    ) -> Result<(), Error> {
        if nano_lp > 100_000_000_000_000 {
            return Err(Error::TooBigTransaction(nano_lp.to_string()));
        }

        let tx_query = format!(
            "
            BEGIN TRANSACTION;

                LET $contract = $contract_input;
                LET $admin = $admin_input;
                LET $lock_amt = {nano_lp};

                if !record::exists($contract) {{
                    THROW 'contract not exist ' + <string>$contract
                }};
                if $contract.in != $admin {{
                    THROW 'Unauthorized'
                }};
                if $admin.balance + $contract.locked_nano < $lock_amt {{
                    THROW 'InsufficientFunds'
                }};

                UPDATE $admin SET balance = $admin.balance + $contract.locked_nano - $lock_amt;
                UPDATE $contract SET locked_nano = $lock_amt;

            COMMIT TRANSACTION;
            "
        );

        log::trace!("extend_time query: {tx_query}");

        let mut query_res = db
            .query(tx_query)
            .bind(("contract_input", RecordId::from((ACTIVE_VM, id))))
            .bind(("admin_input", RecordId::from((ACCOUNT, admin))))
            .await?;

        log::trace!("tx_query response: {query_res:?}");

        let query_err = query_res.take_errors();
        if !query_err.is_empty() {
            let tx_fail_err_str =
                String::from("The query was not executed due to a failed transaction");

            if query_err.contains_key(&3) && query_err[&3].to_string() != tx_fail_err_str {
                log::error!("contract not exist: {}", query_err[&3]);
                return Err(Error::ContractNotFound);
            }

            if query_err.contains_key(&4) && query_err[&4].to_string() != tx_fail_err_str {
                log::error!("Unauthorized: {}", query_err[&4]);
                return Err(Error::AccessDenied);
            }

            if query_err.contains_key(&5) && query_err[&5].to_string() != tx_fail_err_str {
                log::error!("InsufficientFunds: {}", query_err[&5]);
                return Err(Error::InsufficientFunds);
            }

            log::error!("Unknown error in extend_time: {query_err:?}");

            return Err(Error::Unknown("extend_time".to_string()));
        }
        Ok(())
    }
}

#[derive(Debug, Serialize, Deserialize)]
pub struct UpdateVmReq {
    pub id: RecordId,
    #[serde(rename = "in")]
    pub admin: RecordId,
    #[serde(rename = "out")]
    pub vm_node: RecordId,
    pub disk_size_mib: u32,
    pub vcpus: u32,
    pub memory_mib: u32,
    pub dtrfs_url: String,
    pub dtrfs_sha: String,
    pub kernel_sha: String,
    pub kernel_url: String,
    pub created_at: Datetime,
    pub error: String,
}

#[derive(Debug, Serialize, Deserialize)]
pub struct UpdateVmEvent {
    pub vm_id: RecordId,
    #[serde(rename = "in")]
    pub admin: RecordId,
    #[serde(rename = "out")]
    pub vm_node: RecordId,
    pub disk_size_mib: u32,
    pub vcpus: u32,
    pub memory_mib: u32,
    pub dtrfs_url: String,
    pub dtrfs_sha: String,
    pub kernel_sha: String,
    pub kernel_url: String,
    pub executed_at: Datetime,
}

impl From<UpdateVmReq> for UpdateVmEvent {
    fn from(update_vm_req: UpdateVmReq) -> Self {
        Self {
            vm_id: RecordId::from((VM_UPDATE_EVENT, update_vm_req.id.key().to_string())),
            admin: update_vm_req.admin,
            vm_node: update_vm_req.vm_node,
            disk_size_mib: update_vm_req.disk_size_mib,
            vcpus: update_vm_req.vcpus,
            memory_mib: update_vm_req.memory_mib,
            dtrfs_url: update_vm_req.dtrfs_url,
            dtrfs_sha: update_vm_req.dtrfs_sha,
            kernel_sha: update_vm_req.kernel_sha,
            kernel_url: update_vm_req.kernel_url,
            executed_at: Datetime::default(),
        }
    }
}

impl UpdateVmReq {
    pub async fn get(db: &Surreal<Client>, id: &str) -> Result<Option<Self>, Error> {
        let update_vm_req: Option<Self> = db.select((UPDATE_VM_REQ, id)).await?;
        Ok(update_vm_req)
    }

    pub async fn delete(db: &Surreal<Client>, id: &str) -> Result<(), Error> {
        let update_vm_req: Option<Self> = db.delete((UPDATE_VM_REQ, id)).await?;
        if let Some(update_vm_req) = update_vm_req {
            let update_vm_event: UpdateVmEvent = update_vm_req.into();
            let _: Option<UpdateVmEvent> =
                db.create(VM_UPDATE_EVENT).content(update_vm_event).await?;
        }
        Ok(())
    }

    /// returns None if VM does not exist
    /// returns Some(false) if hw update is not needed
    /// returns Some(true) if hw update is needed and got submitted
    /// returns error if something happened with the DB
    pub async fn request_hw_update(mut self, db: &Surreal<Client>) -> Result<Option<bool>, Error> {
        let contract = ActiveVm::get_by_id(db, &self.id.key().to_string()).await?;

        if contract.is_none() {
            return Ok(None);
        }
        let contract = contract.unwrap();
        let mem_per_cpu = contract.memory_mib / contract.vcpus;
        let disk_per_cpu = contract.disk_size_mib / contract.vcpus;
        self.vm_node = contract.vm_node;

        if !((self.vcpus != 0 && contract.vcpus != self.vcpus)
            || (self.memory_mib != 0 && contract.memory_mib != self.memory_mib)
            || (!self.dtrfs_sha.is_empty() && contract.dtrfs_sha != self.dtrfs_sha)
            || (self.disk_size_mib != 0 && contract.disk_size_mib != self.disk_size_mib))
        {
            return Ok(Some(false));
        }

        // Do not allow user to unbalance node resources
        if self.vcpus == 0 {
            self.vcpus = self.memory_mib / mem_per_cpu;
        }
        if self.memory_mib == 0 {
            self.memory_mib = self.vcpus * mem_per_cpu;
        }
        if self.vcpus == 0 {
            self.vcpus = self.disk_size_mib / disk_per_cpu;
        }
        if self.disk_size_mib == 0 {
            self.disk_size_mib = self.vcpus * disk_per_cpu;
        }

        let _: Vec<Self> = db.insert(UPDATE_VM_REQ).relation(self).await?;
        Ok(Some(true))
    }

    pub async fn submit_error(db: &Surreal<Client>, id: &str, error: String) -> Result<(), Error> {
        #[derive(Serialize)]
        struct UpdateVmError {
            error: String,
        }
        let _: Option<Self> = db.update((UPDATE_VM_REQ, id)).merge(UpdateVmError { error }).await?;
        let _: Option<Self> = db.delete((UPDATE_VM_REQ, id)).await?;
        Ok(())
    }
}

#[derive(Debug, Serialize, Deserialize)]
pub struct DeletedVm {
    pub id: RecordId,
    #[serde(rename = "in")]
    pub admin: RecordId,
    #[serde(rename = "out")]
    pub vm_node: RecordId,
    pub hostname: String,
    pub mapped_ports: Vec<(u32, u32)>,
    pub public_ipv4: String,
    pub public_ipv6: String,
    pub disk_size_mib: u32,
    pub vcpus: u32,
    pub memory_mib: u32,
    pub dtrfs_sha: String,
    pub kernel_sha: String,
    pub created_at: Datetime,
    pub deleted_at: Datetime,
    pub price_per_unit: u64,
}

impl From<ActiveVm> for DeletedVm {
    fn from(active_vm: ActiveVm) -> Self {
        Self {
            id: RecordId::from((DELETED_VM, active_vm.id.key().to_string())),
            admin: active_vm.admin,
            vm_node: active_vm.vm_node,
            hostname: active_vm.hostname,
            mapped_ports: active_vm.mapped_ports,
            public_ipv4: active_vm.public_ipv4,
            public_ipv6: active_vm.public_ipv6,
            disk_size_mib: active_vm.disk_size_mib,
            vcpus: active_vm.vcpus,
            memory_mib: active_vm.memory_mib,
            dtrfs_sha: active_vm.dtrfs_sha,
            kernel_sha: active_vm.kernel_sha,
            created_at: active_vm.created_at,
            deleted_at: Datetime::default(),
            price_per_unit: active_vm.price_per_unit,
        }
    }
}

impl DeletedVm {
    pub async fn get_by_id(db: &Surreal<Client>, vm_id: &str) -> Result<Option<Self>, Error> {
        let contract: Option<Self> =
            db.query(format!("select * from {DELETED_VM}:{vm_id};")).await?.take(0)?;
        Ok(contract)
    }

    pub async fn list_by_admin(db: &Surreal<Client>, admin: &str) -> Result<Vec<Self>, Error> {
        let mut result =
            db.query(format!("select * from {DELETED_VM} where in = {ACCOUNT}:{admin};")).await?;
        let contracts: Vec<Self> = result.take(0)?;
        Ok(contracts)
    }

    pub async fn list_by_node(db: &Surreal<Client>, admin: &str) -> Result<Vec<Self>, Error> {
        let mut result =
            db.query(format!("select * from {DELETED_VM} where out = {VM_NODE}:{admin};")).await?;
        let contracts: Vec<Self> = result.take(0)?;
        Ok(contracts)
    }

    pub async fn list_by_operator(
        db: &Surreal<Client>,
        operator: &str,
    ) -> Result<Vec<Self>, Error> {
        let mut result = db
            .query(format!(
                "select
                (select * from ->operator->vm_node<-{DELETED_VM}) as contracts
            from {ACCOUNT}:{operator};"
            ))
            .await?;

        #[derive(Deserialize)]
        struct Wrapper {
            contracts: Vec<DeletedVm>,
        }

        let c: Option<Wrapper> = result.take(0)?;
        match c {
            Some(c) => Ok(c.contracts),
            None => Ok(Vec::new()),
        }
    }

    /// total hardware units of this VM
    fn total_units(&self) -> u64 {
        // TODO: Optimize this based on price of hardware.
        // I tried, but this can be done better.
        // Storage cost should also be based on tier
        (self.vcpus as u64 * 10)
            + ((self.memory_mib + 256) as u64 / 200)
            + (self.disk_size_mib as u64 / 10)
            + (!self.public_ipv4.is_empty() as u64 * 10)
    }

    /// Returns price per minute in nanoLP
    pub fn price_per_minute(&self) -> u64 {
        self.total_units() * self.price_per_unit
    }
}

#[derive(Debug, Serialize, Deserialize)]
pub struct ActiveVmWithNode {
    pub id: RecordId,
    #[serde(rename = "in")]
    pub admin: RecordId,
    #[serde(rename = "out")]
    pub vm_node: VmNode,
    pub hostname: String,
    pub mapped_ports: Vec<(u32, u32)>,
    pub public_ipv4: String,
    pub public_ipv6: String,
    pub disk_size_mib: u32,
    pub vcpus: u32,
    pub memory_mib: u32,
    pub dtrfs_sha: String,
    pub kernel_sha: String,
    pub created_at: Datetime,
    pub price_per_unit: u64,
    pub locked_nano: u64,
    pub collected_at: Datetime,
}

impl From<ActiveVmWithNode> for ActiveVm {
    fn from(val: ActiveVmWithNode) -> Self {
        Self {
            id: val.id,
            admin: val.admin,
            vm_node: val.vm_node.id,
            hostname: val.hostname,
            mapped_ports: val.mapped_ports,
            public_ipv4: val.public_ipv4,
            public_ipv6: val.public_ipv6,
            disk_size_mib: val.disk_size_mib,
            vcpus: val.vcpus,
            memory_mib: val.memory_mib,
            dtrfs_sha: val.dtrfs_sha,
            kernel_sha: val.kernel_sha,
            created_at: val.created_at,
            price_per_unit: val.price_per_unit,
            locked_nano: val.locked_nano,
            collected_at: val.collected_at,
        }
    }
}

impl ActiveVmWithNode {
    pub async fn get_by_id(db: &Surreal<Client>, vm_id: &str) -> Result<Option<Self>, Error> {
        let contract: Option<Self> = db
            .query(format!("select * from {ACTIVE_VM} where id = $vm_id fetch out;"))
            .bind(("vm_id", RecordId::from((ACTIVE_VM, vm_id))))
            .await?
            .take(0)?;
        Ok(contract)
    }

    pub async fn list_by_admin(db: &Surreal<Client>, admin: &str) -> Result<Vec<Self>, Error> {
        let mut result = db
            .query(format!("select * from {ACTIVE_VM} where in = {ACCOUNT}:{admin} fetch out;"))
            .await?;
        let contracts: Vec<Self> = result.take(0)?;
        Ok(contracts)
    }

    pub async fn list_by_node(db: &Surreal<Client>, admin: &str) -> Result<Vec<Self>, Error> {
        let mut result = db
            .query(format!("select * from {ACTIVE_VM} where out = {VM_NODE}:{admin} fetch out;"))
            .await?;
        let contracts: Vec<Self> = result.take(0)?;
        Ok(contracts)
    }

    pub async fn list_by_operator(
        db: &Surreal<Client>,
        operator: &str,
    ) -> Result<Vec<Self>, Error> {
        let mut result = db
            .query(format!(
                "select
                (select * from ->operator->vm_node<-{ACTIVE_VM} fetch out) as contracts
            from {ACCOUNT}:{operator};"
            ))
            .await?;

        #[derive(Deserialize)]
        struct Wrapper {
            contracts: Vec<ActiveVmWithNode>,
        }

        let c: Option<Wrapper> = result.take(0)?;
        match c {
            Some(c) => Ok(c.contracts),
            None => Ok(Vec::new()),
        }
    }

    /// total hardware units of this VM
    fn total_units(&self) -> u64 {
        // TODO: Optimize this based on price of hardware.
        // I tried, but this can be done better.
        // Storage cost should also be based on tier
        (self.vcpus as u64 * 10)
            + ((self.memory_mib + 256) as u64 / 200)
            + (self.disk_size_mib as u64 / 1024 / 10)
            + (!self.public_ipv4.is_empty() as u64 * 10)
    }

    /// Returns price per minute in nanoLP
    pub fn price_per_minute(&self) -> u64 {
        self.total_units() * self.price_per_unit
    }

    pub async fn list_all(db: &Surreal<Client>) -> Result<Vec<Self>, Error> {
        let mut query_response = db.query(format!("SELECT * FROM {ACTIVE_VM} FETCH out;")).await?;
        let active_vms: Vec<Self> = query_response.take(0)?;
        Ok(active_vms)
    }
}