#[perlmod::package(name = "PVE::RS::ResourceScheduling::Static", lib = "pve_rs")]
mod export {
    use std::collections::HashMap;
    use std::sync::Mutex;

    use anyhow::{bail, Error};

    use perlmod::Value;
    use proxmox_resource_scheduling::pve_static::{StaticNodeUsage, StaticServiceUsage};

    perlmod::declare_magic!(Box<Scheduler> : &Scheduler as "PVE::RS::ResourceScheduling::Static");

    struct Usage {
        nodes: HashMap<String, StaticNodeUsage>,
    }

    pub struct Scheduler {
        inner: Mutex<Usage>,
    }

    #[export(raw_return)]
    fn new(#[raw] class: Value) -> Result<Value, Error> {
        let inner = Usage {
            nodes: HashMap::new(),
        };

        Ok(perlmod::instantiate_magic!(
            &class, MAGIC => Box::new(Scheduler { inner: Mutex::new(inner) })
        ))
    }

    #[export]
    fn add_node(
        #[try_from_ref] this: &Scheduler,
        nodename: String,
        maxcpu: usize,
        maxmem: usize,
    ) -> Result<(), Error> {
        let mut usage = this.inner.lock().unwrap();

        if usage.nodes.contains_key(&nodename) {
            bail!("node {} already added", nodename);
        }

        let node = StaticNodeUsage {
            name: nodename.clone(),
            cpu: 0.0,
            maxcpu,
            mem: 0,
            maxmem,
        };

        usage.nodes.insert(nodename, node);
        Ok(())
    }

    #[export]
    fn remove_node(#[try_from_ref] this: &Scheduler, nodename: &str) {
        let mut usage = this.inner.lock().unwrap();

        usage.nodes.remove(nodename);
    }

    #[export]
    fn list_nodes(#[try_from_ref] this: &Scheduler) -> Vec<String> {
        let usage = this.inner.lock().unwrap();

        usage
            .nodes
            .keys()
            .map(|nodename| nodename.to_string())
            .collect()
    }

    #[export]
    fn contains_node(#[try_from_ref] this: &Scheduler, nodename: &str) -> bool {
        let usage = this.inner.lock().unwrap();

        usage.nodes.contains_key(nodename)
    }

    /// Add usage of `service` to the node's usage.
    #[export]
    fn add_service_usage_to_node(
        #[try_from_ref] this: &Scheduler,
        nodename: &str,
        service: StaticServiceUsage,
    ) -> Result<(), Error> {
        let mut usage = this.inner.lock().unwrap();

        match usage.nodes.get_mut(nodename) {
            Some(node) => {
                node.add_service_usage(&service);
                Ok(())
            }
            None => bail!("node '{}' not present in usage hashmap", nodename),
        }
    }

    /// Scores all previously added nodes for starting a `service` on. Scoring is done according to
    /// the static memory and CPU usages of the nodes as if the service would already be running on
    /// each.
    ///
    /// Returns a vector of (nodename, score) pairs. Scores are between 0.0 and 1.0 and a higher
    /// score is better.
    #[export]
    fn score_nodes_to_start_service(
        #[try_from_ref] this: &Scheduler,
        service: StaticServiceUsage,
    ) -> Result<Vec<(String, f64)>, Error> {
        let usage = this.inner.lock().unwrap();
        let nodes = usage.nodes.values().collect::<Vec<&StaticNodeUsage>>();

        proxmox_resource_scheduling::pve_static::score_nodes_to_start_service(&nodes, &service)
    }
}