harmony/adr/003-abstractions/topology2/src/main.rs

// Clean capability-based design using type parameters

trait Capability {}

trait K8sCapability: Capability {
    fn deploy_k8s_resource(&self, resource_yaml: &str);
    fn execute_kubectl(&self, command: &str) -> String;
}

trait LinuxCapability: Capability {
    fn execute_command(&self, command: &str, args: &[&str]);
    fn download_file(&self, url: &str, destination: &str) -> Result<(), String>;
}

trait LoadBalancerCapability: Capability {
    fn configure_load_balancer(&self, services: &[&str], port: u16);
    fn get_load_balancer_status(&self) -> String;
}

// Score trait with capability type parameter
trait Score<C: ?Sized> {
    fn execute(&self, capability: &C) -> String;
}

// Topology implementations with marker trait
trait Topology {}

struct K3DTopology {}
impl Topology for K3DTopology {}
impl Capability for K3DTopology {}
impl K8sCapability for K3DTopology {
    fn deploy_k8s_resource(&self, resource_yaml: &str) {
        todo!()
    }

    fn execute_kubectl(&self, command: &str) -> String {
        todo!()
    }
    // Implementation...
}

struct LinuxTopology {}
impl Topology for LinuxTopology {}
impl Capability for LinuxTopology {}
impl LinuxCapability for LinuxTopology {
    fn execute_command(&self, command: &str, args: &[&str]) {
        todo!()
    }

    fn download_file(&self, url: &str, destination: &str) -> Result<(), String> {
        todo!()
    }
    // Implementation...
}

struct OKDHaClusterTopology {}
impl Topology for OKDHaClusterTopology {}
impl Capability for OKDHaClusterTopology {}
impl K8sCapability for OKDHaClusterTopology {
    fn deploy_k8s_resource(&self, resource_yaml: &str) {
        todo!()
    }

    fn execute_kubectl(&self, command: &str) -> String {
        todo!()
    }
    // Implementation...
}
impl LinuxCapability for OKDHaClusterTopology {
    fn execute_command(&self, command: &str, args: &[&str]) {
        todo!()
    }

    fn download_file(&self, url: &str, destination: &str) -> Result<(), String> {
        todo!()
    }
    // Implementation...
}
impl LoadBalancerCapability for OKDHaClusterTopology {
    fn configure_load_balancer(&self, services: &[&str], port: u16) {
        todo!()
    }

    fn get_load_balancer_status(&self) -> String {
        todo!()
    }
    // Implementation...
}

// Score implementations
struct LAMPScore {}
impl Score<dyn K8sCapability> for LAMPScore {
    fn execute(&self, capability: &dyn K8sCapability) -> String {
        todo!()
        // Implementation...
    }
}

struct BinaryScore {}
impl Score<dyn LinuxCapability> for BinaryScore {
    fn execute(&self, capability: &dyn LinuxCapability) -> String {
        todo!()
        // Implementation...
    }
}

struct LoadBalancerScore {}
impl Score<dyn LoadBalancerCapability> for LoadBalancerScore {
    fn execute(&self, capability: &dyn LoadBalancerCapability) -> String {
        todo!()
        // Implementation...
    }
}

// Generic Maestro
struct Maestro<T> {
    topology: T,
    scores: Vec<Box<dyn FnMut(&T) -> String>>,
}

impl<T: 'static> Maestro<T> {
    fn new(topology: T) -> Self {
        Self {
            topology,
            scores: Vec::new(),
        }
    }
    
    fn interpret_all(&mut self) -> Vec<String> {
        self.scores.iter_mut()
            .map(|score| score(&self.topology))
            .collect()
    }
}

// Capability-specific extensions
impl<T: K8sCapability + 'static> Maestro<T> {
    fn register_k8s_score<S: Score<dyn K8sCapability> + 'static>(&mut self, score: S) {
        let score_box = Box::new(move |topology: &T| {
            score.execute(topology as &dyn K8sCapability)
        });
        self.scores.push(score_box);
    }
}

impl<T: LinuxCapability + 'static> Maestro<T> {
    fn register_linux_score<S: Score<dyn LinuxCapability> + 'static>(&mut self, score: S) {
        let score_box = Box::new(move |topology: &T| {
            score.execute(topology as &dyn LinuxCapability)
        });
        self.scores.push(score_box);
    }
}

impl<T: LoadBalancerCapability + 'static> Maestro<T> {
    fn register_lb_score<S: Score<dyn LoadBalancerCapability> + 'static>(&mut self, score: S) {
        let score_box = Box::new(move |topology: &T| {
            score.execute(topology as &dyn LoadBalancerCapability)
        });
        self.scores.push(score_box);
    }
}

fn main() {
    // Example usage
    let k3d = K3DTopology {};
    let mut k3d_maestro = Maestro::new(k3d);
    
    // These will compile because K3D implements K8sCapability
    k3d_maestro.register_k8s_score(LAMPScore {});
    
    // This would not compile because K3D doesn't implement LoadBalancerCapability
    // k3d_maestro.register_lb_score(LoadBalancerScore {});
    
    let linux = LinuxTopology {};
    let mut linux_maestro = Maestro::new(linux);
    
    // This will compile because Linux implements LinuxCapability
    linux_maestro.register_linux_score(BinaryScore {});
    
    // This would not compile because Linux doesn't implement K8sCapability
    // linux_maestro.register_k8s_score(LAMPScore {});
}