use std::marker::PhantomData;

// Capability Trait Hierarchy
pub trait Capability {}

// Specific Capability Traits
pub trait ShellAccess: Capability {}
pub trait ContainerRuntime: Capability {}
pub trait KubernetesAccess: Capability {}
pub trait FileSystemAccess: Capability {}

// Topology Trait - Defines the core interface for infrastructure topologies
pub trait Topology {
    type Capabilities: Capability;
    
    fn name(&self) -> &str;
}

// Score Trait - Defines the core interface for infrastructure transformation
pub trait Score {
    type RequiredCapabilities: Capability;
    type OutputTopology: Topology;

    fn apply<T: Topology>(&self, topology: T) -> Result<Self::OutputTopology, String>;
}

// Linux Host Topology
pub struct LinuxHostTopology;

impl Topology for LinuxHostTopology {
    type Capabilities = dyn ShellAccess + FileSystemAccess;

    fn name(&self) -> &str {
        "Linux Host"
    }
}

impl ShellAccess for LinuxHostTopology {}
impl FileSystemAccess for LinuxHostTopology {}

// K3D Topology
pub struct K3DTopology;

impl Topology for K3DTopology {
    type Capabilities = dyn ContainerRuntime + KubernetesAccess + ShellAccess;

    fn name(&self) -> &str {
        "K3D Kubernetes Cluster"
    }
}

impl ContainerRuntime for K3DTopology {}
impl KubernetesAccess for K3DTopology {}
impl ShellAccess for K3DTopology {}

// Command Score - A score that requires shell access
pub struct CommandScore {
    command: String,
}

impl Score for CommandScore {
    type RequiredCapabilities = dyn ShellAccess;
    type OutputTopology = LinuxHostTopology;

    fn apply<T: Topology>(&self, _topology: T) -> Result<Self::OutputTopology, String> 
    where 
        T: ShellAccess 
    {
        // Simulate command execution
        println!("Executing command: {}", self.command);
        Ok(LinuxHostTopology)
    }
}

// Kubernetes Resource Score
pub struct K8sResourceScore {
    resource_definition: String,
}

impl Score for K8sResourceScore {
    type RequiredCapabilities = dyn KubernetesAccess;
    type OutputTopology = K3DTopology;

    fn apply<T: Topology>(&self, _topology: T) -> Result<Self::OutputTopology, String> 
    where 
        T: dyn KubernetesAccess 
    {
        // Simulate Kubernetes resource application
        println!("Applying K8s resource: {}", self.resource_definition);
        Ok(K3DTopology)
    }
}

// Maestro - The orchestration coordinator
pub struct Maestro;

impl Maestro {
    // Type-safe score application
    pub fn apply_score<T, S>(topology: T, score: S) -> Result<S::OutputTopology, String>
    where 
        T: Topology,
        S: Score,
        T: S::RequiredCapabilities
    {
        score.apply(topology)
    }
}

fn main() {
    // Example usage demonstrating type-driven design
    let linux_host = LinuxHostTopology;
    let k3d_cluster = K3DTopology;

    // Command score on Linux host
    let command_score = CommandScore {
        command: "echo 'Hello, World!'".to_string(),
    };

    let result = Maestro::apply_score(linux_host, command_score)
        .expect("Command score application failed");

    // K8s resource score on K3D cluster
    let k8s_score = K8sResourceScore {
        resource_definition: "apiVersion: v1\nkind: Pod\n...".to_string(),
    };

    let k8s_result = Maestro::apply_score(k3d_cluster, k8s_score)
        .expect("K8s resource score application failed");
}
