use crate::kube::portforward::PortForwardSessionConfig;
use crate::kube::ClusterClient;
use crate::shell::kubectl::locate_kubectl;
use crate::state::AppState;
use serde::{Deserialize, Serialize};
use serde_yaml::Value;
use std::net::TcpListener;
use std::sync::Arc;
use tauri::State;
use tokio::process::Command;

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ClusterInfo {
    pub id: String,
    pub name: String,
    pub context: String,
    pub cluster_url: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PortForwardRequest {
    pub cluster_id: String,
    pub namespace: String,
    pub pod: String,
    pub container_port: u16,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PortForwardResponse {
    pub id: String,
    pub cluster_id: String,
    pub namespace: String,
    pub pod: String,
    pub container_port: u16,
    pub local_port: u16,
    pub status: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PodInfo {
    pub name: String,
    pub status: String,
    pub ready: String,
    pub age: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ClusterConnectionStatus {
    pub status: ClusterConnectionState,
    pub context: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(tag = "type")]
pub enum ClusterConnectionState {
    Connected,
    Disconnected { error: String },
}

#[tauri::command]
pub async fn add_cluster(
    id: String,
    name: String,
    kubeconfig_content: String,
    state: State<'_, AppState>,
) -> Result<ClusterInfo, String> {
    if kubeconfig_content.trim().is_empty() {
        return Err("Kubeconfig content cannot be empty".to_string());
    }

    let context = extract_context(&kubeconfig_content)?;
    let server_url = extract_server_url(&kubeconfig_content)?;

    let kubeconfig_arc = Arc::new(kubeconfig_content.clone());
    let client = ClusterClient::new(
        id.clone(),
        name.clone(),
        context.clone(),
        server_url.clone(),
        kubeconfig_arc,
    );

    {
        let mut clusters = state.clusters.lock().await;
        clusters.insert(id.clone(), client);
    }

    Ok(ClusterInfo {
        id,
        name,
        context,
        cluster_url: server_url,
    })
}

fn extract_context(content: &str) -> Result<String, String> {
    let value: Value =
        serde_yaml::from_str(content).map_err(|e| format!("Invalid kubeconfig YAML: {}", e))?;

    let contexts = value
        .get("contexts")
        .and_then(|c| c.as_sequence())
        .ok_or("Missing 'contexts' field in kubeconfig")?;

    if contexts.is_empty() {
        return Err("No contexts found in kubeconfig".to_string());
    }

    let first_context = contexts[0].get("name").and_then(|n| n.as_str());
    first_context
        .map(|s| s.to_string())
        .ok_or_else(|| "Context name not found".to_string())
}

fn extract_server_url(content: &str) -> Result<String, String> {
    let value: Value =
        serde_yaml::from_str(content).map_err(|e| format!("Invalid kubeconfig YAML: {}", e))?;

    let clusters = value
        .get("clusters")
        .and_then(|c| c.as_sequence())
        .ok_or("Missing 'clusters' field in kubeconfig")?;

    if clusters.is_empty() {
        return Err("No clusters found in kubeconfig".to_string());
    }

    let cluster = &clusters[0];
    let server = cluster
        .get("cluster")
        .and_then(|c| c.get("server"))
        .and_then(|s| s.as_str());

    server
        .map(|s| s.to_string())
        .ok_or_else(|| "Server URL not found in cluster".to_string())
}

#[tauri::command]
pub async fn remove_cluster(id: String, state: State<'_, AppState>) -> Result<(), String> {
    let mut clusters = state.clusters.lock().await;

    if clusters.remove(&id).is_none() {
        return Err(format!("Cluster {id} not found"));
    }

    Ok(())
}

#[tauri::command]
pub async fn list_clusters(state: State<'_, AppState>) -> Result<Vec<ClusterInfo>, String> {
    let clusters = state.clusters.lock().await;

    let cluster_list: Vec<ClusterInfo> = clusters
        .values()
        .map(|c| ClusterInfo {
            id: c.id.clone(),
            name: c.name.clone(),
            context: c.context.clone(),
            cluster_url: c.server_url.clone(),
        })
        .collect();

    Ok(cluster_list)
}

#[tauri::command]
pub async fn test_cluster_connection(
    cluster_id: String,
    state: State<'_, AppState>,
) -> Result<ClusterConnectionStatus, String> {
    let clusters = state.clusters.lock().await;
    let cluster = clusters
        .get(&cluster_id)
        .ok_or_else(|| format!("Cluster {} not found", cluster_id))?;

    let kubeconfig_content = cluster.kubeconfig_content.as_ref();
    let context = &cluster.context;

    // Write kubeconfig to temp file
    let temp_dir = std::env::temp_dir();
    let temp_path = temp_dir.join(format!("kubeconfig-{}.yaml", cluster_id));

    std::fs::write(&temp_path, kubeconfig_content)
        .map_err(|e| format!("Failed to write kubeconfig temp file: {e}"))?;

    // Run kubectl cluster-info
    let kubectl_path = locate_kubectl()?;

    let output = Command::new(kubectl_path)
        .arg("cluster-info")
        .env("KUBECONFIG", temp_path.to_string_lossy().to_string())
        .env("KUBERNETES_CONTEXT", context)
        .output()
        .await
        .map_err(|e| format!("Failed to execute kubectl: {e}"))?;

    let status = if output.status.success() {
        ClusterConnectionState::Connected
    } else {
        let stderr = String::from_utf8_lossy(&output.stderr);
        ClusterConnectionState::Disconnected {
            error: stderr.to_string(),
        }
    };

    Ok(ClusterConnectionStatus {
        status,
        context: context.clone(),
    })
}

#[tauri::command]
pub async fn discover_pods(
    cluster_id: String,
    namespace: String,
    state: State<'_, AppState>,
) -> Result<Vec<PodInfo>, String> {
    let clusters = state.clusters.lock().await;
    let cluster = clusters
        .get(&cluster_id)
        .ok_or_else(|| format!("Cluster {} not found", cluster_id))?;

    let kubeconfig_content = cluster.kubeconfig_content.as_ref();
    let context = &cluster.context;

    // Write kubeconfig to temp file
    let temp_dir = std::env::temp_dir();
    let temp_path = temp_dir.join(format!("kubeconfig-{}-pods.yaml", cluster_id));

    std::fs::write(&temp_path, kubeconfig_content)
        .map_err(|e| format!("Failed to write kubeconfig temp file: {e}"))?;

    // Run kubectl get pods
    let kubectl_path = locate_kubectl()?;

    let output = Command::new(kubectl_path)
        .arg("get")
        .arg("pods")
        .arg("-n")
        .arg(&namespace)
        .arg("-o")
        .arg("jsonpath={.items[*].metadata.name}")
        .env("KUBECONFIG", temp_path.to_string_lossy().to_string())
        .env("KUBERNETES_CONTEXT", context)
        .output()
        .await
        .map_err(|e| format!("Failed to execute kubectl: {e}"))?;

    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        return Err(format!("Failed to list pods: {}", stderr));
    }

    let stdout = String::from_utf8_lossy(&output.stdout);
    let pod_names: Vec<&str> = stdout.split_whitespace().collect();

    // For now, return basic pod info - in production, parse full JSON output
    let pods: Vec<PodInfo> = pod_names
        .into_iter()
        .map(|name| PodInfo {
            name: name.to_string(),
            status: "Unknown".to_string(),
            ready: "N/A".to_string(),
            age: "N/A".to_string(),
        })
        .collect();

    Ok(pods)
}

#[tauri::command]
pub async fn start_port_forward(
    request: PortForwardRequest,
    state: State<'_, AppState>,
) -> Result<PortForwardResponse, String> {
    let session_id = uuid::Uuid::now_v7().to_string();

    let clusters = state.clusters.lock().await;
    let cluster = clusters
        .get(&request.cluster_id)
        .ok_or_else(|| format!("Cluster {} not found", request.cluster_id))?;

    let cluster_name = cluster.name.clone();
    let kubeconfig_content = cluster.kubeconfig_content.clone();

    // Allocate local port using TcpListener::bind("127.0.0.1:0")
    let listener = TcpListener::bind("127.0.0.1:0")
        .map_err(|e| format!("Failed to allocate local port: {e}"))?;
    let local_port = listener
        .local_addr()
        .map_err(|e| format!("Failed to get local port address: {e}"))?
        .port();

    // Drop the listener - the port is now reserved for kubectl
    drop(listener);

    tracing::info!(
        session_id = %session_id,
        cluster_id = %request.cluster_id,
        namespace = %request.namespace,
        pod = %request.pod,
        container_port = request.container_port,
        local_port,
        "Allocating local port for port-forward"
    );

    // Write kubeconfig to temp file
    let temp_dir = std::env::temp_dir();
    let temp_path = temp_dir.join(format!("kubeconfig-{}.yaml", request.cluster_id));

    std::fs::write(&temp_path, kubeconfig_content.as_ref())
        .map_err(|e| format!("Failed to write kubeconfig temp file: {e}"))?;

    // Build kubectl command
    let kubectl_path = locate_kubectl()?;
    let args = vec![
        "port-forward".to_string(),
        format!("pod/{}", request.pod),
        format!("{}:{}", local_port, request.container_port),
        "-n".to_string(),
        request.namespace.clone(),
    ];

    tracing::info!(
        session_id = %session_id,
        command = ?args,
        "Spawning kubectl port-forward subprocess"
    );

    // Spawn kubectl subprocess
    let child = Command::new(kubectl_path)
        .args(&args)
        .env("KUBECONFIG", temp_path.to_string_lossy().to_string())
        .env("KUBERNETES_CONTEXT", &cluster.context)
        .spawn()
        .map_err(|e| format!("Failed to spawn kubectl: {e}"))?;

    let child_mutex = Arc::new(std::sync::Mutex::new(child));

    // Create session with allocated port
    let _session = crate::kube::PortForwardSession::new(PortForwardSessionConfig {
        id: session_id.clone(),
        cluster_id: request.cluster_id.clone(),
        cluster_name,
        namespace: request.namespace.clone(),
        pod: request.pod.clone(),
        container: None,
        ports: vec![request.container_port],
        local_ports: vec![local_port],
    });

    // Store child handle in session
    {
        let mut port_forwards = state.port_forwards.lock().await;
        let session_mut = port_forwards.get_mut(&session_id).unwrap();
        session_mut.kubectl_child = Some(child_mutex);
    }

    tracing::info!(
        session_id = %session_id,
        local_port,
        "Port-forward session started"
    );

    Ok(PortForwardResponse {
        id: session_id,
        cluster_id: request.cluster_id,
        namespace: request.namespace,
        pod: request.pod,
        container_port: request.container_port,
        local_port,
        status: "Active".to_string(),
    })
}

#[tauri::command]
pub async fn stop_port_forward(id: String, state: State<'_, AppState>) -> Result<(), String> {
    let mut port_forwards = state.port_forwards.lock().await;

    if let Some(session) = port_forwards.get_mut(&id) {
        session.stop();
        tracing::info!(session_id = %id, "Port-forward session stopped");
        Ok(())
    } else {
        Err(format!("Port forward session {id} not found"))
    }
}

#[tauri::command]
pub async fn list_port_forwards(
    state: State<'_, AppState>,
) -> Result<Vec<PortForwardResponse>, String> {
    let port_forwards = state.port_forwards.lock().await;

    let forwards: Vec<PortForwardResponse> = port_forwards
        .values()
        .map(|s| PortForwardResponse {
            id: s.id.clone(),
            cluster_id: s.cluster_id.clone(),
            namespace: s.namespace.clone(),
            pod: s.pod.clone(),
            container_port: s.ports.first().copied().unwrap_or(0),
            local_port: s.local_ports.first().copied().unwrap_or(0),
            status: match s.status {
                crate::kube::PortForwardStatus::Active => "Active".to_string(),
                crate::kube::PortForwardStatus::Stopped => "Stopped".to_string(),
                crate::kube::PortForwardStatus::Error(ref e) => e.clone(),
            },
        })
        .collect();

    Ok(forwards)
}

#[tauri::command]
pub async fn delete_port_forward(id: String, state: State<'_, AppState>) -> Result<(), String> {
    let mut port_forwards = state.port_forwards.lock().await;

    if port_forwards.remove(&id).is_none() {
        return Err(format!("Port forward session {id} not found"));
    }

    Ok(())
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_cluster_info_serialization() {
        let info = ClusterInfo {
            id: "cluster-1".to_string(),
            name: "Production".to_string(),
            context: "prod-context".to_string(),
            cluster_url: "https://k8s.example.com".to_string(),
        };

        let json = serde_json::to_string(&info).unwrap();
        let parsed: ClusterInfo = serde_json::from_str(&json).unwrap();

        assert_eq!(info.id, parsed.id);
        assert_eq!(info.name, parsed.name);
        assert_eq!(info.context, parsed.context);
        assert_eq!(info.cluster_url, parsed.cluster_url);
    }

    #[test]
    fn test_cluster_connection_state_serialization() {
        let connected = ClusterConnectionState::Connected;
        let json = serde_json::to_string(&connected).unwrap();
        let parsed: ClusterConnectionState = serde_json::from_str(&json).unwrap();

        assert!(matches!(parsed, ClusterConnectionState::Connected));

        let disconnected = ClusterConnectionState::Disconnected {
            error: "connection refused".to_string(),
        };
        let json = serde_json::to_string(&disconnected).unwrap();
        let parsed: ClusterConnectionState = serde_json::from_str(&json).unwrap();

        assert!(matches!(
            parsed,
            ClusterConnectionState::Disconnected { .. }
        ));
    }

    #[test]
    fn test_port_forward_request_serialization() {
        let request = PortForwardRequest {
            cluster_id: "cluster-1".to_string(),
            namespace: "default".to_string(),
            pod: "my-pod-abc123".to_string(),
            container_port: 8080,
        };

        let json = serde_json::to_string(&request).unwrap();
        let parsed: PortForwardRequest = serde_json::from_str(&json).unwrap();

        assert_eq!(request.cluster_id, parsed.cluster_id);
        assert_eq!(request.namespace, parsed.namespace);
        assert_eq!(request.pod, parsed.pod);
        assert_eq!(request.container_port, parsed.container_port);
    }
}