zinit-client 0.4.0

use crate::connection::ConnectionManager;
use crate::error::{Result, ZinitError};
use crate::models::{
    LogEntry, LogStream, Protocol, ServerCapabilities, ServiceState, ServiceStatus, ServiceTarget,
};
use crate::protocol::ProtocolHandler;
use crate::retry::RetryStrategy;
use chrono::Utc;
use std::collections::HashMap;
use std::path::{Path, PathBuf};
use std::sync::atomic::{AtomicU64, Ordering};
use std::sync::Arc;
use std::time::Duration;
use tokio::io::{AsyncBufReadExt, BufReader};
use tokio::sync::OnceCell;
use tracing::{debug, trace};

/// Configuration for the Zinit client
#[derive(Debug, Clone)]
pub struct ClientConfig {
    /// Path to the Zinit Unix socket
    pub socket_path: PathBuf,
    /// Timeout for connection attempts
    pub connection_timeout: Duration,
    /// Timeout for operations
    pub operation_timeout: Duration,
    /// Maximum number of retry attempts
    pub max_retries: usize,
    /// Base delay between retries
    pub retry_delay: Duration,
    /// Maximum delay between retries
    pub max_retry_delay: Duration,
    /// Whether to add jitter to retry delays
    pub retry_jitter: bool,
}

impl Default for ClientConfig {
    fn default() -> Self {
        Self {
            socket_path: PathBuf::from("/var/run/zinit.sock"),
            connection_timeout: Duration::from_secs(5),
            operation_timeout: Duration::from_secs(30),
            max_retries: 3,
            retry_delay: Duration::from_millis(100),
            max_retry_delay: Duration::from_secs(5),
            retry_jitter: true,
        }
    }
}

/// Client for interacting with Zinit
#[derive(Debug)]
pub struct ZinitClient {
    /// Connection manager
    connection_manager: ConnectionManager,
    /// Client configuration
    #[allow(dead_code)]
    config: ClientConfig,
    /// Detected protocol (lazy initialization)
    protocol: OnceCell<Protocol>,
    /// Server capabilities (lazy initialization)
    capabilities: OnceCell<ServerCapabilities>,
    /// Request ID counter for JSON-RPC
    request_id: Arc<AtomicU64>,
}

impl ZinitClient {
    /// Create a new Zinit client with the default configuration
    pub fn new(socket_path: impl AsRef<Path>) -> Self {
        Self::with_config(ClientConfig {
            socket_path: socket_path.as_ref().to_path_buf(),
            ..Default::default()
        })
    }

    /// Create a new Zinit client with a custom configuration
    pub fn with_config(config: ClientConfig) -> Self {
        let retry_strategy = RetryStrategy::new(
            config.max_retries,
            config.retry_delay,
            config.max_retry_delay,
            config.retry_jitter,
        );

        let connection_manager = ConnectionManager::new(
            &config.socket_path,
            config.connection_timeout,
            config.operation_timeout,
            retry_strategy,
        );

        Self {
            connection_manager,
            config,
            protocol: OnceCell::new(),
            capabilities: OnceCell::new(),
            request_id: Arc::new(AtomicU64::new(1)),
        }
    }

    /// Get the next request ID for JSON-RPC calls
    fn next_request_id(&self) -> u64 {
        self.request_id.fetch_add(1, Ordering::SeqCst)
    }

    /// Detect the protocol used by the server
    async fn detect_protocol(&self) -> Result<Protocol> {
        debug!("Detecting server protocol");

        // Try JSON-RPC first (new servers)
        let request_id = self.next_request_id();
        let json_rpc_request = ProtocolHandler::format_json_rpc_request(
            "service_list",
            serde_json::Value::Array(vec![]),
            request_id,
        )?;

        match self
            .connection_manager
            .send_command(&json_rpc_request)
            .await
        {
            Ok(response) => {
                // Check if response looks like JSON-RPC
                if response.contains("\"jsonrpc\":\"2.0\"") {
                    debug!("Detected JSON-RPC protocol (new server)");
                    return Ok(Protocol::JsonRpc);
                }
            }
            Err(_) => {
                // JSON-RPC failed, continue to try raw commands
            }
        }

        // Try raw commands (old servers)
        let raw_command = ProtocolHandler::format_raw_command("list", &[]);
        match self.connection_manager.send_command(&raw_command).await {
            Ok(response) => {
                // Check if response looks like old server format
                if response.contains("\"state\":\"ok\"") || response.contains("\"state\":\"error\"")
                {
                    debug!("Detected raw command protocol (old server)");
                    return Ok(Protocol::RawCommands);
                }
            }
            Err(e) => {
                return Err(ZinitError::ProtocolDetectionFailed(format!(
                    "Failed to detect protocol: {e}"
                )));
            }
        }

        Err(ZinitError::ProtocolDetectionFailed(
            "Unable to determine server protocol".to_string(),
        ))
    }

    /// Detect server capabilities based on protocol
    async fn detect_capabilities(&self) -> Result<ServerCapabilities> {
        let protocol = self.get_protocol().await?;
        debug!("Detecting server capabilities for protocol: {}", protocol);

        let capabilities = match protocol {
            Protocol::JsonRpc => {
                // New servers support all features
                ServerCapabilities::full()
            }
            Protocol::RawCommands => {
                // Old servers have limited capabilities
                ServerCapabilities::legacy()
            }
        };

        debug!("Detected capabilities: {:?}", capabilities);
        Ok(capabilities)
    }

    /// Get the detected protocol (with lazy initialization)
    async fn get_protocol(&self) -> Result<Protocol> {
        if let Some(protocol) = self.protocol.get() {
            return Ok(*protocol);
        }

        let protocol = self.detect_protocol().await?;
        let _ = self.protocol.set(protocol);
        Ok(protocol)
    }

    /// Get the server capabilities (with lazy initialization)
    async fn get_capabilities(&self) -> Result<&ServerCapabilities> {
        if let Some(capabilities) = self.capabilities.get() {
            return Ok(capabilities);
        }

        let capabilities = self.detect_capabilities().await?;
        let _ = self.capabilities.set(capabilities);
        Ok(self.capabilities.get().unwrap())
    }

    /// Execute a command using the appropriate protocol
    async fn execute_command(
        &self,
        method: &str,
        args: &[&str],
        params: Option<serde_json::Value>,
    ) -> Result<serde_json::Value> {
        let protocol = self.get_protocol().await?;
        let request_id = self.next_request_id();

        let request = ProtocolHandler::format_request(protocol, method, args, params, request_id)?;
        let response = self.connection_manager.send_command(&request).await?;
        ProtocolHandler::parse_response_by_protocol(protocol, &response)
    }

    /// List all services and their states
    pub async fn list(&self) -> Result<HashMap<String, ServiceState>> {
        debug!("Listing all services");

        let protocol = self.get_protocol().await?;
        let response = match protocol {
            Protocol::JsonRpc => self.execute_command("service_list", &[], None).await?,
            Protocol::RawCommands => self.execute_command("list", &[], None).await?,
        };

        let map: HashMap<String, String> = serde_json::from_value(response)?;
        let result = map
            .into_iter()
            .map(|(name, state_str)| {
                let state = match state_str.as_str() {
                    "Unknown" => ServiceState::Unknown,
                    "Blocked" => ServiceState::Blocked,
                    "Spawned" => ServiceState::Spawned,
                    "Running" => ServiceState::Running,
                    "Success" => ServiceState::Success,
                    "Error" => ServiceState::Error,
                    "TestFailure" => ServiceState::TestFailure,
                    _ => ServiceState::Unknown,
                };
                (name, state)
            })
            .collect();

        Ok(result)
    }

    /// Get the status of a service
    pub async fn status(&self, service: impl AsRef<str>) -> Result<ServiceStatus> {
        let service_name = service.as_ref();
        debug!("Getting status for service: {}", service_name);

        let protocol = self.get_protocol().await?;
        let response = match protocol {
            Protocol::JsonRpc => {
                let params = serde_json::json!([service_name]);
                self.execute_command("service_status", &[], Some(params))
                    .await?
            }
            Protocol::RawCommands => {
                self.execute_command("status", &[service_name], None)
                    .await?
            }
        };

        // Parse the response based on protocol
        let status = self.parse_status_response(response, service_name).await?;
        Ok(status)
    }

    /// Parse status response handling different formats between protocols
    async fn parse_status_response(
        &self,
        response: serde_json::Value,
        service_name: &str,
    ) -> Result<ServiceStatus> {
        let protocol = self.get_protocol().await?;

        match protocol {
            Protocol::JsonRpc => {
                // New server JSON-RPC format
                let name = response
                    .get("name")
                    .and_then(|v| v.as_str())
                    .unwrap_or(service_name)
                    .to_string();

                let pid = response.get("pid").and_then(|v| v.as_u64()).unwrap_or(0) as u32;

                let state_str = response
                    .get("state")
                    .and_then(|v| v.as_str())
                    .unwrap_or("Unknown");

                let target_str = response
                    .get("target")
                    .and_then(|v| v.as_str())
                    .unwrap_or("Down");

                let after = response
                    .get("after")
                    .and_then(|v| v.as_object())
                    .map(|obj| {
                        obj.iter()
                            .map(|(k, v)| (k.clone(), v.as_str().unwrap_or("Unknown").to_string()))
                            .collect()
                    })
                    .unwrap_or_default();

                Ok(ServiceStatus {
                    name,
                    pid,
                    state: self.parse_service_state(state_str),
                    target: self.parse_service_target(target_str),
                    after,
                })
            }
            Protocol::RawCommands => {
                // Old server format - try direct deserialization first
                match serde_json::from_value::<ServiceStatus>(response.clone()) {
                    Ok(mut status) => {
                        // Convert state and target strings to enums
                        status.state = self.parse_service_state(&status.state.to_string());
                        status.target = self.parse_service_target(&status.target.to_string());
                        Ok(status)
                    }
                    Err(_) => {
                        // Fallback parsing for old format
                        let name = service_name.to_string();
                        let pid = response.get("pid").and_then(|v| v.as_u64()).unwrap_or(0) as u32;

                        let state_str = response
                            .get("state")
                            .and_then(|v| v.as_str())
                            .unwrap_or("Unknown");

                        let target_str = response
                            .get("target")
                            .and_then(|v| v.as_str())
                            .unwrap_or("Down");

                        let after = response
                            .get("after")
                            .and_then(|v| v.as_object())
                            .map(|obj| {
                                obj.iter()
                                    .map(|(k, v)| {
                                        (k.clone(), v.as_str().unwrap_or("Unknown").to_string())
                                    })
                                    .collect()
                            })
                            .unwrap_or_default();

                        Ok(ServiceStatus {
                            name,
                            pid,
                            state: self.parse_service_state(state_str),
                            target: self.parse_service_target(target_str),
                            after,
                        })
                    }
                }
            }
        }
    }

    /// Parse service state string to enum
    fn parse_service_state(&self, state_str: &str) -> ServiceState {
        match state_str {
            "Unknown" => ServiceState::Unknown,
            "Blocked" => ServiceState::Blocked,
            "Spawned" => ServiceState::Spawned,
            "Running" => ServiceState::Running,
            "Success" => ServiceState::Success,
            "Error" => ServiceState::Error,
            "TestFailure" => ServiceState::TestFailure,
            _ => ServiceState::Unknown,
        }
    }

    /// Parse service target string to enum
    fn parse_service_target(&self, target_str: &str) -> ServiceTarget {
        match target_str {
            "Up" => ServiceTarget::Up,
            "Down" => ServiceTarget::Down,
            _ => ServiceTarget::Down,
        }
    }

    /// Start a service
    pub async fn start(&self, service: impl AsRef<str>) -> Result<()> {
        let service_name = service.as_ref();
        debug!("Starting service: {}", service_name);

        let protocol = self.get_protocol().await?;
        match protocol {
            Protocol::JsonRpc => {
                let params = serde_json::json!([service_name]);
                self.execute_command("service_start", &[], Some(params))
                    .await?;
            }
            Protocol::RawCommands => {
                self.execute_command("start", &[service_name], None).await?;
            }
        }

        Ok(())
    }

    /// Stop a service
    pub async fn stop(&self, service: impl AsRef<str>) -> Result<()> {
        let service_name = service.as_ref();
        debug!("Stopping service: {}", service_name);

        let protocol = self.get_protocol().await?;
        match protocol {
            Protocol::JsonRpc => {
                let params = serde_json::json!([service_name]);
                self.execute_command("service_stop", &[], Some(params))
                    .await?;
            }
            Protocol::RawCommands => {
                self.execute_command("stop", &[service_name], None).await?;
            }
        }

        Ok(())
    }

    /// Restart a service
    pub async fn restart(&self, service: impl AsRef<str>) -> Result<()> {
        let service_name = service.as_ref();
        debug!("Restarting service: {}", service_name);

        // First stop the service
        self.stop(service_name).await?;

        // Wait for the service to stop
        let mut attempts = 0;
        let max_attempts = 20;

        while attempts < max_attempts {
            let status = self.status(service_name).await?;
            if status.pid == 0 && status.target == ServiceTarget::Down {
                // Service is stopped, now start it
                return self.start(service_name).await;
            }

            attempts += 1;
            tokio::time::sleep(Duration::from_secs(1)).await;
        }

        // Service didn't stop gracefully, try to kill it
        self.kill(service_name, "SIGKILL").await?;
        self.start(service_name).await
    }

    /// Monitor a service
    pub async fn monitor(&self, service: impl AsRef<str>) -> Result<()> {
        let service_name = service.as_ref();
        debug!("Monitoring service: {}", service_name);

        let protocol = self.get_protocol().await?;
        match protocol {
            Protocol::JsonRpc => {
                let params = serde_json::json!([service_name]);
                self.execute_command("service_monitor", &[], Some(params))
                    .await?;
            }
            Protocol::RawCommands => {
                self.execute_command("monitor", &[service_name], None)
                    .await?;
            }
        }

        Ok(())
    }

    /// Forget a service
    pub async fn forget(&self, service: impl AsRef<str>) -> Result<()> {
        let service_name = service.as_ref();
        debug!("Forgetting service: {}", service_name);

        let protocol = self.get_protocol().await?;
        match protocol {
            Protocol::JsonRpc => {
                let params = serde_json::json!([service_name]);
                self.execute_command("service_forget", &[], Some(params))
                    .await?;
            }
            Protocol::RawCommands => {
                self.execute_command("forget", &[service_name], None)
                    .await?;
            }
        }

        Ok(())
    }

    /// Send a signal to a service
    pub async fn kill(&self, service: impl AsRef<str>, signal: impl AsRef<str>) -> Result<()> {
        let service_name = service.as_ref();
        let signal_name = signal.as_ref();
        debug!(
            "Sending signal {} to service: {}",
            signal_name, service_name
        );

        let protocol = self.get_protocol().await?;
        match protocol {
            Protocol::JsonRpc => {
                let params = serde_json::json!([service_name, signal_name]);
                self.execute_command("service_kill", &[], Some(params))
                    .await?;
            }
            Protocol::RawCommands => {
                self.execute_command("kill", &[service_name, signal_name], None)
                    .await?;
            }
        }

        Ok(())
    }

    /// Stream logs from services
    pub async fn logs(&self, follow: bool, filter: Option<impl AsRef<str>>) -> Result<LogStream> {
        let command = if follow {
            "log".to_string()
        } else {
            "log snapshot".to_string()
        };

        debug!("Streaming logs with command: {}", command);
        let stream = self.connection_manager.stream_logs(&command).await?;
        let reader = BufReader::new(stream);
        let mut lines = reader.lines();

        // Create a stream of log entries
        let filter_str = filter.as_ref().map(|f| f.as_ref().to_string());

        let log_stream = async_stream::stream! {
            while let Some(line_result) = lines.next_line().await.transpose() {
                match line_result {
                    Ok(line) => {
                        trace!("Received log line: {}", line);

                        // Parse the log line
                        if let Some(entry) = parse_log_line(&line, &filter_str) {
                            yield Ok(entry);
                        }
                    }
                    Err(e) => {
                        yield Err(ZinitError::ConnectionError(e));
                        break;
                    }
                }
            }
        };

        Ok(LogStream {
            inner: Box::pin(log_stream),
        })
    }

    /// Shutdown the system
    pub async fn shutdown(&self) -> Result<()> {
        debug!("Shutting down the system");
        self.connection_manager.execute_command("shutdown").await?;
        Ok(())
    }

    /// Reboot the system
    pub async fn reboot(&self) -> Result<()> {
        debug!("Rebooting the system");
        self.connection_manager.execute_command("reboot").await?;
        Ok(())
    }

    /// Get raw service information
    pub async fn get_service(&self, service: impl AsRef<str>) -> Result<serde_json::Value> {
        let service_name = service.as_ref();
        debug!("Getting raw service info for: {}", service_name);

        // Use the universal interface
        let protocol = self.get_protocol().await?;
        match protocol {
            Protocol::JsonRpc => {
                // New servers: use service_status RPC call
                let params = serde_json::json!([service_name]);
                self.execute_command("service_status", &[], Some(params))
                    .await
            }
            Protocol::RawCommands => {
                // Old servers: use status command
                self.execute_command("status", &[service_name], None).await
            }
        }
    }

    /// Create a new service
    pub async fn create_service(
        &self,
        name: impl AsRef<str>,
        config: serde_json::Value,
    ) -> Result<()> {
        let service_name = name.as_ref();
        debug!("Creating service: {}", service_name);

        // Check if the server supports dynamic service creation
        let capabilities = self.get_capabilities().await?;
        if !capabilities.supports_create {
            return Err(ZinitError::FeatureNotSupported(format!(
                "Dynamic service creation is not supported by this zinit server ({}). \
                     Please create a service configuration file manually in /etc/zinit/{}.yaml",
                capabilities.protocol, service_name
            )));
        }

        // Use the appropriate protocol
        let protocol = self.get_protocol().await?;
        match protocol {
            Protocol::JsonRpc => {
                // New servers: use service_create RPC call
                let params = serde_json::json!([service_name, config]);
                self.execute_command("service_create", &[], Some(params))
                    .await?;
            }
            Protocol::RawCommands => {
                // This should not happen since we checked capabilities above,
                // but handle it gracefully
                return Err(ZinitError::FeatureNotSupported(
                    "Dynamic service creation requires zinit v0.2.25+".to_string(),
                ));
            }
        }

        Ok(())
    }

    /// Delete a service
    pub async fn delete_service(&self, name: impl AsRef<str>) -> Result<()> {
        let service_name = name.as_ref();
        debug!("Deleting service: {}", service_name);

        // Try to get status, but don't fail if it doesn't work
        match self.status(service_name).await {
            Ok(status) => {
                if status.state == ServiceState::Running || status.target == ServiceTarget::Up {
                    // Stop the service first
                    if let Err(e) = self.stop(service_name).await {
                        debug!("Warning: Failed to stop service {}: {}", service_name, e);
                    }

                    // Wait for the service to stop
                    let mut attempts = 0;
                    let max_attempts = 10;

                    while attempts < max_attempts {
                        match self.status(service_name).await {
                            Ok(status) => {
                                if status.pid == 0 && status.target == ServiceTarget::Down {
                                    break;
                                }
                            }
                            Err(_) => {
                                // If status fails, assume service is stopped
                                break;
                            }
                        }

                        attempts += 1;
                        tokio::time::sleep(Duration::from_millis(500)).await;
                    }
                }
            }
            Err(e) => {
                debug!("Warning: Could not get status for {}: {}", service_name, e);
                // Continue with deletion anyway
            }
        }

        // Now forget the service and delete the config file
        self.forget(service_name).await?;

        // For new servers, also delete the service configuration file
        let protocol = self.get_protocol().await?;
        if let Protocol::JsonRpc = protocol {
            let params = serde_json::json!([service_name]);
            if let Err(e) = self
                .execute_command("service_delete", &[], Some(params))
                .await
            {
                debug!(
                    "Warning: Could not delete service config file for {}: {}",
                    service_name, e
                );
                // Don't fail the whole operation if config file deletion fails
            }
        }

        Ok(())
    }
}

/// Parse a log line into a LogEntry
fn parse_log_line(line: &str, filter: &Option<String>) -> Option<LogEntry> {
    // Example log line: "zinit: INFO (service) message"
    let parts: Vec<&str> = line.splitn(4, ' ').collect();

    if parts.len() < 4 || !parts[0].starts_with("zinit:") {
        return None;
    }

    let level = parts[1];
    let service = parts[2].trim_start_matches('(').trim_end_matches(')');

    // Apply filter if provided
    if let Some(filter_str) = filter {
        if service != filter_str {
            return None;
        }
    }

    let message = parts[3];
    let timestamp = Utc::now(); // Zinit doesn't include timestamps, so we use current time

    Some(LogEntry {
        timestamp,
        service: service.to_string(),
        message: format!("[{level}] {message}"),
    })
}