ubiquity-core 0.1.1

//! Cloudflare Workers Durable Objects command execution implementation

use async_trait::async_trait;
use futures::{Stream, StreamExt};
use reqwest::Client;
use serde::{Deserialize, Serialize};
use std::pin::Pin;
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::mpsc;
use tracing::error;
use uuid::Uuid;

use crate::command::{
    CommandContext, CommandEvent, CommandExecutor, CommandHandle, CommandRequest, CommandResult,
};
use crate::error::UbiquityError;

/// Cloud command executor using Cloudflare Workers Durable Objects
pub struct CloudCommandExecutor {
    context: Arc<CommandContext>,
    event_buffer_size: usize,
    client: Client,
    worker_url: String,
    api_token: String,
    namespace_id: String,
}

/// Request to create a new command execution in Durable Object
#[derive(Debug, Clone, Serialize, Deserialize)]
struct CloudExecuteRequest {
    pub request: CommandRequest,
    pub namespace_id: String,
}

/// Response from cloud execution
#[derive(Debug, Clone, Serialize, Deserialize)]
struct CloudExecuteResponse {
    pub durable_object_id: String,
    pub websocket_url: String,
}

/// WebSocket message types for streaming events
#[derive(Debug, Clone, Serialize, Deserialize)]
#[serde(tag = "type")]
enum CloudWebSocketMessage {
    Subscribe {
        command_id: Uuid,
    },
    Event {
        event: CommandEvent,
    },
    Cancel {
        command_id: Uuid,
    },
    Status {
        command_id: Uuid,
    },
    StatusResponse {
        result: Option<CommandResult>,
    },
    Error {
        message: String,
    },
}

impl CloudCommandExecutor {
    pub fn new(worker_url: String, api_token: String, namespace_id: String) -> Self {
        Self {
            context: Arc::new(CommandContext::new()),
            event_buffer_size: 1024,
            client: Client::builder()
                .timeout(Duration::from_secs(30))
                .build()
                .unwrap(),
            worker_url,
            api_token,
            namespace_id,
        }
    }

    async fn create_durable_object(
        &self,
        request: CommandRequest,
    ) -> Result<CloudExecuteResponse, UbiquityError> {
        let url = format!("{}/api/commands/execute", self.worker_url);
        
        let cloud_request = CloudExecuteRequest {
            request,
            namespace_id: self.namespace_id.clone(),
        };

        let response = self
            .client
            .post(&url)
            .header("Authorization", format!("Bearer {}", self.api_token))
            .json(&cloud_request)
            .send()
            .await
            .map_err(|e| UbiquityError::Network(format!("Failed to create durable object: {}", e)))?;

        if !response.status().is_success() {
            let status = response.status();
            let body = response.text().await.unwrap_or_default();
            return Err(UbiquityError::CloudExecution(format!(
                "Failed to create durable object: {} - {}",
                status, body
            )));
        }

        response
            .json::<CloudExecuteResponse>()
            .await
            .map_err(|e| UbiquityError::Serialization(format!("Failed to parse response: {}", e)))
    }

    async fn connect_websocket(
        &self,
        websocket_url: &str,
        command_id: Uuid,
        event_tx: mpsc::Sender<CommandEvent>,
    ) -> Result<(), UbiquityError> {
        use tokio_tungstenite::{connect_async, tungstenite::Message};
        
        let (ws_stream, _) = connect_async(websocket_url)
            .await
            .map_err(|e| UbiquityError::Network(format!("Failed to connect WebSocket: {}", e)))?;

        let (write, read) = ws_stream.split();
        let (internal_tx, mut internal_rx) = mpsc::channel::<Message>(100);

        // Send subscribe message
        let subscribe_msg = CloudWebSocketMessage::Subscribe { command_id };
        let msg_text = serde_json::to_string(&subscribe_msg)
            .map_err(|e| UbiquityError::Serialization(e.to_string()))?;
        
        internal_tx
            .send(Message::Text(msg_text))
            .await
            .map_err(|_| UbiquityError::Internal("Failed to send subscribe message".to_string()))?;

        // Spawn task to handle writing
        let write_task = tokio::spawn(async move {
            use futures::SinkExt;
            let mut write = write;
            while let Some(msg) = internal_rx.recv().await {
                if let Err(e) = write.send(msg).await {
                    error!("WebSocket write error: {}", e);
                    break;
                }
            }
        });

        // Handle reading
        let read_task = tokio::spawn(async move {
            use futures::StreamExt;
            let mut read = read;
            while let Some(result) = read.next().await {
                match result {
                    Ok(Message::Text(text)) => {
                        match serde_json::from_str::<CloudWebSocketMessage>(&text) {
                            Ok(CloudWebSocketMessage::Event { event }) => {
                                if event_tx.send(event).await.is_err() {
                                    break;
                                }
                            }
                            Ok(CloudWebSocketMessage::Error { message }) => {
                                error!("Cloud execution error: {}", message);
                                let _ = event_tx
                                    .send(CommandEvent::Failed {
                                        command_id,
                                        error: message,
                                        duration_ms: 0,
                                        timestamp: chrono::Utc::now(),
                                    })
                                    .await;
                                break;
                            }
                            _ => {}
                        }
                    }
                    Ok(Message::Close(_)) => break,
                    Err(e) => {
                        error!("WebSocket read error: {}", e);
                        break;
                    }
                    _ => {}
                }
            }
        });

        // Wait for both tasks
        tokio::select! {
            _ = write_task => {}
            _ = read_task => {}
        }

        Ok(())
    }

    async fn execute_cloud(
        request: CommandRequest,
        event_tx: mpsc::Sender<CommandEvent>,
        executor: CloudCommandExecutor,
    ) -> Result<(), UbiquityError> {
        let command_id = request.id;

        // Create durable object
        let response = executor.create_durable_object(request).await?;

        // Connect to WebSocket for streaming events
        executor
            .connect_websocket(&response.websocket_url, command_id, event_tx)
            .await
    }
}

#[async_trait]
impl CommandExecutor for CloudCommandExecutor {
    async fn execute(
        &self,
        request: CommandRequest,
    ) -> Result<Pin<Box<dyn Stream<Item = CommandEvent> + Send>>, UbiquityError> {
        let (event_tx, event_rx) = mpsc::channel(self.event_buffer_size);
        let (cancel_tx, _cancel_rx) = mpsc::channel(1);
        let (status_tx, _status_rx) = mpsc::channel(1);

        let command_id = request.id;
        let handle = CommandHandle::new(command_id, cancel_tx, status_tx);
        
        // Register the command
        self.context.register(command_id, handle).await;

        // Clone executor for the spawned task
        let executor = self.clone();
        let context = self.context.clone();

        // Spawn the execution task
        tokio::spawn(async move {
            let result = Self::execute_cloud(request, event_tx, executor).await;
            
            // Unregister the command when done
            context.unregister(&command_id).await;
            
            if let Err(e) = result {
                error!("Cloud command execution error: {}", e);
            }
        });

        Ok(Box::pin(tokio_stream::wrappers::ReceiverStream::new(event_rx)))
    }

    async fn cancel(&self, command_id: Uuid) -> Result<(), UbiquityError> {
        // Send cancel request to durable object
        let url = format!("{}/api/commands/{}/cancel", self.worker_url, command_id);
        
        let response = self
            .client
            .post(&url)
            .header("Authorization", format!("Bearer {}", self.api_token))
            .send()
            .await
            .map_err(|e| UbiquityError::Network(format!("Failed to cancel command: {}", e)))?;

        if !response.status().is_success() {
            let status = response.status();
            let body = response.text().await.unwrap_or_default();
            return Err(UbiquityError::CloudExecution(format!(
                "Failed to cancel command: {} - {}",
                status, body
            )));
        }

        Ok(())
    }

    async fn status(&self, command_id: Uuid) -> Result<Option<CommandResult>, UbiquityError> {
        // Query durable object for status
        let url = format!("{}/api/commands/{}/status", self.worker_url, command_id);
        
        let response = self
            .client
            .get(&url)
            .header("Authorization", format!("Bearer {}", self.api_token))
            .send()
            .await
            .map_err(|e| UbiquityError::Network(format!("Failed to get command status: {}", e)))?;

        if response.status() == 404 {
            return Ok(None);
        }

        if !response.status().is_success() {
            let status = response.status();
            let body = response.text().await.unwrap_or_default();
            return Err(UbiquityError::CloudExecution(format!(
                "Failed to get command status: {} - {}",
                status, body
            )));
        }

        let result = response
            .json::<CommandResult>()
            .await
            .map_err(|e| UbiquityError::Serialization(format!("Failed to parse status: {}", e)))?;

        Ok(Some(result))
    }
}

impl Clone for CloudCommandExecutor {
    fn clone(&self) -> Self {
        Self {
            context: self.context.clone(),
            event_buffer_size: self.event_buffer_size,
            client: self.client.clone(),
            worker_url: self.worker_url.clone(),
            api_token: self.api_token.clone(),
            namespace_id: self.namespace_id.clone(),
        }
    }
}

/// Cloudflare Worker implementation (to be deployed separately)
#[cfg(feature = "cloudflare-worker")]
pub mod worker {
    use super::*;
    
    #[durable_object]
    pub struct CommandDurableObject {
        state: State,
        env: Env,
        websockets: Vec<WebSocket>,
        command_result: Option<CommandResult>,
        event_history: Vec<CommandEvent>,
    }
    
    #[durable_object]
    impl DurableObject for CommandDurableObject {
        fn new(state: State, env: Env) -> Self {
            Self {
                state,
                env,
                websockets: Vec::new(),
                command_result: None,
                event_history: Vec::new(),
            }
        }
        
        async fn fetch(&mut self, req: Request) -> Result<Response> {
            let path = req.path();
            
            match path.as_str() {
                "/execute" => self.handle_execute(req).await,
                "/websocket" => self.handle_websocket(req).await,
                "/cancel" => self.handle_cancel(req).await,
                "/status" => self.handle_status(req).await,
                _ => Response::error("Not Found", 404),
            }
        }
    }
    
    impl CommandDurableObject {
        async fn handle_execute(&mut self, mut req: Request) -> Result<Response> {
            let request: CommandRequest = req.json().await?;
            
            // Start command execution in the background
            let event_tx = self.create_event_broadcaster();
            
            // Simulate command execution (in real implementation, this would
            // use a sandboxed environment or container)
            self.simulate_command_execution(request, event_tx).await;
            
            Response::ok("Command execution started")
        }
        
        async fn handle_websocket(&mut self, req: Request) -> Result<Response> {
            let pair = WebSocketPair::new()?;
            let server = pair.server;
            
            server.accept()?;
            self.websockets.push(server);
            
            Response::from_websocket(pair.client)
        }
        
        async fn handle_cancel(&mut self, _req: Request) -> Result<Response> {
            // Broadcast cancellation event
            let event = CommandEvent::Cancelled {
                command_id: self.get_command_id()?,
                duration_ms: 0,
                timestamp: chrono::Utc::now(),
            };
            
            self.broadcast_event(event).await;
            Response::ok("Command cancelled")
        }
        
        async fn handle_status(&mut self, _req: Request) -> Result<Response> {
            match &self.command_result {
                Some(result) => Response::ok(serde_json::to_string(result)?),
                None => Response::error("Command not found", 404),
            }
        }
        
        async fn simulate_command_execution(
            &mut self,
            request: CommandRequest,
            event_tx: mpsc::Sender<CommandEvent>,
        ) {
            // This is a simplified simulation
            // In production, this would execute in a secure sandbox
            
            let start = std::time::Instant::now();
            let command_id = request.id;
            
            // Send start event
            let _ = event_tx.send(CommandEvent::Started {
                command_id,
                command: request.command.clone(),
                args: request.args.clone(),
                timestamp: chrono::Utc::now(),
            }).await;
            
            // Simulate some output
            let _ = event_tx.send(CommandEvent::Stdout {
                command_id,
                data: format!("Executing: {} {}", request.command, request.args.join(" ")),
                timestamp: chrono::Utc::now(),
            }).await;
            
            // Simulate completion
            let duration_ms = start.elapsed().as_millis() as u64;
            let _ = event_tx.send(CommandEvent::Completed {
                command_id,
                exit_code: 0,
                duration_ms,
                timestamp: chrono::Utc::now(),
            }).await;
            
            // Store result
            self.command_result = Some(CommandResult {
                id: command_id,
                exit_code: Some(0),
                stdout: format!("Executed: {} {}", request.command, request.args.join(" ")),
                stderr: String::new(),
                duration_ms,
                cancelled: false,
            });
        }
        
        fn create_event_broadcaster(&self) -> mpsc::Sender<CommandEvent> {
            let (tx, mut rx) = mpsc::channel(100);
            
            let websockets = self.websockets.clone();
            wasm_bindgen_futures::spawn_local(async move {
                while let Some(event) = rx.recv().await {
                    let msg = CloudWebSocketMessage::Event { event };
                    let text = serde_json::to_string(&msg).unwrap();
                    
                    for ws in &websockets {
                        let _ = ws.send_with_str(&text);
                    }
                }
            });
            
            tx
        }
        
        async fn broadcast_event(&mut self, event: CommandEvent) {
            self.event_history.push(event.clone());
            
            let msg = CloudWebSocketMessage::Event { event };
            let text = serde_json::to_string(&msg).unwrap();
            
            self.websockets.retain(|ws| {
                ws.send_with_str(&text).is_ok()
            });
        }
        
        fn get_command_id(&self) -> Result<Uuid> {
            self.command_result
                .as_ref()
                .map(|r| r.id)
                .ok_or_else(|| Error::RustError("No command ID found".to_string()))
        }
    }
}

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

    #[tokio::test]
    async fn test_cloud_executor_creation() {
        let executor = CloudCommandExecutor::new(
            "https://example.workers.dev".to_string(),
            "test-token".to_string(),
            "test-namespace".to_string(),
        );

        assert_eq!(executor.worker_url, "https://example.workers.dev");
        assert_eq!(executor.api_token, "test-token");
        assert_eq!(executor.namespace_id, "test-namespace");
    }
}