robson-core 0.1.0

use std::collections::HashMap;
use std::sync::Arc;
use std::time::Duration;

use anyhow::Result;
use async_trait::async_trait;
use regex::Regex;
use sea_orm::DatabaseConnection;
use tracing::{debug, error, info, warn};
use uuid::Uuid;

use crate::llm::LlmProvider;
use crate::AppState;

/// Carries events emitted by Workers back through the SensoriumLoop to Gateways.
#[derive(Debug, Clone)]
pub struct ProcessEvent {
    pub id: Uuid,
    pub kind: ProcessEventKind,
    pub content: String,
}

#[derive(Debug, Clone)]
pub enum ProcessEventKind {
    Started,
    Progress,
    Completed,
    Failed,
}

impl ProcessEventKind {
    pub fn as_str(&self) -> &'static str {
        match self {
            ProcessEventKind::Started => "started",
            ProcessEventKind::Progress => "progress",
            ProcessEventKind::Completed => "completed",
            ProcessEventKind::Failed => "failed",
        }
    }
}

/// Carries messages between Gateways and the SensoriumLoop.
#[derive(Debug, Clone)]
pub struct MessageEvent {
    pub id: Uuid,
    pub kind: MessageEventKind,
    pub content: String,
    pub channel_id: String,
    pub user_id: String,
    pub thread_ts: Option<String>,
    /// The `conversations.id` that originated this event.
    /// Set by SensoriumLoop when dispatching inbound messages; used for routing
    /// `ProcessEvent` deliveries back to the correct gateway channel.
    pub conversation_id: Option<i32>,
}

#[derive(Debug, Clone)]
pub enum MessageEventKind {
    Received,
    Delivered,
}

impl ProcessEvent {
    pub fn started(content: impl Into<String>) -> Self {
        let content = content.into();
        debug!(kind = "started", preview = %&content[..content.len().min(80)], "ProcessEvent::started");
        Self {
            id: Uuid::new_v4(),
            kind: ProcessEventKind::Started,
            content,
        }
    }
    pub fn progress(content: impl Into<String>) -> Self {
        let content = content.into();
        debug!(kind = "progress", preview = %&content[..content.len().min(80)], "ProcessEvent::progress");
        Self {
            id: Uuid::new_v4(),
            kind: ProcessEventKind::Progress,
            content,
        }
    }
    pub fn completed(content: impl Into<String>) -> Self {
        let content = content.into();
        debug!(kind = "completed", preview = %&content[..content.len().min(80)], "ProcessEvent::completed");
        Self {
            id: Uuid::new_v4(),
            kind: ProcessEventKind::Completed,
            content,
        }
    }
    pub fn failed(content: impl Into<String>) -> Self {
        let content = content.into();
        debug!(kind = "failed", preview = %&content[..content.len().min(80)], "ProcessEvent::failed");
        Self {
            id: Uuid::new_v4(),
            kind: ProcessEventKind::Failed,
            content,
        }
    }
}

impl MessageEvent {
    pub fn received(
        content: impl Into<String>,
        channel_id: impl Into<String>,
        user_id: impl Into<String>,
    ) -> Self {
        Self {
            id: Uuid::new_v4(),
            kind: MessageEventKind::Received,
            content: content.into(),
            channel_id: channel_id.into(),
            user_id: user_id.into(),
            thread_ts: None,
            conversation_id: None,
        }
    }

    pub fn with_thread_ts(mut self, thread_ts: impl Into<String>) -> Self {
        self.thread_ts = Some(thread_ts.into());
        self
    }

    /// Set the target channel for delivery routing (gateway_channel_id from the conversation).
    pub fn with_channel(mut self, channel_id: impl Into<String>) -> Self {
        self.channel_id = channel_id.into();
        self
    }

    /// Attach the originating conversation id for downstream routing.
    pub fn with_conversation_id(mut self, id: i32) -> Self {
        self.conversation_id = Some(id);
        self
    }

    pub fn delivered(content: impl Into<String>) -> Self {
        Self {
            id: Uuid::new_v4(),
            kind: MessageEventKind::Delivered,
            content: content.into(),
            channel_id: String::new(),
            user_id: String::new(),
            thread_ts: None,
            conversation_id: None,
        }
    }
}

/// Common interface for all agent gateways (TUI, Slack, etc.).
///
/// Implementors provide access to their config, shared state, and optional LLM.
/// The `on_message` method is called whenever an inbound message is received;
/// the default implementation saves it to the `conversations` table.
#[async_trait]
pub trait AgentGateway: Send + Sync {
    type Config: Send + Sync;

    fn config(&self) -> &Self::Config;
    fn state(&self) -> Option<&AppState>;
    fn llm(&self) -> Option<&dyn LlmProvider>;

    async fn on_message(&self, event: MessageEvent) -> Result<()> {
        use crate::entities::conversation::{ConversationRole, Model as Conversation};
        if let Some(state) = self.state() {
            let thread = event.thread_ts.as_deref().unwrap_or("");
            Conversation::insert(
                &state.db,
                None, // gateway_id unknown in the legacy AgentGateway path
                &event.channel_id,
                thread,
                &event.user_id,
                ConversationRole::User,
                &event.content,
            )
            .await?;
        }
        Ok(())
    }
}

/// A Worker receives a MessageEvent from the SensoriumLoop and handles it.
///
/// # Contract
/// - The worker writes any `ProcessEvent`s it generates to the `process_events` table via `db`.
/// - Return `Ok(true)` if the message was accepted and handled, `Ok(false)` to pass.
#[async_trait]
pub trait Worker: Send + Sync {
    /// Human-readable name used in log output to identify this worker.
    fn name(&self) -> &'static str;
    /// One-line description shown in /help output.
    fn description(&self) -> &'static str;
    /// Example invocation shown in /help output (e.g. "`/task list`").
    fn example(&self) -> &'static str;
    async fn handle(
        &self,
        db: DatabaseConnection,
        msg: MessageEvent,
        args: HashMap<String, String>,
    ) -> Result<bool>;
}

/// Parse key=value pairs from a Slack message content string.
/// Strips a leading bot-mention (`<@Uxxxx>`) and the command token before parsing.
/// Keys are lowercased. Quoted values (`key="value with spaces"`) are supported.
pub fn parse_kv(content: &str) -> HashMap<String, String> {
    let s = content.trim();
    let s = if s.starts_with("<@") {
        s.find('>').map(|i| s[i + 1..].trim_start()).unwrap_or(s)
    } else {
        s
    };
    let s = if s.starts_with('/') {
        match s.split_once(|c: char| c.is_whitespace()) {
            Some((_, rest)) => rest.trim(),
            None => "",
        }
    } else {
        s
    };
    let s = {
        let trimmed = s.trim();
        match trimmed.split_once(|c: char| c.is_whitespace()) {
            Some((first, rest)) if !first.contains('=') => rest.trim(),
            _ => trimmed,
        }
    };
    parse_kv_pairs(s)
}

fn parse_kv_pairs(input: &str) -> HashMap<String, String> {
    let mut map = HashMap::new();
    let mut chars = input.chars().peekable();
    loop {
        // skip whitespace
        while chars.peek().map(|c| c.is_whitespace()).unwrap_or(false) {
            chars.next();
        }
        if chars.peek().is_none() {
            break;
        }
        // collect key
        let mut key = String::new();
        let mut has_eq = false;
        loop {
            match chars.peek() {
                Some(&'=') => {
                    chars.next();
                    has_eq = true;
                    break;
                }
                Some(&c) if c.is_whitespace() => break,
                Some(&c) => {
                    key.push(c);
                    chars.next();
                }
                None => break,
            }
        }
        if key.is_empty() {
            break;
        }
        if !has_eq {
            // bare token with no '=', skip it
            continue;
        }
        // collect value
        let value = match chars.peek() {
            Some(&'"') => {
                chars.next();
                let mut v = String::new();
                loop {
                    match chars.next() {
                        Some('"') => break,
                        Some(c) => v.push(c),
                        None => break,
                    }
                }
                v
            }
            _ => {
                let mut v = String::new();
                while chars.peek().map(|c| !c.is_whitespace()).unwrap_or(false) {
                    v.push(chars.next().unwrap());
                }
                v
            }
        };
        map.insert(key.to_lowercase(), value);
    }
    map
}

/// Builds the formatted /help response from the registered workers list.
pub fn build_help_response(workers: &[WorkerRegistration]) -> String {
    let mut out = String::from(":book: *Robson \u{2014} Available Commands*\n\n");
    for reg in workers {
        out.push_str(&format!(
            "{} \u{2014} {}\n",
            reg.worker.example(),
            reg.worker.description()
        ));
    }
    out
}

pub struct WorkerRegistration {
    pub pattern: Regex,
    pub worker: Arc<dyn Worker>,
}

/// A Gateway bridges the sensorium loop with an external communication channel
/// (Slack, HTTP webhook, chat TUI, etc).
#[async_trait]
pub trait Gateway: Send + Sync {
    /// Unique, stable identifier for this gateway (e.g. "slack", "tui").
    /// Used as the key in `process_event_deliveries` to track per-gateway delivery state.
    fn name(&self) -> &'static str;

    /// Deliver a message to the external system (called for each ProcessEvent).
    async fn send(&self, msg: MessageEvent) -> Result<()>;

    /// Start listening for inbound messages, writing them directly to the `conversations` table.
    /// This is expected to run until the gateway shuts down.
    async fn start(&self, db: DatabaseConnection) -> Result<()>;
}

/// The SensoriumLoop orchestrates workers and gateways.
///
/// Flow:
///   Gateway.start(db) → writes to conversations (processed=false)
///   → Loop 1: polls conversations → matches message content against registered worker patterns
///             in registration order; first match wins and is dispatched via tokio::spawn
///   → Workers write ProcessEvents to process_events table
///   → Loop 2: polls process_event_deliveries → retries delivery per gateway
pub struct SensoriumLoop {
    workers: Vec<WorkerRegistration>,
    gateways: Vec<Arc<dyn Gateway>>,
    conversations_poll_interval_secs: u64,
    process_event_deliveries_poll_interval_secs: u64,
    help_re: Regex,
}

impl Default for SensoriumLoop {
    fn default() -> Self {
        Self::new()
    }
}

impl SensoriumLoop {
    pub fn new() -> Self {
        info!("SensoriumLoop created");
        Self {
            workers: Vec::new(),
            gateways: Vec::new(),
            conversations_poll_interval_secs: 1,
            process_event_deliveries_poll_interval_secs: 1,
            help_re: Regex::new(r"(?i)(^<@\S+>\s*)?/help\b").expect("help regex is valid"),
        }
    }

    pub fn with_conversations_poll_interval(mut self, secs: u64) -> Self {
        info!(
            conversations_poll_interval_secs = secs,
            "SensoriumLoop conversations poll interval set"
        );
        self.conversations_poll_interval_secs = secs;
        self
    }

    pub fn with_process_event_deliveries_poll_interval(mut self, secs: u64) -> Self {
        info!(
            process_event_deliveries_poll_interval_secs = secs,
            "SensoriumLoop deliveries poll interval set"
        );
        self.process_event_deliveries_poll_interval_secs = secs;
        self
    }

    pub fn register_worker(&mut self, pattern: &str, worker: Arc<dyn Worker>) -> Result<()> {
        let compiled = Regex::new(pattern)
            .map_err(|e| anyhow::anyhow!("invalid worker pattern {:?}: {}", pattern, e))?;
        let help_probes = ["/help", "/HELP", "<@U1234> /help", "<@U1234> /HELP"];
        if help_probes.iter().any(|s| compiled.is_match(s)) {
            return Err(anyhow::anyhow!(
                "worker pattern {:?} collides with the reserved /help command",
                pattern
            ));
        }
        if let Some(existing) = self.workers.iter().find(|r| r.pattern.as_str() == pattern) {
            return Err(anyhow::anyhow!(
                "worker pattern {:?} already registered by worker {:?}",
                pattern,
                existing.worker.name()
            ));
        }
        debug!(
            worker = worker.name(),
            pattern,
            total_workers = self.workers.len() + 1,
            "Worker registered"
        );
        self.workers.push(WorkerRegistration {
            pattern: compiled,
            worker,
        });
        Ok(())
    }

    pub fn workers(&self) -> &[WorkerRegistration] {
        &self.workers
    }

    pub fn register_gateway(&mut self, gateway: Arc<dyn Gateway>) {
        let idx = self.gateways.len();
        debug!(
            gateway = gateway.name(),
            gateway_index = idx,
            total_gateways = idx + 1,
            "Gateway registered"
        );
        self.gateways.push(gateway);
    }

    pub async fn run(self, db: DatabaseConnection) -> Result<()> {
        use crate::entities::conversation::Model as Conversation;
        use crate::entities::process_event::Model as ProcessEventModel;
        use crate::entities::process_event_deliveries::Model as Delivery;

        let workers = Arc::new(self.workers);
        let gateways = Arc::new(self.gateways);
        let help_re = Arc::new(self.help_re);
        let conversations_poll_interval =
            Duration::from_secs(self.conversations_poll_interval_secs);
        let deliveries_poll_interval =
            Duration::from_secs(self.process_event_deliveries_poll_interval_secs);

        info!(
            worker_count = workers.len(),
            gateway_count = gateways.len(),
            conversations_poll_interval_secs = self.conversations_poll_interval_secs,
            process_event_deliveries_poll_interval_secs =
                self.process_event_deliveries_poll_interval_secs,
            "SensoriumLoop starting"
        );

        // Start all gateways — each writes inbound messages to the conversations table
        for (idx, gateway) in gateways.iter().enumerate() {
            let gateway = gateway.clone();
            let db_clone = db.clone();
            debug!(
                gateway = gateway.name(),
                gateway_index = idx,
                "Spawning gateway listener"
            );
            tokio::spawn(async move {
                if let Err(e) = gateway.start(db_clone).await {
                    error!(error = %e, gateway_index = idx, "gateway stopped with error");
                }
            });
        }

        info!(
            gateway_count = gateways.len(),
            "All gateways spawned, starting poll loops"
        );

        // Loop 2: delivery poll — forwards process_events to gateways with per-gateway retry/backoff
        let gateways_delivery = gateways.clone();
        let db_delivery = db.clone();
        tokio::spawn(async move {
            loop {
                // Ensure every undelivered process_event has a delivery row per registered gateway,
                // then attempt delivery for rows whose retry window has elapsed.
                let undelivered_events = match ProcessEventModel::find_undelivered(&db_delivery)
                    .await
                {
                    Ok(rows) => rows,
                    Err(e) => {
                        warn!(error = %e, "delivery poll: failed to query undelivered process_events");
                        tokio::time::sleep(deliveries_poll_interval).await;
                        continue;
                    }
                };

                for event in &undelivered_events {
                    // Resolve the originating conversation and its gateway
                    let conv = match Conversation::find_by_id(&db_delivery, event.conversation_id)
                        .await
                    {
                        Ok(Some(c)) => c,
                        Ok(None) => {
                            debug!(
                                process_event_id = event.id,
                                conversation_id = event.conversation_id,
                                "delivery poll: conversation not found, skipping"
                            );
                            continue;
                        }
                        Err(e) => {
                            warn!(error = %e, process_event_id = event.id, "delivery poll: failed to load conversation");
                            continue;
                        }
                    };

                    // Determine target gateway: use conversation's gateway_id if set,
                    // otherwise broadcast to all registered gateways (legacy path).
                    let target_gateways: Vec<_> = match conv.gateway_id {
                        Some(gw_id) => {
                            use crate::entities::gateway::Model as GatewayModel;
                            match GatewayModel::find_by_id(&db_delivery, gw_id).await {
                                Ok(Some(gw_row)) => gateways_delivery
                                    .iter()
                                    .filter(|g| g.name() == gw_row.name)
                                    .cloned()
                                    .collect(),
                                _ => {
                                    warn!(
                                        process_event_id = event.id,
                                        gateway_id = gw_id,
                                        "delivery poll: gateway row not found, skipping"
                                    );
                                    continue;
                                }
                            }
                        }
                        None => gateways_delivery.iter().cloned().collect(),
                    };

                    for gateway in target_gateways.iter() {
                        let gateway_name = gateway.name();

                        // Ensure a delivery row exists for this (event, gateway) pair
                        let delivery_id =
                            match Delivery::upsert_pending(&db_delivery, event.id, gateway_name)
                                .await
                            {
                                Ok(id) => id,
                                Err(e) => {
                                    warn!(
                                        error = %e,
                                        process_event_id = event.id,
                                        gateway = gateway_name,
                                        "delivery poll: failed to upsert delivery record"
                                    );
                                    continue;
                                }
                            };

                        // Check eligibility: undelivered and retry window elapsed
                        let pending =
                            match Delivery::find_pending_for_gateway(&db_delivery, gateway_name)
                                .await
                            {
                                Ok(rows) => rows,
                                Err(e) => {
                                    warn!(
                                        error = %e,
                                        gateway = gateway_name,
                                        "delivery poll: failed to find pending deliveries"
                                    );
                                    continue;
                                }
                            };

                        let is_eligible = pending.iter().any(|r| r.id == delivery_id);
                        if !is_eligible {
                            debug!(
                                process_event_id = event.id,
                                gateway = gateway_name,
                                delivery_id,
                                "delivery poll: skipping — within backoff window"
                            );
                            continue;
                        }

                        // Attempt delivery; pass gateway_channel_id so the gateway
                        // routes to the originating channel rather than a default.
                        let msg = MessageEvent::delivered(event.content.clone())
                            .with_channel(conv.gateway_channel_id.clone());
                        match gateway.send(msg).await {
                            Ok(_) => {
                                debug!(
                                    process_event_id = event.id,
                                    gateway = gateway_name,
                                    "delivery poll: delivered successfully"
                                );
                                if let Err(e) =
                                    Delivery::mark_delivered(&db_delivery, delivery_id).await
                                {
                                    warn!(error = %e, delivery_id, "delivery poll: failed to mark delivery record");
                                }

                                // Check if all gateways have now delivered this event
                                match Delivery::count_pending_for_event(&db_delivery, event.id)
                                    .await
                                {
                                    Ok(0) => {
                                        if let Err(e) = ProcessEventModel::mark_delivered(
                                            &db_delivery,
                                            event.id,
                                        )
                                        .await
                                        {
                                            warn!(
                                                error = %e,
                                                process_event_id = event.id,
                                                "delivery poll: failed to mark process_event delivered"
                                            );
                                        } else {
                                            info!(
                                                process_event_id = event.id,
                                                "delivery poll: all gateways delivered — process_event marked done"
                                            );
                                        }
                                    }
                                    Ok(pending_count) => {
                                        debug!(
                                            process_event_id = event.id,
                                            pending_count,
                                            "delivery poll: still waiting on other gateways"
                                        );
                                    }
                                    Err(e) => {
                                        warn!(
                                            error = %e,
                                            process_event_id = event.id,
                                            "delivery poll: failed to count pending deliveries"
                                        );
                                    }
                                }
                            }
                            Err(e) => {
                                warn!(
                                    error = %e,
                                    process_event_id = event.id,
                                    gateway = gateway_name,
                                    "delivery poll: delivery failed, scheduling retry"
                                );
                                if let Err(re) = Delivery::record_failure(
                                    &db_delivery,
                                    delivery_id,
                                    &format!("{:#}", e),
                                )
                                .await
                                {
                                    warn!(error = %re, delivery_id, "delivery poll: failed to record failure");
                                }
                            }
                        }
                    }
                }

                tokio::time::sleep(deliveries_poll_interval).await;
            }
        });

        // Loop 1: conversations poll — dispatches inbound messages to workers
        loop {
            let unprocessed = match Conversation::find_unprocessed(&db).await {
                Ok(rows) => rows,
                Err(e) => {
                    warn!(error = %e, "conversations poll: failed to query unprocessed conversations");
                    tokio::time::sleep(conversations_poll_interval).await;
                    continue;
                }
            };

            if !unprocessed.is_empty() {
                debug!(
                    count = unprocessed.len(),
                    "conversations poll: found unprocessed rows"
                );
            }

            for row in unprocessed {
                let conversation_id = row.id;
                let msg = MessageEvent {
                    id: Uuid::new_v4(),
                    kind: MessageEventKind::Received,
                    content: row.content.clone(),
                    channel_id: row.gateway_channel_id.clone(),
                    user_id: row.user_id.clone(),
                    thread_ts: if row.thread_ts.is_empty() {
                        None
                    } else {
                        Some(row.thread_ts.clone())
                    },
                    conversation_id: Some(conversation_id),
                };

                info!(
                    conversation_id,
                    channel_id = %row.gateway_channel_id,
                    user_id = %row.user_id,
                    thread_ts = ?msg.thread_ts,
                    preview = %&row.content[..row.content.len().min(80)],
                    "Conversation picked up for dispatch"
                );

                // Intercept /help before dispatching to workers
                if help_re.is_match(&msg.content) {
                    let response = build_help_response(&workers);
                    if let Some(conv_id) = msg.conversation_id {
                        let db_h = db.clone();
                        tokio::spawn(async move {
                            if let Err(e) = crate::entities::process_event::Model::insert(
                                &db_h,
                                conv_id,
                                ProcessEventKind::Completed.as_str(),
                                &response,
                            )
                            .await
                            {
                                warn!(error = %e, conversation_id = conv_id, "help: failed to persist process event");
                            }
                        });
                    }
                    if let Err(e) = Conversation::mark_processed(&db, conversation_id).await {
                        warn!(error = %e, conversation_id, "conversations poll: failed to mark conversation as processed");
                    }
                    continue;
                }

                // Mark processed before dispatching so a restart won't re-deliver
                if let Err(e) = Conversation::mark_processed(&db, conversation_id).await {
                    warn!(error = %e, conversation_id, "conversations poll: failed to mark conversation as processed");
                    continue;
                }

                // Find first worker whose pattern matches message content
                let matched = workers.iter().find(|r| r.pattern.is_match(&msg.content));

                match matched {
                    Some(registration) => {
                        let args = parse_kv(&msg.content);
                        let worker = registration.worker.clone();
                        let worker_name = worker.name();
                        debug!(
                            worker = worker_name,
                            conversation_id,
                            pattern = registration.pattern.as_str(),
                            "Dispatching to matched worker"
                        );
                        let db_w = db.clone();
                        let msg = msg.clone();
                        tokio::spawn(async move {
                            match worker.handle(db_w, msg, args).await {
                                Ok(_) => {
                                    info!(worker = worker_name, conversation_id, "Worker completed")
                                }
                                Err(e) => {
                                    error!(error = %e, worker = worker_name, conversation_id, "Worker failed")
                                }
                            }
                        });
                    }
                    None => {
                        warn!(conversation_id, preview = %&row.content[..row.content.len().min(80)], "No worker matched message, skipping");
                    }
                }
            }

            tokio::time::sleep(conversations_poll_interval).await;
        }
    }
}

#[cfg(test)]
#[path = "plugin_tests.rs"]
mod plugin_tests;