mod access;
mod ai_common;
mod ai_nonstreaming;
mod ai_react_nonstreaming;
mod ai_react_streaming;
mod ai_streaming;
mod history;
mod mentions;
mod notifications;
mod patterns;
mod sequence;
mod workers;

pub use access::{check_room_access, check_project_member, require_room_member, find_room_or_404};
pub use ai_common::create_and_publish_ai_message;
pub use ai_nonstreaming::process_message_ai_nonstreaming;
pub use ai_react_nonstreaming::process_message_ai_react_nonstreaming;
pub use ai_react_streaming::process_message_ai_react_streaming;
pub use ai_streaming::process_message_ai_streaming;
pub use history::{get_room_history, get_user_names, get_room_ai_config, extract_mention_context};
pub use mentions::extract_mentions;
pub use notifications::{notify_project_members, publish_room_event};
pub use sequence::next_room_message_seq_internal;
pub use workers::{start_workers, spawn_agent_task, spawn_room_workers, PushNotificationFn};

use std::sync::Arc;

use chrono::Utc;
use db::cache::AppCache;
use db::database::AppDatabase;
use models::rooms::room;
use models::rooms::room_ai;
use queue::{MessageProducer, ProjectRoomEvent};
use sea_orm::{ColumnTrait, EntityTrait, QueryFilter};
use uuid::Uuid;

use crate::connection::{RoomConnectionManager, DedupCache};
use crate::error::RoomError;
use agent::chat::{AiRequest, ChatService};
use agent::embed::EmbedService;
use agent::TaskService;
use models::agent_task::AgentType;

use crate::service::patterns::{mention_bracket_re, mention_tag_re};

const DEFAULT_MAX_CONCURRENT_WORKERS: usize = 1024;

#[derive(Clone)]
pub struct RoomService {
    pub db: AppDatabase,
    pub cache: AppCache,
    pub config: config::AppConfig,
    pub room_manager: Arc<RoomConnectionManager>,
    pub queue: MessageProducer,
    pub redis_url: String,
    pub chat_service: Option<Arc<ChatService>>,
    pub task_service: Option<Arc<TaskService>>,
    pub embed_service: Option<Arc<EmbedService>>,
    pub push_fn: Option<workers::PushNotificationFn>,
    worker_semaphore: Arc<tokio::sync::Semaphore>,
    dedup_cache: DedupCache,
}

impl RoomService {
    pub fn new(
        db: AppDatabase,
        cache: AppCache,
        config: config::AppConfig,
        queue: MessageProducer,
        room_manager: Arc<RoomConnectionManager>,
        redis_url: String,
        chat_service: Option<Arc<ChatService>>,
        task_service: Option<Arc<TaskService>>,
        max_concurrent_workers: Option<usize>,
        push_fn: Option<workers::PushNotificationFn>,
        embed_service: Option<Arc<EmbedService>>,
    ) -> Self {
        let dedup_cache: DedupCache =
            Arc::new(dashmap::DashMap::with_capacity_and_hasher(10000, Default::default()));
        Self {
            db,
            cache,
            config,
            room_manager,
            queue,
            redis_url,
            chat_service,
            task_service,
            embed_service,
            worker_semaphore: Arc::new(tokio::sync::Semaphore::new(
                max_concurrent_workers.unwrap_or(DEFAULT_MAX_CONCURRENT_WORKERS),
            )),
            dedup_cache,
            push_fn,
        }
    }

    pub async fn start_workers(
        &self,
        shutdown_rx: tokio::sync::broadcast::Receiver<()>,
    ) -> anyhow::Result<()> {
        workers::start_workers(
            self.db.clone(),
            self.cache.clone(),
            self.room_manager.clone(),
            self.queue.clone(),
            self.redis_url.clone(),
            self.dedup_cache.clone(),
            self.task_service.clone(),
            None, // max_concurrent_workers handled by semaphore
            shutdown_rx,
            self.embed_service.clone(),
        )
        .await
    }

    pub async fn spawn_agent_task<F, Fut>(
        &self,
        project_id: Uuid,
        agent_type: AgentType,
        input: String,
        _title: Option<String>,
        execute: F,
    ) -> anyhow::Result<i64>
    where
        F: FnOnce(i64, Arc<TaskService>) -> Fut + Send + 'static,
        Fut: std::future::Future<Output = Result<String, String>> + Send,
    {
        let task_service = match &self.task_service {
            Some(ts) => ts.clone(),
            None => return Err(anyhow::anyhow!("task service not configured")),
        };

        workers::spawn_agent_task(
            project_id,
            agent_type,
            input,
            task_service,
            self.queue.clone(),
            self.room_manager.clone(),
            self.worker_semaphore.clone(),
            execute,
        )
        .await
    }

    pub fn spawn_room_workers(&self, room_id: uuid::Uuid) {
        workers::spawn_room_workers(
            room_id,
            self.db.clone(),
            self.room_manager.clone(),
            self.queue.clone(),
            self.redis_url.clone(),
            self.worker_semaphore.clone(),
            self.embed_service.clone(),
        );
    }

    pub async fn publish_room_event(
        &self,
        project_id: uuid::Uuid,
        event_type: super::RoomEventType,
        room_id: Option<uuid::Uuid>,
        category_id: Option<uuid::Uuid>,
        message_id: Option<uuid::Uuid>,
        seq: Option<i64>,
    ) {
        let event = ProjectRoomEvent {
            event_type: event_type.as_str().into(),
            project_id,
            room_id,
            category_id,
            message_id,
            seq,
            timestamp: Utc::now(),
        };
        self.queue
            .publish_project_room_event(project_id, event)
            .await;
    }

    pub fn notify_project_members(
        &self,
        project_id: uuid::Uuid,
        notification_type: super::NotificationType,
        title: String,
        content: Option<String>,
        related_room_id: Option<uuid::Uuid>,
    ) {
        notifications::notify_project_members(
            self.db.clone(),
            project_id,
            notification_type,
            title,
            content,
            related_room_id,
        );
    }

    pub fn extract_mentions(content: &str) -> Vec<Uuid> {
        mentions::extract_mentions(content)
    }

    pub async fn resolve_mentions(&self, content: &str) -> Vec<Uuid> {
        use models::users::User;
        use sea_orm::EntityTrait;

        let mut resolved: Vec<Uuid> = Vec::new();
        let mut seen_usernames: Vec<String> = Vec::new();

        for cap in mention_bracket_re().captures_iter(content) {
            if let (Some(type_m), Some(id_m)) = (cap.get(1), cap.get(2)) {
                if type_m.as_str() == "user" {
                    let id = id_m.as_str().trim();
                    if let Ok(uuid) = Uuid::parse_str(id) {
                        if !resolved.contains(&uuid) {
                            resolved.push(uuid);
                        }
                    } else if let Some(label_m) = cap.get(3) {
                        let label = label_m.as_str().trim();
                        if !label.is_empty() {
                            let label_lower = label.to_lowercase();
                            if seen_usernames.contains(&label_lower) {
                                continue;
                            }
                            seen_usernames.push(label_lower.clone());

                            if let Some(user) = User::find()
                                .filter(models::users::user::Column::Username.eq(label_lower))
                                .one(&self.db)
                                .await
                                .ok()
                                .flatten()
                            {
                                if !resolved.contains(&user.uid) {
                                    resolved.push(user.uid);
                                }
                            }
                        }
                    }
                }
            }
        }

        resolved
    }

    pub async fn check_room_access(&self, room_id: Uuid, user_id: Uuid) -> Result<(), RoomError> {
        access::check_room_access(&self.db, room_id, user_id).await
    }

    pub async fn check_project_member(
        &self,
        project_id: Uuid,
        user_id: Uuid,
    ) -> Result<(), RoomError> {
        access::check_project_member(&self.db, project_id, user_id).await
    }

    pub async fn should_ai_respond(&self, room_id: Uuid, content: &str) -> Result<bool, RoomError> {
        let ai_config = history::get_room_ai_config(&self.db, room_id).await?;

        let config = match ai_config {
            Some(c) => c,
            None => return Ok(false),
        };

        if !config.use_exact {
            return Ok(true);
        }

        let model_id_str = config.model.to_string();

        for cap in mention_bracket_re().captures_iter(content) {
            if let (Some(type_m), Some(id_m)) = (cap.get(1), cap.get(2)) {
                if type_m.as_str() == "ai" && id_m.as_str().trim() == model_id_str {
                    return Ok(true);
                }
            }
        }

        for cap in mention_tag_re().captures_iter(content) {
            if let (Some(type_m), Some(id_m)) = (cap.get(1), cap.get(2)) {
                if type_m.as_str() == "ai" && id_m.as_str().trim() == model_id_str {
                    return Ok(true);
                }
            }
        }

        Ok(false)
    }

    pub async fn get_room_ai_config(
        &self,
        room_id: Uuid,
    ) -> Result<Option<room_ai::Model>, RoomError> {
        history::get_room_ai_config(&self.db, room_id).await
    }

    pub async fn get_user_names(
        &self,
        user_ids: &[Uuid],
    ) -> std::collections::HashMap<Uuid, String> {
        history::get_user_names(&self.db, user_ids).await
    }

    pub async fn require_room_member(&self, room_id: Uuid, user_id: Uuid) -> Result<(), RoomError> {
        access::require_room_member(&self.db, room_id, user_id).await
    }

    pub async fn find_room_or_404(&self, room_id: Uuid) -> Result<room::Model, RoomError> {
        access::find_room_or_404(&self.db, room_id).await
    }

    pub async fn process_message_ai(
        &self,
        room_id: Uuid,
        _message_id: Uuid,
        sender_id: Uuid,
        content: String,
    ) -> Result<(), RoomError> {
        let Some(chat_service) = &self.chat_service else {
            return Ok(());
        };

        let Some(ai_config) = self.get_room_ai_config(room_id).await? else {
            return Ok(());
        };

        let Some(lock_guard) =
            crate::room_ai_queue::acquire_room_ai_lock(&self.cache, room_id).await?
        else {
            return Ok(());
        };

        let room = self.find_room_or_404(room_id).await?;

        let project = models::projects::project::Entity::find_by_id(room.project)
            .one(&self.db)
            .await?
            .ok_or_else(|| RoomError::NotFound("Project not found".to_string()))?;

        let mentioned_model_id = {
            let mut found = None;
            for cap in mention_bracket_re().captures_iter(&content) {
                if let (Some(type_m), Some(id_m)) = (cap.get(1), cap.get(2)) {
                    if type_m.as_str() == "ai" {
                        if let Ok(uuid) = Uuid::parse_str(id_m.as_str().trim()) {
                            found = Some(uuid);
                            break;
                        }
                    }
                }
            }
            found
        };

        let model_id = mentioned_model_id.unwrap_or(ai_config.model);
        let model = models::agents::model::Entity::find_by_id(model_id)
            .one(&self.db)
            .await?
            .ok_or_else(|| RoomError::NotFound("AI model not found".to_string()))?;

        let sender = models::users::User::find_by_id(sender_id)
            .one(&self.db)
            .await?
            .ok_or_else(|| RoomError::NotFound("Sender not found".to_string()))?;

        let history = history::get_room_history(&self.db, room_id, 50).await?;

        let user_ids: Vec<Uuid> = history
            .iter()
            .filter_map(|m| m.sender_id)
            .chain(std::iter::once(sender_id))
            .collect();
        let user_names = self.get_user_names(&user_ids).await;

        let mentions = history::extract_mention_context(&self.db, room.project, &content).await;

        let request = AiRequest {
            db: self.db.clone(),
            cache: self.cache.clone(),
            config: self.config.clone(),
            model,
            project: project.clone(),
            sender,
            room: room.clone(),
            input: content,
            mention: mentions,
            history,
            user_names,
            temperature: ai_config.temperature.unwrap_or(0.7),
            max_tokens: ai_config.max_tokens.unwrap_or(4096) as i32,
            top_p: 1.0,
            frequency_penalty: 0.0,
            presence_penalty: 0.0,
            think: ai_config.think,
            tools: Some(chat_service.tools()),
            max_tool_depth: 1000,
        };

        let use_streaming = ai_config.stream;
        let is_react = ai_config.agent_type.as_deref() == Some("react");

        if is_react {
            if use_streaming {
                ai_react_streaming::process_message_ai_react_streaming(
                    chat_service.clone(),
                    request,
                    room_id,
                    room.project,
                    model_id,
                    lock_guard,
                    self.db.clone(),
                    self.cache.clone(),
                    self.queue.clone(),
                    self.room_manager.clone(),
                )
                .await;
            } else {
                ai_react_nonstreaming::process_message_ai_react_nonstreaming(
                    chat_service.clone(),
                    request,
                    room_id,
                    room.project,
                    model_id,
                    lock_guard,
                    self.db.clone(),
                    self.cache.clone(),
                    self.queue.clone(),
                    self.room_manager.clone(),
                )
                .await;
            }
        } else if use_streaming {
            ai_streaming::process_message_ai_streaming(
                chat_service.clone(),
                request,
                room_id,
                room.project,
                model_id,
                lock_guard,
                self.db.clone(),
                self.cache.clone(),
                self.queue.clone(),
                self.room_manager.clone(),
            )
            .await;
        } else {
            ai_nonstreaming::process_message_ai_nonstreaming(
                chat_service.clone(),
                request,
                room_id,
                room.project,
                model_id,
                lock_guard,
                self.db.clone(),
                self.cache.clone(),
                self.queue.clone(),
                self.room_manager.clone(),
            )
            .await;
        }

        Ok(())
    }
}