mod participant;
pub mod room;

use anyhow::{anyhow, Result};
use client::{proto, Client, TypedEnvelope, User, UserStore};
use gpui::{
    AppContext, AsyncAppContext, Entity, ModelContext, ModelHandle, MutableAppContext,
    Subscription, Task,
};
pub use participant::ParticipantLocation;
use postage::watch;
use project::Project;
pub use room::Room;
use std::sync::Arc;

pub fn init(client: Arc<Client>, user_store: ModelHandle<UserStore>, cx: &mut MutableAppContext) {
    let active_call = cx.add_model(|cx| ActiveCall::new(client, user_store, cx));
    cx.set_global(active_call);
}

#[derive(Clone)]
pub struct IncomingCall {
    pub room_id: u64,
    pub caller: Arc<User>,
    pub participants: Vec<Arc<User>>,
    pub initial_project_id: Option<u64>,
}

pub struct ActiveCall {
    room: Option<(ModelHandle<Room>, Vec<Subscription>)>,
    incoming_call: (
        watch::Sender<Option<IncomingCall>>,
        watch::Receiver<Option<IncomingCall>>,
    ),
    client: Arc<Client>,
    user_store: ModelHandle<UserStore>,
    _subscriptions: Vec<client::Subscription>,
}

impl Entity for ActiveCall {
    type Event = room::Event;
}

impl ActiveCall {
    fn new(
        client: Arc<Client>,
        user_store: ModelHandle<UserStore>,
        cx: &mut ModelContext<Self>,
    ) -> Self {
        Self {
            room: None,
            incoming_call: watch::channel(),
            _subscriptions: vec![
                client.add_request_handler(cx.handle(), Self::handle_incoming_call),
                client.add_message_handler(cx.handle(), Self::handle_call_canceled),
            ],
            client,
            user_store,
        }
    }

    async fn handle_incoming_call(
        this: ModelHandle<Self>,
        envelope: TypedEnvelope<proto::IncomingCall>,
        _: Arc<Client>,
        mut cx: AsyncAppContext,
    ) -> Result<proto::Ack> {
        let user_store = this.read_with(&cx, |this, _| this.user_store.clone());
        let call = IncomingCall {
            room_id: envelope.payload.room_id,
            participants: user_store
                .update(&mut cx, |user_store, cx| {
                    user_store.get_users(envelope.payload.participant_user_ids, cx)
                })
                .await?,
            caller: user_store
                .update(&mut cx, |user_store, cx| {
                    user_store.get_user(envelope.payload.caller_user_id, cx)
                })
                .await?,
            initial_project_id: envelope.payload.initial_project_id,
        };
        this.update(&mut cx, |this, _| {
            *this.incoming_call.0.borrow_mut() = Some(call);
        });

        Ok(proto::Ack {})
    }

    async fn handle_call_canceled(
        this: ModelHandle<Self>,
        _: TypedEnvelope<proto::CallCanceled>,
        _: Arc<Client>,
        mut cx: AsyncAppContext,
    ) -> Result<()> {
        this.update(&mut cx, |this, _| {
            *this.incoming_call.0.borrow_mut() = None;
        });
        Ok(())
    }

    pub fn global(cx: &AppContext) -> ModelHandle<Self> {
        cx.global::<ModelHandle<Self>>().clone()
    }

    pub fn invite(
        &mut self,
        recipient_user_id: u64,
        initial_project: Option<ModelHandle<Project>>,
        cx: &mut ModelContext<Self>,
    ) -> Task<Result<()>> {
        let room = self.room.as_ref().map(|(room, _)| room.clone());
        let client = self.client.clone();
        let user_store = self.user_store.clone();
        cx.spawn(|this, mut cx| async move {
            let room = if let Some(room) = room {
                room
            } else {
                cx.update(|cx| Room::create(client, user_store, cx)).await?
            };

            let initial_project_id = if let Some(initial_project) = initial_project {
                let room_id = room.read_with(&cx, |room, _| room.id());
                Some(
                    initial_project
                        .update(&mut cx, |project, cx| project.share(room_id, cx))
                        .await?,
                )
            } else {
                None
            };

            this.update(&mut cx, |this, cx| this.set_room(Some(room.clone()), cx));
            room.update(&mut cx, |room, cx| {
                room.call(recipient_user_id, initial_project_id, cx)
            })
            .await?;

            Ok(())
        })
    }

    pub fn cancel_invite(
        &mut self,
        recipient_user_id: u64,
        cx: &mut ModelContext<Self>,
    ) -> Task<Result<()>> {
        let client = self.client.clone();
        cx.foreground().spawn(async move {
            client
                .request(proto::CancelCall { recipient_user_id })
                .await?;
            anyhow::Ok(())
        })
    }

    pub fn incoming(&self) -> watch::Receiver<Option<IncomingCall>> {
        self.incoming_call.1.clone()
    }

    pub fn accept_incoming(&mut self, cx: &mut ModelContext<Self>) -> Task<Result<()>> {
        if self.room.is_some() {
            return Task::ready(Err(anyhow!("cannot join while on another call")));
        }

        let call = if let Some(call) = self.incoming_call.1.borrow().clone() {
            call
        } else {
            return Task::ready(Err(anyhow!("no incoming call")));
        };

        let join = Room::join(&call, self.client.clone(), self.user_store.clone(), cx);
        cx.spawn(|this, mut cx| async move {
            let room = join.await?;
            this.update(&mut cx, |this, cx| this.set_room(Some(room.clone()), cx));
            Ok(())
        })
    }

    pub fn decline_incoming(&mut self) -> Result<()> {
        *self.incoming_call.0.borrow_mut() = None;
        self.client.send(proto::DeclineCall {})?;
        Ok(())
    }

    pub fn hang_up(&mut self, cx: &mut ModelContext<Self>) -> Result<()> {
        if let Some((room, _)) = self.room.take() {
            room.update(cx, |room, cx| room.leave(cx))?;
        }
        Ok(())
    }

    fn set_room(&mut self, room: Option<ModelHandle<Room>>, cx: &mut ModelContext<Self>) {
        if room.as_ref() != self.room.as_ref().map(|room| &room.0) {
            if let Some(room) = room {
                let subscriptions = vec![
                    cx.observe(&room, |_, _, cx| cx.notify()),
                    cx.subscribe(&room, |_, _, event, cx| cx.emit(event.clone())),
                ];
                self.room = Some((room, subscriptions));
            } else {
                self.room = None;
            }
            cx.notify();
        }
    }

    pub fn room(&self) -> Option<&ModelHandle<Room>> {
        self.room.as_ref().map(|(room, _)| room)
    }
}