use crate::{
  activities::{generate_activity_id, send_lemmy_activity},
  local_instance,
  protocol::activities::following::{accept::AcceptFollowCommunity, follow::FollowCommunity},
  ActorType,
};
use activitypub_federation::{
  core::object_id::ObjectId,
  data::Data,
  traits::ActivityHandler,
  utils::verify_urls_match,
};
use activitystreams_kinds::activity::AcceptType;
use lemmy_api_common::utils::blocking;
use lemmy_db_schema::{source::community::CommunityFollower, traits::Followable};
use lemmy_utils::error::LemmyError;
use lemmy_websocket::LemmyContext;
use url::Url;

impl AcceptFollowCommunity {
  #[tracing::instrument(skip_all)]
  pub async fn send(
    follow: FollowCommunity,
    context: &LemmyContext,
    request_counter: &mut i32,
  ) -> Result<(), LemmyError> {
    let community = follow
      .object
      .dereference_local::<LemmyError>(context)
      .await?;
    let person = follow
      .actor
      .clone()
      .dereference::<LemmyError>(context, local_instance(context), request_counter)
      .await?;
    let accept = AcceptFollowCommunity {
      actor: ObjectId::new(community.actor_id()),
      object: follow,
      kind: AcceptType::Accept,
      id: generate_activity_id(
        AcceptType::Accept,
        &context.settings().get_protocol_and_hostname(),
      )?,
      unparsed: Default::default(),
    };
    let inbox = vec![person.inbox_url()];
    send_lemmy_activity(context, &accept, &accept.id, &community, inbox, true).await
  }
}

/// Handle accepted follows
#[async_trait::async_trait(?Send)]
impl ActivityHandler for AcceptFollowCommunity {
  type DataType = LemmyContext;
  type Error = LemmyError;

  fn id(&self) -> &Url {
    &self.id
  }

  fn actor(&self) -> &Url {
    self.actor.inner()
  }

  #[tracing::instrument(skip_all)]
  async fn verify(
    &self,
    context: &Data<LemmyContext>,
    request_counter: &mut i32,
  ) -> Result<(), LemmyError> {
    verify_urls_match(self.actor.inner(), self.object.object.inner())?;
    self.object.verify(context, request_counter).await?;
    Ok(())
  }

  #[tracing::instrument(skip_all)]
  async fn receive(
    self,
    context: &Data<LemmyContext>,
    request_counter: &mut i32,
  ) -> Result<(), LemmyError> {
    let person = self
      .actor
      .dereference::<LemmyError>(context, local_instance(context), request_counter)
      .await?;
    let community = self
      .object
      .actor
      .dereference::<LemmyError>(context, local_instance(context), request_counter)
      .await?;
    // This will throw an error if no follow was requested
    blocking(context.pool(), move |conn| {
      CommunityFollower::follow_accepted(conn, person.id, community.id)
    })
    .await??;

    Ok(())
  }
}