use crate::{
  api::user::PrivateMessageResponse,
  apub::{
    check_is_apub_id_valid,
    extensions::signatures::verify,
    fetcher::{get_or_fetch_and_upsert_actor, get_or_fetch_and_upsert_community},
    insert_activity,
    FromApub,
  },
  blocking,
  routes::{ChatServerParam, DbPoolParam},
  websocket::{server::SendUserRoomMessage, UserOperation},
  DbPool,
  LemmyError,
};
use activitystreams::{
  activity::{Accept, ActorAndObject, Create, Delete, Undo, Update},
  base::AnyBase,
  object::Note,
  prelude::*,
};
use actix_web::{client::Client, web, HttpRequest, HttpResponse};
use lemmy_db::{
  community::{CommunityFollower, CommunityFollowerForm},
  naive_now,
  private_message::{PrivateMessage, PrivateMessageForm},
  private_message_view::PrivateMessageView,
  user::User_,
  Crud,
  Followable,
};
use log::debug;
use serde::{Deserialize, Serialize};
use std::fmt::Debug;

#[derive(Clone, Debug, Eq, Ord, PartialEq, PartialOrd, Deserialize, Serialize)]
#[serde(rename_all = "PascalCase")]
pub enum ValidTypes {
  Accept,
  Create,
  Update,
  Delete,
  Undo,
}

pub type AcceptedActivities = ActorAndObject<ValidTypes>;

/// Handler for all incoming activities to user inboxes.
pub async fn user_inbox(
  request: HttpRequest,
  input: web::Json<AcceptedActivities>,
  path: web::Path<String>,
  client: web::Data<Client>,
  pool: DbPoolParam,
  chat_server: ChatServerParam,
) -> Result<HttpResponse, LemmyError> {
  let activity = input.into_inner();
  let username = path.into_inner();
  debug!("User {} received activity: {:?}", &username, &activity);

  let actor_uri = activity.actor()?.as_single_xsd_any_uri().unwrap();

  check_is_apub_id_valid(actor_uri)?;

  let actor = get_or_fetch_and_upsert_actor(actor_uri, &client, &pool).await?;
  verify(&request, actor.as_ref())?;

  insert_activity(actor.user_id(), activity.clone(), false, &pool).await?;

  let any_base = activity.clone().into_any_base()?;
  let kind = activity.kind().unwrap();
  match kind {
    ValidTypes::Accept => receive_accept(any_base, username, &client, &pool).await,
    ValidTypes::Create => {
      receive_create_private_message(any_base, &client, &pool, chat_server).await
    }
    ValidTypes::Update => {
      receive_update_private_message(any_base, &client, &pool, chat_server).await
    }
    ValidTypes::Delete => {
      receive_delete_private_message(any_base, &client, &pool, chat_server).await
    }
    ValidTypes::Undo => {
      receive_undo_delete_private_message(any_base, &client, &pool, chat_server).await
    }
  }
}

/// Handle accepted follows.
async fn receive_accept(
  activity: AnyBase,
  username: String,
  client: &Client,
  pool: &DbPool,
) -> Result<HttpResponse, LemmyError> {
  let accept = Accept::from_any_base(activity)?.unwrap();
  let community_uri = accept.actor()?.to_owned().single_xsd_any_uri().unwrap();

  let community = get_or_fetch_and_upsert_community(&community_uri, client, pool).await?;

  let user = blocking(pool, move |conn| User_::read_from_name(conn, &username)).await??;

  // Now you need to add this to the community follower
  let community_follower_form = CommunityFollowerForm {
    community_id: community.id,
    user_id: user.id,
  };

  // This will fail if they're already a follower
  blocking(pool, move |conn| {
    CommunityFollower::follow(conn, &community_follower_form).ok()
  })
  .await?;

  // TODO: make sure that we actually requested a follow
  Ok(HttpResponse::Ok().finish())
}

async fn receive_create_private_message(
  activity: AnyBase,
  client: &Client,
  pool: &DbPool,
  chat_server: ChatServerParam,
) -> Result<HttpResponse, LemmyError> {
  let create = Create::from_any_base(activity)?.unwrap();
  let note = Note::from_any_base(create.object().as_one().unwrap().to_owned())?.unwrap();

  let domain = Some(create.id_unchecked().unwrap().to_owned());
  let private_message = PrivateMessageForm::from_apub(&note, client, pool, domain).await?;

  let inserted_private_message = blocking(pool, move |conn| {
    PrivateMessage::create(conn, &private_message)
  })
  .await??;

  let message = blocking(pool, move |conn| {
    PrivateMessageView::read(conn, inserted_private_message.id)
  })
  .await??;

  let res = PrivateMessageResponse { message };

  let recipient_id = res.message.recipient_id;

  chat_server.do_send(SendUserRoomMessage {
    op: UserOperation::CreatePrivateMessage,
    response: res,
    recipient_id,
    my_id: None,
  });

  Ok(HttpResponse::Ok().finish())
}

async fn receive_update_private_message(
  activity: AnyBase,
  client: &Client,
  pool: &DbPool,
  chat_server: ChatServerParam,
) -> Result<HttpResponse, LemmyError> {
  let update = Update::from_any_base(activity)?.unwrap();
  let note = Note::from_any_base(update.object().as_one().unwrap().to_owned())?.unwrap();

  let domain = Some(update.id_unchecked().unwrap().to_owned());
  let private_message_form = PrivateMessageForm::from_apub(&note, client, pool, domain).await?;

  let private_message_ap_id = private_message_form.ap_id.clone();
  let private_message = blocking(pool, move |conn| {
    PrivateMessage::read_from_apub_id(conn, &private_message_ap_id)
  })
  .await??;

  let private_message_id = private_message.id;
  blocking(pool, move |conn| {
    PrivateMessage::update(conn, private_message_id, &private_message_form)
  })
  .await??;

  let private_message_id = private_message.id;
  let message = blocking(pool, move |conn| {
    PrivateMessageView::read(conn, private_message_id)
  })
  .await??;

  let res = PrivateMessageResponse { message };

  let recipient_id = res.message.recipient_id;

  chat_server.do_send(SendUserRoomMessage {
    op: UserOperation::EditPrivateMessage,
    response: res,
    recipient_id,
    my_id: None,
  });

  Ok(HttpResponse::Ok().finish())
}

async fn receive_delete_private_message(
  activity: AnyBase,
  client: &Client,
  pool: &DbPool,
  chat_server: ChatServerParam,
) -> Result<HttpResponse, LemmyError> {
  let delete = Delete::from_any_base(activity)?.unwrap();
  let note = Note::from_any_base(delete.object().as_one().unwrap().to_owned())?.unwrap();

  let domain = Some(delete.id_unchecked().unwrap().to_owned());
  let private_message_form = PrivateMessageForm::from_apub(&note, client, pool, domain).await?;

  let private_message_ap_id = private_message_form.ap_id;
  let private_message = blocking(pool, move |conn| {
    PrivateMessage::read_from_apub_id(conn, &private_message_ap_id)
  })
  .await??;

  let private_message_form = PrivateMessageForm {
    content: private_message_form.content,
    recipient_id: private_message.recipient_id,
    creator_id: private_message.creator_id,
    deleted: Some(true),
    read: None,
    ap_id: private_message.ap_id,
    local: private_message.local,
    published: None,
    updated: Some(naive_now()),
  };

  let private_message_id = private_message.id;
  blocking(pool, move |conn| {
    PrivateMessage::update(conn, private_message_id, &private_message_form)
  })
  .await??;

  let private_message_id = private_message.id;
  let message = blocking(pool, move |conn| {
    PrivateMessageView::read(&conn, private_message_id)
  })
  .await??;

  let res = PrivateMessageResponse { message };

  let recipient_id = res.message.recipient_id;

  chat_server.do_send(SendUserRoomMessage {
    op: UserOperation::EditPrivateMessage,
    response: res,
    recipient_id,
    my_id: None,
  });

  Ok(HttpResponse::Ok().finish())
}

async fn receive_undo_delete_private_message(
  activity: AnyBase,
  client: &Client,
  pool: &DbPool,
  chat_server: ChatServerParam,
) -> Result<HttpResponse, LemmyError> {
  let undo = Undo::from_any_base(activity)?.unwrap();
  let delete = Delete::from_any_base(undo.object().as_one().unwrap().to_owned())?.unwrap();
  let note = Note::from_any_base(delete.object().as_one().unwrap().to_owned())?.unwrap();

  let domain = Some(undo.id_unchecked().unwrap().to_owned());
  let private_message = PrivateMessageForm::from_apub(&note, client, pool, domain).await?;

  let private_message_ap_id = private_message.ap_id.clone();
  let private_message_id = blocking(pool, move |conn| {
    PrivateMessage::read_from_apub_id(conn, &private_message_ap_id).map(|pm| pm.id)
  })
  .await??;

  let private_message_form = PrivateMessageForm {
    content: private_message.content,
    recipient_id: private_message.recipient_id,
    creator_id: private_message.creator_id,
    deleted: Some(false),
    read: None,
    ap_id: private_message.ap_id,
    local: private_message.local,
    published: None,
    updated: Some(naive_now()),
  };

  blocking(pool, move |conn| {
    PrivateMessage::update(conn, private_message_id, &private_message_form)
  })
  .await??;

  let message = blocking(pool, move |conn| {
    PrivateMessageView::read(&conn, private_message_id)
  })
  .await??;

  let res = PrivateMessageResponse { message };

  let recipient_id = res.message.recipient_id;

  chat_server.do_send(SendUserRoomMessage {
    op: UserOperation::EditPrivateMessage,
    response: res,
    recipient_id,
    my_id: None,
  });

  Ok(HttpResponse::Ok().finish())
}