crates/db_views_actor/src/community_moderator_view.rs

   1 use diesel::{result::Error, *};
   2 use lemmy_db_schema::{
   3   newtypes::{CommunityId, PersonId},
   4   schema::{community, community_moderator, person},
   5   source::{
   6     community::{Community, CommunitySafe},
   7     person::{Person, PersonSafe},
   8   },
   9   traits::{ToSafe, ViewToVec},
  10 };
  11 use serde::{Deserialize, Serialize};
  12
  13 #[derive(Debug, Serialize, Deserialize, Clone)]
  14 pub struct CommunityModeratorView {
  15   pub community: CommunitySafe,
  16   pub moderator: PersonSafe,
  17 }
  18
  19 type CommunityModeratorViewTuple = (CommunitySafe, PersonSafe);
  20
  21 impl CommunityModeratorView {
  22   pub fn for_community(conn: &PgConnection, community_id: CommunityId) -> Result<Vec<Self>, Error> {
  23     let res = community_moderator::table
  24       .inner_join(community::table)
  25       .inner_join(person::table)
  26       .select((
  27         Community::safe_columns_tuple(),
  28         Person::safe_columns_tuple(),
  29       ))
  30       .filter(community_moderator::community_id.eq(community_id))
  31       .order_by(community_moderator::published)
  32       .load::<CommunityModeratorViewTuple>(conn)?;
  33
  34     Ok(Self::from_tuple_to_vec(res))
  35   }
  36
  37   pub fn for_person(conn: &PgConnection, person_id: PersonId) -> Result<Vec<Self>, Error> {
  38     let res = community_moderator::table
  39       .inner_join(community::table)
  40       .inner_join(person::table)
  41       .select((
  42         Community::safe_columns_tuple(),
  43         Person::safe_columns_tuple(),
  44       ))
  45       .filter(community_moderator::person_id.eq(person_id))
  46       .order_by(community_moderator::published)
  47       .load::<CommunityModeratorViewTuple>(conn)?;
  48
  49     Ok(Self::from_tuple_to_vec(res))
  50   }
  51
  52   /// Finds all communities first mods / creators
  53   /// Ideally this should be a group by, but diesel doesn't support it yet
  54   pub fn get_community_first_mods(conn: &PgConnection) -> Result<Vec<Self>, Error> {
  55     let res = community_moderator::table
  56       .inner_join(community::table)
  57       .inner_join(person::table)
  58       .select((
  59         Community::safe_columns_tuple(),
  60         Person::safe_columns_tuple(),
  61       ))
  62       // A hacky workaround instead of group_bys
  63       // https://stackoverflow.com/questions/24042359/how-to-join-only-one-row-in-joined-table-with-postgres
  64       .distinct_on(community_moderator::community_id)
  65       .order_by((
  66         community_moderator::community_id,
  67         community_moderator::person_id,
  68       ))
  69       .load::<CommunityModeratorViewTuple>(conn)?;
  70
  71     Ok(Self::from_tuple_to_vec(res))
  72   }
  73 }
  74
  75 impl ViewToVec for CommunityModeratorView {
  76   type DbTuple = CommunityModeratorViewTuple;
  77   fn from_tuple_to_vec(items: Vec<Self::DbTuple>) -> Vec<Self> {
  78     items
  79       .iter()
  80       .map(|a| Self {
  81         community: a.0.to_owned(),
  82         moderator: a.1.to_owned(),
  83       })
  84       .collect::<Vec<Self>>()
  85   }
  86 }