use crate::structs::{LocalUserSettingsView, LocalUserView};
use diesel::{result::Error, BoolExpressionMethods, ExpressionMethods, JoinOnDsl, QueryDsl};
use diesel_async::RunQueryDsl;
use lemmy_db_schema::{
  aggregates::structs::PersonAggregates,
  newtypes::{LocalUserId, PersonId},
  schema::{local_user, person, person_aggregates},
  source::{
    local_user::{LocalUser, LocalUserSettings},
    person::{Person, PersonSafe},
  },
  traits::{ToSafe, ToSafeSettings, ViewToVec},
  utils::{functions::lower, get_conn, DbPool},
};

type LocalUserViewTuple = (LocalUser, Person, PersonAggregates);

impl LocalUserView {
  pub async fn read(pool: &DbPool, local_user_id: LocalUserId) -> Result<Self, Error> {
    let conn = &mut get_conn(pool).await?;

    let (local_user, person, counts) = local_user::table
      .find(local_user_id)
      .inner_join(person::table)
      .inner_join(person_aggregates::table.on(person::id.eq(person_aggregates::person_id)))
      .select((
        local_user::all_columns,
        person::all_columns,
        person_aggregates::all_columns,
      ))
      .first::<LocalUserViewTuple>(conn)
      .await?;
    Ok(Self {
      local_user,
      person,
      counts,
    })
  }

  pub async fn read_person(pool: &DbPool, person_id: PersonId) -> Result<Self, Error> {
    let conn = &mut get_conn(pool).await?;
    let (local_user, person, counts) = local_user::table
      .filter(person::id.eq(person_id))
      .inner_join(person::table)
      .inner_join(person_aggregates::table.on(person::id.eq(person_aggregates::person_id)))
      .select((
        local_user::all_columns,
        person::all_columns,
        person_aggregates::all_columns,
      ))
      .first::<LocalUserViewTuple>(conn)
      .await?;
    Ok(Self {
      local_user,
      person,
      counts,
    })
  }

  // TODO check where this is used
  pub async fn read_from_name(pool: &DbPool, name: &str) -> Result<Self, Error> {
    let conn = &mut get_conn(pool).await?;
    let (local_user, person, counts) = local_user::table
      .filter(person::name.eq(name))
      .inner_join(person::table)
      .inner_join(person_aggregates::table.on(person::id.eq(person_aggregates::person_id)))
      .select((
        local_user::all_columns,
        person::all_columns,
        person_aggregates::all_columns,
      ))
      .first::<LocalUserViewTuple>(conn)
      .await?;
    Ok(Self {
      local_user,
      person,
      counts,
    })
  }

  pub async fn find_by_email_or_name(pool: &DbPool, name_or_email: &str) -> Result<Self, Error> {
    let conn = &mut get_conn(pool).await?;
    let (local_user, person, counts) = local_user::table
      .inner_join(person::table)
      .inner_join(person_aggregates::table.on(person::id.eq(person_aggregates::person_id)))
      .filter(
        lower(person::name)
          .eq(lower(name_or_email))
          .or(local_user::email.eq(name_or_email)),
      )
      .select((
        local_user::all_columns,
        person::all_columns,
        person_aggregates::all_columns,
      ))
      .first::<LocalUserViewTuple>(conn)
      .await?;
    Ok(Self {
      local_user,
      person,
      counts,
    })
  }

  pub async fn find_by_email(pool: &DbPool, from_email: &str) -> Result<Self, Error> {
    let conn = &mut get_conn(pool).await?;
    let (local_user, person, counts) = local_user::table
      .inner_join(person::table)
      .inner_join(person_aggregates::table.on(person::id.eq(person_aggregates::person_id)))
      .filter(local_user::email.eq(from_email))
      .select((
        local_user::all_columns,
        person::all_columns,
        person_aggregates::all_columns,
      ))
      .first::<LocalUserViewTuple>(conn)
      .await?;
    Ok(Self {
      local_user,
      person,
      counts,
    })
  }
}

type LocalUserSettingsViewTuple = (LocalUserSettings, PersonSafe, PersonAggregates);

impl LocalUserSettingsView {
  pub async fn read(pool: &DbPool, local_user_id: LocalUserId) -> Result<Self, Error> {
    let conn = &mut get_conn(pool).await?;
    let (local_user, person, counts) = local_user::table
      .find(local_user_id)
      .inner_join(person::table)
      .inner_join(person_aggregates::table.on(person::id.eq(person_aggregates::person_id)))
      .select((
        LocalUser::safe_settings_columns_tuple(),
        Person::safe_columns_tuple(),
        person_aggregates::all_columns,
      ))
      .first::<LocalUserSettingsViewTuple>(conn)
      .await?;
    Ok(Self {
      local_user,
      person,
      counts,
    })
  }

  pub async fn list_admins_with_emails(pool: &DbPool) -> Result<Vec<Self>, Error> {
    let conn = &mut get_conn(pool).await?;
    let res = local_user::table
      .filter(person::admin.eq(true))
      .filter(local_user::email.is_not_null())
      .inner_join(person::table)
      .inner_join(person_aggregates::table.on(person::id.eq(person_aggregates::person_id)))
      .select((
        LocalUser::safe_settings_columns_tuple(),
        Person::safe_columns_tuple(),
        person_aggregates::all_columns,
      ))
      .load::<LocalUserSettingsViewTuple>(conn)
      .await?;

    Ok(LocalUserSettingsView::from_tuple_to_vec(res))
  }
}

impl ViewToVec for LocalUserSettingsView {
  type DbTuple = LocalUserSettingsViewTuple;
  fn from_tuple_to_vec(items: Vec<Self::DbTuple>) -> Vec<Self> {
    items
      .into_iter()
      .map(|a| Self {
        local_user: a.0,
        person: a.1,
        counts: a.2,
      })
      .collect::<Vec<Self>>()
  }
}