use crate::structs::{LocalUserView, PostReportView};
use diesel::{
  pg::Pg,
  result::Error,
  BoolExpressionMethods,
  ExpressionMethods,
  JoinOnDsl,
  NullableExpressionMethods,
  QueryDsl,
};
use diesel_async::RunQueryDsl;
use lemmy_db_schema::{
  aliases::{self, creator_community_actions},
  newtypes::{CommunityId, PersonId, PostId, PostReportId},
  schema::{
    community,
    community_actions,
    local_user,
    person,
    person_actions,
    post,
    post_actions,
    post_aggregates,
    post_report,
  },
  source::community::CommunityFollower,
  utils::{
    actions,
    actions_alias,
    functions::coalesce,
    get_conn,
    limit_and_offset,
    DbConn,
    DbPool,
    ListFn,
    Queries,
    ReadFn,
  },
};

fn queries<'a>() -> Queries<
  impl ReadFn<'a, PostReportView, (PostReportId, PersonId)>,
  impl ListFn<'a, PostReportView, (PostReportQuery, &'a LocalUserView)>,
> {
  let all_joins = |query: post_report::BoxedQuery<'a, Pg>, my_person_id: PersonId| {
    query
      .inner_join(post::table)
      .inner_join(community::table.on(post::community_id.eq(community::id)))
      .inner_join(person::table.on(post_report::creator_id.eq(person::id)))
      .inner_join(aliases::person1.on(post::creator_id.eq(aliases::person1.field(person::id))))
      .left_join(actions_alias(
        creator_community_actions,
        post::creator_id,
        post::community_id,
      ))
      .left_join(actions(
        community_actions::table,
        Some(my_person_id),
        post::community_id,
      ))
      .left_join(
        local_user::table.on(
          post::creator_id
            .eq(local_user::person_id)
            .and(local_user::admin.eq(true)),
        ),
      )
      .left_join(actions(post_actions::table, Some(my_person_id), post::id))
      .left_join(actions(
        person_actions::table,
        Some(my_person_id),
        post::creator_id,
      ))
      .inner_join(post_aggregates::table.on(post_report::post_id.eq(post_aggregates::post_id)))
      .left_join(
        aliases::person2
          .on(post_report::resolver_id.eq(aliases::person2.field(person::id).nullable())),
      )
      .select((
        post_report::all_columns,
        post::all_columns,
        community::all_columns,
        person::all_columns,
        aliases::person1.fields(person::all_columns),
        creator_community_actions
          .field(community_actions::received_ban)
          .nullable()
          .is_not_null(),
        creator_community_actions
          .field(community_actions::became_moderator)
          .nullable()
          .is_not_null(),
        local_user::admin.nullable().is_not_null(),
        CommunityFollower::select_subscribed_type(),
        post_actions::saved.nullable().is_not_null(),
        post_actions::read.nullable().is_not_null(),
        post_actions::hidden.nullable().is_not_null(),
        person_actions::blocked.nullable().is_not_null(),
        post_actions::like_score.nullable(),
        coalesce(
          post_aggregates::comments.nullable() - post_actions::read_comments_amount.nullable(),
          post_aggregates::comments,
        ),
        post_aggregates::all_columns,
        aliases::person2.fields(person::all_columns.nullable()),
      ))
  };

  let read = move |mut conn: DbConn<'a>, (report_id, my_person_id): (PostReportId, PersonId)| async move {
    all_joins(
      post_report::table.find(report_id).into_boxed(),
      my_person_id,
    )
    .first(&mut conn)
    .await
  };

  let list = move |mut conn: DbConn<'a>, (options, user): (PostReportQuery, &'a LocalUserView)| async move {
    let mut query = all_joins(post_report::table.into_boxed(), user.person.id);

    if let Some(community_id) = options.community_id {
      query = query.filter(post::community_id.eq(community_id));
    }

    if let Some(post_id) = options.post_id {
      query = query.filter(post::id.eq(post_id));
    }

    // If viewing all reports, order by newest, but if viewing unresolved only, show the oldest
    // first (FIFO)
    if options.unresolved_only {
      query = query
        .filter(post_report::resolved.eq(false))
        .order_by(post_report::published.asc());
    } else {
      query = query.order_by(post_report::published.desc());
    }

    let (limit, offset) = limit_and_offset(options.page, options.limit)?;

    query = query.limit(limit).offset(offset);

    // If its not an admin, get only the ones you mod
    if !user.local_user.admin {
      query = query.filter(community_actions::became_moderator.is_not_null());
    }

    query.load::<PostReportView>(&mut conn).await
  };

  Queries::new(read, list)
}

impl PostReportView {
  /// returns the PostReportView for the provided report_id
  ///
  /// * `report_id` - the report id to obtain
  pub async fn read(
    pool: &mut DbPool<'_>,
    report_id: PostReportId,
    my_person_id: PersonId,
  ) -> Result<Self, Error> {
    queries().read(pool, (report_id, my_person_id)).await
  }

  /// returns the current unresolved post report count for the communities you mod
  pub async fn get_report_count(
    pool: &mut DbPool<'_>,
    my_person_id: PersonId,
    admin: bool,
    community_id: Option<CommunityId>,
  ) -> Result<i64, Error> {
    use diesel::dsl::count;
    let conn = &mut get_conn(pool).await?;
    let mut query = post_report::table
      .inner_join(post::table)
      .filter(post_report::resolved.eq(false))
      .into_boxed();

    if let Some(community_id) = community_id {
      query = query.filter(post::community_id.eq(community_id))
    }

    // If its not an admin, get only the ones you mod
    if !admin {
      query
        .inner_join(
          community_actions::table.on(
            community_actions::community_id
              .eq(post::community_id)
              .and(community_actions::person_id.eq(my_person_id))
              .and(community_actions::became_moderator.is_not_null()),
          ),
        )
        .select(count(post_report::id))
        .first::<i64>(conn)
        .await
    } else {
      query
        .select(count(post_report::id))
        .first::<i64>(conn)
        .await
    }
  }
}

#[derive(Default)]
pub struct PostReportQuery {
  pub community_id: Option<CommunityId>,
  pub post_id: Option<PostId>,
  pub page: Option<i64>,
  pub limit: Option<i64>,
  pub unresolved_only: bool,
}

impl PostReportQuery {
  pub async fn list(
    self,
    pool: &mut DbPool<'_>,
    user: &LocalUserView,
  ) -> Result<Vec<PostReportView>, Error> {
    queries().list(pool, (self, user)).await
  }
}

#[cfg(test)]
#[expect(clippy::indexing_slicing)]
mod tests {

  use crate::{
    post_report_view::{PostReportQuery, PostReportView},
    structs::LocalUserView,
  };
  use lemmy_db_schema::{
    aggregates::structs::PostAggregates,
    assert_length,
    source::{
      community::{Community, CommunityInsertForm, CommunityModerator, CommunityModeratorForm},
      instance::Instance,
      local_user::{LocalUser, LocalUserInsertForm},
      local_user_vote_display_mode::LocalUserVoteDisplayMode,
      person::{Person, PersonInsertForm},
      post::{Post, PostInsertForm},
      post_report::{PostReport, PostReportForm},
    },
    traits::{Crud, Joinable, Reportable},
    utils::build_db_pool_for_tests,
  };
  use lemmy_utils::error::LemmyResult;
  use pretty_assertions::assert_eq;
  use serial_test::serial;

  #[tokio::test]
  #[serial]
  async fn test_crud() -> LemmyResult<()> {
    let pool = &build_db_pool_for_tests();
    let pool = &mut pool.into();

    let inserted_instance = Instance::read_or_create(pool, "my_domain.tld".to_string()).await?;

    let new_person = PersonInsertForm::test_form(inserted_instance.id, "timmy_prv");

    let inserted_timmy = Person::create(pool, &new_person).await?;

    let new_local_user = LocalUserInsertForm::test_form(inserted_timmy.id);
    let timmy_local_user = LocalUser::create(pool, &new_local_user, vec![]).await?;
    let timmy_view = LocalUserView {
      local_user: timmy_local_user,
      local_user_vote_display_mode: LocalUserVoteDisplayMode::default(),
      person: inserted_timmy.clone(),
      counts: Default::default(),
    };

    let new_person_2 = PersonInsertForm::test_form(inserted_instance.id, "sara_prv");

    let inserted_sara = Person::create(pool, &new_person_2).await?;

    // Add a third person, since new ppl can only report something once.
    let new_person_3 = PersonInsertForm::test_form(inserted_instance.id, "jessica_prv");

    let inserted_jessica = Person::create(pool, &new_person_3).await?;

    let new_community = CommunityInsertForm::new(
      inserted_instance.id,
      "test community prv".to_string(),
      "nada".to_owned(),
      "pubkey".to_string(),
    );
    let inserted_community = Community::create(pool, &new_community).await?;

    // Make timmy a mod
    let timmy_moderator_form = CommunityModeratorForm {
      community_id: inserted_community.id,
      person_id: inserted_timmy.id,
    };

    let _inserted_moderator = CommunityModerator::join(pool, &timmy_moderator_form).await?;

    let new_post = PostInsertForm::new(
      "A test post crv".into(),
      inserted_timmy.id,
      inserted_community.id,
    );
    let inserted_post = Post::create(pool, &new_post).await?;

    // sara reports
    let sara_report_form = PostReportForm {
      creator_id: inserted_sara.id,
      post_id: inserted_post.id,
      original_post_name: "Orig post".into(),
      original_post_url: None,
      original_post_body: None,
      reason: "from sara".into(),
    };

    PostReport::report(pool, &sara_report_form).await?;

    let new_post_2 = PostInsertForm::new(
      "A test post crv 2".into(),
      inserted_timmy.id,
      inserted_community.id,
    );
    let inserted_post_2 = Post::create(pool, &new_post_2).await?;

    // jessica reports
    let jessica_report_form = PostReportForm {
      creator_id: inserted_jessica.id,
      post_id: inserted_post_2.id,
      original_post_name: "Orig post".into(),
      original_post_url: None,
      original_post_body: None,
      reason: "from jessica".into(),
    };

    let inserted_jessica_report = PostReport::report(pool, &jessica_report_form).await?;

    let read_jessica_report_view =
      PostReportView::read(pool, inserted_jessica_report.id, inserted_timmy.id).await?;

    // Make sure the triggers are reading the aggregates correctly.
    let agg_1 = PostAggregates::read(pool, inserted_post.id).await?;
    let agg_2 = PostAggregates::read(pool, inserted_post_2.id).await?;

    assert_eq!(
      read_jessica_report_view.post_report,
      inserted_jessica_report
    );
    assert_eq!(read_jessica_report_view.post, inserted_post_2);
    assert_eq!(read_jessica_report_view.community.id, inserted_community.id);
    assert_eq!(read_jessica_report_view.creator.id, inserted_jessica.id);
    assert_eq!(read_jessica_report_view.post_creator.id, inserted_timmy.id);
    assert_eq!(read_jessica_report_view.my_vote, None);
    assert_eq!(read_jessica_report_view.resolver, None);
    assert_eq!(agg_1.report_count, 1);
    assert_eq!(agg_1.unresolved_report_count, 1);
    assert_eq!(agg_2.report_count, 1);
    assert_eq!(agg_2.unresolved_report_count, 1);

    // Do a batch read of timmys reports
    let reports = PostReportQuery::default().list(pool, &timmy_view).await?;

    assert_eq!(reports[1].creator.id, inserted_sara.id);
    assert_eq!(reports[0].creator.id, inserted_jessica.id);

    // Make sure the counts are correct
    let report_count =
      PostReportView::get_report_count(pool, inserted_timmy.id, false, None).await?;
    assert_eq!(2, report_count);

    // Pretend the post was removed, and resolve all reports for that object.
    // This is called manually in the API for post removals
    PostReport::resolve_all_for_object(pool, inserted_jessica_report.post_id, inserted_timmy.id)
      .await?;

    let read_jessica_report_view_after_resolve =
      PostReportView::read(pool, inserted_jessica_report.id, inserted_timmy.id).await?;
    assert!(read_jessica_report_view_after_resolve.post_report.resolved);
    assert_eq!(
      read_jessica_report_view_after_resolve
        .post_report
        .resolver_id,
      Some(inserted_timmy.id)
    );
    assert_eq!(
      read_jessica_report_view_after_resolve
        .resolver
        .map(|r| r.id),
      Some(inserted_timmy.id)
    );

    // Make sure the unresolved_post report got decremented in the trigger
    let agg_2 = PostAggregates::read(pool, inserted_post_2.id).await?;
    assert_eq!(agg_2.report_count, 1);
    assert_eq!(agg_2.unresolved_report_count, 0);

    // Make sure the other unresolved report isn't changed
    let agg_1 = PostAggregates::read(pool, inserted_post.id).await?;
    assert_eq!(agg_1.report_count, 1);
    assert_eq!(agg_1.unresolved_report_count, 1);

    // Do a batch read of timmys reports
    // It should only show saras, which is unresolved
    let reports_after_resolve = PostReportQuery {
      unresolved_only: true,
      ..Default::default()
    }
    .list(pool, &timmy_view)
    .await?;
    assert_length!(1, reports_after_resolve);
    assert_eq!(reports_after_resolve[0].creator.id, inserted_sara.id);

    // Make sure the counts are correct
    let report_count_after_resolved =
      PostReportView::get_report_count(pool, inserted_timmy.id, false, None).await?;
    assert_eq!(1, report_count_after_resolved);

    Person::delete(pool, inserted_timmy.id).await?;
    Person::delete(pool, inserted_sara.id).await?;
    Person::delete(pool, inserted_jessica.id).await?;
    Community::delete(pool, inserted_community.id).await?;
    Instance::delete(pool, inserted_instance.id).await?;

    Ok(())
  }
}