Add migration for custom ACL actions (#1164)

Custom actions for events are now stored in DB with a new column. This
is only the backend side of things, so they won't show up in the ACL UI
yet.

Part of #1004

backend/src/db/migrations.rs

@@ -364,4 +364,5 @@ static MIGRATIONS: Lazy<BTreeMap<u64, Migration>> = include_migrations![
     29: "extend-series-block",
     30: "realm-permissions",
     31: "series-metadata",
+    32: "custom-actions",
 ];

backend/src/db/migrations/32-custom-actions.sql

@@ -0,0 +1,45 @@
+-- Adds a field for custom actions to `events`.
+-- The field's entries are mappings of individual custom actions
+-- and the respective roles that are allowed to carry out that action.
+
+alter table events
+    add column custom_action_roles jsonb;
+
+-- The following function verifies that the custom action column and its
+-- entries follow a predefined format.
+create or replace function check_custom_actions_format() returns trigger as $$
+declare
+    col text := 'events.custom_action_roles';
+    field record;
+    element jsonb;
+begin
+    if jsonb_typeof(new.custom_action_roles) <> 'object' then
+        raise exception '% is %, but should be a JSON object', col, jsonb_typeof(new.custom_actions);
+    end if;
+
+    for field in select * from jsonb_each(new.custom_action_roles) loop
+        if jsonb_typeof(field.value) <> 'array' then
+            raise exception '%: type of field "%" is %, but should be an array',
+                col,
+                field.key,
+                jsonb_typeof(field.value);
+        end if;
+
+        for element in select * from jsonb_array_elements(field.value) loop
+            if jsonb_typeof(element) <> 'string' then
+                raise exception '%: found non-string element "%" in field "%", but that field should be a string array',
+                    col,
+                    element,
+                    field.key;
+            end if;
+        end loop;
+    end loop;
+
+    return new;
+end;
+$$ language plpgsql;
+
+create trigger check_custom_actions_format_on_upsert
+    before insert or update on events
+    for each row
+    execute procedure check_custom_actions_format();

backend/src/db/types.rs

@@ -141,3 +141,40 @@ impl<'a> FromSql<'a> for ExtraMetadata {
         <serde_json::Value as FromSql>::accepts(ty)
     }
 }
+
+/// Represents the type for the `custom_action_roles` field from `32-custom-actions.sql`.
+/// This holds a mapping of actions to lists holding roles that are allowed
+/// to carry out the respective action.
+#[derive(Debug, Serialize, Deserialize)]
+pub(crate) struct CustomActions(pub(crate) HashMap<String, Vec<String>>);
+
+impl ToSql for CustomActions {
+    fn to_sql(
+        &self,
+        ty: &postgres_types::Type,
+        out: &mut BytesMut,
+    ) -> Result<postgres_types::IsNull, Box<dyn std::error::Error + Sync + Send>> {
+        serde_json::to_value(self)
+            .expect("failed to convert `CustomActions` to JSON value")
+            .to_sql(ty, out)
+    }
+
+    fn accepts(ty: &postgres_types::Type) -> bool {
+        <serde_json::Value as ToSql>::accepts(ty)
+    }
+
+    postgres_types::to_sql_checked!();
+}
+
+impl<'a> FromSql<'a> for CustomActions {
+    fn from_sql(
+        ty: &postgres_types::Type,
+        raw: &'a [u8],
+    ) -> Result<Self, Box<dyn std::error::Error + Sync + Send>> {
+        serde_json::from_value(<_>::from_sql(ty, raw)?).map_err(Into::into)
+    }
+
+    fn accepts(ty: &postgres_types::Type) -> bool {
+        <serde_json::Value as FromSql>::accepts(ty)
+    }
+}

backend/src/sync/harvest/mod.rs

@@ -177,6 +177,10 @@ async fn store_in_db(
                 acl.read.retain(|role| role != ROLE_ADMIN);
                 acl.write.retain(|role| role != ROLE_ADMIN);
 
+                for (_, roles) in &mut acl.custom_actions.0 {
+                    roles.retain(|role| role != ROLE_ADMIN);
+                }
+
                 let tracks = tracks.into_iter().map(Into::into).collect::<Vec<EventTrack>>();
                 let captions = captions.into_iter().map(Into::into).collect::<Vec<EventCaption>>();
 
@@ -199,6 +203,7 @@ async fn store_in_db(
                     ("metadata", &metadata),
                     ("read_roles", &acl.read),
                     ("write_roles", &acl.write),
+                    ("custom_action_roles", &acl.custom_actions),
                     ("tracks", &tracks),
                     ("captions", &captions),
                 ]).await?;

backend/src/sync/harvest/response.rs

@@ -1,7 +1,7 @@
 use chrono::{DateTime, Utc};
-use serde::Deserialize;
+use serde::{Deserialize, Serialize};
 
-use crate::db::types::{EventTrack, ExtraMetadata, EventCaption};
+use crate::db::types::{CustomActions, EventCaption, EventTrack, ExtraMetadata};
 
 
 /// What the harvesting API returns.
@@ -128,10 +128,12 @@ impl Into<EventCaption> for Caption {
     }
 }
 
-#[derive(Debug, Deserialize)]
+#[derive(Debug, Serialize, Deserialize)]
 pub(crate) struct Acl {
     #[serde(default)]
     pub(crate) read: Vec<String>,
     #[serde(default)]
     pub(crate) write: Vec<String>,
+    #[serde(flatten)]
+    pub(crate) custom_actions: CustomActions,
 }