Initial affiliate codes implementation (#4382)

* Initial affiliate codes implementation

* some more docs to codes

* sqlx prepare

* Address PR comments

* Address more PR comments

* fix clippy

* Switch to using Json<T> for type-safe responses

apps/labrinth/src/models/v3/affiliate_code.rs

@@ -0,0 +1,67 @@
+use ariadne::ids::UserId;
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+
+use crate::models::ids::AffiliateCodeId;
+
+/// Affiliate code used to track referral purchases.
+///
+/// See [`AffiliateCode`].
+///
+/// This struct contains information which should only be visible to admins.
+#[derive(Serialize, Deserialize)]
+pub struct AdminAffiliateCode {
+    /// Affiliate code ID.
+    pub id: AffiliateCodeId,
+    /// When the code was created.
+    pub created_at: DateTime<Utc>,
+    /// User who created the code.
+    pub created_by: UserId,
+    /// User who refers the purchaser.
+    pub affiliate: UserId,
+}
+
+/// Affiliate code used to track referral purchases.
+///
+/// When a user follows a URL with [`AffiliateCode::id`] as an affiliate
+/// parameter, the code will be saved as a cookie. When the same user purchases
+/// a product with an affiliate code cookie, the purchase under that code is
+/// tracked.
+///
+/// This struct contains information which is allowed to be seen by an
+/// affiliate.
+#[derive(Serialize, Deserialize)]
+pub struct AffiliateCode {
+    /// Affiliate code ID.
+    pub id: AffiliateCodeId,
+    /// User who refers the purchaser.
+    pub affiliate: UserId,
+}
+
+impl From<crate::database::models::affiliate_code_item::DBAffiliateCode>
+    for AdminAffiliateCode
+{
+    fn from(
+        data: crate::database::models::affiliate_code_item::DBAffiliateCode,
+    ) -> Self {
+        Self {
+            id: data.id.into(),
+            created_at: data.created_at,
+            created_by: data.created_by.into(),
+            affiliate: data.affiliate.into(),
+        }
+    }
+}
+
+impl From<crate::database::models::affiliate_code_item::DBAffiliateCode>
+    for AffiliateCode
+{
+    fn from(
+        data: crate::database::models::affiliate_code_item::DBAffiliateCode,
+    ) -> Self {
+        Self {
+            id: data.id.into(),
+            affiliate: data.affiliate.into(),
+        }
+    }
+}

apps/labrinth/src/models/v3/ids.rs

@@ -25,3 +25,4 @@ base62_id!(ThreadId);
 base62_id!(ThreadMessageId);
 base62_id!(UserSubscriptionId);
 base62_id!(VersionId);
+base62_id!(AffiliateCodeId);

apps/labrinth/src/models/v3/mod.rs

@@ -1,3 +1,4 @@
+pub mod affiliate_code;
 pub mod analytics;
 pub mod billing;
 pub mod collections;