WIP: Model Implementation

adr/2025-03-23-database-design.md.md

@@ -47,7 +47,7 @@ CREATE TABLE registered_project(
     group TEXT NOT NULL,
     name TEXT NOT NULL,
     registered_at TIMESTAMPTZ NOT NULL,
-    git_url TIMESTAMPTZ NOT NULL
+    git_url TEXT NOT NULL
 );
 ```
 

modules/model/src/main/scala/gs/maintainer/model/ArtifactGroup.scala

@@ -0,0 +1,40 @@
+package gs.maintainer.model
+
+import cats.Eq
+import cats.Show
+
+/**
+  * Represents the _group_ part of the artifact coordinates.
+  */
+opaque type ArtifactGroup = String
+
+/**
+  * Represents the _group_ part of the artifact coordinates.
+  */
+object ArtifactGroup:
+
+  /**
+   * Instantiate a new [[ArtifactGroup]] based on the given candidate string.
+   *
+   * @param candidate The string to validate.
+   * @return The new [[ArtifactGroup]], or an error if the candidate was invalid.
+   */
+  def validate(candidate: String): Either[ModelError, ArtifactGroup] =
+    if candidate.isBlank() then
+      Left(ModelError.InvalidArtifactGroup(candidate))
+    else
+      Right(candidate)
+
+  given CanEqual[ArtifactGroup, ArtifactGroup] = CanEqual.derived
+
+  given Eq[ArtifactGroup] = (x, y) => x == y
+
+  given Show[ArtifactGroup] = _.toString()
+
+  extension (ag: ArtifactGroup)
+    /**
+     * @return The underlying string for this [[ArtifactGroup]].
+     */
+    def unwrap(): String = ag
+
+end ArtifactGroup

modules/model/src/main/scala/gs/maintainer/model/ArtifactName.scala

@@ -0,0 +1,41 @@
+package gs.maintainer.model
+
+import cats.Eq
+import cats.Show
+
+/**
+  * Represents the _name_ part of the artifact coordinates.
+  */
+opaque type ArtifactName = String
+
+/**
+  * Represents the _name_ part of the artifact coordinates.
+  */
+object ArtifactName:
+
+  /**
+   * Instantiate a new [[ArtifactName]] based on the given candidate string.
+   *
+   * @param candidate The string to validate.
+   * @return The new [[ArtifactName]], or an error if the candidate was invalid.
+   */
+  def validate(candidate: String): Either[ModelError, ArtifactName] =
+    if candidate.isBlank() then
+      Left(ModelError.InvalidArtifactName(candidate))
+    else
+      Right(candidate)
+
+  given CanEqual[ArtifactName, ArtifactName] = CanEqual.derived
+
+  given Eq[ArtifactName] = (x, y) => x == y
+
+  given Show[ArtifactName] = _.toString()
+
+  extension (an: ArtifactName)
+    /**
+     * @return The underlying string for this [[ArtifactName]].
+     */
+    def unwrap(): String = an
+
+end ArtifactName
+

modules/model/src/main/scala/gs/maintainer/model/ModelError.scala

@@ -0,0 +1,37 @@
+package gs.maintainer.model
+
+/**
+  * Base type for all model errors.
+  */
+sealed trait ModelError
+
+/**
+  * Enumerates all model errors.
+  */
+object ModelError:
+
+  /**
+   * Produced when attempting to instantiate an [[ArtifactGroup]] and the 
+   * candidate string is invalid (blank).
+   *
+   * @param candidate The candidate artifact group.
+   */
+  case class InvalidArtifactGroup(candidate: String) extends ModelError
+
+  /**
+   * Produced when attempting to instantiate an [[ArtifactName]] and the 
+   * candidate string is invalid (blank).
+   *
+   * @param candidate The candidate artifact name.
+   */
+  case class InvalidArtifactName(candidate: String) extends ModelError
+
+  /**
+      * Produced when parsing a timestamp and the candidate string is not a 
+      * valid timestamp emitted by `ISO_INSTANT`.
+      *
+      * @param candidate The candidate timestamp.
+      */
+  case class InvalidTimestamp(candidate: String) extends ModelError
+
+end ModelError

modules/model/src/main/scala/gs/maintainer/model/Project.scala

@@ -0,0 +1,9 @@
+package gs.maintainer.model
+
+import gs.uuid.v0.UUID
+
+case class Project(
+  id: UUID,
+  group: ArtifactGroup,
+  name: ArtifactName
+)

modules/model/src/main/scala/gs/maintainer/model/RegisteredAt.scala

@@ -0,0 +1,56 @@
+package gs.maintainer.model
+
+import cats.Eq
+import cats.Show
+import java.time.Instant
+import scala.util.Try
+
+/**
+  * Represents the instant a [[Project]] was registered.
+  */
+opaque type RegisteredAt = Instant
+
+/**
+  * Represents the instant a [[Project]] was registered.
+  */
+object RegisteredAt:
+
+  /**
+   * Instantiate a new [[RegisteredAt]] from the given timestamp.
+   *
+   * @param value The timestamp.
+   * @return The new [[RegisteredAt]] instance.
+   */
+  def apply(value: Instant): RegisteredAt = value
+
+  /**
+   * Parse the given string as a [[RegisteredAt]]. This function uses the
+   * default parser for the `java.time.Instant` type (`ISO_INSTANT`).
+   *
+   * @param candidate The candidate string.
+   * @return The new [[RegisteredAt]] instance, or an error if parsing failed.
+   */
+  def parse(candidate: String): Either[ModelError, RegisteredAt] =
+    Try(Instant.parse(candidate))
+      .toOption
+      .map(Right(_))
+      .getOrElse(Left(ModelError.InvalidTimestamp(candidate)))
+
+  given CanEqual[RegisteredAt, RegisteredAt] = CanEqual.derived
+
+  given Eq[RegisteredAt] = (x, y) => x == y
+
+  given Show[RegisteredAt] = _.unwrap().toString()
+
+  extension (ra: RegisteredAt)
+    /**
+     * @return The underlying `java.time.Instant`.
+     */
+    def unwrap(): Instant = ra
+
+    /**
+     * @return The epoch milliseconds represented by this timestamp.
+     */
+    def toEpochMillis(): Long = ra.toEpochMilli()
+
+end RegisteredAt