separate typed key implementation

1 files changed, 48 insertions, 0 deletions

diff --git a/src/main/scala/TypedIdTable.scala b/src/main/scala/TypedIdTable.scala
new file mode 100644
index 0000000..b5c6056
--- /dev/null
+++ b/src/main/scala/TypedIdTable.scala
@@ -0,0 +1,48 @@
+import slick.codegen.SourceCodeGenerator
+import slick.{model => m}
+
+class TypedIdSourceCodeGenerator(
+  model: m.Model,
+  idType: Option[String],
+  manualForeignKeys: Map[(String, String), (String, String)]
+) extends SourceCodeGenerator(model) {
+  val manualReferences = SchemaParser.references(model, manualForeignKeys)
+
+  def derefColumn(table: m.Table,
+    column: m.Column): (m.Table, m.Column) = {
+    val referencedColumn: Seq[(m.Table, m.Column)] =
+      table.foreignKeys
+        .filter(tableFk => tableFk.referencingColumns.forall(_ == column))
+        .filter(columnFk => columnFk.referencedColumns.length == 1)
+        .flatMap(_.referencedColumns.map(c =>
+          (model.tablesByName(c.table), c)))
+    assert(referencedColumn.distinct.length <= 1, referencedColumn)
+
+    referencedColumn.headOption
+      .orElse(manualReferences.get((table.name.asString, column.name)))
+      .map((derefColumn _).tupled)
+      .getOrElse((table, column))
+  }
+
+  override def Table = new Table(_){ table =>
+    override def Column = new Column(_) { column =>
+
+      def tableReferenceName(tableName: m.QualifiedName) = {
+        val schemaObjectName = tableName.schema.getOrElse("`public`")
+        val rowTypeName = entityName(tableName.table)
+        val idTypeName = idType.getOrElse("Id")
+        s"$idTypeName[$schemaObjectName.$rowTypeName]"
+      }
+
+      override def rawType: String = {
+        // write key columns as Id types
+        val (referencedTable, referencedColumn) =
+          derefColumn(table.model, column.model)
+        if (referencedColumn.options.contains(
+              slick.ast.ColumnOption.PrimaryKey))
+          tableReferenceName(referencedTable.name)
+        else super.rawType
+      }
+    }
+  }
+}