move schema parser to separate file

1 files changed, 60 insertions, 0 deletions

diff --git a/src/main/scala/SchemaParser.scala b/src/main/scala/SchemaParser.scala
new file mode 100644
index 0000000..1186f11
--- /dev/null
+++ b/src/main/scala/SchemaParser.scala
@@ -0,0 +1,60 @@
+import scala.concurrent.ExecutionContext.Implicits.global
+
+import slick.dbio.DBIO
+import slick.driver.JdbcProfile
+import slick.jdbc.meta.MTable
+import slick.{model => m}
+
+object SchemaParser {
+  def references(dbModel: m.Model,
+                 tcMappings: Map[(String, String), (String, String)])
+    : Map[(String, String), (m.Table, m.Column)] = {
+    def getTableColumn(tc: (String, String)): (m.Table, m.Column) = {
+      val (tableName, columnName) = tc
+      val table = dbModel.tables
+        .find(_.name.asString == tableName)
+        .getOrElse(throw new RuntimeException("No table " + tableName))
+      val column = table.columns
+        .find(_.name == columnName)
+        .getOrElse(throw new RuntimeException(
+          "No column " + columnName + " in table " + tableName))
+      (table, column)
+    }
+
+    tcMappings.map {
+      case (from, to) => ({ getTableColumn(from); from }, getTableColumn(to))
+    }
+  }
+
+  def parse(schemaTableNames: List[String]): Map[String, List[String]] =
+    schemaTableNames
+      .map(_.split('.'))
+      .groupBy(_.head)
+      .mapValues(_.flatMap(_.tail))
+
+  def createModel(
+      jdbcProfile: JdbcProfile,
+      mappedSchemasOpt: Option[Map[String, List[String]]]): DBIO[m.Model] = {
+    import slick.jdbc.meta.MQName
+
+    val filteredTables = mappedSchemasOpt.map { mappedSchemas =>
+      MTable.getTables.map { (tables: Vector[MTable]) =>
+        mappedSchemas.flatMap {
+          case (schemaName, tableNames) =>
+            tableNames.map(
+              tableName =>
+                tables
+                  .find(table =>
+                    table.name match {
+                      case MQName(_, Some(`schemaName`), `tableName`) => true
+                      case _ => false
+                  })
+                  .getOrElse(throw new IllegalArgumentException(
+                    s"$schemaName.$tableName does not exist in the connected database.")))
+        }.toList
+      }
+    }
+
+    jdbcProfile.createModel(filteredTables)
+  }
+}