[Editor] Create DatabaseService and add support for fetching database tables

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/database/model/Column.kt

@@ -0,0 +1,3 @@
+package com.bartlomiejpluta.base.editor.database.model
+
+class Column(val table: Table, val name: String, val type: ColumnType, val nullable: Boolean, val primary: Boolean)

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/database/model/ColumnType.kt

@@ -0,0 +1,31 @@
+package com.bartlomiejpluta.base.editor.database.model
+
+enum class ColumnType {
+   INT,
+   BOOLEAN,
+   TINYINT,
+   SMALLINT,
+   BIGINT,
+   IDENTITY,
+   DECIMAL,
+   DOUBLE,
+   REAL,
+   TIME,
+   TIME_WITH_TIME_ZONE,
+   DATE,
+   TIMESTAMP,
+   TIMESTAMP_WITH_TIME_ZONE,
+   BINARY,
+   OTHER,
+   VARCHAR,
+   VARCHAR_IGNORECASE,
+   CHAR,
+   BLOB,
+   CLOB,
+   UUID,
+   ARRAY,
+   ENUM,
+   GEOMETRY,
+   JSON,
+   INTERVAL
+}

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/database/model/Table.kt

@@ -0,0 +1,12 @@
+package com.bartlomiejpluta.base.editor.database.model
+
+class Table(val name: String) {
+   private val mutableColumns = mutableListOf<Column>()
+   val columns: List<Column>
+      get() = mutableColumns
+
+   fun addColumn(name: String, type: ColumnType, nullable: Boolean, primary: Boolean) {
+      val column = Column(this, name, type, nullable, primary)
+      mutableColumns += column
+   }
+}

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/database/service/DatabaseService.kt

@@ -0,0 +1,7 @@
+package com.bartlomiejpluta.base.editor.database.service
+
+import com.bartlomiejpluta.base.editor.database.model.Table
+
+interface DatabaseService {
+   val tables: List<Table>
+}

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/database/service/H2DatabaseService.kt

@@ -0,0 +1,51 @@
+package com.bartlomiejpluta.base.editor.database.service
+
+import com.bartlomiejpluta.base.editor.database.model.ColumnType
+import com.bartlomiejpluta.base.editor.database.model.Table
+import com.bartlomiejpluta.base.editor.project.context.ProjectContext
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.stereotype.Service
+import java.sql.Connection
+
+@Service
+class H2DatabaseService : DatabaseService {
+
+   @Autowired
+   private lateinit var projectContext: ProjectContext
+
+   override val tables: List<Table>
+      get() {
+         val tables = connection {
+            val tables = mutableListOf<Table>()
+            val results = prepareStatement("SHOW TABLES").executeQuery()
+            while (results.next()) {
+               if (results.getString("TABLE_SCHEMA") == "PUBLIC") {
+                  tables.add(Table(results.getString("TABLE_NAME")))
+               }
+            }
+
+            tables
+         } ?: emptyList()
+
+         tables.forEach { table ->
+            connection {
+               val results = prepareStatement("SHOW COLUMNS FROM ${table.name}").executeQuery()
+               while (results.next()) {
+                  table.addColumn(
+                     results.getString("FIELD"),
+                     parseType(results.getString("TYPE")),
+                     results.getBoolean("NULL"),
+                     results.getString("KEY") == "PRI"
+                  )
+               }
+            }
+         }
+
+         return tables
+      }
+
+   private inline fun <reified T> connection(op: Connection.() -> T) =
+      projectContext.project?.database?.connection?.use(op)
+
+   private fun parseType(type: String) = ColumnType.valueOf(type.replace(" ", "_").substringBefore("("))
+}