1 files changed, 387 insertions, 0 deletions
diff --git a/src/main/scala/xyz/driver/restquery/db/SlickQueryBuilder.scala b/src/main/scala/xyz/driver/restquery/db/SlickQueryBuilder.scala
new file mode 100644
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--- /dev/null
+++ b/src/main/scala/xyz/driver/restquery/db/SlickQueryBuilder.scala
@@ -0,0 +1,387 @@
+package xyz.driver.pdsuicommon.db
+
+import java.sql.{JDBCType, PreparedStatement}
+import java.time.LocalDateTime
+
+import slick.jdbc.{JdbcProfile, PositionedParameters, SQLActionBuilder, SetParameter}
+import xyz.driver.pdsuicommon.db.Sorting.{Dimension, Sequential}
+import xyz.driver.pdsuicommon.db.SortingOrder.{Ascending, Descending}
+import xyz.driver.pdsuicommon.domain.{LongId, StringId, UuidId}
+
+import scala.concurrent.{ExecutionContext, Future}
+
+object SlickQueryBuilder {
+
+  type Runner[T] = SlickQueryBuilderParameters => Future[Seq[T]]
+
+  type CountResult = Future[(Int, Option[LocalDateTime])]
+
+  type CountRunner = SlickQueryBuilderParameters => CountResult
+
+  /**
+    * Binder for PreparedStatement
+    */
+  type Binder = PreparedStatement => PreparedStatement
+
+  final case class TableData(tableName: String,
+                             lastUpdateFieldName: Option[String] = None,
+                             nullableFields: Set[String] = Set.empty)
+
+  val AllFields = Set("*")
+
+  implicit class SQLActionBuilderConcat(a: SQLActionBuilder) {
+    def concat(b: SQLActionBuilder): SQLActionBuilder = {
+      SQLActionBuilder(a.queryParts ++ b.queryParts, new SetParameter[Unit] {
+        def apply(p: Unit, pp: PositionedParameters): Unit = {
+          a.unitPConv.apply(p, pp)
+          b.unitPConv.apply(p, pp)
+        }
+      })
+    }
+  }
+
+  implicit object SetQueryParameter extends SetParameter[AnyRef] {
+    def apply(v: AnyRef, pp: PositionedParameters) = {
+      pp.setObject(v, JDBCType.BINARY.getVendorTypeNumber)
+    }
+  }
+
+  implicit def setLongIdQueryParameter[T]: SetParameter[LongId[T]] = SetParameter[LongId[T]] { (v, pp) =>
+    pp.setLong(v.id)
+  }
+
+  implicit def setStringIdQueryParameter[T]: SetParameter[StringId[T]] = SetParameter[StringId[T]] { (v, pp) =>
+    pp.setString(v.id)
+  }
+
+  implicit def setUuidIdQueryParameter[T]: SetParameter[UuidId[T]] = SetParameter[UuidId[T]] { (v, pp) =>
+    pp.setObject(v.id, JDBCType.BINARY.getVendorTypeNumber)
+  }
+}
+
+final case class SlickTableLink(keyColumnName: String, foreignTableName: String, foreignKeyColumnName: String)
+
+object SlickQueryBuilderParameters {
+  val AllFields = Set("*")
+}
+
+sealed trait SlickQueryBuilderParameters {
+  import SlickQueryBuilder._
+
+  def databaseName: String
+  def tableData: SlickQueryBuilder.TableData
+  def links: Map[String, SlickTableLink]
+  def filter: SearchFilterExpr
+  def sorting: Sorting
+  def pagination: Option[Pagination]
+
+  def qs: String
+
+  def findLink(tableName: String): SlickTableLink = links.get(tableName) match {
+    case None       => throw new IllegalArgumentException(s"Cannot find a link for `$tableName`")
+    case Some(link) => link
+  }
+
+  def toSql(countQuery: Boolean = false)(implicit profile: JdbcProfile): SQLActionBuilder = {
+    toSql(countQuery, SlickQueryBuilderParameters.AllFields)
+  }
+
+  def toSql(countQuery: Boolean, fields: Set[String])(implicit profile: JdbcProfile): SQLActionBuilder = {
+    import profile.api._
+    val escapedTableName = s"""$qs$databaseName$qs.$qs${tableData.tableName}$qs"""
+    val fieldsSql: String = if (countQuery) {
+      val suffix: String = tableData.lastUpdateFieldName match {
+        case Some(lastUpdateField) => s", max($escapedTableName.$qs$lastUpdateField$qs)"
+        case None                  => ""
+      }
+      s"count(*) $suffix"
+    } else {
+      if (fields == SlickQueryBuilderParameters.AllFields) {
+        s"$escapedTableName.*"
+      } else {
+        fields
+          .map { field =>
+            s"$escapedTableName.$qs$field$qs"
+          }
+          .mkString(", ")
+      }
+    }
+    val where   = filterToSql(escapedTableName, filter)
+    val orderBy = sortingToSql(escapedTableName, sorting)
+
+    val limitSql = limitToSql()
+
+    val sql = sql"""select #$fieldsSql from #$escapedTableName"""
+
+    val filtersTableLinks: Seq[SlickTableLink] = {
+      import SearchFilterExpr._
+      def aux(expr: SearchFilterExpr): Seq[SlickTableLink] = expr match {
+        case Atom.TableName(tableName) => List(findLink(tableName))
+        case Intersection(xs)          => xs.flatMap(aux)
+        case Union(xs)                 => xs.flatMap(aux)
+        case _                         => Nil
+      }
+      aux(filter)
+    }
+
+    val sortingTableLinks: Seq[SlickTableLink] = Sorting.collect(sorting) {
+      case Dimension(Some(foreignTableName), _, _) => findLink(foreignTableName)
+    }
+
+    // Combine links from sorting and filter without duplicates
+    val foreignTableLinks = (filtersTableLinks ++ sortingTableLinks).distinct
+
+    def fkSql(fkLinksSql: SQLActionBuilder, tableLinks: Seq[SlickTableLink]): SQLActionBuilder = {
+      if (tableLinks.nonEmpty) {
+        tableLinks.head match {
+          case SlickTableLink(keyColumnName, foreignTableName, foreignKeyColumnName) =>
+            val escapedForeignTableName = s"$qs$databaseName$qs.$qs$foreignTableName$qs"
+            val join                    = sql""" inner join #$escapedForeignTableName
+             on #$escapedTableName.#$qs#$keyColumnName#$qs=#$escapedForeignTableName.#$qs#$foreignKeyColumnName#$qs"""
+            fkSql(fkLinksSql concat join, tableLinks.tail)
+        }
+      } else fkLinksSql
+    }
+    val foreignTableLinksSql = fkSql(sql"", foreignTableLinks)
+
+    val whereSql = if (where.queryParts.size > 1) {
+      sql" where " concat where
+    } else sql""
+
+    val orderSql = if (orderBy.nonEmpty && !countQuery) {
+      sql" order by #$orderBy"
+    } else sql""
+
+    val limSql = if (limitSql.queryParts.size > 1 && !countQuery) {
+      sql" " concat limitSql
+    } else sql""
+
+    sql concat foreignTableLinksSql concat whereSql concat orderSql concat limSql
+  }
+
+  /**
+    * Converts filter expression to SQL expression.
+    *
+    * @return Returns SQL string and list of values for binding in prepared statement.
+    */
+  protected def filterToSql(escapedTableName: String, filter: SearchFilterExpr)(
+          implicit profile: JdbcProfile): SQLActionBuilder = {
+    import SearchFilterBinaryOperation._
+    import SearchFilterExpr._
+    import profile.api._
+
+    def isNull(string: AnyRef) = Option(string).isEmpty || string.toString.toLowerCase == "null"
+
+    def escapeDimension(dimension: SearchFilterExpr.Dimension) = {
+      s"${dimension.tableName.map(t => s"$qs$databaseName$qs.$qs$t$qs").getOrElse(escapedTableName)}.$qs${dimension.name}$qs"
+    }
+
+    def filterToSqlMultiple(operands: Seq[SearchFilterExpr]) = operands.collect {
+      case x if !SearchFilterExpr.isEmpty(x) => filterToSql(escapedTableName, x)
+    }
+
+    def multipleSqlToAction(first: Boolean,
+                            op: String,
+                            conditions: Seq[SQLActionBuilder],
+                            sql: SQLActionBuilder): SQLActionBuilder = {
+      if (conditions.nonEmpty) {
+        val condition = conditions.head
+        if (first) {
+          multipleSqlToAction(first = false, op, conditions.tail, condition)
+        } else {
+          multipleSqlToAction(first = false, op, conditions.tail, sql concat sql" #${op} " concat condition)
+        }
+      } else sql
+    }
+
+    def concatenateParameters(sql: SQLActionBuilder, first: Boolean, tail: Seq[AnyRef]): SQLActionBuilder = {
+      if (tail.nonEmpty) {
+        if (!first) {
+          concatenateParameters(sql concat sql""",${tail.head}""", first = false, tail.tail)
+        } else {
+          concatenateParameters(sql"""(${tail.head}""", first = false, tail.tail)
+        }
+      } else sql concat sql")"
+    }
+
+    filter match {
+      case x if isEmpty(x) =>
+        sql""
+
+      case AllowAll =>
+        sql"1=1"
+
+      case DenyAll =>
+        sql"1=0"
+
+      case Atom.Binary(dimension, Eq, value) if isNull(value) =>
+        sql"#${escapeDimension(dimension)} is NULL"
+
+      case Atom.Binary(dimension, NotEq, value) if isNull(value) =>
+        sql"#${escapeDimension(dimension)} is not NULL"
+
+      case Atom.Binary(dimension, NotEq, value) if tableData.nullableFields.contains(dimension.name) =>
+        // In MySQL NULL <> Any === NULL
+        // So, to handle NotEq for nullable fields we need to use more complex SQL expression.
+        // http://dev.mysql.com/doc/refman/5.7/en/working-with-null.html
+        val escapedColumn = escapeDimension(dimension)
+        sql"(#${escapedColumn} is null or #${escapedColumn} != $value)"
+
+      case Atom.Binary(dimension, op, value) =>
+        val operator = op match {
+          case Eq    => sql"="
+          case NotEq => sql"!="
+          case Like  => sql" like "
+          case Gt    => sql">"
+          case GtEq  => sql">="
+          case Lt    => sql"<"
+          case LtEq  => sql"<="
+        }
+        sql"#${escapeDimension(dimension)}" concat operator concat sql"""$value"""
+
+      case Atom.NAry(dimension, op, values) =>
+        val sqlOp = op match {
+          case SearchFilterNAryOperation.In    => sql" in "
+          case SearchFilterNAryOperation.NotIn => sql" not in "
+        }
+
+        if (values.nonEmpty) {
+          val formattedValues = concatenateParameters(sql"", first = true, values)
+          sql"#${escapeDimension(dimension)}" concat sqlOp concat formattedValues
+        } else {
+          sql"1=0"
+        }
+
+      case Intersection(operands) =>
+        val filter = multipleSqlToAction(first = true, "and", filterToSqlMultiple(operands), sql"")
+        sql"(" concat filter concat sql")"
+
+      case Union(operands) =>
+        val filter = multipleSqlToAction(first = true, "or", filterToSqlMultiple(operands), sql"")
+        sql"(" concat filter concat sql")"
+    }
+  }
+
+  protected def limitToSql()(implicit profile: JdbcProfile): SQLActionBuilder
+
+  /**
+    * @param escapedMainTableName Should be escaped
+    */
+  protected def sortingToSql(escapedMainTableName: String, sorting: Sorting)(implicit profile: JdbcProfile): String = {
+    sorting match {
+      case Dimension(optSortingTableName, field, order) =>
+        val sortingTableName =
+          optSortingTableName.map(x => s"$qs$databaseName$qs.$qs$x$qs").getOrElse(escapedMainTableName)
+        val fullName = s"$sortingTableName.$qs$field$qs"
+
+        s"$fullName ${orderToSql(order)}"
+
+      case Sequential(xs) =>
+        xs.map(sortingToSql(escapedMainTableName, _)).mkString(", ")
+    }
+  }
+
+  protected def orderToSql(x: SortingOrder): String = x match {
+    case Ascending  => "asc"
+    case Descending => "desc"
+  }
+
+  protected def binder(bindings: List[AnyRef])(bind: PreparedStatement): PreparedStatement = {
+    bindings.zipWithIndex.foreach {
+      case (binding, index) =>
+        bind.setObject(index + 1, binding)
+    }
+
+    bind
+  }
+
+}
+
+final case class SlickPostgresQueryBuilderParameters(databaseName: String,
+                                                     tableData: SlickQueryBuilder.TableData,
+                                                     links: Map[String, SlickTableLink] = Map.empty,
+                                                     filter: SearchFilterExpr = SearchFilterExpr.Empty,
+                                                     sorting: Sorting = Sorting.Empty,
+                                                     pagination: Option[Pagination] = None)
+    extends SlickQueryBuilderParameters {
+
+  def limitToSql()(implicit profile: JdbcProfile): SQLActionBuilder = {
+    import profile.api._
+    pagination.map { pagination =>
+      val startFrom = (pagination.pageNumber - 1) * pagination.pageSize
+      sql"limit #${pagination.pageSize} OFFSET #$startFrom"
+    } getOrElse (sql"")
+  }
+
+  val qs = """""""
+
+}
+
+/**
+  * @param links Links to another tables grouped by foreignTableName
+  */
+final case class SlickMysqlQueryBuilderParameters(databaseName: String,
+                                                  tableData: SlickQueryBuilder.TableData,
+                                                  links: Map[String, SlickTableLink] = Map.empty,
+                                                  filter: SearchFilterExpr = SearchFilterExpr.Empty,
+                                                  sorting: Sorting = Sorting.Empty,
+                                                  pagination: Option[Pagination] = None)
+    extends SlickQueryBuilderParameters {
+
+  def limitToSql()(implicit profile: JdbcProfile): SQLActionBuilder = {
+    import profile.api._
+    pagination
+      .map { pagination =>
+        val startFrom = (pagination.pageNumber - 1) * pagination.pageSize
+        sql"limit #$startFrom, #${pagination.pageSize}"
+      }
+      .getOrElse(sql"")
+  }
+
+  val qs = """`"""
+
+}
+
+abstract class SlickQueryBuilder[T](val parameters: SlickQueryBuilderParameters)(
+        implicit runner: SlickQueryBuilder.Runner[T],
+        countRunner: SlickQueryBuilder.CountRunner) {
+
+  def run()(implicit ec: ExecutionContext): Future[Seq[T]] = runner(parameters)
+
+  def runCount()(implicit ec: ExecutionContext): SlickQueryBuilder.CountResult = countRunner(parameters)
+
+  /**
+    * Runs the query and returns total found rows without considering of pagination.
+    */
+  def runWithCount()(implicit ec: ExecutionContext): Future[(Seq[T], Int, Option[LocalDateTime])] = {
+    for {
+      all                 <- run
+      (total, lastUpdate) <- runCount
+    } yield (all, total, lastUpdate)
+  }
+
+  def withFilter(newFilter: SearchFilterExpr): SlickQueryBuilder[T]
+
+  def withFilter(filter: Option[SearchFilterExpr]): SlickQueryBuilder[T] = {
+    filter.fold(this)(withFilter)
+  }
+
+  def resetFilter: SlickQueryBuilder[T] = withFilter(SearchFilterExpr.Empty)
+
+  def withSorting(newSorting: Sorting): SlickQueryBuilder[T]
+
+  def withSorting(sorting: Option[Sorting]): SlickQueryBuilder[T] = {
+    sorting.fold(this)(withSorting)
+  }
+
+  def resetSorting: SlickQueryBuilder[T] = withSorting(Sorting.Empty)
+
+  def withPagination(newPagination: Pagination): SlickQueryBuilder[T]
+
+  def withPagination(pagination: Option[Pagination]): SlickQueryBuilder[T] = {
+    pagination.fold(this)(withPagination)
+  }
+
+  def resetPagination: SlickQueryBuilder[T]
+
+}