Lifted Embedding DSL

// Base trait for all query representations
sealed trait QueryBase[T] extends Rep[T]

// Main query class
sealed abstract class Query[+E, U, C[_]] extends QueryBase[C[U]] {
  def shaped: ShapedValue[_ <: E, U]
}

// Base representation trait
trait Rep[T]

sealed abstract class Query[+E, U, C[_]] extends QueryBase[C[U]] {
  // Monadic operations
  def map[F, G, T](f: E => F)(implicit shape: Shape[_ <: FlatShapeLevel, F, T, G]): Query[G, T, C]
  def flatMap[F, T, D[_]](f: E => Query[F, T, D]): Query[F, T, C]
  
  // Filtering
  def filter[T <: Column[_]](f: E => T)(implicit wt: CanBeQueryCondition[T]): Query[E, U, C]
  def withFilter[T <: Column[_]](f: E => T)(implicit wt: CanBeQueryCondition[T]): Query[E, U, C]
  def filterNot[T <: Column[_]](f: E => T)(implicit wt: CanBeQueryCondition[T]): Query[E, U, C]
  
  // Sorting
  def sortBy[T <% Ordered](f: E => T): Query[E, U, C]
  
  // Grouping  
  def groupBy[K, T, G, P](f: E => K)(implicit kshape: Shape[_ <: FlatShapeLevel, K, T, G]): Query[G, P, C]
  
  // Joins
  def join[E2, U2, D[_]](q2: Query[E2, U2, D]): Query[(E, E2), (U, U2), C]
  def leftJoin[E2, U2, D[_]](q2: Query[E2, U2, D]): Query[(E, Option[E2]), (U, Option[U2]), C]
  def rightJoin[E2, U2, D[_]](q2: Query[E2, U2, D]): Query[(Option[E], E2), (Option[U], U2), C]
  def outerJoin[E2, U2, D[_]](q2: Query[E2, U2, D]): Query[(Option[E], Option[E2]), (Option[U], Option[U2]), C]
  def zip[E2, U2, D[_]](q2: Query[E2, U2, D]): Query[(E, E2), (U, U2), C]
  def zipWith[E2, U2, F, G, T, D[_]](q2: Query[E2, U2, D], f: (E, E2) => F): Query[G, T, C]
  def zipWithIndex: Query[(E, Column[Long]), (U, Long), C]
  
  // Pagination
  def take(num: Long): Query[E, U, C]
  def drop(num: Long): Query[E, U, C]
  
  // Aggregation
  def length: Column[Int]
  def countDistinct: Column[Int]
  def exists: Column[Boolean]
  
  // Set operations
  def union[O >: E, R, D[_]](other: Query[O, R, D]): Query[O, R, C]
  def unionAll[O >: E, R, D[_]](other: Query[O, R, D]): Query[O, R, C]
  def ++[O >: E, R, D[_]](other: Query[O, R, D]): Query[O, R, C]
  
  // Execution (when imported from driver)
  def list()(implicit session: Session): List[U]
  def first()(implicit session: Session): U  
  def firstOption()(implicit session: Session): Option[U]
  def run()(implicit session: Session): C[U]
}

class TableQuery[E <: AbstractTable[_]] extends Query[E, E#TableElementType, Seq] {
  // Insert operations
  def +=(value: E#TableElementType)(implicit session: Session): Unit
  def ++=(values: Iterable[E#TableElementType])(implicit session: Session): Unit
  def insert(value: E#TableElementType)(implicit session: Session): Int
  def insertAll(values: E#TableElementType*)(implicit session: Session): Option[Int]
  
  // Update operations
  def update(value: E#TableElementType)(implicit session: Session): Int
  
  // Delete operations  
  def delete()(implicit session: Session): Int
  
  // DDL operations
  def ddl: DDL
}

// Factory object
object TableQuery {
  def apply[E <: AbstractTable[_]](cons: Tag => E): TableQuery[E]
  def apply[E <: AbstractTable[_]](implicit tt: TypeTag[E]): TableQuery[E] = macro TableQueryMacro.apply[E]
}

// Base column representation
abstract class Column[T] extends Rep[T] {
  // Ordering
  def asc: ColumnOrdered[T]
  def desc: ColumnOrdered[T]
  
  // Null operations
  def isNull: Column[Boolean]
  def isNotNull: Column[Boolean]
  def ifNull[S >: T](replacement: S): Column[S]
  
  // Optional conversion
  def ? : Column[Option[T]]
}

// Constant columns (client-side values)  
abstract class ConstColumn[T] extends Column[T]

// Literal values known at compile-time
class LiteralColumn[T](val value: T) extends ConstColumn[T]

// Runtime parameters
class ParameterColumn[T] extends ConstColumn[T]

// Ordered columns for sorting
sealed trait ColumnOrdered[+T]

// Base extension framework
trait ExtensionMethods[B1, P1] {
  protected implicit def c1: Column[P1]
}

// Core column operations
final class ColumnExtensionMethods[B1, P1](val c: Column[P1]) extends ExtensionMethods[B1, P1] {
  // Equality operations (type-safe)
  def ===[P2, R](e: Column[P2])(implicit om: o#arg[B1, P2]#to[Boolean, R]): Column[R]
  def =!=[P2, R](e: Column[P2])(implicit om: o#arg[B1, P2]#to[Boolean, R]): Column[R]
  
  // Comparison operations
  def <[P2, R](e: Column[P2])(implicit om: o#arg[B1, P2]#to[Boolean, R]): Column[R]
  def <=[P2, R](e: Column[P2])(implicit om: o#arg[B1, P2]#to[Boolean, R]): Column[R]
  def >[P2, R](e: Column[P2])(implicit om: o#arg[B1, P2]#to[Boolean, R]): Column[R]
  def >=[P2, R](e: Column[P2])(implicit om: o#arg[B1, P2]#to[Boolean, R]): Column[R]
  
  // Set membership
  def inSet[R](values: Traversable[B1]): Column[Boolean]
  def inSetBind[R](values: Traversable[B1]): Column[Boolean]
  def between[P2, P3, R](start: Column[P2], end: Column[P3]): Column[Boolean]
}

// String-specific operations
final class StringColumnExtensionMethods[P1](val c: Column[P1]) extends ExtensionMethods[String, P1] {
  def like[R](e: Column[String]): Column[Boolean]
  def ++[P2, R](e: Column[P2]): Column[String]  // String concatenation
  def startsWith[R](s: String): Column[Boolean]
  def endsWith[R](s: String): Column[Boolean]
  def toUpperCase: Column[String]  
  def toLowerCase: Column[String]
  def ltrim: Column[String]
  def rtrim: Column[String]
  def trim: Column[String]
}

// Numeric operations  
final class NumericColumnExtensionMethods[B1, P1](val c: Column[P1]) extends ExtensionMethods[B1, P1] {
  def +[P2, R](e: Column[P2]): Column[R] 
  def -[P2, R](e: Column[P2]): Column[R]
  def *[P2, R](e: Column[P2]): Column[R]
  def /[P2, R](e: Column[P2]): Column[R]
  def %[P2, R](e: Column[P2]): Column[R]
  def abs: Column[B1]
  def ceil: Column[B1]
  def floor: Column[B1]
  def sign: Column[Int]
}

// Boolean operations
final class BooleanColumnExtensionMethods[P1](val c: Column[P1]) extends ExtensionMethods[Boolean, P1] {
  def &&[P2, R](b: Column[P2]): Column[Boolean]
  def ||[P2, R](b: Column[P2]): Column[Boolean]  
  def unary_! : Column[Boolean]
}

import scala.slick.driver.H2Driver.simple._

// Table definition
class Users(tag: Tag) extends Table[(Int, String, Option[String])](tag, "users") {
  def id = column[Int]("id", O.PrimaryKey, O.AutoInc)
  def name = column[String]("name")
  def email = column[Option[String]]("email")
  def * = (id, name, email)
}

val users = TableQuery[Users]

// Basic queries
val query1 = users.filter(_.name === "John")
val query2 = users.map(_.email)
val query3 = users.filter(_.id > 10).map(u => (u.name, u.email))

// Chaining operations
val activeUsers = users
  .filter(_.email.isDefined)
  .sortBy(_.name.asc)
  .take(50)

class Orders(tag: Tag) extends Table[(Int, Int, String)](tag, "orders") {
  def id = column[Int]("id", O.PrimaryKey, O.AutoInc)
  def userId = column[Int]("user_id")
  def product = column[String]("product")
  def * = (id, userId, product)
}

val orders = TableQuery[Orders]

// Inner join
val userOrders = users.join(orders).on(_.id === _.userId)
val userOrdersQuery = userOrders.map { case (u, o) => (u.name, o.product) }

// Left join  
val allUsersOrders = users.joinLeft(orders).on(_.id === _.userId)
val leftJoinQuery = allUsersOrders.map { case (u, o) => (u.name, o.map(_.product)) }

// Complex join with filtering
val recentOrders = users
  .join(orders).on(_.id === _.userId)
  .filter { case (u, o) => u.email.isDefined && o.product.like("%laptop%") }
  .map { case (u, o) => (u.name, o.product) }

// Count operations
val userCount = users.length
val usersWithEmail = users.filter(_.email.isDefined).length

// Grouping
val ordersByUser = orders
  .groupBy(_.userId)
  .map { case (userId, orders) => (userId, orders.length) }

// Complex aggregation
class OrderItems(tag: Tag) extends Table[(Int, Int, Double)](tag, "order_items") {
  def orderId = column[Int]("order_id")
  def quantity = column[Int]("quantity")  
  def price = column[Double]("price")
  def * = (orderId, quantity, price)
}

val orderItems = TableQuery[OrderItems]

val orderTotals = orderItems
  .groupBy(_.orderId)
  .map { case (orderId, items) => 
    (orderId, items.map(i => i.quantity * i.price).sum)
  }

// Subqueries  
val richUsers = users.filter(_.id in orders.filter(_.product === "luxury").map(_.userId))

// Exists  
val usersWithOrders = users.filter(u => orders.filter(_.userId === u.id).exists)

// Union
val activeUsers = users.filter(_.email.isDefined)
val vipUsers = users.filter(_.name.startsWith("VIP"))
val combinedUsers = activeUsers.union(vipUsers)

// Case expressions
val userType = users.map { u =>
  Case
    .when(u.email.isDefined).then("active")
    .when(u.name.startsWith("VIP")).then("vip") 
    .otherwise("regular")
}

// Window functions (if supported by database)
val rankedUsers = users
  .map(u => (u.name, Functions.rowNumber.over.sortBy(u.id.desc)))
  .sortBy(_._2.asc)

// Typeclass for valid query conditions
trait CanBeQueryCondition[-T] {
  def apply(value: T): Column[Boolean]
}

// Standard instances
implicit val columnCanBeQueryCondition: CanBeQueryCondition[Column[Boolean]]
implicit val booleanCanBeQueryCondition: CanBeQueryCondition[Boolean]
implicit def optionCanBeQueryCondition[T](implicit ev: CanBeQueryCondition[T]): CanBeQueryCondition[Option[T]]

// Valid conditions
users.filter(_.email.isDefined)  // Column[Boolean]
users.filter(_ => true)          // Boolean literal
users.filter(_.name === "John")  // Column comparison

// Combining conditions
users.filter(u => u.email.isDefined && u.name.startsWith("J"))
users.filter(u => u.id > 10 || u.name === "Admin")

// Core shape abstraction
abstract class Shape[Level, -Mixed_, Unpacked_, Packed_] {
  def pack(from: Mixed_): Packed_  
  def unpack(from: Packed_): Mixed_
  def packedShape: Shape[Level, Packed_, Unpacked_, Packed_]
  def toNode(value: Mixed_): Node
}

// Proven shape for table projections
type ProvenShape[T] = Shape[FlatShapeLevel, T, T, Column[T]]

// Shape levels
sealed trait ShapeLevel
trait FlatShapeLevel extends ShapeLevel
trait NestedShapeLevel extends ShapeLevel

// Shaped values  
case class ShapedValue[T, U](value: T, shape: Shape[_ <: ShapeLevel, T, U, _]) {
  def toNode: Node = shape.toNode(value)
}

// Single column
val nameShape: ProvenShape[String] = users.map(_.name).shaped

// Tuple shapes
val userTuple: ProvenShape[(Int, String)] = users.map(u => (u.id, u.name)).shaped

// Case class mapping (with macro support)
case class User(id: Int, name: String, email: Option[String])

val userProjection = users.map(u => (u.id, u.name, u.email)) <> (User.tupled, User.unapply)

// Compiled query wrapper
class Compiled[T] {
  def apply(param: T#Param): T#Result
}

// Compilation functions
object Compiled {
  def apply[V, R](f: V => R): Compiled[V => R]
}

// Simple parameter
val userById = Compiled { id: Column[Int] =>
  users.filter(_.id === id)
}

// Multiple parameters  
val userByNameAndEmail = Compiled { (name: Column[String], email: Column[String]) =>
  users.filter(u => u.name === name && u.email === email)
}

// Usage
Database.forURL("...") withSession { implicit session =>
  val user1 = userById(1).first
  val user2 = userByNameAndEmail("John", "john@example.com").firstOption
}

// Simple function calls
object SimpleFunction {
  def apply[R](name: String): SimpleBinaryOperator[R]
  def apply[T1, R](name: String): SimpleFunction[T1, R]
  def apply[T1, T2, R](name: String): SimpleFunction[(T1, T2), R]
  // ... up to 22 parameters
}

// Binary operators
object SimpleBinaryOperator {
  def apply[R](name: String): SimpleBinaryOperator[R]
}

// Custom functions
val upper = SimpleFunction.unary[String]("upper")
val concat = SimpleFunction.binary[String]("concat")
val random = SimpleFunction.nullary[Double]("random")

// Usage in queries  
val upperNames = users.map(u => upper(u.name))
val fullNames = users.map(u => concat(u.name, " Suffix"))
val randomScores = users.map(u => (u.name, random()))

// Base trait for custom mappings
trait MappedTo[T] extends Any {
  def value: T
}

// Column type construction
trait ColumnType[T] extends TypedType[T]

// Status enum mapping
sealed trait Status extends MappedTo[String]
case object Active extends Status { val value = "active" }
case object Inactive extends Status { val value = "inactive" }

implicit val statusColumnType = MappedColumnType.base[Status, String](
  _.value, 
  {
    case "active" => Active
    case "inactive" => Inactive  
  }
)

// Usage in tables
class Users(tag: Tag) extends Table[(Int, String, Status)](tag, "users") {
  def id = column[Int]("id", O.PrimaryKey, O.AutoInc)
  def name = column[String]("name")
  def status = column[Status]("status")  // Uses custom mapping
  def * = (id, name, status)
}