package scala.dbc2.syntax

import java.math.{BigDecimal, BigInteger}

import scala.dbc2.datatype.Digits

object DataTypeSyntax {
  /* Data types */
  def boolean = new datatype.Boolean
  def smallint = new datatype.ExactNumeric {
    type NativeType = Short
    val nativeTypeId = dbc2.DataType.SHORT
    val precision = Digits.TwoBytes
    val signed = true
    val scale = Digits.Zero
  }
  def integer = new datatype.ExactNumeric {
    type NativeType = Int
    val nativeTypeId = dbc2.DataType.INT
    val precision = Digits.FourBytes
    val signed = true
    val scale = Digits.Zero
  }
  def bigint = new datatype.ExactNumeric {
    type NativeType = Long
    val nativeTypeId = dbc2.DataType.LONG
    val precision = Digits.EightBytes
    val signed = true
    val scale = Digits.Zero
  }
  def numeric (_precision:Int): datatype.ExactNumeric = numeric(_precision,0)
  def numeric (_precision:Int, _scale:Int): datatype.ExactNumeric =
    Pair(datatype.Factory.bytePrecision(_precision,true),_scale == 0) match {
      case Pair(Digits.FourBytes | Digits.TwoBytes, true) =>
        new datatype.ExactNumeric {
          type NativeType = Int
          val nativeTypeId = DataType.INT
          val precision = Digits.Decimal(_precision)
          val signed = true
          val scale = Digits.Zero
        }
      case Pair(Digits.EightBytes, true) =>
        new datatype.ExactNumeric {
          type NativeType = Long
          val nativeTypeId = DataType.LONG
          val precision = Digits.Decimal(_precision)
          val signed = true
          val scale = Digits.Zero
        }
      case Pair(_,true) =>
        new datatype.ExactNumeric {
          type NativeType = BigInteger
          val nativeTypeId = DataType.BIG_INTEGER
          val precision = Digits.Decimal(_precision)
          val signed = true
          val scale = Digits.Zero
        }
      case Pair(_,false) =>
        new datatype.ExactNumeric {
          type NativeType = BigDecimal
          val nativeTypeId = DataType.BIG_DECIMAL
          val precision = Digits.Decimal(_precision)
          val signed = true
          val scale = Digits.Decimal(_scale)
        }
    }
  def real = new datatype.ApproximateNumeric {
    type NativeType = Float
    val nativeTypeId = DataType.FLOAT
    val precision = Digits.FourBytes
    val signed = true
  }
  def doublePrecision = new datatype.ApproximateNumeric {
    type NativeType = Double
    val nativeTypeId = DataType.DOUBLE
    val precision = Digits.EightBytes
    val signed = true
  }
  def character (_length: Int) = new datatype.Character {
    val length = _length
  }
  def characterVarying (_length: Int) = new datatype.CharacterVarying {
    def length = _length
  }
  def characterLargeObject = new datatype.CharacterLargeObject
  def string = new datatype.CharacterString {}
}