#
# FOURJS_START_COPYRIGHT(U,2011)
# Property of Four Js*
# (c) Copyright Four Js 2011, 2019. All Rights Reserved.
# * Trademark of Four Js Development Tools Europe Ltd
#   in the United States and elsewhere
# 
# Four Js and its suppliers do not warrant or guarantee that these samples
# are accurate and suitable for your purposes. Their inclusion is purely for
# information purposes only.
# FOURJS_END_COPYRIGHT
#

IMPORT XML
IMPORT COM
IMPORT SECURITY

GLOBALS "Types.4gl"

 
PRIVATE DEFINE GoodsInStock DYNAMIC ARRAY OF Good  

PRIVATE DEFINE Sessions DYNAMIC ARRAY OF ShoppingCart

#
# Initialize the list of goods
#  
#
FUNCTION InitGoods()
  CALL GoodsInStock.appendElement()
  LET GoodsInStock[1].serial = 101
  LET GoodsInStock[1].desc = "Air conditioners"
  LET GoodsInStock[1].UnitPrice = 1000.0 

  CALL GoodsInStock.appendElement()
  LET GoodsInStock[2].serial = 102
  LET GoodsInStock[2].desc = "Flower decorations"
  LET GoodsInStock[2].UnitPrice = 4.99
  
  CALL GoodsInStock.appendElement()
  LET GoodsInStock[3].serial = 103
  LET GoodsInStock[3].desc = "Gloves"
  LET GoodsInStock[3].UnitPrice = 14.99
  
  CALL GoodsInStock.appendElement()
  LET GoodsInStock[4].SERIAL = 104
  LET GoodsInStock[4].desc = "Guitar"
  LET GoodsInStock[4].UnitPrice = 355.59
  
  CALL GoodsInStock.appendElement()
  LET GoodsInStock[5].SERIAL = 105
  LET GoodsInStock[5].desc = "Hammer"
  LET GoodsInStock[5].UnitPrice = 12.99

  CALL GoodsInStock.appendElement()
  LET GoodsInStock[6].SERIAL = 106
  LET GoodsInStock[6].desc = "Milk"
  LET GoodsInStock[6].UnitPrice = 2.99

  CALL GoodsInStock.appendElement()
  LET GoodsInStock[7].SERIAL = 107
  LET GoodsInStock[7].desc = "Mirror"
  LET GoodsInStock[7].UnitPrice = 29.99

  CALL GoodsInStock.appendElement()
  LET GoodsInStock[8].SERIAL = 108
  LET GoodsInStock[8].desc = "Mug"
  LET GoodsInStock[8].UnitPrice = 7.99

  CALL GoodsInStock.appendElement()
  LET GoodsInStock[9].SERIAL = 109
  LET GoodsInStock[9].desc = "Ball"
  LET GoodsInStock[9].UnitPrice = 3.99

  CALL GoodsInStock.appendElement()
  LET GoodsInStock[10].SERIAL = 110
  LET GoodsInStock[10].desc = "Pencils"
  LET GoodsInStock[10].UnitPrice = 11.99

  CALL GoodsInStock.appendElement()
  LET GoodsInStock[11].SERIAL = 111
  LET GoodsInStock[11].desc = "Watch"
  LET GoodsInStock[11].UnitPrice = 109.49

  CALL GoodsInStock.appendElement()
  LET GoodsInStock[12].SERIAL = 112
  LET GoodsInStock[12].desc = "Postcard"
  LET GoodsInStock[12].UnitPrice = 0.79

  CALL GoodsInStock.appendElement()
  LET GoodsInStock[13].SERIAL = 113
  LET GoodsInStock[13].desc = "School bag"
  LET GoodsInStock[13].UnitPrice = 24.99
END FUNCTION

#
# Returns the list of goods
#
FUNCTION GetGoodsList()
  RETURN GoodsInStock
END FUNCTION
  
#
# Creates a new shopping cart
#  and returns an identifier
#
FUNCTION MgrGetSessionId(login)
  DEFINE login  STRING
  DEFINE ind INTEGER
  FOR ind = 1 TO Sessions.getLength()
    IF Sessions[ind].cust.login == login THEN
      RETURN Sessions[ind].cust.id
    END IF
  END FOR
  RETURN MgrCreateNewSession(login)
END FUNCTION

#
# Creates a new session
#  and returns the identifier
#
PRIVATE FUNCTION MgrCreateNewSession(login)
  DEFINE login  STRING
  DEFINE ind    STRING
  CALL Sessions.appendElement()
  LET ind = Sessions.getLength()
  LET Sessions[ind].cust.login = login
  LET Sessions[ind].cust.id = security.RandomGenerator.CreateUUIDString()
  LET Sessions[ind].cust.DATE = CURRENT
  RETURN Sessions[ind].cust.id 
END FUNCTION

#
# Scans all sessions and remove them if expiration date is reached
#  Session lifetime is 10 minutes
#
FUNCTION MgrRemoveExpiredSessions()
  DEFINE ind  INTEGER
  DEFINE id   STRING
  FOR ind = 1 TO Sessions.getLength()
    IF CURRENT > Sessions[ind].cust.DATE + INTERVAL (10) MINUTE TO MINUTE THEN
      LET id = Sessions[ind].cust.id
      CALL Sessions.deleteElement(ind)
      DISPLAY "  Sessions "||id||" has expired"
      
    END IF
  END FOR
END FUNCTION

#
# Adds given good to given session
#  return TRUE if added, FALSE otherwise
#
FUNCTION MgrAddGoodToCart(id,serial)
  DEFINE id STRING
  DEFINE SERIAL INTEGER
  DEFINE ind  INTEGER
  FOR ind = 1 TO Sessions.getLength()
    IF Sessions[ind].cust.id = id THEN
      CALL AddGoods(Sessions[ind].goods,serial)
      RETURN TRUE
    END IF
  END FOR
  RETURN FALSE
END FUNCTION

PRIVATE FUNCTION AddGoods(goods,serial)
  DEFINE goods DYNAMIC ARRAY OF GoodValue
  DEFINE SERIAL INTEGER
  DEFINE ind  INTEGER
  FOR ind = 1 TO goods.getLength()
    IF goods[ind].SERIAL = SERIAL THEN
      LET goods[ind].Qte = goods[ind].Qte + 1
       RETURN 
    END IF
  END FOR
  # New Good
  CALL goods.appendElement()
  LET ind = goods.getLength()
  LET goods[ind].SERIAL = SERIAL
  LET goods[ind].DESC = RetrieveGoodDescription(serial)
  LET goods[ind].Qte = 1
END FUNCTION

#
# Removes given good from given session
#  return TRUE if removed, FALSE otherwise
#
FUNCTION MgrRemoveGoodFromCart(id,serial)
  DEFINE id STRING
  DEFINE SERIAL INTEGER
  DEFINE ind  INTEGER
  FOR ind = 1 TO Sessions.getLength()
    IF Sessions[ind].cust.id = id THEN
      CALL RemoveGoods(Sessions[ind].goods,serial)
      RETURN TRUE
    END IF
  END FOR
  RETURN FALSE
END FUNCTION

PRIVATE FUNCTION RemoveGoods(goods,serial)
  DEFINE goods DYNAMIC ARRAY OF GoodValue
  DEFINE SERIAL INTEGER
  DEFINE ind  INTEGER
  FOR ind = 1 TO goods.getLength()
    IF goods[ind].SERIAL = SERIAL THEN
      LET goods[ind].Qte = goods[ind].Qte - 1
      IF goods[ind].Qte == 0 THEN
        CALL goods.deleteElement(ind)
      END IF
      EXIT FOR
    END IF
  END FOR
END FUNCTION

#
# Returns the list of goods in shopping cart
#
FUNCTION MgrGetGoodsInCart(id)
  DEFINE id STRING
  DEFINE ind  INTEGER
  FOR ind = 1 TO Sessions.getLength()
    IF Sessions[ind].cust.id = id THEN
      RETURN TRUE,Sessions[ind].goods
    END IF
  END FOR
  RETURN FALSE,NULL
END FUNCTION

#
# Removes the session of given id
# Note: session is closed
#
FUNCTION MgrDiscardShoppingCart(id)
  DEFINE id STRING
  DEFINE ind  INTEGER
  FOR ind = 1 TO Sessions.getLength()
    IF Sessions[ind].cust.id = id THEN
      CALL Sessions[ind].goods.clear()
      RETURN
    END IF
  END FOR
END FUNCTION

#
# Order the cart and returns the
#  total price
# Note: session is closed
#
FUNCTION MgrOrderCart(id)
  DEFINE id STRING
  DEFINE ind  INTEGER
  DEFINE TOTAL  FLOAT
  FOR ind = 1 TO Sessions.getLength()
    IF Sessions[ind].cust.id = id THEN
      LET TOTAL = ComputePrice(Sessions[ind].goods)
      CALL Sessions.deleteElement(ind)
      RETURN TRUE, total
    END IF
  END FOR
  RETURN FALSE,0
END FUNCTION

#
# Returns the UnitPrice of a good
#
PRIVATE FUNCTION RetrieveGoodUnitPrice(serial)
  DEFINE SERIAL INTEGER
  DEFINE ind    INTEGER
  FOR ind = 1 TO GoodsInStock.getLength()
    IF GoodsInStock[ind].SERIAL = SERIAL THEN
      RETURN GoodsInStock[ind].UnitPrice
    END IF
  END FOR
  RETURN 0
END FUNCTION

#
# Returns the Description of a good
#
PRIVATE FUNCTION RetrieveGoodDescription(serial)
  DEFINE SERIAL INTEGER
  DEFINE ind    INTEGER
  FOR ind = 1 TO GoodsInStock.getLength()
    IF GoodsInStock[ind].SERIAL = SERIAL THEN
      RETURN GoodsInStock[ind].DESC
    END IF
  END FOR
  RETURN 0
END FUNCTION

#
# Computes the total price of all goods
#  
PRIVATE FUNCTION ComputePrice(goods)
  DEFINE goods DYNAMIC ARRAY OF GoodValue
  DEFINE ind  INTEGER
  DEFINE TOTAL  FLOAT
  DEFINE unit   FLOAT
  LET TOTAL = 0
  FOR ind = 1 TO goods.getLength()
    LET unit = RetrieveGoodUnitPrice(goods[ind].SERIAL)
    LET TOTAL = TOTAL + unit * goods[ind].Qte
  END FOR
  RETURN TOTAL
END FUNCTION