Android Academy exercise

src_Main.kt

import java.math.BigDecimal
import java.time.LocalDateTime

fun main() {
    // Setup Test Orders
    val firstOrderLines = listOf(OrdersAnalyzer.OrderLine(9872, "Pencil", 3, BigDecimal.valueOf(3)))
    val firstOrder = OrdersAnalyzer.Order(554, LocalDateTime.parse("2017-03-25T10:35:20"), firstOrderLines)

    val secondOrderLines = listOf(OrdersAnalyzer.OrderLine(9872, "Pencil", 2, BigDecimal.valueOf(3)),
        OrdersAnalyzer.OrderLine(1746, "Eraser", 1, BigDecimal.valueOf(1)))
    val secondOrder = OrdersAnalyzer.Order(555, LocalDateTime.parse("2017-03-25T11:24:20"), secondOrderLines)

    val thirdOrderLines = listOf(OrdersAnalyzer.OrderLine(5723, "Pen", 4, BigDecimal.valueOf(4.22)),
        OrdersAnalyzer.OrderLine(9872, "Pencil", 3, BigDecimal.valueOf(3.12)),
        OrdersAnalyzer.OrderLine(3433, "Erasers Set", 1, BigDecimal.valueOf(6.15)))
    val thirdOrder = OrdersAnalyzer.Order(453, LocalDateTime.parse("2017-03-27T14:53:12"), thirdOrderLines)

    val fourthOrderLines = listOf(OrdersAnalyzer.OrderLine(5723, "Pen", 7, BigDecimal.valueOf(4.22)),
        OrdersAnalyzer.OrderLine(3433, "Erasers Set", 2, BigDecimal.valueOf(6.15)))
    val fourthOrder = OrdersAnalyzer.Order(431, LocalDateTime.parse("2017-03-20T12:15:02"), fourthOrderLines)

    val fifthOrderLines = listOf(OrdersAnalyzer.OrderLine(9872, "Pencil", 4, BigDecimal.valueOf(3.12)),
        OrdersAnalyzer.OrderLine(4098, "Marker", 5, BigDecimal.valueOf(4.50)))
    val fifthOrder = OrdersAnalyzer.Order(690, LocalDateTime.parse("2017-03-26T11:14:00"), fifthOrderLines)

    val orderList = listOf(firstOrder, secondOrder, thirdOrder, fourthOrder, fifthOrder)

    // Run test
    val ordersAnalyzer = OrdersAnalyzer()
    print(ordersAnalyzer.totalDailySales(orderList))
}

src_OrdersAnalyzer.kt

import java.math.BigDecimal
import java.time.DayOfWeek
import java.time.LocalDateTime

class OrdersAnalyzer {
    data class Order(val orderId: Int, val creationDate: LocalDateTime, val orderLines: List<OrderLine>)

    data class OrderLine(val productId: Int, val name: String, val quantity: Int, val unitPrice: BigDecimal)

    fun totalDailySales(orders: List<Order>): Map<DayOfWeek, Int> {
        val dailySalesMap = mutableMapOf<DayOfWeek, Int>()
        
        for (dayOfWeek in DayOfWeek.values()) {
            dailySalesMap[dayOfWeek] = 0
        }

        var tempOrderDayOfWeek: DayOfWeek
        var tempOrderQty: Int
        var tempDayOfWeekQty: Int

        // Get each orderLine quantity and add to the day within dailySalesMap
        for (order in orders) {
            tempOrderDayOfWeek = order.creationDate.dayOfWeek

            tempOrderQty = 0
            order.orderLines.forEach { tempOrderQty += it.quantity }

            tempDayOfWeekQty = dailySalesMap.getOrDefault(tempOrderDayOfWeek, 0)

            dailySalesMap[tempOrderDayOfWeek] = tempDayOfWeekQty + tempOrderQty
        }

        return dailySalesMap
    }
}

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