// Advanced Part 3 about a really dumb investment strategy

//==========================================================

object CW6c {

//two test portfolios

                            "DLR", "EQIX", "EQR", "ESS", "EXR", "FRT", "GGP", "HCP") 

// (1.a) The function below takes a stock symbol and a year as arguments.

//       It should read the corresponding CSV-file and read the January 

//       data from the given year. The data should be collected in a list of

//       strings for each line in the CSV-file.

import io.Source

import scala.util._

//def get_january_data(symbol: String, year: Int) : List[String] = ...

// (1.b) From the output of the get_january_data function, the next function 

//       should extract the first line (if it exists) and the corresponding

//       first trading price in that year as Option[Double]. If no line is 

//       generated by get_january_data then the result is None

//def get_first_price(symbol: String, year: Int) : Option[Double] = ...

// (1.c) Complete the function below that obtains all first prices

//       for the stock symbols from a portfolio (list of strings) and 

//       for the given range of years. The inner lists are for the

//       stock symbols and the outer list for the years.

//def get_prices(portfolio: List[String], years: Range) : List[List[Option[Double]]] = ...

// (2) The first function below calculates the change factor (delta) between

//     a price in year n and a price in year n + 1. The second function calculates

//     all change factors for all prices (from a portfolio). The input to this

//     function are the nested lists created by get_prices above.

//def get_delta(price_old: Option[Double], price_new: Option[Double]) : Option[Double] = ...

//def get_deltas(data: List[List[Option[Double]]]) :  List[List[Option[Double]]] = ...

// (3) Write a function that given change factors, a starting balance and a year

//     calculates the yearly yield, i.e. new balance, according to our dump investment 

//     strategy. Another function calculates given the same data calculates the

//     compound yield up to a given year. Finally a function combines all 

//     calculations by taking a portfolio, a range of years and a start balance

//     as arguments.

//def yearly_yield(data: List[List[Option[Double]]], balance: Long, year: Int) : Long = ... 

//def compound_yield(data: List[List[Option[Double]]], balance: Long, year: Int) : Long = ... 

//def investment(portfolio: List[String], years: Range, start_balance: Long) : Long = ...

//test cases for the two portfolios given above

//investment(rstate_portfolio, 1978 to 2017, 100)

//investment(blchip_portfolio, 1978 to 2017, 100)

}