// Advanvced Part 3 about a really dumb investment strategy

val rstate_portfolio = List("PLD", "PSA", "AMT", "AIV", "AVB", "BXP", "CCI", 

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

// (1) The function below should obtain the first trading price

// for a stock symbol by using the query

//

//    http://ichart.yahoo.com/table.csv?s=<<symbol>>&a=0&b=1&c=<<year>>&d=1&e=1&f=<<year>> 

// 

// and extracting the first January Adjusted Close price in a year.

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

  Source.fromFile(symbol ++ ".csv")("ISO-8859-1").getLines.toList.filter(_.startsWith(year.toString))

  val data = Try(Some(get_january_data(symbol, year).head)) getOrElse None 

  data.map(_.split(",").toList(1).toDouble)

get_first_price("GOOG", 1980)

get_first_price("GOOG", 2010)

get_first_price("FB", 2014)

// Complete the function below that obtains all first prices

// for the stock symbols from a portfolio for the given

// range of years

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

  for (year <- years.toList) yield

    for (symbol <- portfolio) yield get_first_price(symbol, year)

// test case

val prices_fb    = get_prices(List("FB"), 2012 to 2014)

val prices_goap = get_prices(List("GOOG", "AAPL"), 2010 to 2014)

val prices_bidu = get_prices(List("BIDU"), 2004 to 2008)

val prices_goapfb = get_prices(List("GOOG", "AAPL", "FB"), 2010 to 2016)

// (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).

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

  (price_old, price_new) match {

    case (Some(x), Some(y)) => Some((y - x) / x)

    case _ => None

  }

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

  for (i <- (0 until (data.length - 1)).toList) yield 

    for (j <- (0 until (data(0).length)).toList) yield get_delta(data(i)(j), data(i + 1)(j))

// test case using the prices calculated above

val deltas_fb   = get_deltas(prices_fb)

val deltas_goap = get_deltas(prices_goap)

val deltas_bidu = get_deltas(prices_bidu)

val deltas_goapfb = get_deltas(prices_goapfb)

// calculates the yearly yield, i.e. new balanace, 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 = {

  val somes = data(year).flatten

  val somes_length = somes.length

  if (somes_length == 0) balance

  else {

    val portion: Double = balance.toDouble / somes_length.toDouble

    (for (x <- somes) yield ((1.0 + x) * portion)).sum.toLong

    //balance + (for (x <- somes) yield (x * portion)).sum.toLong

  }

}

def yearly_yield_double(data: List[List[Option[Double]]], balance: Double, year: Int): Double = {

  val somes = data(year).flatten

  val somes_length = somes.length

  if (somes_length == 0) balance

  else {

    val portion: Double = balance / somes_length.toDouble

    balance + (for (x <- somes) yield (x * portion)).sum

  }

}

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

  println(balance)

  if (year >= data.length) balance else {

    val new_balance = yearly_yield(data, balance, year)

    compound_yield(data, new_balance, year + 1)

  }

}

def compound_yield_double(data: List[List[Option[Double]]], balance: Double, year: Int): Long = {

  if (year >= data.length) balance.toLong else {

    val new_balance = yearly_yield_double(data, balance.toDouble, year)

    compound_yield_double(data, new_balance, year + 1)

  }

val prices_fb    = get_prices(List("FB"), 2012 to 2014)

val prices_goap = get_prices(List("GOOG", "AAPL"), 2010 to 2014)

val prices_bidu = get_prices(List("BIDU"), 2004 to 2008)

val prices_goapfb = get_prices(List("GOOG", "AAPL", "FB"), 2010 to 2016)

val deltas_fb   = get_deltas(prices_fb)

val deltas_goap = get_deltas(prices_goap)

val deltas_bidu = get_deltas(prices_bidu)

val deltas_goapfb = get_deltas(prices_goapfb)

yearly_yield(deltas_bidu, 100, 0)

yearly_yield(deltas_bidu, 100, 1)

yearly_yield(deltas_bidu, 100, 2)

yearly_yield(deltas_bidu, 192, 3)

//598

yearly_yield(deltas_fb, 100, 0)

yearly_yield(deltas_fb, 100, 1)

//yearly_yield(deltas_fb, 195, 2)

yearly_yield(deltas_goap, 100, 0)

yearly_yield(deltas_goap, 125, 1)

yearly_yield(deltas_goap, 146, 2)

yearly_yield(deltas_goap, 177, 3)

//yearly_yield(deltas_goap, 227, 4)

yearly_yield(deltas_goapfb, 100, 0)

yearly_yield(deltas_goapfb, 125, 1)

yearly_yield(deltas_goapfb, 146, 2)

yearly_yield(deltas_goapfb, 177, 3)

yearly_yield(deltas_goapfb, 267, 4)

yearly_yield(deltas_goapfb, 337, 5)

//416

compound_yield(deltas_goapfb.take(1), 100, 0)

compound_yield(deltas_goapfb.take(2), 100, 0)

compound_yield(deltas_goapfb.take(3), 100, 0)

compound_yield(deltas_goapfb.take(4), 100, 0)

compound_yield(deltas_goapfb.take(5), 100, 0)

compound_yield(deltas_goapfb.take(6), 100, 0)

compound_yield_double(deltas_goapfb.take(1), 100.0, 0)

compound_yield_double(deltas_goapfb.take(2), 100.0, 0)

compound_yield_double(deltas_goapfb.take(3), 100.0, 0)

compound_yield_double(deltas_goapfb.take(4), 100.0, 0)

compound_yield_double(deltas_goapfb.take(5), 100.0, 0)

compound_yield_double(deltas_goapfb.take(6), 100.0, 0)

//yearly_yield(d, 100, 0)

//compound_yield(d.take(6), 100, 0)

//test case

//yearly_yield(d, 100, 0)

//yearly_yield(d, 225, 1)

//yearly_yield(d, 246, 2)

//yearly_yield(d, 466, 3)

//yearly_yield(d, 218, 4)

//yearly_yield(d, 100, 0)

//yearly_yield(d, 125, 1)

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

  compound_yield(get_deltas(get_prices(portfolio, years)), start_balance, 0)

def investment_double(portfolio: List[String], years: Range, start_balance: Long): Long = {

  compound_yield_double(get_deltas(get_prices(portfolio, years)), start_balance.toDouble, 0)

}

investment_double(rstate_portfolio, 1978 to 2017, 100)

investment_double(blchip_portfolio, 1978 to 2017, 100)

/*

val q1 = get_deltas(get_prices(List("GOOG", "AAPL", "BIDU"), 2000 to 2017))

yearly_yield(q1, 100, 0)

yearly_yield(q1, 100, 1)

yearly_yield(q1, 100, 2)

yearly_yield(q1, 100, 3)

yearly_yield(q1, 100, 4)

yearly_yield(q1, 100, 5)

yearly_yield(q1, 100, 6)

investment(List("GOOG", "AAPL", "BIDU"), 2004 to 2017, 100)

val one = get_deltas(get_prices(rstate_portfolio, 1978 to 1984))

val two = get_deltas(get_prices(blchip_portfolio, 1978 to 1984))

val one_full = get_deltas(get_prices(rstate_portfolio, 1978 to 2017))

val two_full = get_deltas(get_prices(blchip_portfolio, 1978 to 2017))

one_full.map(_.flatten).map(_.sum).sum

two_full.map(_.flatten).map(_.sum).sum

//test cases for the two portfolios given above

//println("Real data: " + investment(rstate_portfolio, 1978 to 2017, 100))

//println("Blue data: " + investment(blchip_portfolio, 1978 to 2017, 100))

for (i <- 2000 to 2017) {

  println("Year " + i)

  //println("Real data: " + investment(rstate_portfolio, 1978 to i, 100))

  //println("Blue data: " + investment(blchip_portfolio, 1978 to i, 100))

  println("test: " + investment(List("GOOG", "AAPL", "BIDU"), 2000 to i, 100))

*/ 

//1984

//1992

}