# Evolutionary Genetics, Bioinformatics, HS 2020
# Blackjack function
# Simona Ruffener
# --------------------------------------------------------------------

blackjack <- function() {
  # One-player against the dealer
  # The player gets two cards and can decide whether to draw another or not as long as his/her toal points are below 21.
  # The dealer starts with one card and has to draw cards as long as his/her score is below 17.
  # Then the player's and the dealer's scores are compared, the higher one wins (if <= 21).
  # With a score over 21, the player/dealer is "busted" and thus loses. This leads to the end of the game.
  # A direct win either for the dealer or player is caused by a score of 21 points (blackjack).
  # The value of the drawn cards is indicated, aces count 11 or 1.
  
  ## Build a deck
  
  cards <-  c(rep("two", 4), rep("three", 4), rep("four", 4), rep("five", 4), rep("six", 4), rep("seven", 4),
      rep("eight", 4),rep("nine", 4), rep("ten", 4), rep("jack", 4), rep("queen", 4), rep("king", 4), rep("ace", 4))
  
  values <- c(rep(2, 4), rep(3, 4), rep(4, 4), rep(5, 4), rep(6, 4), rep(7, 4), rep(8, 4), rep(9, 4),
      rep(10, 16), rep(11, 4))
  
  # create a data frame with all cards from the deck in one column and their values in another column
  df <-  data.frame(cards, values) 
  
  #--------------------------------------------------------------------
  # Getting started
  #--------------------------------------------------------------------
  
  # Define variable for two linebreaks
  lb <- c("\n", "\n")
  
  # Start the game by drawing two cards
  cat("Let me draw two cards for you. ", "\n")
  
  # two rows from the dataframe are randomly sampled without replacement
  playercards <-  df[sample(nrow(df), 2, replace = FALSE),]
  
  # ???
  # Delete the rows that were sampled (delete playercards from dataframe)
  # df <- df[which(!df %in% playercards),]
  # ???
  
  cat("These are your cards and their values: ", lb)
  print(playercards, row.names = FALSE) # row names are omitted
  cat("\n")
  
  # If an ace was drawn, choose if it should count 1 or 11 points
  if (any(playercards == "ace")) {
    acecount <- readline("Should the ace count 1 or 11? (1/11) ")
    if (acecount == 1) playercards[playercards == 11] <- 1
  }
  
  ## Count score
  
  sumplayer <- sum(playercards[, 2])
  cat("Total points: ", sumplayer, lb)
  
  ## Score > 21, busted
  
  if (sumplayer > 21) {
    cat("You're busted!", lb)
  }
  
  ## Black-Jack (21 points)
  
  if (sumplayer  == 21) {
    cat("Winner, winner, chicken dinner! Congratulations!", lb)
  }
  
  #---------------------------------------------------------------------
  # Player's turn
  #---------------------------------------------------------------------
  
  ## Does the player want to draw another card?
  
  answerplayer <- readline("Would you like another card? (yes/no) ")
  cat("\n")
  
  while (answerplayer == "yes" || answerplayer == "y") {
    
    # add another randomly sampled row from the dataframe (a card and it's value) to "playercards"
    playercards <- rbind(playercards, df[sample(nrow(df), 1),])
    cat("These are your cards:", lb)
    print(playercards, row.names = FALSE)
    cat("\n")
    if (any(playercards == "ace")) {
      acecount <- readline("Should the ace count 1 or 11? (1/11) ")
      if (acecount == 1) playercards[playercards == 11] <- 1
    }
    
    ## Count score
    
    sumplayer <-  sum(playercards[, 2]) # sum up the playercard's second column (values)
    cat("Total points: ", sumplayer, lb)
    
    ## Busted if > 21 points
    
    if (sumplayer > 21) {
      cat("You're busted! Maybe next time...", lb)
      break #to exit the while loop
    }
    
    ## Win if  = 21 points (blackjack)
    
    if (sumplayer  == 21) {
      cat("Winner, winner, chicken dinner! You win!", lb)
      break
    }
    
    ## Does the player want another card (if score < 21)?
    
    if (sumplayer < 21) {
      answerplayer <- readline("Would you like another card? (yes/no) ")
      cat("\n")
    }
  }
  
  #---------------------------------------------------------------------
  # Dealer's turn
  #---------------------------------------------------------------------
  
  ## It's the dealer's turn if the player does not want any more cards or is busted.
  
  if (sumplayer < 21) {
    cat("Now it is my turn.", lb)
    dealercard <- df[sample(nrow(df), 1),] # draw first card for the dealer
    cat("My first card: ", lb)
    print(dealercard, row.names = FALSE)
    cat("\n")
    dealercard <- rbind(dealercard, df[sample(nrow(df), 1),])
    cat("My next card: ", lb)
    print(dealercard, row.names = FALSE)
    cat(lb)
    
    ## Score count
    
    sumdealer <- sum(dealercard[, 2])
    # If an ace was drawn and the dealer has > 21 points, the ace should only count 1 point
    if (any(dealercard == "ace")) {
      if (sumdealer > 21) dealercard[dealercard == 11] <- 1
    }
    cat("Total points: ", sumdealer, lb)
    
    ## Draw more cards if score < 17
    
    while (sumdealer < 17) {
      cat("My score is below 17, I'll draw another card.", lb)
      dealercard <- rbind(dealercard, df[sample(nrow(df), 1),])
      cat("My next card: ", lb)
      print(dealercard, row.names = FALSE)
      cat("\n")
      sumdealer <- sum(dealercard[, 2])
      cat("Total points: ", sumdealer, lb)
    }
    
    ## No more cards if the score is between > 17, score comparison
    
    if (sumdealer >= 17 && sumdealer <= 20) {
      cat("Enough cards for me. ", lb)
      cat("Your score: ", sumplayer, ", my score: ", sumdealer, lb)
      if (sumplayer > sumdealer)
        cat("Congratulations, you win!", lb)
      if (sumdealer > sumplayer)
        cat("I win, maybe you're lucky next time.", lb)
    }
    
    ## Blackjack 
    
    if (sumdealer == 21) {
      cat("Winner, winner, chicken dinner! I win.", lb)
    }
    
    ## Busted
    
    if (sumdealer > 21) {
      cat("I'm busted. Congratulations, you win!", lb)
    }
  }
}