// Nik Johnson
// 1-25-2024
// TA: Andy Ruan
// modified attempt for resubmission 1

import java.util.*;
import java.io.*;

// stock simulator
// stock market sandbox which reads fake market data from "stonks.tsv", and allows users to:
// buy and sell stocks, and save their portfolio to a file.
// upon quitting, the value of the users portfolio will be calculated and printed.

public class Stonks {
    public static final String STOCKS_FILE_NAME = "stonks.tsv";

    public static void main(String[] args) throws FileNotFoundException {
        Scanner console = new Scanner(System.in);
        File stonks = new File(STOCKS_FILE_NAME);
        Scanner stonklines = new Scanner(stonks);
        int numStocks = Integer.parseInt(stonklines.nextLine());

        String[] tickers = new String[numStocks];
        Double[] prices = new Double[numStocks];
        Double[] portfolio = new Double[numStocks];

        // fill portfolio with zeros to prevent null exceptions
        // without using Arrays.fill()
        for (int n = 0; n < numStocks; n++) {
            portfolio[n] = 0.0;
        }

        String info = stonklines.nextLine();                    
        
        // this runs once.
        // functionally decomposing it would add lines of code, but no functionality. 
        int index = 0;
        while (stonklines.hasNextLine()) {
            String nextline = stonklines.nextLine();
            Scanner token = new Scanner(nextline);
            tickers[index] = token.next();
            prices[index] = token.nextDouble();
            index++;
        }

        System.out.println("Welcome to the CSE 122 Stocks Simulator!");
        System.out.println("There are " + numStocks + " stocks on the market:");

        for (int i = 0; i < numStocks; i++) {
            System.out.println(tickers[i] + ": " + prices[i]);

        }

        System.out.println();
        String next = navigator(console);

        while (!next.equals("quit")) {
            if (next.equals("buy")) {
                portfolio = buy(console, tickers, prices, portfolio);
            } else if (next.equals("sell")) {
                portfolio = sell(console, tickers, prices, portfolio);
            } else if (next.equals("save")) {
                save(console, tickers, portfolio);
            } else {
                System.out.println("Invalid choice: " + next);
                System.out.println("Please try again");
                System.out.println();
            }
            next = navigator(console);
        }

        Double value = quit(prices, portfolio);
        System.out.println("Your portfolio is currently valued at: $" + value);
    }

    // menu method, called for inital prompt and then after using any other methods
    // returns String which decides which function to use

    public static String navigator(Scanner console) {
        System.out.println("Menu: buy, sell, save, quit");
        System.out.print("Enter your choice: ");
        String destination = console.next();
        return destination;
    }

    // add (buy) to portfolio according to user input, no lower than $5.0
    // takes console scanner, and all data arrays defined in main lines 24-26
    // return modified portfolio with MORE shares than before

    public static Double[] buy(Scanner console, String[] tickers, 
    Double[] prices, Double[] portfolio) {
        System.out.print("Enter the stock ticker: ");
        String order = console.next();
        System.out.print("Enter your budget: ");
        Double budget = console.nextDouble();

        if (budget >= 5.0) {
            for (int i = 0; i < tickers.length; i++) {
                if (order.equals(tickers[i])) {
                    portfolio[i] += (budget / prices[i]);
                    System.out.println("You successfully bought " + tickers[i] + ".");
                    System.out.println();
            }
        } 
        } else {
            System.out.println("Budget must be at least $5");
            System.out.println();
        }       
        return portfolio;
    }

    // subtract (sell) from portfolio according to user input, if they have enough to sell
    // takes console scanner, and all data arrays defined in main lines 24-26
    // return modified portfolio with LESS shares than before

    public static Double[] sell(Scanner console, String[] tickers, 
    Double[] prices, Double[] portfolio) {
        System.out.print("Enter the stock ticker: ");
        String ticker = console.next();
        System.out.print("Enter the number of shares to sell: ");
        Double sellAmount = console.nextDouble();
        for (int i = 0; i < tickers.length; i++) {
            if (ticker.equals(tickers[i])) {
                if (sellAmount > portfolio[i]) {
                    System.out.println("You do not have enough shares of " + ticker + " to sell " + sellAmount + " shares.");
                    System.out.println();
                } else if (sellAmount <= portfolio[i]) {
                    portfolio[i] = portfolio[i] - sellAmount;
                    System.out.println("You successfully sold " + sellAmount + " shares of " + ticker + ".");
                    System.out.println();
                }
            }
        }
        return portfolio;
    }

    // write current portfolio to file named according to user input
    // takes console scanner, array of tickers and the users current portfolio

    public static void save(Scanner console, String[] tickers, Double[] portfolio) throws FileNotFoundException {
        System.out.print("Enter new portfolio file name: ");
        String fileName = console.next();
        System.out.println();
        File saveData = new File(fileName);
        PrintStream savePortfolio = new PrintStream(saveData);
        for (int i = 0; i < tickers.length; i++) {
            if (portfolio[i] != 0.0) {
                savePortfolio.println(tickers[i] + " " + portfolio[i]);
            }
        }
    }

    // upon quitting, calculate total portfolio value using-
    // -values in portfolio and current market prices
    // return total value for printing

    public static double quit(Double[] prices, Double[] portfolio) {
        System.out.println();
        Double portfolioValue = 0.0;
        for (int i = 0; i < prices.length; i++) {
            if (portfolio[i] != null) {
                Double currValue = prices[i]*portfolio[i];
                portfolioValue += currValue;
            } else portfolioValue += 0;
        }
        return portfolioValue;
    }

}