Savings.java

import java.io.IOException;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.time.Instant;
import java.util.InputMismatchException;

/**
 * Total Savings
 * @author Luke
 */
public class Savings {
	private boolean running;

	/**
	 * Will show all options when managing their savings pools and prompt for them to choose one
	 */
	public void mainMenu(){
		running = true;
		while (running) {
			System.out.println("Please select an option by using the number associated with each command:\n" +
					"1. Add new savings pool\n" +
					"2. Edit an existing savings pool\n" +
					"3. Delete a savings pool\n" +
					"4. View your savings pools\n" +
					"5. Return to main menu");
			try {
				String input = App.userIn.readLine();
				inputChecker(input);
			} catch (IOException e) {
				e.printStackTrace();
				System.out.println("Unable to take input from console");
			} catch (SQLException e){
				e.printStackTrace();
				System.out.println("Unable to get info from table");
			}
		}
	}

	/**
	 * takes input from main menu and calls correct method
	 * @param input their choice from main menu options
	 */
	private void inputChecker(String input) throws IOException, SQLException {
		switch (input) {
		case "1":
			newSavingPool();
			break;
		case "2":
			editSavingPool();
			break;
		case "3":
			removeSavingPool();
			break;
		case "4":
			printAllSavingPools();
			break;
		case "5":
			running = false;
			System.out.println("Exiting to Main Menu...\n\n");
			break;
		default:
			System.out.println("Not an option. Choose again");

		}
	}

	/**
	 * Will prompt for the following and add them as a new pool in table:
	 * - Name
	 * - Amount to save
	 * - starting amount (optional)
	 * - monthly contribution (option)
	 * - date to save until
	 *
	 * @throws InputMismatchException security incase they give a int for string, or something similar
	 * @throws IOException if we cant read from console
	 */
	public void newSavingPool() throws InputMismatchException, IOException, SQLException {
		boolean cont = false;

		// Name
		System.out.println("First, what is the name of the category?");
		String name = App.userIn.readLine();
		while(!cont){
			if(RetrieveAndStore.exists("tblSavings","SavingsAccountName", name)){
				System.out.println("A pool with that name already exists, try another:");
				name = App.userIn.readLine();
			} else {
				cont = true;
			}
		}

		cont = false;
		// Amount they want to save in the new pool
		System.out.println("Awesome, how much do you want to save? (in £)");
		String goalString = App.userIn.readLine();
		if (!Validation.isDouble(goalString)) return;
		double goal = Double.parseDouble(goalString);
		while (!cont) { // Will loop until they give a valid input for the amount they want to save
			if (goal > 0) {
				cont = true;
			} else {
				System.out.println("Invalid amount, how much do you want to save?");
				goalString = App.userIn.readLine();
				if (!Validation.isDouble(goalString)) continue;
				goal = Double.parseDouble(goalString);
			}
		}

		// If they already have something saved in the account (Optional)
		System.out.println("And do you have anything saved here already? (Y/N)");
		cont = false;
		double startingAmount = 0;
		String temp = App.userIn.readLine();
		if (temp.toLowerCase().equals("y") || temp.toLowerCase().equals("yes")) {
			// If they say yes or y to haveing something pre-saved
			System.out.println("How much?");
			String startingAmountString = App.userIn.readLine();
			if (!Validation.isDouble(startingAmountString)) return;
			startingAmount = Double.parseDouble(startingAmountString);
			while (!cont) { // Loop until they give a valid amount
				if (startingAmount > 0) {
					cont = true;
				} else {
					System.out.println("Invalid amount, how much do you want to save?");
					startingAmountString = App.userIn.readLine();
					if (!Validation.isDouble(startingAmountString)) continue;
					startingAmount = Double.parseDouble(startingAmountString);
				}
			}
		}

		// If they will be making a monthly contribution to their pool (Optional)
		System.out.println("And will you be making monthly contributions? (Y/N)");
		temp = App.userIn.readLine();
		double monthlyContribution = 0;
		if (temp.toLowerCase().equals("y") || temp.toLowerCase().equals("yes")) {
			// If they say yes or y to making monthly contributions
			cont = false;
			System.out.println("How much?");
			String monthlyContributionString = App.userIn.readLine();
			if (!Validation.isDouble(monthlyContributionString)) return;
			monthlyContribution = Double.parseDouble(monthlyContributionString);
			while (!cont) { // Loop until they give a valid amount
				if (monthlyContribution > 0) {
					cont = true;
				} else {
					System.out.println("Invalid amount, how much do you want to save?");
					monthlyContributionString = App.userIn.readLine();
					if (!Validation.isDouble(monthlyContributionString)) continue;
					monthlyContribution = Double.parseDouble(monthlyContributionString);
				}
			}
		}


		//will get todays date, for use when creating a new table entry
		String today = Instant.now().toString();
		today = today.substring(8,10) + "/" + today.substring(5,7) + "/" + today.substring(0,4);
		//When they want to have the money saved by
		System.out.println("Lastly, when do you want to meet this goal? (DD/MM/YYYY)");
		String dateToAchieve = App.userIn.readLine();
		// Will check if date is in valid format and it is after today
		if (!validDate.validFormat(dateToAchieve) || !validDate.compareStringDates(today,dateToAchieve)) {
			System.out.println("Invalid date!");
			return;
		}

		if (doesGoalExist(name)) {
			RetrieveAndStore.sqlExecute("DELETE FROM tblSavings WHERE SavingsAccountName = '" + name + "'");
		}

		RetrieveAndStore.sqlExecute("INSERT INTO tblSavings (ID, SavingsAccountName, SavingsGoal, CurrentSavings, " +
				"MonthlyContribution, DateCreated, DateProjected) VALUES ("
				+ (RetrieveAndStore.maxID("tblSavings", "ID") + 1) + ", '" + name + "', " + goal + ", " +
				startingAmount + ", " + monthlyContribution + ", '"  + today + "', '" + dateToAchieve + "')");



		RetrieveAndStore.rowNumberUpdater("tblSavings","ID");
		System.out.println("Great stuff, lets get saving!\n\n");
	}

	/**
	 * Allow a user to see all their saving pools
	 * Made static so can be used in RequestData
	 * @see RequestData
	 */
	public static void printAllSavingPools(){
		ResultSet rs = RetrieveAndStore.readAllRecords("tblSavings");
		try {
			while (rs.next()) //Loop through the resultset
			{
				//Store each budget record to print
				int id = rs.getInt("ID");
				String name = rs.getString("SavingsAccountName");
				double goal = rs.getDouble("SavingsGoal");
				double currentSavings = rs.getDouble("CurrentSavings");
				double contribution = rs.getDouble("MonthlyContribution");
				String dateCreated = rs.getString("DateCreated");
				String dateLimit = rs.getString("DateProjected");

				// Work out todays date in dd/mm/yyyy format
				String today = Instant.now().toString();
				today = today.substring(8,10) + "/" + today.substring(5,7) + "/" + today.substring(0,4);
				//calculate projections
				String projection = "You'll hit your goal "; // Pre-write first half of string to stop repeat code
				double time;
				double leftToGo = goal-currentSavings; // How far they are from their goal in £
				// Checks we wont get 0 division and they haven't yet hit their goal
				if (contribution != 0 && currentSavings < goal) {
					// If they'll hit their goal EXACTLY on a payment (extra month needed if they dont)
					if (leftToGo % contribution == 0) {
						if ((time = leftToGo / contribution) == 1) {
							projection += "next month! Good Job";
						} else { // Tells them how long till they hit their goal
							projection += "in " + (int) time + " months, the " + validDate.addMonths(today, (int) time)
							+ "\nTIP: Dont worry if that seems like a long time off, with the right bank " +
							"(and possibly the right investments too!) that time can always be reduced!";
						}
					} else { // If they wont hit it on a payment, an extra month will be needed
						if ((time = leftToGo / contribution) < 1) { // Check if they will be overpaying
							projection += "next month! Good Job";
						} else { // Tells them how long till they hit their goal
							projection += "in " + (int) time + " months, the " + validDate.addMonths(today, (int) time + 1)
							+ "\nTIP: Dont worry if that seems like a long time off, with the right bank " +
							"(and possibly the right investments too!) that time can always be reduced!";
						}
					}
				} else if (goal < currentSavings){ // If they hit they hit the saving goal already
					projection = "Great work, you've already met your savings goal!";
				} else { // If they not contributing offer a friendly reminder that 'every little helps' - Tesco (TM)
					projection = "Oh no, it looks like you not saving any extra per month.\n" +
							"TIP: Remember, even the smallest amounts of savings can add up in time, especially in a high interest account!";
				}

				// print the results
				System.out.format("%d: %s\nPool: £%.2f/£%.2f @ £%.2fpm\n%s - %s\n%s\n\n", id, name, currentSavings, goal, contribution,
						dateCreated, dateLimit, projection);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	/**
	 * Allow them to edit any field (except ID) for a pool
	 * @throws IOException if we cant read from console
	 */
	public void editSavingPool() throws IOException {
		printAllSavingPools(); // Show them all their pools

		System.out.println("Please enter the ID number of the Pool you would like to update:");
		String poolIDString = App.userIn.readLine();
		if (!Validation.isInteger(poolIDString)) return;
		int poolID = Integer.parseInt(poolIDString); // Must be less than one as row ID's start from 0 (not anymore they don't)
		// Check it is a valid ID
		if (!Validation.isRangeValid(1, RetrieveAndStore.maxID("tblSavings", "ID"), poolID)) return;
		ResultSet rs = RetrieveAndStore.readAllRecords("tblSavings");
		try {
			ResultSetMetaData rsmd = rs.getMetaData();
			System.out.println("Great, which entry would you liked to update?");
			for (int i = 2; i <= rsmd.getColumnCount(); i++) { // Loop through all columns and print column name
				System.out.println(String.format("%d: %s", i-1, rsmd.getColumnName(i)));
			}
			// They choose one of the columns printed above
			String columnIntString = App.userIn.readLine();
			if (!Validation.isInteger(columnIntString)) return;
			int columnInt = Integer.parseInt(columnIntString)+1;
			if (!Validation.isRangeValid(2, rsmd.getColumnCount(), columnInt)) return;
			String columnName = rsmd.getColumnName(columnInt);
			System.out.println("Please input a new value for " + columnName);

			if (3<=columnInt && columnInt<=5) { // If they choose a column which takes an integer (e.g. Savings goal) - Double
				String newValueString = App.userIn.readLine();
				if (!Validation.isDouble(newValueString) || Double.parseDouble(newValueString) <= 0) return;
				if(newValueString.contains(".")){
					int decimalPos = newValueString.indexOf('.');
					if ((newValueString.length() - 1) - decimalPos > 2) {
						System.out.println("Invalid number, too precise");
						return;
					}
				}
				double newValue = Double.parseDouble(newValueString);
				RetrieveAndStore.sqlExecute(String.format("UPDATE %s SET %s = %.2f WHERE %s = %d", "tblSavings",
						columnName, newValue, "ID", poolID));
			} else if (columnInt == 6 || columnInt == 7){ // For date created and date they aim to meet their goal - String, but in date format
				String newValue = App.userIn.readLine();
				String today = Instant.now().toString();
				today = today.substring(8,10) + "/" + today.substring(5,7) + "/" + today.substring(0,4);
				if(!validDate.validFormat(newValue)){
					System.out.println("Not a valid date format");
					return;
				}
				rs.next();
				for (; rs.getInt("ID") == poolID; rs.next());
				if(columnInt == 6 && validDate.compareStringDates(today, newValue, true)
					&& validDate.compareStringDates(newValue, rs.getString("DateProjected"))){
					// If they change date created, they can choose today as a date.
					// No need to let them choose an earlier date but cant be later then when they want it to be done
					RetrieveAndStore.sqlExecute(String.format("UPDATE %s SET %s = '%s' WHERE %s = %s", "tblSavings",
							columnName, newValue, "ID", poolID));
				} else if(columnInt == 7 && validDate.compareStringDates(today, newValue)
						&& validDate.compareStringDates(rs.getString("DateCreated"),newValue)){
					// Check its after today and after the day the pool was created
					RetrieveAndStore.sqlExecute(String.format("UPDATE %s SET %s = '%s' WHERE %s = %s", "tblSavings",
							columnName, newValue, "ID", poolID));
				} else {
					System.out.println("Invalid Time Frame");
					return;
				}
			}  else { // For everything else (i.e. category name) - String
				String newValue = App.userIn.readLine();
				if(RetrieveAndStore.exists("tblSavings","SavingsAccountName",newValue)) {
					System.out.println("A pool with that name already exists.\n");
					return;
				}
				RetrieveAndStore.sqlExecute(String.format("UPDATE %s SET %s = '%s' WHERE %s = %d", "tblSavings",
						columnName, newValue, "ID", poolID));
			}
			System.out.println("\n\nSuccessfully update field " + columnName);
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}

	/**
	 * Remove a pool from the table
	 * @throws IOException if it cant receive input from console
	 */
	public void removeSavingPool() throws IOException {
		System.out.println("\n\n");
		printAllSavingPools(); // Show them all their current pools
		System.out.println("Please enter the ID number of the Pool you would like to delete:");
		String poolIDString = App.userIn.readLine();
		if (!Validation.isInteger(poolIDString)) return;
		int poolID = Integer.parseInt(poolIDString);
		if (!Validation.isRangeValid(1, RetrieveAndStore.maxID("tblSavings", "ID"), poolID)) return;
		RetrieveAndStore.sqlExecute(String.format("DELETE FROM %s WHERE %s = %d", "tblSavings", "ID", poolID));
		RetrieveAndStore.rowNumberUpdater("tblSavings", "ID");
		System.out.println("Done, its deleted, gone forever, turned to smithereens, never to be seen again...\n\n");
	}

	public boolean doesGoalExist(String proposedName) {
		ResultSet rs = RetrieveAndStore.readAllRecords("tblSavings");
		try {
			while (rs.next()) // Loop through the user table
			{
				// Store username and password to verify inputs
				String name = rs.getString("SavingsAccountName");

				//compare inputs to db records
				if ((proposedName.equals(name))) {
					return true;
				}
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
		return false;
	}
}