package de.hs_mannheim.informatik.spreadsheet;

import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Part of a simplified spreadsheet system for the PR1 programming lab at Hochschule Mannheim.
 *
 * @author  Oliver Hummel & Victor Waitz
 */
public class Axel {
	static Scanner keyboard = new Scanner(System.in);
	static Spreadsheet spr = new Spreadsheet(11,11);

	public static void main(String[] args) throws FileNotFoundException {
		// Spreadsheet spr = new Spreadsheet(6,9);


		spr.put("A1", "1");
		spr.put("A2", "1");	
		spr.put("A3", "123");
		spr.put("B1", "2");
		spr.put("B2", "4");
		spr.put("B3", "1");

		spr.put("B4", "=41+A2");
		spr.put("C5", "=7*6");
		spr.put("D1", "=3/2");
		
		System.out.println(spr);
		
		// spr.saveCsv("/tmp/test.csv");
		
		// DONE: You might want to put "UI loop" for entering value and formulas here resp. in some UI methods.
		// TODO ME: Implement program commands
		System.out.println("Welcome to Axel (Totally not Excel)");
		System.out.println();

		while(true) {
			String userCommandPositionInput = userCommandPositionInput();
			if (userCommandPositionInput.charAt(0) == '*'){
				executeCommand(userCommandPositionInput);
				System.out.println(spr);
				continue;
			}
			String userPositionInput = userCommandPositionInput;

			String userValueFormulaInput = userValueFormulaInput();

			spr.put(userPositionInput, userValueFormulaInput);

			System.out.println(spr);
		}

	}


	//? User input for a program command or a position
	public static String userCommandPositionInput(){
		System.out.println();
		System.out.println("Input a command for the program or a position");
		System.out.printf("List of program commands: *exit, *save, *load or *help %nFormat for position: A1 or B14%n");
		System.out.print("Input: ");
		String userCommandPositionInput = keyboard.nextLine();

		return userCommandPositionComputation(userCommandPositionInput);
	}

	public static String userCommandPositionComputation(String userCommandPositionInput){

		if (userCommandPositionInput.isEmpty()){
			System.out.println("Input is empty!");
			return userCommandPositionInput();
		}

		//? Program command
		if (userCommandPositionInput.charAt(0) == '*'){
			if (!(userCommandErrorCheck(userCommandPositionInput))) {
				System.out.println("Invalid command!");
				return userCommandPositionInput();
			}
			return userCommandPositionInput;
		}

		//? Position
		if (!(userPositionErrorCheck(userCommandPositionInput))){
			System.out.println("Invalid position!");
			return userCommandPositionInput();
		}

		if (!(userPositionBoundsErrorCheck(userCommandPositionInput, spr))){
			System.out.println("Position out of bounds!");
			return userCommandPositionInput();
		}

		return userCommandPositionInput;
	}

	public static boolean userCommandErrorCheck(String CommandToCheck){
		//? true if valid
		//? valid inputs are: *exit, *save, *load, *help (and all upper case variants)

		CommandToCheck = CommandToCheck.toLowerCase();
		if (CommandToCheck.equals("*exit") || CommandToCheck.equals("*save") || CommandToCheck.equals("*load") || CommandToCheck.equals("*help")){
			return true;
		}
		return false;
	}

	public static boolean userPositionErrorCheck(String positionToCheck){
		//? true if valid
		//? valid inputs are: A1, B14, C79, E99, F1, G99, J1, M98, ... (and all lower case variants)

		positionToCheck = positionToCheck.toUpperCase();

		//? Check if input is the right length
		if (positionToCheck.length() < 2 || positionToCheck.length() > 3){
			return false;
		}

		//? Check if input is in the right format
		if (!(Character.isLetter(positionToCheck.charAt(0)) && Character.isDigit(positionToCheck.charAt(1)))){
			return false;
		}

		if (positionToCheck.length() == 3){
			if (!(Character.isDigit(positionToCheck.charAt(2)))){
				return false;
			}
		}

		return true;
	}

    public static boolean userPositionBoundsErrorCheck(String positionToCheck, Spreadsheet spr){
		//? true if valid

		positionToCheck = positionToCheck.toUpperCase();

		if ((spr.getRow(positionToCheck) >= spr.getRowsLCount()) || (spr.getCol(positionToCheck) >= spr.getColsCount())) {
			return false;
		}

		return true;
	}


	//? User input for a value or a formula
	public static String userValueFormulaInput(){
		System.out.println();
		System.out.printf("Input a value of a formula for the selected position.%n");
		System.out.printf("Format for a value: 7 or 1337 %nFormat for a formula: =7*6 or =SUMME(A1:A3)%n");
		System.out.print("Input: ");
		String userCommandInput = keyboard.nextLine();

		return userValueFormulaComputation(userCommandInput);
	}

	public static String userValueFormulaComputation(String userValueFormulaInput){
		if (userValueFormulaInput.isEmpty()){
			System.out.println("Input is empty!");
			return userValueFormulaInput();
		}

		//? Formula
		if (userValueFormulaInput.charAt(0) == '='){
			if (!(userFormulaErrorCheck(userValueFormulaInput))) {
				System.out.println("Invalid formula!");
				return userValueFormulaInput();
			}
			return userValueFormulaInput;
		}

		//? Value
		if (!(userValueErrorCheck(userValueFormulaInput))){
			System.out.println("Invalid value!");
			return userValueFormulaInput();
		}

		return userValueFormulaInput;
	}

	public static boolean userFormulaErrorCheck(String formulaToCheck){
		//? true if valid
		//? valid inputs are: =7*6, =SUM(A1:A3), =A1, =A1+A2, =A1-A2, ... (and all lower case variants)

		//TODO ME: Formula format check, maybe too much work
		//TODO ME: Check if formula vars are in bounds

		//? remove '=' at the beginning and make everything upper case
		formulaToCheck = formulaToCheck.toUpperCase().substring(1);

		if (formulaToCheck.startsWith("SUMME(") || formulaToCheck.startsWith("PRODUKT(") || formulaToCheck.startsWith("MITTELWERT(") || formulaToCheck.startsWith("STABW(") || formulaToCheck.startsWith("MIN(") || formulaToCheck.startsWith("MAX(")){
			return userFormulaFunctionErrorCheck(formulaToCheck);
		}

		return userFormulaExpressionErrorCheck(formulaToCheck);
	}

	public static boolean userFormulaFunctionErrorCheck(String functionToCheck){
		String[] functionCorners = spr.isolateFunctionCorners(functionToCheck);
		String[] functionBlock= spr.wholeFunctionBlock(functionToCheck);

		if (functionCorners.length != 2){
			return false;
		}

		for (String functionCorner: functionCorners){
			System.out.printf("Corner: %s - Cell test: %s %n", functionCorner, spr.isValueCellName(functionCorner));
			if (!(spr.isValueCellName(functionCorner).equals("cellName"))){
				return false;
			}

			if (!userPositionBoundsErrorCheck(functionCorner, spr)){
				return false;
			}
		}
		return true;
	}

	public static boolean userFormulaExpressionErrorCheck(String expressionToCheck){

		return true;
	}

	public static boolean userValueErrorCheck(String valueToCheck){
		//? true if valid
		//? valid inputs are: 7, 1337, 0, , -213,...

		//? For floating point numbers
		// String digitCheckRegex = "-?\\d+(\\.\\d+)?";
		//? For integers
		String digitCheckRegex = "-?\\d+";
		if (!(valueToCheck.matches(digitCheckRegex))){
			return false;
		}

		return true;
	}


	public static void executeCommand(String command) {
		System.out.printf("Executing command: %s%n", command);
		//TODO ME:
		switch (command){
			case "*load":
				progLoad();
				break;
		}
	}

	private static void progLoad(){
		int rows = spr.getRowsLCount();
		int cols = spr.getColsCount();

		for (int r = 0; r < rows; r++){
			for (int c = 0; c < cols; c++){
				spr.cells[r][c].setValue("");
			}
		}
		spr.put("A1", "1");
		spr.put("A2", "2");
		spr.put("A3", "3");
		spr.put("A4", "4");
		spr.put("B1", "5");
		spr.put("B2", "6");
		spr.put("B3", "7");
		spr.put("B4", "8");
		spr.put("K1", "200");
		spr.put("K11", "100");
		spr.put("J4", "4");
		spr.put("I10", "69");

	}
}