Ledger

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;

public class LedgerEntry{
public LedgerEntry(DateTime date, string desc, decimal chg){
Date = date;
Desc = desc;
Chg = chg;
}

public DateTime Date { get; }
public string Desc { get; }
public decimal Chg { get; }

}

public static class Ledger{

public static LedgerEntry CreateEntry(string date, string desc, int chng) => new LedgerEntry(DateTime.Parse(date, CultureInfo.InvariantCulture), desc, chng / 100.0m);


private static CultureInfo CreateCulture(string cur, string loc){
    string curSymb = null;
    int curNeg = 0;
    string datPat = null;

    if (cur != "USD" && cur != "EUR") throw new ArgumentException("Invalid currency");
    
    
    if (loc != "nl-NL" && loc != "en-US") throw new ArgumentException("Invalid currency");
    if (cur == "USD") {
            if (loc == "en-US"){
                curSymb = "$";
                datPat = "MM/dd/yyyy";
            }
            else{
                curSymb = "$";
                curNeg = 12;
                datPat = "dd/MM/yyyy";
            }
        }

        else {
            if (loc == "en-US"){
                curSymb = "€";
                datPat = "MM/dd/yyyy";
            }
            else {
                curSymb = "€";
                curNeg = 12;
                datPat = "dd/MM/yyyy";
            }    
    }

    var culture = new CultureInfo(loc, false);
    culture.NumberFormat.CurrencySymbol = curSymb;
    culture.NumberFormat.CurrencyNegativePattern = curNeg;
    culture.DateTimeFormat.ShortDatePattern = datPat;
    return culture;
}

private static string PrintHead(string loc){
    if (loc == "en-US") return "Date       | Description               | Change       ";
    
    else{
        if (loc == "nl-NL") return "Datum      | Omschrijving              | Verandering  ";
        else throw new ArgumentException("Invalid locale");
    }
}

private static string Date(IFormatProvider culture, DateTime date) => date.ToString("d", culture);

private static string Description(string desc){
    if (desc.Length > 25) return $"{desc.Substring(0, 22)}...";
    return desc;
}

private static string Change(IFormatProvider culture, decimal cgh) => cgh < 0.0m ? cgh.ToString("C", culture) : $"{cgh.ToString("C", culture)} ";


private static string PrintEntry(IFormatProvider culture, LedgerEntry entry) => $"{Date(culture, entry.Date)} | {Description(entry.Desc), -25} | {Change(culture, entry.Chg), 13}";


private static IEnumerable<LedgerEntry> sort(LedgerEntry[] entries) {
    var neg = entries.Where(e => e.Chg < 0).OrderBy(x => $"{x.Date} @ {x.Desc} @ {x.Chg}");
    var post = entries.Where(e => e.Chg >= 0).OrderBy(x => $"{x.Date} @ {x.Desc} @ {x.Chg}");
    return new List<LedgerEntry>(neg.Concat(post));
}

public static string Format(string currency, string locale, LedgerEntry[] entries){
    var culture = CreateCulture(currency, locale);
    return sort(entries).Select(length => PrintEntry(culture, length)).
        Aggregate(PrintHead(locale),(a,c) => $"{a}\n{c}");
}

}