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

namespace pkNX.Structures
{
    public static class TableUtil
    {
        /// <summary>
        /// Converts an enumerable list of <see cref="T"/> to a tab separated sheet.
        /// </summary>
        /// <typeparam name="T">Object Type</typeparam>
        /// <param name="arr">Array of type T</param>
        /// <returns>2 dimensional sheet of cells</returns>
        public static string GetTable<T>(IEnumerable<T> arr) where T : new() => string.Join(Environment.NewLine, GetTableRaw(arr));

        private const string sep = "\t";
        private static IEnumerable<string> GetTableRaw<T>(IEnumerable<T> arr) => Table(arr).Select(row => string.Join(sep, row));
        private static IEnumerable<string> GetTableRaw<T>(IEnumerable<T> arr, Type t) => Table(arr, t).Select(row => string.Join(sep, row));

        public static string GetNamedTable<T>(IEnumerable<T> arr, IList<string> names, string name = null)
        {
            var list = GetTableRaw(arr).ToArray();

            // slap in name to column header
            list[0] = $"Index{sep}{name ?? typeof(T).Name}{sep}{list[0]}";

            // slap in row name to row
            for (int i = 1; i < list.Length; i++)
                list[i] = $"{i - 1}{sep}{names[i - 1]}{sep}{list[i]}";

            return string.Join(Environment.NewLine, list);
        }

        public static string GetNamedTypeTable<T>(IList<T> arr, IList<string> names, string name = null)
        {
            var t = arr[0].GetType();
            var list = GetTableRaw(arr, t).ToArray();

            // slap in name to column header
            list[0] = $"Index{sep}{name ?? t.Name}{sep}{list[0]}";

            // slap in row name to row
            for (int i = 1; i < list.Length; i++)
                list[i] = $"{i - 1}{sep}{names[i - 1]}{sep}{list[i]}";

            return string.Join(Environment.NewLine, list);
        }

        private static IEnumerable<IEnumerable<string>> Table<T>(IEnumerable<T> arr)
        {
            var type = typeof(T);
            yield return GetNames(type);
            foreach (var z in arr)
                yield return GetValues(z, type);
        }

        private static IEnumerable<IEnumerable<string>> Table<T>(IEnumerable<T> arr, Type type)
        {
            yield return GetNames(type);
            foreach (var z in arr)
                yield return GetValues(z, type);
        }

        private static IEnumerable<string> GetNames(Type type)
        {
            foreach (var z in type.GetProperties())
                yield return z.Name;
            foreach (var z in type.GetFields())
                yield return z.Name;
        }

        private static IEnumerable<string> GetValues(object obj, Type type)
        {
            foreach (var z in type.GetProperties())
                yield return GetFormattedString(z.GetValue(obj, null));

            foreach (var z in type.GetFields())
                yield return GetFormattedString(z.GetValue(obj));
        }

        private static string GetFormattedString(object obj)
        {
            if (obj == null)
                return string.Empty;
            if (obj is ulong u)
                return u.ToString("X16");
            if (obj is IEnumerable x)
                return string.Join("|", JoinEnumerator(x.GetEnumerator()).Select(v => v?.ToString() ?? string.Empty));
            return obj.ToString();
        }

        private static IEnumerable<object> JoinEnumerator(IEnumerator x)
        {
            while (x.MoveNext())
                yield return x.Current;
        }
    }
}