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

namespace AuroraRecordGenerator
{
	public static class Utility
	{
		public static IList<string> LineSplit(this string source) =>
			source.Split('\n').Where(item => item.Trim().Length != 0).ToList();

		public static string CmToFeet(double cm)
		{
			return "0'0\"";
		}

		/// <summary>
		///	Converts a weight in Kilograms to Pounds.
		/// </summary>
		/// <param name="kg">The weight in kilograms.</param>
		/// <returns>The weight converted to pounds.</returns>
		public static double KgToLb(double kg) => Math.Round(kg * 2.2046, 2);

		/// <summary>
		/// Returns <paramref name="val"/> and a trailing space if val is not whitespace, <see cref="string.Empty"/> otherwise.
		/// </summary>
		/// <param name="val"></param>
		/// <returns></returns>
		public static string SpaceIfValue(this string val) => string.IsNullOrWhiteSpace(val) ? string.Empty : " " + val + " ";

		public static string IfEmpty(this string target, string fallback) =>
			target.IsEmpty() ? fallback : target;

		public static bool IsEmpty(this string val) => string.IsNullOrWhiteSpace(val);

		public static string FormatAsList(this IEnumerable<string> target) =>
			target.Aggregate(new StringBuilder(), (b, s) => b.AppendLine($" - {s.Trim()}")).ToString();

		public static string Repeat(this string target, int repeatNum)
		{
			var builder = new StringBuilder(target.Length * repeatNum);
			for (var i = 0; i < repeatNum; i++)
				builder.Append(target);

			return builder.ToString();
		}

		/// <summary>
		///		Returns true if the specified species has gender.
		/// </summary>
		/// <param name="species"></param>
		/// <returns></returns>
		public static bool HasGender(this SpeciesType species) =>
			!(species == SpeciesType.Diona || species == SpeciesType.IPC || species == SpeciesType.Vaurca);

		public static string SubspeciesNiceName(SpeciesSubType species)
		{
			var attr = species.GetAttributeOfType<SubspeciesMetaAttribute>();
			return attr?.NiceName ?? Enum.GetName(typeof(SpeciesSubType), species);
		}

		public static SpeciesSubType SubspeciesNiceNameToEnum(string nicename)
		{
			return (from item in Enum.GetValues(typeof(SpeciesSubType)).Cast<SpeciesSubType>()
				let attr = item.GetAttributeOfType<SubspeciesMetaAttribute>()
				where attr != null && attr.NiceName == nicename
				select item).FirstOrDefault();
		}
	}

	// From https://stackoverflow.com/questions/1799370/getting-attributes-of-enums-value
	public static class EnumHelper
	{
		/// <summary>
		/// Gets an attribute on an enum field value
		/// </summary>
		/// <typeparam name="T">The type of the attribute you want to retrieve</typeparam>
		/// <param name="enumVal">The enum value</param>
		/// <returns>The attribute of type T that exists on the enum value</returns>
		/// <example>string desc = myEnumVariable.GetAttributeOfType<DescriptionAttribute>().Description;</example>
		public static T GetAttributeOfType<T>(this Enum enumVal) where T : Attribute
		{
			var type = enumVal.GetType();
			var memInfo = type.GetMember(enumVal.ToString());
			var attributes = memInfo[0].GetCustomAttributes(typeof(T), false);
			return attributes.Length > 0 ? (T)attributes[0] : null;
		}
	}
}