using System;
using System.Linq;

// ReSharper disable once CheckNamespace
namespace GameDevWare.Serialization
{
	public struct JsonMember : IEquatable<JsonMember>, IEquatable<string>
	{
		internal string NameString;
		internal char[] NameChars;
		internal bool IsEscapedAndQuoted;

		public int Length
		{
			get { return this.NameString != null ? this.NameString.Length : this.NameChars.Length; }
		}

		public JsonMember(string name)
			: this(name, false)
		{
		}

		public JsonMember(string name, bool escapedAndQuoted)
		{
			if (name == null)
				throw new ArgumentNullException("name");

			this.NameString = name;
			this.IsEscapedAndQuoted = escapedAndQuoted;
			this.NameChars = null;
		}

		public JsonMember(char[] name)
			: this(name, false)
		{
		}

		public JsonMember(char[] name, bool escapedAndQuoted)
		{
			if (name == null)
				throw new ArgumentNullException("name");

			this.NameChars = name;
			this.IsEscapedAndQuoted = escapedAndQuoted;
			this.NameString = null;
		}

		public override int GetHashCode()
		{
			return this.NameString != null ? this.NameString.GetHashCode() : this.NameChars.Aggregate(0, (a, c) => a ^ (int) c);
		}

		public override bool Equals(object obj)
		{
			if (obj is JsonMember)
				return this.Equals((JsonMember) obj);
			else if (obj is string)
				return this.Equals((string) obj);
			else
				return false;
		}

		public bool Equals(JsonMember other)
		{
			return this.ToString().Equals(other.ToString(), StringComparison.Ordinal);
		}

		public bool Equals(string other)
		{
			return this.ToString().Equals(other, StringComparison.Ordinal);
		}

		public static explicit operator string(JsonMember member)
		{
			return member.ToString();
		}

		public static explicit operator JsonMember(string memberName)
		{
			return new JsonMember(memberName);
		}

		public override string ToString()
		{
			var name = NameString;
			if (this.NameChars != null)
				name = new string(NameChars, 0, NameChars.Length);

			// this is used in tests, so perf is not primary
			if (this.IsEscapedAndQuoted)
			{
				if (name.EndsWith(":"))
					name = name.Substring(0, name.Length - 1);

				name = JsonUtils.UnescapeAndUnquote(name);
			}

			return name;
		}
	}
}