using System.Text.RegularExpressions;
using Newtonsoft.Json;

namespace RhSolutions.Models;
public class ProductSku
{
	[JsonIgnore]
	public string Id
	{
		get
		{
			return $"1{Article}{Delimiter}{Variant}";
		}
		set
		{
			var matches = GetMatches(value);
			if (matches.Count == 0)
			{
				throw new ArgumentException($"Wrong Id: {value}");
			}
			else
			{
				var p = GetProducts(matches).First();
				_article = p.Article;
				_delimiter = p.Delimiter;
				_variant = p.Variant;
			}
		}
	}
	private const string matchPattern = @"(?<Lead>[1\s]|^|\b)(?<Article>\d{6})(?<Delimiter>[\s13-])(?<Variant>\d{3})(\b|$)";
	private string _article;
	private string _variant;
	private char _delimiter = '1';
	
	[JsonConstructor]
	public ProductSku(string article, string delimiter, string variant)
	{
		_article = article;
		_delimiter = delimiter[0];
		_variant = variant;
	}

	public ProductSku(string article, string variant)
	{
		_article = IsCorrectArticle(article) ? article
			: throw new ArgumentException($"Wrong Article: {article}");
		_variant = IsCorrectVariant(variant) ? variant
			: throw new ArgumentException($"Wrong Variant: {variant}");
	}
	public ProductSku(string line)
	{
		var matches = GetMatches(line);
		if (matches.Count == 0)
		{
			throw new ArgumentException($"Wrong new Sku input {line}");
		}
		else
		{
			var p = GetProducts(matches).First();
			_article = p.Article;
			_delimiter = p.Delimiter;
			_variant = p.Variant;
		}
	}

	private ProductSku(Match match)
	{
		_article = match.Groups["Article"].Value;
		_delimiter = match.Groups["Delimiter"].Value switch
		{
			"3" => '3',
			_ => '1'
		};
		_variant = match.Groups["Variant"].Value;
	}
	public string Article
	{
		get => _article;
		set
		{
			_article = IsCorrectArticle(value) ? value
				: throw new ArgumentException($"Wrong Article: {value}");
		}
	}
	public string Variant
	{
		get => _variant;
		set
		{
			_variant = IsCorrectVariant(value) ? value
				: throw new ArgumentException($"Wrong Variant: {value}");
		}
	}

	public char Delimiter
	{
		get => _delimiter;
		set
		{
			if (value != '1' || value != '3')
			{
				throw new ArgumentException($"Wrong Delimiter: {value}");
			}
			else
			{
				_delimiter = value;
			}
		}
	}

	public static IEnumerable<ProductSku> Parse(string line)
	{
		MatchCollection matches = GetMatches(line);
		if (matches.Count == 0)
		{
			return Enumerable.Empty<ProductSku>();
		}
		else
		{
			return GetProducts(matches);
		}
	}

	public static bool TryParse(string line, out IEnumerable<ProductSku> skus)
	{
		MatchCollection matches = GetMatches(line);
		if (matches.Count == 0)
		{
			skus = Enumerable.Empty<ProductSku>();
			return false;
		}

		else
		{
			skus = GetProducts(matches);
			return true;
		}
	}

	private static MatchCollection GetMatches(string line)
	{
		return Regex.Matches(line, matchPattern);
	}

	private static IEnumerable<ProductSku> GetProducts(MatchCollection matches)
	{
		foreach (Match match in matches)
		{
			yield return new ProductSku(match);
		}
	}

	private static bool IsCorrectArticle(string line)
	{
		return line != null
			&& line.Length == 6
			&& line.All(c => char.IsDigit(c));
	}

	private static bool IsCorrectVariant(string line)
	{
		return line != null
			&& line.Length == 3
			&& line.All(c => char.IsDigit(c));
	}

	public override string ToString()
	{
		return Id;
	}

	public override bool Equals(object obj)
	{
		if (obj == null || GetType() != obj.GetType())
		{
			return false;
		}

		ProductSku other = (ProductSku)obj;

		return this.Article == other.Article &&
			this.Delimiter == other.Delimiter &&
			this.Variant == other.Variant;
	}

	public override int GetHashCode()
	{
		HashCode hash = new();
		hash.Add(_article);
		hash.Add(_variant);
		hash.Add(_delimiter);
		return hash.ToHashCode();
	}
}