using System.Text.RegularExpressions;

namespace RhSolutions.Services;

public class CouplingsCalculator : IFittingsCalculator
{
    private static readonly string pattern = 
        @"(^|\W)труба.*(?'Diameter'16|20|25|32|40|50|63).*(отрезки|бухт[ае])\D*(?'Length'\d{1,3})(\D|$)";

    public Dictionary<Product, double> Calculate(Dictionary<Product, double> products)
    {
        Dictionary<string, double> result = new()
        {
            ["16"] = 0,
            ["20"] = 0,
            ["25"] = 0,
            ["32"] = 0,
            ["40"] = 0,
            ["50"] = 0,
            ["63"] = 0,
        };

        var rautitanProducts = products.Where(kvp => kvp.Key.ProductLines.Contains("RAUTITAN"));
        Regex regex = new(pattern, RegexOptions.Multiline | RegexOptions.IgnoreCase);

        foreach (var kvp in rautitanProducts)
        {
            var match = regex.Match(kvp.Key.Name);
            if (match.Success)
            {
                string diameter = match.Groups["Diameter"].Value;
                int packingLength = int.Parse(match.Groups["Length"].Value);
                result[diameter] += GetCouplesCount(kvp.Value, packingLength);
            }
        }

        return result
            .ToDictionary(kvp =>
        kvp.Key switch
        {
            "16" => new Product("11600111001"),
            "20" => new Product("11600121001"),
            "25" => new Product("11600131001"),
            "32" => new Product("11600141001"),
            "40" => new Product("11600151001"),
            "50" => new Product("14563021001"),
            "63" => new Product("14563031001"),
            _ => throw new Exception($"Неизвестный диаметр {kvp.Key}")
        }, kvp => kvp.Value);
    }

    private int GetCouplesCount(double amount, int packingLength)
    {
        if (amount < packingLength)
        {
            return 0;
        }
        else if (amount % packingLength == 0)
        {
            return (int)amount / packingLength - 1;
        }
        else
        {
            return (int)amount / packingLength;
        }
    }
}