using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using PartSource.Data.Contexts;
using PartSource.Data.Dtos;
using PartSource.Data.Models;

namespace PartSource.Services
{
    public class FitmentService
    {
		private readonly FitmentContext _fitmentContext;

		public FitmentService(FitmentContext fitmentContext)
        {
			_fitmentContext = fitmentContext;
        }

		public IList<string> GetYmmFitment(IList<Vehicle> vehicles)
		{
			if (vehicles.Count == 0)
			{
				return new string[0];
			}

			IList<string> fitmentTags = new List<string>();

			IList<string> makeModels = vehicles.OrderBy(v => v.MakeName).ThenBy(v => v.ModelName).Select(v => $"{v.MakeName},{v.ModelName}").Distinct().ToList();

			foreach (string makeModel in makeModels)
			{
				string make = makeModel.Split(',')[0];
				string model = makeModel.Split(',')[1];

				List<string> years = vehicles
					.Where(v => v.MakeName == make && v.ModelName == model)
					.OrderBy(v => v.Year)
					.Select(v => v.Year.ToString().Trim())
					.Distinct()
					.ToList();

				string tag = $"{string.Join('-', years)} {make.Trim()} {model.Trim()}";

				System.Diagnostics.Debug.WriteLine(tag);

				fitmentTags.Add(tag);
			}

			return fitmentTags;
		}

		public IList<string> GetYmmFitmentRange(IList<Vehicle> vehicles)
		{
			if (vehicles.Count == 0)
			{
				return new string[0];
			}

			IList<string> fitmentTags = new List<string>();

			IList<string> makeModels = vehicles.Select(v => $"{v.MakeName},{v.ModelName}").Distinct().ToList();

			foreach (string makeModel in makeModels)
			{
				string make = makeModel.Split(',')[0];
				string model = makeModel.Split(',')[1];

				int minYear = vehicles
					.Where(v => v.MakeName == make && v.ModelName == model)
					.Min(v => v.Year);

				int maxYear = vehicles
					.Where(v => v.MakeName == make && v.ModelName == model)
					.Max(v => v.Year);

				string tag = minYear == maxYear
					? $"{minYear} {make.Trim()} {model.Trim()}"
					: $"{minYear}-{maxYear} {make.Trim()} {model.Trim()}";

				System.Diagnostics.Debug.WriteLine(tag);

				fitmentTags.Add(tag);
			}

			return fitmentTags;
		}

		public IList<int> GetVehicleIdFitment(IList<Vehicle> vehicles)
		{
			return vehicles.Select(v => v.VehicleToEngineConfigId).Distinct().ToList();
		}

		public IList<Vehicle> GetVehiclesForPart(string partNumber, string lineCode, int maxVehicles = 0)
		{
			if (string.IsNullOrEmpty(partNumber) || string.IsNullOrEmpty(lineCode))
			{
				return null;
			}

			partNumber = Regex.Replace(partNumber, "[^a-zA-Z0-9]", string.Empty);

			IQueryable<string> whiCodes = _fitmentContext.DcfMappings
				.Where(d => d.LineCode == lineCode)
				.Select(d => d.WhiCode);

			IQueryable<Vehicle> vehicles = _fitmentContext.Fitments
				.Where(f => f.PartNumber == partNumber && whiCodes.Contains(f.LineCode))
				.Join(_fitmentContext.Vehicles,
					f => new { f.BaseVehicleId, f.EngineConfigId },
					v => new { v.BaseVehicleId, v.EngineConfigId },
					(f, v) => v)
				.Distinct()
				.OrderByDescending(x => x.Year);

			if (maxVehicles > 0)
			{
				vehicles = vehicles.Take(maxVehicles);
			}

			return vehicles.ToList();
		}

		public IList<VehicleFitmentDto> GetVehicleFitmentForPart(string partNumber, string lineCode, int maxVehicles = 0)
		{
			if (string.IsNullOrEmpty(partNumber) || string.IsNullOrEmpty(lineCode))
			{
				return null;
			}

			partNumber = Regex.Replace(partNumber, "[^a-zA-Z0-9\\-]", string.Empty);

			IQueryable<string> whiCodes = _fitmentContext.DcfMappings
				.Where(d => d.LineCode == lineCode)
				.Select(d => d.WhiCode);

			IQueryable<VehicleFitmentDto> vehicles = _fitmentContext.Fitments
				.Where(f => f.PartNumber == partNumber && whiCodes.Contains(f.LineCode))
				.Join(_fitmentContext.Vehicles,
					f => new { f.BaseVehicleId, f.EngineConfigId },
					v => new { v.BaseVehicleId, v.EngineConfigId },
					(f, v) => new VehicleFitmentDto
					{
						Fitment = f,
						Vehicle = v
					})
				.Distinct();

			if (maxVehicles > 0)
			{
				vehicles = vehicles.Take(maxVehicles);
			}

			return vehicles.ToList();
		}
	}
}