using System.Text.Json.Serialization;
using System.Text.Json;
using Microsoft.Extensions.Configuration;
using Persistence.Models;
using Persistence.Repositories;
using Persistence.Services.Interfaces;
using Persistence.Models.Configurations;
using Persistence.Models.Enumerations;
using System.Globalization;

namespace Persistence.Services;
public class WitsDataService : IWitsDataService
{
	private readonly IParameterRepository witsDataRepository;

	private readonly WitsInfo[] witsInfo;

	private const int multiplier = 1000;
	private const string witsConfigPath = "Persistence.Services.Config.WitsConfig.json";

	public WitsDataService(IParameterRepository witsDataRepository)
	{
		this.witsDataRepository = witsDataRepository;

		this.witsInfo = GetWitsInfo();
	}

	public Task<DatesRangeDto> GetDatesRangeAsync(Guid idDiscriminator, CancellationToken token)
	{
		var result = witsDataRepository.GetDatesRangeAsync(idDiscriminator, token);

		return result;
	}

	public async Task<IEnumerable<WitsDataDto>> GetPart(Guid idDiscriminator, DateTimeOffset dateBegin, int take, CancellationToken token)
	{
		var dtos = await witsDataRepository.GetPart(idDiscriminator, dateBegin, take, token);
		
		var result = AdaptToWitsData(dtos);

		return result;
	}

	public async Task<IEnumerable<WitsDataDto>> GetValuesForGraph(Guid discriminatorId, DateTimeOffset dateFrom, DateTimeOffset dateTo,
		int approxPointsCount, CancellationToken token)
	{
		var intervalSec = (dateTo - dateFrom).TotalSeconds;

		int? ratio = null;
		if (intervalSec > 2 * approxPointsCount)
		{
			ratio = (int) intervalSec / approxPointsCount;
		}

		var dtos = await witsDataRepository.GetValuesForGraph(discriminatorId, dateFrom, dateTo, approxPointsCount, ratio, token);

		var result = AdaptToWitsData(dtos);

		return result;
	}

	public async Task<int> AddRange(IEnumerable<WitsDataDto> dtos, CancellationToken token)
	{
		var parameterDtos = dtos.SelectMany(e => e.Values.Select(t => new ParameterDto()
		{
			DiscriminatorId = e.DiscriminatorId,
			ParameterId = EncodeId(t.RecordId, t.ItemId),
			Value = t.Value.ToString()!,
			Timestamp = e.Timestamped
		}));
		var result = await witsDataRepository.AddRange(parameterDtos, token);

		return result;
	}

	private int EncodeId(int recordId, int itemId)
	{
		var resultId = multiplier * recordId + itemId;
		return resultId;
	}

	private int DecodeRecordId(int id)
	{
		var resultId = id / multiplier;

		return resultId;
	}

	private int DecodeItemId(int id) 
	{
		var resultId = id % multiplier;

		return resultId; 
	}

	private IEnumerable<WitsDataDto> AdaptToWitsData(IEnumerable<ParameterDto> dtos)
	{
		var result = new List<WitsDataDto>();
		var witsGroup = dtos
			.GroupBy(e => new { e.DiscriminatorId, e.Timestamp });
		foreach (var witsInGroup in witsGroup)
		{
			var witsDataDto = new WitsDataDto()
			{
				DiscriminatorId = witsInGroup.Key.DiscriminatorId,
				Timestamped = witsInGroup.Key.Timestamp
			};

			witsDataDto.Values = witsInGroup.Select(e =>
			{
				var recordId = DecodeRecordId(e.ParameterId);
				var itemId = DecodeItemId(e.ParameterId);

				return new WitsValueDto()
				{
					RecordId = recordId,
					ItemId = itemId,
					Value = ConvertValue(recordId, itemId, e.Value)
				};
			});

			result.Add(witsDataDto);
		}

		return result;
	}

	private object ConvertValue(int recordId, int itemId, string value)
	{
		var witsType = witsInfo.FirstOrDefault(e => e.ItemId == itemId 
			&& e.RecordId == recordId)?.ValueType;

		switch(witsType)
		{
			default:
			{
				return value;
			}
			case WitsType.S:
			{
				var result = Int16.Parse(value);

				return result;
			}
			case WitsType.L:
			{
				var result = Int32.Parse(value);

				return result;
			}
			case WitsType.F:
			{
				var result = float.Parse(value, CultureInfo.InvariantCulture);

				return result;
			}
		}
	}

	private WitsInfo[] GetWitsInfo()
	{
		var stream = System.Reflection.Assembly.GetExecutingAssembly()
			.GetManifestResourceStream(witsConfigPath);
		var options = new JsonSerializerOptions
		{
			Converters =
			{
				new JsonStringEnumConverter(JsonNamingPolicy.CamelCase)
			},
		};
		var records = JsonSerializer.Deserialize<WitsInfo[]>(stream!, options) ?? [];
		return records;
	}
}