using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.IO;
using System.Linq;
using AsbCloudApp.Data;
using AsbCloudApp.Requests.ParserOptions;
using AsbCloudApp.Services;
using ClosedXML.Excel;

namespace AsbCloudInfrastructure;

public abstract class ParserServiceBase<TDto, TOptions> : IParserService<TDto, TOptions>
	where TDto : class, IId
	where TOptions : IParserOptionsRequest
{
	protected readonly IServiceProvider serviceProvider;

	protected ParserServiceBase(IServiceProvider serviceProvider)
	{
		this.serviceProvider = serviceProvider;
	}

	protected virtual ICollection<ValidationResult> ValidationResults { get; } = new List<ValidationResult>();

	protected abstract string SheetName { get; }

	public abstract ParserResultDto<TDto> Parse(Stream file, TOptions options);

	public abstract Stream GetTemplateFile();

	protected virtual ValidationResultDto<TDto> ValidateRow(int rowNumber,
		IDictionary<string, int> columnNumbers,
		TDto dto)
	{
		var validationContext = new ValidationContext(dto, serviceProvider: null, items: null);

		if (Validator.TryValidateObject(dto, validationContext, ValidationResults, true))
		{
			var validRow = new ValidationResultDto<TDto>
			{
				Item = dto
			};

			return validRow;
		}

		var invalidRow = new ValidationResultDto<TDto>
		{
			Item = dto,
		};

		var warnings = new List<ValidationResult>();

		foreach (var validationResult in from v in ValidationResults
				let memberNames = v.MemberNames.Where(columnNumbers.ContainsKey)
				select memberNames.Select(x =>
				{
					var columnNumber = columnNumbers[x];
					var errorMessage = v.ErrorMessage;
					var warningMessage = string.Format(IParserService.MessageTemplate, SheetName, rowNumber, columnNumber, errorMessage);
					var warning = new ValidationResult(warningMessage, new[] { x });
					return warning;
				}))
		{
			warnings.AddRange(validationResult);
		}

		invalidRow.Warnings = warnings;

		return invalidRow;
	}

	protected virtual ParserResultDto<TDto> ParseExcelSheet(IXLWorksheet sheet,
		Func<IXLRow, ValidationResultDto<TDto>> parseRow,
		int columnCount,
		int headerRowsCount = 0)
	{
		if (sheet.RangeUsed().RangeAddress.LastAddress.ColumnNumber < columnCount)
			throw new FileFormatException($"Лист {SheetName} содержит меньшее количество столбцов.");

		var count = sheet.RowsUsed().Count() - headerRowsCount;

		if (count > 1024)
			throw new FileFormatException($"Лист {SheetName} содержит слишком большое количество строк.");

		if (count <= 0)
			return new ParserResultDto<TDto>();

		var dtos = new List<ValidationResultDto<TDto>>(count);
		var warnings = new List<ValidationResult>();

		for (var i = 0; i < count; i++)
		{
			var row = sheet.Row(1 + i + headerRowsCount);

			try
			{
				var dto = parseRow.Invoke(row);
				dtos.Add(dto);
			}
			catch (FileFormatException ex)
			{
				var warning = new ValidationResult(ex.Message);
				warnings.Add(warning);
			}
		}

		var parserResult = new ParserResultDto<TDto>
		{
			Item = dtos
		};

		if (warnings.Any())
			parserResult.Warnings = warnings;

		return parserResult;
	}
}