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.Services;

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

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

	protected abstract string SheetName { get; }
	
	protected abstract IDictionary<string, int> PropertyColumnNumbers { get; }

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

	public abstract Stream GetTemplateFile();

	protected abstract TDto ParseRow(IXLRow xlRow);

	private ValidationResultDto<TDto> Validate(TDto dto, int rowNumber)
	{
		var validationResults = new List<ValidationResult>();
		
		var isValid = dto.Validate(validationResults);

		if (isValid)
		{
			var validDto = new ValidationResultDto<TDto>()
			{
				Item = dto
			};

			return validDto;
		}
		
		var invalidDto = new ValidationResultDto<TDto>
		{
			Item = dto,
			Warnings = validationResults
				.SelectMany(v => v.MemberNames
					.Where(PropertyColumnNumbers.ContainsKey)
					.Select(m =>
					{
						var columnNumber = PropertyColumnNumbers[m];
						var errorMessage = v.ErrorMessage;
						var warningMessage = string.Format(XLMessageTemplates.ProblemDetailsTemplate, SheetName, rowNumber, columnNumber, errorMessage);
						var warning = new ValidationResult(warningMessage, new[] { m });
						return warning;
					}))
		};

		return invalidDto;
	}

	protected virtual ParserResultDto<TDto> ParseExcelSheet(IXLWorksheet sheet,
		int columnCount,
		int headerRowsCount = 0)
	{
		if (sheet.RangeUsed().RangeAddress.LastAddress.ColumnNumber < columnCount)
			throw new FileFormatException(string.Format(XLMessageTemplates.FewerColumnsTemplate, SheetName));

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

		if (count > 1024)
			throw new FileFormatException(string.Format(XLMessageTemplates.ExceedingMaxRowLimitTemplate, SheetName));

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

		var valiationResults = 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(row);
				var validationResult = Validate(dto, row.RowNumber());
				valiationResults.Add(validationResult);
			}
			catch (FileFormatException ex)
			{
				var warning = new ValidationResult(ex.Message);
				warnings.Add(warning);
			}
		}

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

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

		return parserResult;
	}
}