using System;
using System.Collections.Generic;
using System.IO;
using LCU.Api.Internal.FileOperations.Validations;
using LCU.Library.Internal.FileOperationsModels.Enums;
using LCU.Library.Internal.FileOperationsModels.Models;
using LCU.Library.Internal.FileOperationsModels.Models.Requests;
using LCU.Library.Internal.FileOperationsModels.Models.Responses;
using LCU.Library.Internal.FileOperationsModels.Shared;

namespace LCU.Api.Internal.FileOperations.Services.FileActionServices;

public class FileSizeService : IFileSizeService
{

    public List<FileSizeResponse> GetFileSize(FileSizeRequest fileSizeRequest)
    {
        var fileSizeResponses = new List<FileSizeResponse>();
        try
        {
            var requests = DynamicNameBuilder.BuildListOfRequests(fileSizeRequest);
            foreach (var request in requests)
            {
                var response = DetermineFileSize(request);
                fileSizeResponses.Add(response);
            }
            
            return fileSizeResponses;
        }
        catch (Exception exception)
        {
            throw new Exception($"Failed to get file size. Exception: {exception.Message}");
        }
    }
    
    public decimal ConvertFileSize(decimal fileSizeInBytes, FileSizeTypes returnFileSizeType)
        => returnFileSizeType switch
        {
            FileSizeTypes.Byte => fileSizeInBytes,
            FileSizeTypes.Kilobyte => fileSizeInBytes/1024,
            FileSizeTypes.Megabyte => fileSizeInBytes/1024/1024,
            FileSizeTypes.Gigabyte => fileSizeInBytes/1024/1024/1024,
            FileSizeTypes.Terabyte => fileSizeInBytes/1024/1024/1024/1024,
            _ => throw new ArgumentOutOfRangeException(nameof(returnFileSizeType), $"Not expected FileSizeType value: {returnFileSizeType}"),
        };
    
    public RequestResponse PreQueueValidation(FileSizeRequest fileSizeRequest)
    {
        var requestResponse = new RequestResponse();
        try
        {
            var requestList = DynamicNameBuilder.BuildListOfRequests(fileSizeRequest);
            requestResponse = FileValidation.ValidateIfAnyRequest(requestList, fileSizeRequest.FileSourceRequest.SourcePath, requestResponse);
            foreach (var request in requestList)
            {
                requestResponse = IsRequestValid(request, requestResponse);
            }

            return requestResponse;
        }
        catch (Exception exception)
        {
            requestResponse.IsSuccessful = false;
            requestResponse.MessageStack.Add(exception.Message);    
            return requestResponse;
        }
    }

    private static RequestResponse IsRequestValid(FileSizeRequest request, RequestResponse requestResponse)
    {
        return FileValidation.ValidateFileExists(request.FileSourceRequest.Source, requestResponse);
    }

    private FileSizeResponse DetermineFileSize(FileSizeRequest request)
    {
        var file = new FileInfo(request.FileSourceRequest.Source);
        var length = Convert.ToDecimal(file.Length);
        return new FileSizeResponse
        {
            FileName = file.Name,
            FileSize = ConvertFileSize(length, request.FileSizeType),
            FileSizeType = request.FileSizeType
        };
    }
}