using System;
using System.Collections.Generic;
using Newtonsoft.Json;
using ICSharpCode.SharpZipLib.Zip;
using ICSharpCode.SharpZipLib.Core;
using System.IO;
using LCU.Library.Internal.FileOperationsModels.Models;
using LCU.Library.Internal.FileOperationsModels.Shared;
using LCU.Api.Internal.FileOperations.Validations;
using LCU.Library.Internal.LCUServiceFactory.Configurations;

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

public class UnzipPasswordProtectedFileService : FileActionService, IFileActionService, IActionService<UnzipPasswordProtectedFileRequest>
{
	public UnzipPasswordProtectedFileService(ServicesFactoryConfiguration servicesFactoryConfiguration)
        : base(servicesFactoryConfiguration)
	{
	}

	public RequestResponse ExecuteAction(QueueRequest queueRequest)
    {
        var requestResponse = new RequestResponse();
        try
        {
            var unzipPasswordProtectedFileRequest = JsonConvert.DeserializeObject<UnzipPasswordProtectedFileRequest>(queueRequest.Request);
            var requests = BuildFileList(unzipPasswordProtectedFileRequest);
            requestResponse = FileValidation.ValidateIfAnyRequest(requests, unzipPasswordProtectedFileRequest.FormattedSourceDirectoryPath, requestResponse);

            foreach (var request in requests)
            {
                var temporaryRequestResponse = PerformRequest(request);
                if (!temporaryRequestResponse.IsSuccessful)
                {
                    requestResponse.IsSuccessful = temporaryRequestResponse.IsSuccessful;
                    requestResponse.MessageStack.AddRange(temporaryRequestResponse.MessageStack);
                }
            }

            requestResponse.ReturnResponse = unzipPasswordProtectedFileRequest;
            return requestResponse;
        }
        catch (Exception exception)
        {
            return RequestResponseHelper.ExceptionUpdateRequestResponse(requestResponse,
                                                                   queueRequest.FileOperationType,
                                                                   exception.Message);
        }
    }

    public RequestResponse PerformRequest(UnzipPasswordProtectedFileRequest request)
    {
        return OperationService.PerformOperation(request, IsRequestValid, UnzipPasswordProtectedFile);
    }

    public void UnzipPasswordProtectedFile(UnzipPasswordProtectedFileRequest request)
    {
        ZipFile passwordProtectedZipFile = null;
        try
        {
            var fileStream = File.OpenRead(request.SourceFilePath);
            passwordProtectedZipFile = new ZipFile(fileStream)
            {
                Password = request.Password
            };

            foreach (ZipEntry zipEntry in passwordProtectedZipFile)
            {
                if (!zipEntry.IsFile)
                {
                    // Ignore directories
                    continue;
                }

                var entryFileName = zipEntry.Name;
                // to remove the folder from the entry:- entryFileName = Path.GetFileName(entryFileName);
                // Optionally match entrynames against a selection list here to skip as desired.
                // The unpacked length is available in the zipEntry.Size property.

                // 4K is optimum
                var buffer = new byte[4096];
                var zipStream = passwordProtectedZipFile.GetInputStream(zipEntry);

                // Manipulate the output filename here as desired.
                var finalDestinationPath = request.FormattedDestinationPath;
                if (request.UseZipFileNameAsFinalDestination)
                {
                    var zipFilename = request.PasswordProtectedZipFileNameWithDate.ToUpper().EndsWith(".ZIP") ? 
                                      request.PasswordProtectedZipFileNameWithDate.ToUpper().Replace(".ZIP", "") : 
                                      request.PasswordProtectedZipFileNameWithDate;
                    finalDestinationPath = $"{finalDestinationPath}{zipFilename}\\";
                }

                var fullZipToPath = Path.Combine(finalDestinationPath, entryFileName);
                var directoryName = Path.GetDirectoryName(fullZipToPath);
                if (directoryName.Length > 0)
                {
                    Directory.CreateDirectory(directoryName);
                }

                // Unzip file in buffered chunks. This is just as fast as unpacking to a buffer the full size
                // of the file, but does not waste memory.
                // The "using" will close the stream even if an exception occurs.
                using (FileStream streamWriter = File.Create(fullZipToPath))
                {
                    StreamUtils.Copy(zipStream, streamWriter, buffer);
                }
            }
        }
        catch (Exception exception)
        {
            throw new Exception($"Exception thrown while trying to ExecuteRequestAction. " +
                                $"Request: {JsonConvert.SerializeObject(request)}" +
                                $"ExceptionMessage: {exception.Message}");
        }
        finally
        {
            if (passwordProtectedZipFile != null)
            {
                passwordProtectedZipFile.IsStreamOwner = true; // Makes close also shut the underlying stream
                passwordProtectedZipFile.Close(); // Ensure we release resources
            }
        }

    }

    public RequestResponse PreQueueValidation(UnzipPasswordProtectedFileRequest originalRequest)
    {
        var requestResponse = new RequestResponse();
        var requestList = BuildFileList(originalRequest);
        requestResponse = FileValidation.ValidateIfAnyRequest(requestList, originalRequest.FormattedSourceDirectoryPath, requestResponse);
        foreach (var request in requestList)
        {
            requestResponse = IsRequestValid(request, requestResponse);
        }

        return requestResponse;
    }

    public List<UnzipPasswordProtectedFileRequest> BuildFileList(UnzipPasswordProtectedFileRequest originalRequest)
    {
        var nameList = RegexNameHandler.BuildFileList(originalRequest.FormattedSourceDirectoryPath,
                                                        originalRequest.FinalPasswordProtectedZipFileName,
                                                        originalRequest.FileNameSetting);
        var requests = new List<UnzipPasswordProtectedFileRequest>();

        foreach (var name in nameList)
        {
            var newRequest = Clone.DeepClone(originalRequest);
            newRequest.PasswordProtectedZipFileName = name;

            requests.Add(newRequest);
        }

        return requests;
    }

    public RequestResponse IsRequestValid(UnzipPasswordProtectedFileRequest fileRequest, RequestResponse requestResponse)
    {
        requestResponse = DirectoryValidation.ValidateDirectoryExists(fileRequest.FormattedSourceDirectoryPath, requestResponse);
        requestResponse = FileValidation.ValidateFileExists(fileRequest.SourceFilePath, requestResponse);
        requestResponse = DirectoryValidation.ValidateDirectoryExists(fileRequest.FormattedDestinationPath, requestResponse);
        return requestResponse;
    }
}