using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Azure.Management.AppService.Fluent;
using Microsoft.Azure.Management.Fluent;
using Microsoft.WindowsAzure.Storage;
using Microsoft.WindowsAzure.Storage.Blob;
using Tango.AzureUtils.Database;
using Tango.BL.Entities;
using Tango.BL.Enumerations;
using Tango.Core.IO;

namespace Tango.AzureUtils.Storage
{
    public class StorageManager : AzureUtilsComponentBase
    {
        private String _account;
        private CloudBlobClient _client;
        private DatabaseManager _databaseManager;

        public StorageManager(IAzure azure) : base(azure)
        {
            _databaseManager = CreateManager<DatabaseManager>();
        }

        public Task Connect(String account)
        {
            OnProgress(AzureUtilsStage.Storage, $"Connecting to storage account...");
            _account = account;
            var targetAccount = CloudStorageAccount.Parse(_account);
            _client = targetAccount.CreateCloudBlobClient();

            return Task.FromResult(true);
        }

        public CloudBlobClient GetClient()
        {
            return _client;
        }

        private async Task<CloudBlockBlob> CreateEmptyBlob(CloudBlobContainer container, String name)
        {
            OnProgress(AzureUtilsStage.Storage, $"Creating blob '{name}'...");

            CloudBlockBlob targetBlob = container.GetBlockBlobReference(name);
            using (MemoryStream ms = new MemoryStream())
            {
                await targetBlob.UploadFromStreamAsync(ms);//Empty memory stream. Will create an empty blob.
            }

            return targetBlob;
        }

        public async Task<CloudBlobContainer> CreateContainer(String name)
        {
            OnProgress(AzureUtilsStage.Storage, $"Creating storage container '{name}'...");
            var container = _client.GetContainerReference(name);
            await container.CreateIfNotExistsAsync();
            return container;
        }

        public async Task RemoveContainer(String name)
        {
            OnProgress(AzureUtilsStage.Storage, $"Removing storage container '{name}'...");
            var container = _client.GetContainerReference(name);
            await container.DeleteAsync();
        }

        public async Task RemoveBlob(String containerName, String blobName)
        {
            OnProgress(AzureUtilsStage.Storage, $"Removing blob '{blobName}'...");
            var container = _client.GetContainerReference(containerName);
            var blob = container.GetBlockBlobReference(blobName);
            await blob.DeleteAsync();
        }

        public async Task UpgradeTangoStorage(IWebAppBase sourceApp, IWebAppBase targetApp, MachineTypes machineType, String versionTag)
        {
            OnProgress(AzureUtilsStage.Storage, $"Retrieving source and target settings...");

            var sourceSettings = await sourceApp.GetMachineServiceSettingsAsync();
            var targetSettings = await targetApp.GetMachineServiceSettingsAsync();

            var latestTangoVersion = await _databaseManager.GetLatestTangoVersion(sourceApp, machineType, versionTag);

            OnProgress(AzureUtilsStage.Storage, $"Upgrading {machineType.ToDescription()} version storage...");

            var sourceAccount = CloudStorageAccount.Parse(sourceSettings.STORAGE_ACCOUNT);
            var sourceClient = sourceAccount.CreateCloudBlobClient();

            var targetAccount = CloudStorageAccount.Parse(targetSettings.STORAGE_ACCOUNT);
            var targetClient = targetAccount.CreateCloudBlobClient();

            var sourceTangoContainer = sourceClient.GetContainerReference(sourceSettings.TANGO_VERSIONS_CONTAINER);
            var targetTangoContainer = targetClient.GetContainerReference(targetSettings.TANGO_VERSIONS_CONTAINER);

            var sourceTangoBlob = sourceTangoContainer.GetBlockBlobReference(latestTangoVersion.BlobName);
            var sourceTangoInstallerBlob = sourceTangoContainer.GetBlockBlobReference(latestTangoVersion.InstallerBlobName);

            var targetTangoBlob = await CreateEmptyBlob(targetTangoContainer, sourceTangoBlob.Name);
            var targetTangoInstallerBlob = await CreateEmptyBlob(targetTangoContainer, sourceTangoInstallerBlob.Name);

            await Task.Factory.StartNew(() =>
            {
                targetTangoBlob.StartCopy(sourceTangoBlob);
                targetTangoInstallerBlob.StartCopy(sourceTangoInstallerBlob);
            });
        }


        public async Task UpgradeFSEStorage(IWebAppBase sourceApp, IWebAppBase targetApp, FSEBuildVariants build)
        {
            OnProgress(AzureUtilsStage.Storage, $"Retrieving source and target settings...");

            var sourceSettings = await sourceApp.GetMachineServiceSettingsAsync();
            var targetSettings = await targetApp.GetMachineServiceSettingsAsync();

            var latestFSEVersion = await _databaseManager.GetLatestFSEVersion(sourceApp, build);

            OnProgress(AzureUtilsStage.Storage, $"Upgrading {build} version storage...");

            var sourceAccount = CloudStorageAccount.Parse(sourceSettings.STORAGE_ACCOUNT);
            var sourceClient = sourceAccount.CreateCloudBlobClient();

            var targetAccount = CloudStorageAccount.Parse(targetSettings.STORAGE_ACCOUNT);
            var targetClient = targetAccount.CreateCloudBlobClient();

            var sourceFSEContainer = sourceClient.GetContainerReference(sourceSettings.FSE_VERSIONS_CONTAINER);
            var targetFSEContainer = targetClient.GetContainerReference(targetSettings.FSE_VERSIONS_CONTAINER);

            //var sourceFSEBlob = sourceFSEContainer.GetBlockBlobReference(latestPPCVersion.BlobName);
            var sourceFSEInstallerBlob = sourceFSEContainer.GetBlockBlobReference(latestFSEVersion.InstallerBlobName);

            //var targetFSEBlob = await CreateEmptyBlob(targetFSEContainer, sourceFSEBlob.Name);
            var targetFSEInstallerBlob = await CreateEmptyBlob(targetFSEContainer, sourceFSEInstallerBlob.Name);

            await Task.Factory.StartNew(() =>
            {
                //targetFSEBlob.StartCopy(sourceFSEBlob);
                targetFSEInstallerBlob.StartCopy(sourceFSEInstallerBlob);
            });
        }

        public async Task UpgradeMachineStudioStorage(IWebAppBase sourceApp, IWebAppBase targetApp)
        {
            OnProgress(AzureUtilsStage.Storage, $"Retrieving source and target settings...");

            var latestMachineStudioVersion = await _databaseManager.GetLatestMachineStudioVersion(sourceApp);

            var sourceSettings = await sourceApp.GetMachineServiceSettingsAsync();
            var targetSettings = await targetApp.GetMachineServiceSettingsAsync();

            OnProgress(AzureUtilsStage.Storage, $"Upgrading Machine Studio version storage...");

            var sourceAccount = CloudStorageAccount.Parse(sourceSettings.STORAGE_ACCOUNT);
            var sourceClient = sourceAccount.CreateCloudBlobClient();

            var targetAccount = CloudStorageAccount.Parse(targetSettings.STORAGE_ACCOUNT);
            var targetClient = targetAccount.CreateCloudBlobClient();

            var sourceMachineStudioContainer = sourceClient.GetContainerReference(sourceSettings.MACHINE_STUDIO_VERSIONS_CONTAINER);
            var targetMachineStudioContainer = targetClient.GetContainerReference(targetSettings.MACHINE_STUDIO_VERSIONS_CONTAINER);

            var sourceMachineStudioBlob = sourceMachineStudioContainer.GetBlockBlobReference(latestMachineStudioVersion.BlobName);
            var sourceMachineStudioInstallerBlob = sourceMachineStudioContainer.GetBlockBlobReference(latestMachineStudioVersion.InstallerBlobName);

            var targetMachineStudioBlob = await CreateEmptyBlob(targetMachineStudioContainer, sourceMachineStudioBlob.Name);
            var targetMachineStudioInstallerBlob = await CreateEmptyBlob(targetMachineStudioContainer, sourceMachineStudioInstallerBlob.Name);

            await Task.Factory.StartNew(() =>
            {
                targetMachineStudioBlob.StartCopy(sourceMachineStudioBlob);
                targetMachineStudioInstallerBlob.StartCopy(sourceMachineStudioInstallerBlob);
            });
        }

        public async Task DowngradeMachineStudioStorage(IWebAppBase app)
        {
            OnProgress(AzureUtilsStage.Storage, $"Retrieving settings...");

            var latestMachineStudioVersion = await _databaseManager.GetLatestMachineStudioVersion(app);
            var settings = await app.GetMachineServiceSettingsAsync();

            await RemoveBlob(settings.MACHINE_STUDIO_VERSIONS_CONTAINER, latestMachineStudioVersion.BlobName);
            await RemoveBlob(settings.MACHINE_STUDIO_VERSIONS_CONTAINER, latestMachineStudioVersion.InstallerBlobName);

            OnCompleted("Latest Machine Studio storage blobs removed.");
        }

        public async Task DowngradeTangoStorage(IWebAppBase app, MachineTypes machineType, String versionTag)
        {
            OnProgress(AzureUtilsStage.Storage, $"Retrieving settings...");

            var latestTangoVersion = await _databaseManager.GetLatestTangoVersion(app, machineType, versionTag);
            var settings = await app.GetMachineServiceSettingsAsync();

            await RemoveBlob(settings.TANGO_VERSIONS_CONTAINER, latestTangoVersion.BlobName);
            await RemoveBlob(settings.TANGO_VERSIONS_CONTAINER, latestTangoVersion.InstallerBlobName);

            OnCompleted($"Latest {machineType.ToDescription()} storage blobs removed.");
        }

        public async Task ValidateTangoStorageUpgrade(IWebAppBase sourceApp, IWebAppBase targetApp, MachineTypes machineType, String versionTag)
        {
            OnProgress(AzureUtilsStage.Validating, $"Validating {machineType.ToDescription()} storage upgrade...");

            var sourceSettings = await sourceApp.GetMachineServiceSettingsAsync();
            var targetSettings = await targetApp.GetMachineServiceSettingsAsync();

            var latestSourceTangoVersion = await _databaseManager.GetLatestTangoVersion(sourceApp, machineType, versionTag);
            var latestTargetTangoVersion = await _databaseManager.GetLatestTangoVersion(targetApp, machineType, versionTag);

            var targetAccount = CloudStorageAccount.Parse(targetSettings.STORAGE_ACCOUNT);
            var targetClient = targetAccount.CreateCloudBlobClient();

            var targetTangoContainer = targetClient.GetContainerReference(targetSettings.TANGO_VERSIONS_CONTAINER);

            //Check version binaries blob not exists on the target.
            var targetTangoBlob = targetTangoContainer.GetBlockBlobReference(latestSourceTangoVersion.BlobName);
            if (await targetTangoBlob.ExistsAsync())
            {
                throw new ValidationException($"{machineType.ToDescription()} Block blob '{latestSourceTangoVersion.BlobName}' already exists on the target storage.");
            }

            //Check PPC installer blob not exists on the target.
            var targetTangoInstallerBlob = targetTangoContainer.GetBlockBlobReference(latestSourceTangoVersion.InstallerBlobName);
            if (await targetTangoInstallerBlob.ExistsAsync())
            {
                throw new ValidationException($"{machineType.ToDescription()} Block blob '{latestSourceTangoVersion.InstallerBlobName}' already exists on the target storage.");
            }
        }

        public async Task ValidateFSEStorageUpgrade(IWebAppBase sourceApp, IWebAppBase targetApp, FSEBuildVariants build)
        {
            OnProgress(AzureUtilsStage.Validating, $"Validating {build} storage upgrade...");

            var sourceSettings = await sourceApp.GetMachineServiceSettingsAsync();
            var targetSettings = await targetApp.GetMachineServiceSettingsAsync();

            var latestSourceFSEVersion = await _databaseManager.GetLatestFSEVersion(sourceApp, build);
            var latestTargetFSEVersion = await _databaseManager.GetLatestFSEVersion(targetApp, build);

            var targetAccount = CloudStorageAccount.Parse(targetSettings.STORAGE_ACCOUNT);
            var targetClient = targetAccount.CreateCloudBlobClient();

            var targetFSEContainer = targetClient.GetContainerReference(targetSettings.FSE_VERSIONS_CONTAINER);

            //Check FSE binaries blob not exists on the target.
            var targetFSEBlob = targetFSEContainer.GetBlockBlobReference(latestSourceFSEVersion.BlobName);
            if (await targetFSEBlob.ExistsAsync())
            {
                throw new ValidationException($"{build} Block blob '{latestSourceFSEVersion.BlobName}' already exists on the target storage.");
            }

            //Check FSE installer blob not exists on the target.
            var targetFSEInstallerBlob = targetFSEContainer.GetBlockBlobReference(latestSourceFSEVersion.InstallerBlobName);
            if (await targetFSEInstallerBlob.ExistsAsync())
            {
                throw new ValidationException($"{build} Block blob '{latestSourceFSEVersion.InstallerBlobName}' already exists on the target storage.");
            }
        }

        public async Task ValidateMachineStudioStorageUpgrade(IWebAppBase sourceApp, IWebAppBase targetApp)
        {
            OnProgress(AzureUtilsStage.Validating, "Validating machine studio storage upgrade...");

            var sourceSettings = await sourceApp.GetMachineServiceSettingsAsync();
            var targetSettings = await targetApp.GetMachineServiceSettingsAsync();

            var latestSourceMachineStudioVersion = await _databaseManager.GetLatestMachineStudioVersion(sourceApp);
            var latestTargetMachineStudioVersion = await _databaseManager.GetLatestMachineStudioVersion(targetApp);

            var targetAccount = CloudStorageAccount.Parse(targetSettings.STORAGE_ACCOUNT);
            var targetClient = targetAccount.CreateCloudBlobClient();

            var targetMachineStudioContainer = targetClient.GetContainerReference(targetSettings.MACHINE_STUDIO_VERSIONS_CONTAINER);

            //Check machine studio binaries blob not exists on the target.
            var targetMachineStudioBlob = targetMachineStudioContainer.GetBlockBlobReference(latestSourceMachineStudioVersion.BlobName);
            if (await targetMachineStudioBlob.ExistsAsync())
            {
                throw new ValidationException($"Machine Studio Block blob '{latestSourceMachineStudioVersion.BlobName}' already exists on the target storage.");
            }

            //Check machine studio installer blob not exists on the target.
            var targetMachineStudioInstallerBlob = targetMachineStudioContainer.GetBlockBlobReference(latestSourceMachineStudioVersion.InstallerBlobName);
            if (await targetMachineStudioInstallerBlob.ExistsAsync())
            {
                throw new ValidationException($"Machine Studio Block blob '{latestSourceMachineStudioVersion.InstallerBlobName}' already exists on the target storage.");
            }
        }

        public async Task DownloadLatestTangoVersion(IWebAppBase app, MachineTypes machineType, String filePath, String versionTag)
        {
            OnProgress(AzureUtilsStage.Storage, $"Retrieving source and target settings...");

            var settings = await app.GetMachineServiceSettingsAsync();

            TangoVersion version = await _databaseManager.GetLatestTangoVersion(app, machineType, versionTag);

            OnProgress(AzureUtilsStage.Storage, $"Downloading {machineType.ToDescription()} version '{version.Version}'...");

            var account = CloudStorageAccount.Parse(settings.STORAGE_ACCOUNT);
            var client = account.CreateCloudBlobClient();

            var container = client.GetContainerReference(settings.TANGO_VERSIONS_CONTAINER);

            var blob = container.GetBlockBlobReference(version.BlobName);
            await blob.FetchAttributesAsync();
            var length = blob.Properties.Length;

            using (FileStreamWrapper st = new FileStreamWrapper(filePath, FileMode.Create, (progress) =>
            {
                OnProgress(AzureUtilsStage.Storage, $"Downloading {machineType.ToDescription()} version '{version.VersionAndTag}'...", progress, length, false);
            }))
            {
                await blob.DownloadToStreamAsync(st);
            }
        }

        public async Task ReplaceLatestTangoVersion(IWebAppBase app, MachineTypes machineType, String filePath, String versionTag)
        {
            OnProgress(AzureUtilsStage.Storage, $"Retrieving source and target settings...");

            var settings = await app.GetMachineServiceSettingsAsync();

            TangoVersion version = await _databaseManager.GetLatestTangoVersion(app, machineType, versionTag);

            OnProgress(AzureUtilsStage.Storage, $"Uploading {machineType.ToDescription()} version '{version.VersionAndTag}'...");

            var account = CloudStorageAccount.Parse(settings.STORAGE_ACCOUNT);
            var client = account.CreateCloudBlobClient();

            var container = client.GetContainerReference(settings.TANGO_VERSIONS_CONTAINER);

            var blob = container.GetBlockBlobReference(version.BlobName);

            FileStreamWrapper st = null;

            using (st = new FileStreamWrapper(filePath, FileMode.Open, (progress) =>
            {
                OnProgress(AzureUtilsStage.Storage, $"Uploading {machineType.ToDescription()} version '{version.Version}'...", progress, st.Length, false);
            }))
            {
                await blob.UploadFromStreamAsync(st);
            }
        }
    }
}