using System;
using System.IO;
using System.Windows.Forms;
using AdvertisingProfitControlData;

namespace AdvertsingProfitControl
{
    public partial class DatabaseRecovery : Form
    {
        public bool RestoredDatabase;
        private string _informationText = string.Empty;

        public DatabaseRecovery()
        {
            InitializeComponent();
            exisitingBackupsListView.ItemSelectionChanged += UpdateRestoreLocationTextBoxOnItemSelectionChange;
            restoreLocationTextBox.TextChanged += UpdateRestoreButtonOnRestoreLocationTextChange;
            //Grab the list of backups and fill the list box.
            var headerColumn = new ColumnHeader
            {
                Width = exisitingBackupsListView.Width - 10,
                TextAlign = HorizontalAlignment.Center
            };
            exisitingBackupsListView.Columns.Add(headerColumn);
            UpdateBackupList();
        }

        private void OnBackupLabelClick(object sender, EventArgs e)
        {
            MessageBox.Show(_informationText, @"Verification Failed Information", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        private void UpdateRestoreButtonOnRestoreLocationTextChange(object sender, EventArgs e)
        {
            restoreBackupButton.Enabled = restoreLocationTextBox.Text.Length != 0;
        }

        private void UpdateRestoreLocationTextBoxOnItemSelectionChange(object sender, ListViewItemSelectionChangedEventArgs e)
        {
            //Update the restore location text box when an item is selected.
            restoreLocationTextBox.Text = ((FileInfo) e.Item.Tag).FullName;
            deleteBackupFileButton.Enabled = true;
        }

        private void UpdateBackupList()
        {
            var backup = new Backup();
            var fileList = backup.GetSingleFileBackupFilesList();
            exisitingBackupsListView.Items.Clear();

            if (fileList.Count > 0)
            {
                foreach (var file in fileList)
                {
                    var item = new ListViewItem
                    {
                        Text = file.Name,
                        Tag = file
                    };
                    exisitingBackupsListView.Items.Add(item);
                }
                exisitingBackupsListView.Columns[0].Text = @"Current Backups";
            }
            else
            {
                exisitingBackupsListView.Columns[0].Text = @"No Backups Exist";          
            }
        }

        private void CreateBackupOnButtonClick(object sender, EventArgs e)
        {
            var backup = new Backup();
            var customBackupLocation = string.Empty;
            backupResultLabel.Click -= OnBackupLabelClick;

            if (!string.IsNullOrWhiteSpace(customBackupLocationTextBox.Text))
            {
                //Check to see if the folder selected or typed exists.
                var folder = new DirectoryInfo(customBackupLocationTextBox.Text);

                if (folder.Exists)
                {
                    customBackupLocation = customBackupLocationTextBox.Text;
                }
                else
                {
                    MessageBox.Show(
                        @"The selected backup folder doesn't exist. Please choose a different folder to store the backup.",
                        @"Backup Folder Location Invalid", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    backupResultLabel.Text = @"Custom backup location invalid.";
                    return;
                }
            }

            if (backup.SingleFileBackup(customBackupLocation))
            {
                //Check the state of the backup.
                if (backup.State == 0)
                {
                    backupResultLabel.Text = @"Successfully created backup(s).";
                    customBackupLocationTextBox.Text = string.Empty;
                }
                else
                {
                    switch (backup.State)
                    {
                        case Backup.PrimaryBackupVerifyFailed:
                            backupResultLabel.Text = @"Verification failed click to learn more.";
                            SetVerifcationInformationText("default backup file");
                            backupResultLabel.Click += OnBackupLabelClick;
                            break;
                        case Backup.OptionalBackupVerifyFailed:
                            backupResultLabel.Text = @"Verification failed click to learn more.";
                            SetVerifcationInformationText("optional backup file in '" + customBackupLocation + @"'");
                            backupResultLabel.Click += OnBackupLabelClick;
                            break;
                        case Backup.PrimaryBackupVerifyFailed + Backup.OptionalBackupVerifyFailed:
                            backupResultLabel.Text = @"Verification failed click to learn more.";
                            SetVerifcationInformationText("default and optional backup (located in " + customBackupLocation + ") files");
                            backupResultLabel.Click += OnBackupLabelClick;
                            break;
                    }
                }
            }
            else
            {
                switch (backup.State)
                {
                    case Backup.PrimaryBackupFailed:
                        MessageBox.Show(@"Failed to create the default backup file but if an optional backup location was supplied, that backup was created successfully.", @"Default Backup Failed", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        backupResultLabel.Text = @"Failed to default backup.";
                        break;
                    case Backup.OptionalBackupFailed:
                        MessageBox.Show(@"Default backup was successfully created, however the backup to be created in '" + customBackupLocation + @"' failed to be created.", @"Optional Backup Failed", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        backupResultLabel.Text = @"Failed to create optional backup.";
                        break;
                    case Backup.PrimaryBackupFailed + Backup.OptionalBackupFailed:
                        MessageBox.Show(@"Both the default and the optional backup (in the folder '" + customBackupLocation + @"') failed to be created entirely.", @"Backups Failed", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        backupResultLabel.Text = @"Failed to create backups.";
                        break;
                    case Backup.PrimaryBackupFailed + Backup.OptionalBackupVerifyFailed:
                        MessageBox.Show(@"The default backup file failed to be created and the optional backup (in the folder '" + customBackupLocation + @"') failed verification by the SQL server, click the text to the left of the 'Create Backup' button to learn more.", @"Backup And Verification Errors Detected", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        backupResultLabel.Text = @"Verification failed click to learn more.";
                        SetVerifcationInformationText("optional backup (located in " + customBackupLocation + ") file");
                        backupResultLabel.Click += OnBackupLabelClick;
                        break;
                    case Backup.PrimaryBackupVerifyFailed + Backup.OptionalBackupFailed:
                        MessageBox.Show(@"The optional backup file (in the folder '" + customBackupLocation + @"') failed to be created. The default backup file failed verification by the SQL server, click the text to the left of the 'Create Backup' button to learn more.", @"Backup And Verification Errors Detected", MessageBoxButtons.OK, MessageBoxIcon.Error);
                        backupResultLabel.Text = @"Verification failed click to learn more.";
                        SetVerifcationInformationText("default backup file");
                        backupResultLabel.Click += OnBackupLabelClick;
                        break;
                    default:
                        MessageBox.Show(backup.ErrorMessage, @"Unknown Error", MessageBoxButtons.OK,
                            MessageBoxIcon.Error);
                        break;
                }
            }

            UpdateBackupList();
        }

        private void UpdateCustomBackupLocationOnBackupLocationButtonClick(object sender, EventArgs e)
        {
            var dialog = new FolderBrowserDialog {Description = @"Select a folder to place the backup file into."};
            dialog.ShowDialog();

            if (dialog.SelectedPath != string.Empty)
            {
                customBackupLocationTextBox.Text = dialog.SelectedPath;
            }
        }

        private void UpdateRestoreLocationOnCustomBackupLocationButtonClick(object sender, EventArgs e)
        {
            var dialog = new OpenFileDialog
            {
                Multiselect = false,
                Filter = @"Backup Files | *." + Backup.DefaultBackupExtension,
                Title = @"Select your backup file to restore from."
            };

            dialog.ShowDialog();

            restoreLocationTextBox.Text = dialog.FileName;
        }

        private void RestoreSelectedBackupOnBackupRestoreButtonClick(object sender, EventArgs e)
        {
            var restore = new Restore();
            //Check for the file's existence before proceeding.
            if (!File.Exists(restoreLocationTextBox.Text))
            {
                MessageBox.Show(@"Database backup file could not be found at the location" + Environment.NewLine + @"'" + restoreLocationTextBox.Text + @"'.", @"Database Backup File Not Found", MessageBoxButtons.OK, MessageBoxIcon.Error);
                restoreInfoLabel.Text = @"Restore file location invalid.";
                return;
            }

            if (restore.SingleFileRestore(restoreLocationTextBox.Text, Properties.Settings.Default.DefaultServer))
            {
                restoreResultLabel.Text = @"Successfully restored the database.";
                restoreLocationTextBox.Text = string.Empty;
                RestoredDatabase = true;
            }
            else
            {
                MessageBox.Show(restore.ErrorMessage, @"Failed to Restore Backup", MessageBoxButtons.OK, MessageBoxIcon.Error);
                restoreResultLabel.Text = @"Failed to restore the database.";
            }
        }

        private void deleteBackupFileButton_Click(object sender, EventArgs e)
        {
            if (exisitingBackupsListView.SelectedItems.Count == 0)
            {
                deleteBackupFileButton.Enabled = false;
                return;
            }

            var selectedItem = exisitingBackupsListView.SelectedItems[0];
            var fileInfo = (FileInfo) selectedItem.Tag;

            try
            {
                File.Delete(fileInfo.FullName);
                restoreLocationTextBox.Text = string.Empty;
                deleteBackupFileButton.Enabled = false;
            }
            catch (IOException exception)
            {
                MessageBox.Show(exception.Message, @"Failed to Delete File " + fileInfo.Name, MessageBoxButtons.OK, MessageBoxIcon.Error);
            }

            UpdateBackupList();
        }

        private void SetVerifcationInformationText(string backupType)
        {
            _informationText = @"The recently created " + backupType + " failed verification checks by the SQL Server."
                              + Environment.NewLine +
                              @"This is shown by the '(Verification Failed)' text in the 'Current Backups' column. This means that the backup data could be damaged." +
                              Environment.NewLine +
                              @"While it is NOT recommended that you use this backup data to restore the database you may do so but it could result in data loss.";
        }
    }
}