StatsForm.cs

using System;
using System.Globalization;
using Eto.Drawing;
using Eto.Forms;

namespace devtime
{
    public class StatsForm : Dialog
    {
        private readonly string _context;
        private readonly DateTimePicker _fromPicker;
        private readonly DateTimePicker _toPicker;

        private readonly Label _hoursLabel;
        private readonly Label _minutesLabel;
        private readonly Label _secondsLabel;
        private readonly Label _msLabel;

        private readonly DropDown _formatDropDown;
        private readonly CheckBox _exportDateCheck;
        private readonly CheckBox _exportTimeCheck;
        private readonly CheckBox _exportLogCheck;

        private readonly DropDown _timeFormatDropDown;
        private readonly DropDown _timeApproxDropDown;

        public StatsForm(string context)
        {
            Title = "Stats";
            Icon = IconLoader.LoadIcon("export.png");
            Resizable = false;
            _context = context;

            _fromPicker = new DateTimePicker { Mode = DateTimePickerMode.Date, Width = 110 };
            _toPicker = new DateTimePicker { Mode = DateTimePickerMode.Date, Width = 110 };

            _fromPicker.ValueChanged += (s, e) => OnRangeChanged();
            _toPicker.ValueChanged += (s, e) => OnRangeChanged();

            string? oldest = DB.SelectOldestDate(context);
            string? newest = DB.SelectNewestDate(context);

            if (oldest == null || newest == null)
            {
                oldest = DateTime.Today.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture);
                newest = oldest;
            }

            if (DateTime.TryParseExact(oldest, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None, out DateTime oDate))
            {
                _fromPicker.Value = oDate;
            }
            if (DateTime.TryParseExact(newest, "yyyy-MM-dd", CultureInfo.InvariantCulture, DateTimeStyles.None, out DateTime nDate))
            {
                _toPicker.Value = nDate;
            }

            _hoursLabel = new Label();
            _minutesLabel = new Label();
            _secondsLabel = new Label();
            _msLabel = new Label();

            var workedGroup = new GroupBox { Text = "Worked Time", Width = 270, Height = 85 };
            workedGroup.Content = new StackLayout
            {
                Padding = new Padding(8, 3),
                Spacing = 2,
                Items = { _hoursLabel, _minutesLabel, _secondsLabel, _msLabel }
            };

            _formatDropDown = new DropDown { Width = 110 };
            foreach (var val in Enum.GetValues(typeof(Exporter.ExportFormat)))
            {
                _formatDropDown.Items.Add(val.ToString() ?? "");
            }
            _formatDropDown.SelectedIndex = 0;

            _exportDateCheck = new CheckBox { Text = "Date", Checked = true };
            _exportTimeCheck = new CheckBox { Text = "Logged time", Checked = true };
            _exportLogCheck = new CheckBox { Text = "Log", Checked = true };

            _timeFormatDropDown = new DropDown { Width = 110 };
            foreach (var val in Enum.GetValues(typeof(Exporter.TimeFormat)))
            {
                _timeFormatDropDown.Items.Add(val.ToString() ?? "");
            }
            _timeFormatDropDown.SelectedIndex = 0;

            _timeApproxDropDown = new DropDown { Width = 110 };
            foreach (var val in Enum.GetValues(typeof(Exporter.TimeApproximation)))
            {
                _timeApproxDropDown.Items.Add(val.ToString() ?? "");
            }
            _timeApproxDropDown.SelectedIndex = 0;

            _exportTimeCheck.CheckedChanged += (s, e) =>
            {
                _timeFormatDropDown.Enabled = _exportTimeCheck.Checked ?? false;
                _timeApproxDropDown.Enabled = _exportTimeCheck.Checked ?? false;
            };

            var exportButton = new Button { Text = "Export", Width = 80, Height = 23 };
            exportButton.Click += (s, e) => ExportClick();

            var closeButton = new Button { Text = "Close", Width = 80, Height = 23 };
            closeButton.Click += (s, e) => Close();

            var dateRangeRow = new TableLayout
            {
                Spacing = new Size(5, 3),
                Rows =
                {
                    new TableRow(new Label { Text = "From:" }, _fromPicker),
                    new TableRow(new Label { Text = "To:" }, _toPicker)
                }
            };

            var exportOptions = new TableLayout
            {
                Spacing = new Size(5, 3),
                Rows =
                {
                    new TableRow(new Label { Text = "Format:" }, _formatDropDown),
                    new TableRow(new Label { Text = "Fields:" }, new StackLayout { Orientation = Orientation.Horizontal, Spacing = 5, Items = { _exportDateCheck, _exportTimeCheck, _exportLogCheck } }),
                    new TableRow(new Label { Text = "Time unit:" }, _timeFormatDropDown),
                    new TableRow(new Label { Text = "Rounding:" }, _timeApproxDropDown)
                }
            };

            var exportGroup = new GroupBox { Text = "Export" };
            exportGroup.Content = new StackLayout
            {
                Padding = new Padding(8, 3),
                Spacing = 5,
                Items = { exportOptions, exportButton }
            };

            Content = new StackLayout
            {
                Padding = new Padding(8, 5),
                Spacing = 5,
                HorizontalContentAlignment = HorizontalAlignment.Stretch,
                Items =
                {
                    dateRangeRow,
                    workedGroup,
                    exportGroup,
                    new StackLayout { HorizontalContentAlignment = HorizontalAlignment.Right, Items = { closeButton } }
                }
            };

            OnRangeChanged();
        }

        private void OnRangeChanged()
        {
            if (_fromPicker.Value == null || _toPicker.Value == null) return;
            string fromStr = _fromPicker.Value.Value.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture);
            string toStr = _toPicker.Value.Value.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture);

            long time = 0;
            try
            {
                time = DB.SelectTotalLoggedTime(_context, fromStr, toStr);
            }
            catch { }

            long remaining = time;
            long hours = remaining / 3600000;
            remaining %= 3600000;

            long minutes = remaining / 60000;
            remaining %= 60000;

            long seconds = remaining / 1000;
            remaining %= 1000;

            long ms = remaining;

            _hoursLabel.Text = $"{hours} hour{(hours != 1 ? "s" : "")}";
            _minutesLabel.Text = $"{minutes} minute{(minutes != 1 ? "s" : "")}";
            _secondsLabel.Text = $"{seconds} second{(seconds != 1 ? "s" : "")}";
            _msLabel.Text = $"{ms} millisecond{(ms != 1 ? "s" : "")}";
        }

        private void ExportClick()
        {
            if (!(_exportDateCheck.Checked ?? false) && !(_exportTimeCheck.Checked ?? false) && !(_exportLogCheck.Checked ?? false))
            {
                MessageBox.Show(this, "At least one field needs to be exported (date, logged time, log).", "devtime error", MessageBoxButtons.OK, MessageBoxType.Error);
                return;
            }

            var sfd = new SaveFileDialog();
            var format = (Exporter.ExportFormat)Enum.Parse(typeof(Exporter.ExportFormat), _formatDropDown.SelectedKey ?? nameof(Exporter.ExportFormat.CSV));
            if (format == Exporter.ExportFormat.CSV)
            {
                sfd.Filters.Add(new FileFilter("CSV Files (*.csv)", new[] { "*.csv" }));
                sfd.FileName = "devtime_export.csv";
            }
            else
            {
                sfd.Filters.Add(new FileFilter("JSON Files (*.json)", new[] { "*.json" }));
                sfd.FileName = "devtime_export.json";
            }

            if (sfd.ShowDialog(this) == DialogResult.Ok)
            {
                if (_fromPicker.Value == null || _toPicker.Value == null) return;
                string fromStr = _fromPicker.Value.Value.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture);
                string toStr = _toPicker.Value.Value.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture);

                var exportForm = new ExportForm(
                    sfd.FileName,
                    _context,
                    fromStr,
                    toStr,
                    format,
                    _exportDateCheck.Checked ?? false,
                    _exportTimeCheck.Checked ?? false,
                    _exportLogCheck.Checked ?? false,
                    (Exporter.TimeFormat)Enum.Parse(typeof(Exporter.TimeFormat), _timeFormatDropDown.SelectedKey ?? nameof(Exporter.TimeFormat.Milliseconds)),
                    (Exporter.TimeApproximation)Enum.Parse(typeof(Exporter.TimeApproximation), _timeApproxDropDown.SelectedKey ?? nameof(Exporter.TimeApproximation.None))
                );

                var result = exportForm.ShowModal(this);

                switch (result)
                {
                    case DialogResult.Ok:
                        MessageBox.Show(this, "Export completed successfully.", "devtime", MessageBoxButtons.OK, MessageBoxType.Information);
                        break;
                    case DialogResult.Retry:
                        MessageBox.Show(this, "Export completed successfully.\nHowever, there are no entries in the specified time range. Therefore, the exported file is empty.", "devtime", MessageBoxButtons.OK, MessageBoxType.Warning);
                        break;
                }
            }
        }
    }
}