using qdr.app.studiou.orders2printpack.Extensions;
using qdr.app.studiou.orders2printpack.Labels;
using qdr.app.studiou.orders2printpack.Properties;
using System.Data;
using System.IO.Abstractions;

namespace qdr.app.studiou.orders2printpack
{
    public partial class FormLabelPrint : Form
    {

        private string? _csvPath;
        private string? _xlsPath;

        private DataTable? _data;

        public FormLabelPrint()
        {
            InitializeComponent();
        }


        #region *** Form Handlers *** 
        private void butOpenCsv_Click(object sender, EventArgs e)
        {
            BlockErrorHandled(() =>
            {
                if (dlgOpenCsv.ShowDialog(this) == DialogResult.OK)
                {
                    _csvPath = dlgOpenCsv.FileName;
                    tbCsvPath.Text = _csvPath;

                    _data = CsvUtils.CsvToDataTable(new FileSystem(), _csvPath, AppSettings.Default.CSVDelimiter );

                    RefreshParameters();
                }
            });
        }

        private void butOpenXls_Click(object sender, EventArgs e)
        {
            BlockErrorHandled(() =>
            {
                if (dlgSaveXls.ShowDialog(this) == DialogResult.OK)
                {
                    _xlsPath = dlgSaveXls.FileName;
                    tbXslxPath.Text = _xlsPath;
                }
            });
        }

        private void butGenerate_Click(object sender, EventArgs e)
        {
            BlockErrorHandled(() =>
            {
                if (string.IsNullOrEmpty(_csvPath)) throw new Exception($"Vstupní CSV soubor musí být vybrán.");
                if (string.IsNullOrEmpty(_xlsPath)) throw new Exception($"Výstupní XSLX soubor musí být vybrán.");
                if (!File.Exists(_csvPath)) throw new Exception($"Vstupní CSV soubor '{_csvPath}' neexistuje, vyberte existující soubor.");
                if (_data == null) throw new Exception($"Vstupní CSV soubor '{_csvPath}' musí být otevřen.");

                _data = ProcessData(_data);

                var generator = new ExcelLabelGenerator(AppSettings.Default.LabelTemplate.Replace("{cr}","\n"));

                if (generator.GenerateLabels(_data, _xlsPath, int.Parse(AppSettings.Default.LabelPerRow), int.Parse(AppSettings.Default.LabelPerCol), double.Parse(AppSettings.Default.LabelWidth), double.Parse(AppSettings.Default.LabelHeight)))
                    MessageBox.Show(this, $"Výstupní soubor '{_xlsPath}' byl vygenerován.", "Export", MessageBoxButtons.OK, MessageBoxIcon.Information);
                
                RefreshParameters();
            });
        }

        private DataTable ProcessData(DataTable data)
        {
            // Aggregate data first
            data = AggregateData(data);

            var expressionParts = AppSettings.Default.LabelAggegationDataExpression.Split('=');
            var expressionColumnName = expressionParts[0];
            var expressionValue = expressionParts[1];
            data.Columns.Add(expressionColumnName, typeof(string));

            var result = data.Clone();
            result.Rows.Clear();

            foreach (DataRow row in data.Rows)
            {
                var rowNew = result.Select($"order_no = '{row["order_no"]}' AND prod_cat = '{row["prod_cat"]}'");
                if (rowNew.Length == 0)
                {
                    var newRow = result.NewRow();
                    newRow.ItemArray = row.ItemArray.ToArray();
                    newRow[expressionColumnName] = expressionValue.Replace("{prod_var_type}", row["prod_var_type"].ToString())
                        .Replace("{qty}",row["qty"].ToString()).Replace("{cr}","\n");
                    result.Rows.Add(newRow);
                }
                else
                {
                    rowNew[0][expressionColumnName] = rowNew[0][expressionColumnName] + expressionValue.Replace("{prod_var_type}", row["prod_var_type"].ToString())
                        .Replace("{qty}", row["qty"].ToString()).Replace("{cr}", "\n");
                }
            }
            return result;

        }
        /// <summary>
        /// Aggregates order data by grouping order numbers, product categories, and product variant types,
        /// then summing the quantities for each group.
        /// </summary>
        /// <param name="data">Input DataTable containing order details</param>
        /// <returns>Aggregated DataTable with columns: order_no, prod_cat, prod_var_type, qty (sum)</returns>
        private DataTable AggregateData(DataTable data)
        {
            if (data == null)
                throw new ArgumentNullException(nameof(data));

            // Create result DataTable with appropriate columns
            DataTable result = new DataTable();
            result.Columns.Add("order_no", typeof(string));
            result.Columns.Add("email", typeof(string));
            result.Columns.Add("prod_cat", typeof(string));
            result.Columns.Add("prod_var_type", typeof(string));
            result.Columns.Add("qty", typeof(string));

            // Group and aggregate using LINQ
            var aggregatedData = data.AsEnumerable()
                .GroupBy(row => new
                {
                    OrderNo = row.Field<string>("order_no"),
                    Email = row.Field<string>("email"),
                    ProdCat = row.Field<string>("prod_cat"),
                    ProdVarType = row.Field<string>("prod_var_type")
                })
                .Select(group => new
                {
                    group.Key.OrderNo,
                    group.Key.Email,
                    group.Key.ProdCat,
                    group.Key.ProdVarType,
                    TotalQty = group.Sum(row => int.Parse(row.Field<string>("qty"))).ToString()
                })
                .OrderBy(x => x.OrderNo)
                .ThenBy(x => x.ProdCat)
                .ThenBy(x => x.ProdVarType);


            // Populate result DataTable
            foreach (var item in aggregatedData)
            {
                result.Rows.Add(
                    item.OrderNo,
                    item.Email,
                    item.ProdCat,
                    item.ProdVarType,
                    int.Parse(item.TotalQty)
                );
            }

            return result;
        }


        private void butConfig_Click(object sender, EventArgs e)
        {
            var dlg = new dlgLabelSettings();
            if (dlg.ShowDialog(this) == DialogResult.OK)
            {
                // Save settings
                RefreshParameters();
            }
        }

        private void butClose_Click(object sender, EventArgs e)
        {
            Close();
        }
        #endregion


        #region *** Private Methods ***
        private void RefreshParameters()
        {
            lParCount.Text = $"Štítků/záznamů: {_data?.Rows.Count}";
            lParCol.Text = $"Štítků ve sloupci: {AppSettings.Default.LabelPerCol}";
            lParRow.Text = $"Štítků řádků na stránku: {AppSettings.Default.LabelPerRow}";
        }

        private void BlockErrorHandled(Action block)
        {
            try
            {
                block();
            }
            catch (Exception ex)
            {
                // Log("Error: " + ex.Message);
                MessageBox.Show(this, ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }
        }
        #endregion

        #region *** Nested classes ***

        #endregion
    }
}