using OfficeOpenXml;
using OfficeOpenXml.FormulaParsing.Excel.Functions.Math;
using OfficeOpenXml.Style;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Runtime.InteropServices;
using VolPro.Core.UserManager;
using VolPro.Core.Utilities;

namespace VolPro.Core.Generic
{
    /// <summary>
    /// 通用导入模板 Excel 生成辅助类（基于 TableColumnField 元数据）
    /// </summary>
    internal static class GenericExcelTemplateHelper
    {
        /// <summary>
        /// 根据表配置生成导入模板 Excel 的二进制内容
        /// </summary>
        /// <param name="tableDisplayName">表中文名/标题</param>
        /// <param name="columns">表字段配置</param>
        /// <returns>Excel 文件字节数组</returns>
        public static byte[] BuildTemplateBytes(string tableDisplayName, List<TableColumnField> columns)
        {
            if (columns == null || columns.Count == 0)
            {
                return [];
            }
            //仅导出实际表字段
            var exportColumns = columns
                .Where(c => c.IsDisplay == 1 && c.ReferenceField == 0)
                .ToList();

            if (exportColumns.Count == 0)
            {
                return [];
            }
            using var package = new ExcelPackage();

            string sheetName = string.IsNullOrWhiteSpace(tableDisplayName)
                ? (exportColumns.First().TableName ?? "sheet1")
                : tableDisplayName;

            var worksheet = package.Workbook.Worksheets.Add(sheetName);

            int colIndex = 1;
            foreach (var col in exportColumns)
            {
                worksheet.Cells[1, colIndex].Style.Fill.PatternType = ExcelFillStyle.Solid;
                worksheet.Cells[1, colIndex].Style.Fill.BackgroundColor.SetColor(col.IsNull == 0 ? Color.Red : Color.White);
                string columnName = col.ColumnName;
                worksheet.Cells[1, colIndex].Value = string.IsNullOrWhiteSpace(col.ColumnCnName)
                    ? columnName
                    : col.ColumnCnName.Translator();
                colIndex++;
            }
            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            {
                // 自动列宽
                if (worksheet.Dimension != null)
                {
                    worksheet.Cells[worksheet.Dimension.Address].AutoFitColumns();
                }
            }
            return package.GetAsByteArray();
        }
    }
}