using OfficeOpenXml;
using OfficeOpenXml.Style;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using VolPro.Core.Extensions;
using VolPro.Core.Utilities;

namespace VolPro.Core.Generic
{
    /// <summary>
    /// 通用导出 Excel 辅助类（参照 EPPlusHelper.Export 的行为，
    /// 实现字典数据源转换、字段类型显示、语言翻译等操作），仅返回内存字节，不落地文件。
    /// </summary>
    internal static class GenericExcelExportHelper
    {
        public static byte[] BuildExportBytes(
            string tableName,
            List<Dictionary<string, object>> rows,
            string[] exportColumns,
            List<string> ignoreColumns)
        {
            // 1. 列配置（CellOptions）
            var mi = typeof(EPPlusHelper).GetMethod("GetExportColumnInfo",
               BindingFlags.NonPublic | BindingFlags.Static);
            if (mi == null) return null;
            var cellOptions = mi.Invoke(null, new object[] { tableName, false, true, exportColumns }) as List<CellOptions>;
            if (cellOptions == null || cellOptions.Count == 0)
                return Array.Empty<byte>();

            // 2. 最终要导出的列
            var exportCols = BuildExportColumns(cellOptions, ignoreColumns);
            if (exportCols.Count == 0)
                return [];

            // 3. 字典列元数据
            var dicNoKeys = cellOptions
              .Where(x => !string.IsNullOrEmpty(x.DropNo) && x.KeyValues != null && x.KeyValues.Keys.Count > 0)
              .Select(x => (x.ColumnName, x.SearchType, x.EditType))
              .Distinct()
              .ToList();

            var multiSelectColumns = dicNoKeys
                .Where(x => x.SearchType == "checkbox" || x.SearchType == "selectList" || x.SearchType == "treeSelect"
                         || x.EditType == "checkbox" || x.EditType == "selectList" || x.EditType == "treeSelect")
                .Select(x => x.ColumnName)
                .ToArray();

            using var package = new ExcelPackage();
            var sheet = package.Workbook.Worksheets.Add("sheet1");

            // 4. 表头
            WriteHeaderRow(sheet, cellOptions, exportCols);

            // 5. 数据行
            WriteDataRows(sheet, rows, exportCols, cellOptions, dicNoKeys, multiSelectColumns);

            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            {
                // 6. 自动列宽
                if (sheet.Dimension != null) 
                    sheet.Cells[sheet.Dimension.Address].AutoFitColumns();
            }
    
            using var ms = new MemoryStream();
            package.SaveAs(ms);
            return ms.ToArray();
        }
        /// <summary>确定最终导出的列顺序，并应用忽略字段</summary>
        private static List<string> BuildExportColumns(List<CellOptions> cellOptions, List<string> ignoreColumns)
        {
            var cols = cellOptions.Select(c => c.ColumnName).ToList();
            if (ignoreColumns != null && ignoreColumns.Count > 0)
            {
                var ignoreSet = new HashSet<string>(ignoreColumns.Select(x => x.ToLower()));
                cols = cols.Where(c => !ignoreSet.Contains(c.ToLower())).ToList();
            }
            return cols;
        }


        /// <summary>写表头行（颜色、宽度、翻译与 EPPlusHelper.Export 中模板=false 一致）</summary>
        private static void WriteHeaderRow(
            ExcelWorksheet sheet,
            List<CellOptions> cellOptions,
            List<string> exportCols)
        {
            for (int i = 0; i < exportCols.Count; i++)
            {
                string colName = exportCols[i];
                using (var cell = sheet.Cells[1, i + 1])
                {
                    cell.Style.Fill.PatternType = ExcelFillStyle.Solid;
                    cell.Style.Fill.BackgroundColor.SetColor(Color.Gray);
                    cell.Style.Font.Color.SetColor(Color.White);
                }

                var opt = cellOptions.FirstOrDefault(x => x.ColumnName == colName);
                if (opt == null)
                {
                    sheet.Column(i + 1).Width = 15;
                    sheet.Cells[1, i + 1].Value = colName.Translator();
                    continue;
                }

                sheet.Column(i + 1).Width = opt.ColumnWidth / 6.0;
                var header = opt.ColumnCNName;
                sheet.Cells[1, i + 1].Value = header.Translator();
            }
        }

        /// <summary>写数据行，包括日期格式、字典转换、图片及 long 文本处理</summary>
        private static void WriteDataRows(
            ExcelWorksheet sheet,
            List<Dictionary<string, object>> rows,
            List<string> exportCols,
            List<CellOptions> cellOptions,
            List<(string ColumnName, string SearchType, string EditType)> dicNoKeys,
            string[] multiSelectColumns)
        {
            if (rows == null || rows.Count == 0) return;

            const long imageLimitBytes = 10 * 1024 * 1024;
            long embeddedBytes = 0;

            for (int r = 0; r < rows.Count; r++)
            {
                var row = rows[r];
                for (int c = 0; c < exportCols.Count; c++)
                {
                    string colName = exportCols[c];
                    row.TryGetValue(colName, out object value);

                    int? viewType = cellOptions
                        .Where(x => x.ColumnName == colName)
                        .Select(x => x.ViewType)
                        .FirstOrDefault();

                    // 日期格式
                    value = FormatDate(value, viewType);

                    // 字典转换
                    if (value != null && dicNoKeys.Any(x => x.ColumnName == colName))
                        value = TranslateDictionary(cellOptions, multiSelectColumns, colName, value);

                    // 图片
                    if (viewType == 1 && value != null)
                    {
                        embeddedBytes = HandleImageCell(sheet, r, c, value, embeddedBytes, imageLimitBytes);
                        continue;
                    }

                    // long 按文本导出
                    if (value is long || value is long?)
                    {
                        sheet.Cells[r + 2, c + 1].Style.Numberformat.Format = "@";
                        value = value?.ToString();
                    }

                    sheet.Cells[r + 2, c + 1].Value = value;
                }
            }
        }

        /// <summary>按 viewType/类型格式化日期</summary>
        private static object FormatDate(object value, int? viewType)
        {
            if (value == null) return null;

            // 6year年、5month年月、4date年月日
            if (viewType == 6 || viewType == 5 || viewType == 4)
            {
                if (value is DateTime dt)
                {
                    return viewType switch
                    {
                        6 => (object)dt.Year,
                        5 => dt.ToString("yyyy-MM"),
                        _ => dt.ToString("yyyy-MM-dd")
                    };
                }
                return value;
            }

            if (value is DateTime dt2)
                return dt2.ToString("yyyy-MM-dd HH:mm:sss");

            return value;
        }

        /// <summary>字典数据源转换（多选 / 单选）</summary>
        private static object TranslateDictionary(
            List<CellOptions> cellOptions,
            string[] multiSelectColumns,
            string colName,
            object value)
        {
            if (value == null) return null;

            if (multiSelectColumns.Contains(colName))
            {
                return string.Join(",", GetMultiDictValues(cellOptions, colName, value.ToString()));
            }

            var map = cellOptions
                .Where(x => x.ColumnName == colName)
                .Select(x => x.KeyValues)
                .FirstOrDefault();

            if (map == null) return value;
            return map.TryGetValue(value.ToString(), out var show) ? (object)show : value;
        }

        /// <summary>多选字典列：“1,2,3” => “名称1,名称2,名称3”</summary>
        private static IEnumerable<string> GetMultiDictValues(
            List<CellOptions> cellOptions,
            string colName,
            string raw)
        {
            var map = cellOptions
                .Where(x => x.ColumnName == colName)
                .Select(x => x.KeyValues)
                .FirstOrDefault();

            var parts = raw.Split(',');
            if (map == null)
            {
                foreach (var p in parts) yield return p;
                yield break;
            }

            foreach (var p in parts)
            {
                yield return map.TryGetValue(p, out var show) ? show : p;
            }
        }

        /// <summary>图片导出：嵌入或超链接</summary>
        private static long HandleImageCell(
            ExcelWorksheet sheet,
            int rowIndex,
            int colIndex,
            object value,
            long embeddedBytes,
            long imageLimitBytes)
        {
            string imgPath = value.ToString();
            if (string.IsNullOrWhiteSpace(imgPath))
                return embeddedBytes;

            bool isHttp = imgPath.StartsWith("http", StringComparison.OrdinalIgnoreCase);

            if (!isHttp)
            {
                imgPath = ("".MapPath(true) + "\\" + imgPath).ReplacePath();
                if (!File.Exists(imgPath))
                {
                    sheet.Cells[rowIndex + 2, colIndex + 1].Value = value;
                    return embeddedBytes;
                }

                var fi = new FileInfo(imgPath);
                long size = fi.Length;
                bool canEmbed = embeddedBytes + size <= imageLimitBytes;

                if (canEmbed)
                {
                    var pic = sheet.Drawings.AddPicture($"img_{rowIndex}_{colIndex}_{Guid.NewGuid():N}", fi);
                    pic.SetPosition(rowIndex + 1, 1, colIndex, 1);
                    pic.SetSize(80, 80);

                    if (sheet.Row(rowIndex + 2).Height < 60)
                        sheet.Row(rowIndex + 2).Height = 60;
                    if (sheet.Column(colIndex + 1).Width < 15)
                        sheet.Column(colIndex + 1).Width = 15;

                    sheet.Cells[rowIndex + 2, colIndex + 1].Value = null;
                    return embeddedBytes + size;
                }

                var fileUri = new Uri(fi.FullName);
                sheet.Cells[rowIndex + 2, colIndex + 1].Hyperlink = fileUri;
                sheet.Cells[rowIndex + 2, colIndex + 1].Value = Path.GetFileName(imgPath);
                return embeddedBytes;
            }

            if (Uri.TryCreate(imgPath, UriKind.Absolute, out var uri))
            {
                sheet.Cells[rowIndex + 2, colIndex + 1].Hyperlink = uri;
                sheet.Cells[rowIndex + 2, colIndex + 1].Value = Path.GetFileName(imgPath);
            }

            return embeddedBytes;
        }
    }
}