using OfficeOpenXml;
using OfficeOpenXml.Style;
using SixLabors.ImageSharp;
using SixLabors.ImageSharp.Processing;
using SixLabors.ImageSharp.Formats.Jpeg;
using WorkCameraExport.Models;

namespace WorkCameraExport.Services
{
    /// <summary>
    /// Excel 服务类 - 生成带图片的 Excel 文件
    /// </summary>
    public class ExcelService
    {
        // 图片尺寸配置
        private const int ImageWidth = 100;
        private const int ImageHeight = 60;
        private const int JpegQuality = 50;

        // Excel 列配置
        private static readonly string[] Headers = new[]
        {
            "序号", "部门名称", "拍照时间", "经度", "纬度", "位置",
            "工作内容", "施工人员", "状态", "施工图片", "创建时间", "更新时间"
        };

        private static readonly int[] ColumnWidths = new[]
        {
            8, 20, 18, 12, 12, 30, 40, 20, 10, 15, 18, 18
        };

        static ExcelService()
        {
            // 设置 EPPlus 许可证（非商业用途）
            ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
        }

        /// <summary>
        /// 生成 Excel 文件
        /// </summary>
        /// <param name="filePath">输出文件路径</param>
        /// <param name="records">工作记录列表</param>
        /// <param name="images">图片数据字典（URL -> 图片字节数组）</param>
        /// <param name="progressCallback">进度回调（当前行, 总行数）</param>
        public void GenerateExcel(
            string filePath,
            List<WorkRecordExportDto> records,
            Dictionary<string, byte[]> images,
            Action<int, int>? progressCallback = null)
        {
            using var package = new ExcelPackage();
            var worksheet = package.Workbook.Worksheets.Add("工作记录");

            // 设置表头
            SetupHeaders(worksheet);

            // 填充数据
            int rowIndex = 2;
            int totalRows = records.Count;

            foreach (var record in records)
            {
                FillRecordRow(worksheet, rowIndex, record, images);
                progressCallback?.Invoke(rowIndex - 1, totalRows);
                rowIndex++;
            }

            // 设置列宽
            SetColumnWidths(worksheet);

            // 冻结首行
            worksheet.View.FreezePanes(2, 1);

            // 保存文件
            package.SaveAs(new FileInfo(filePath));
        }

        /// <summary>
        /// 设置表头
        /// </summary>
        private void SetupHeaders(ExcelWorksheet worksheet)
        {
            for (int i = 0; i < Headers.Length; i++)
            {
                var cell = worksheet.Cells[1, i + 1];
                cell.Value = Headers[i];
                cell.Style.Font.Bold = true;
                cell.Style.Fill.PatternType = ExcelFillStyle.Solid;
                cell.Style.Fill.BackgroundColor.SetColor(System.Drawing.Color.FromArgb(0, 122, 204));
                cell.Style.Font.Color.SetColor(System.Drawing.Color.White);
                cell.Style.HorizontalAlignment = ExcelHorizontalAlignment.Center;
                cell.Style.VerticalAlignment = ExcelVerticalAlignment.Center;
                cell.Style.Border.BorderAround(ExcelBorderStyle.Thin);
            }

            // 设置表头行高
            worksheet.Row(1).Height = 25;
        }

        /// <summary>
        /// 填充单行数据
        /// </summary>
        private void FillRecordRow(
            ExcelWorksheet worksheet,
            int rowIndex,
            WorkRecordExportDto record,
            Dictionary<string, byte[]> images)
        {
            // 序号
            SetCellValue(worksheet, rowIndex, 1, rowIndex - 1);
            
            // 部门名称
            SetCellValue(worksheet, rowIndex, 2, record.DeptName);
            
            // 拍照时间
            SetCellValue(worksheet, rowIndex, 3, record.RecordTime?.ToString("yyyy-MM-dd HH:mm:ss") ?? "");
            
            // 经度
            SetCellValue(worksheet, rowIndex, 4, record.Longitude);
            
            // 纬度
            SetCellValue(worksheet, rowIndex, 5, record.Latitude);
            
            // 位置
            SetCellValue(worksheet, rowIndex, 6, record.Address);
            
            // 工作内容
            SetCellValue(worksheet, rowIndex, 7, record.Content);
            worksheet.Cells[rowIndex, 7].Style.WrapText = true;
            
            // 施工人员
            SetCellValue(worksheet, rowIndex, 8, string.Join(", ", record.Workers));
            
            // 状态
            SetCellValue(worksheet, rowIndex, 9, record.StatusName);
            
            // 施工图片 - 嵌入图片
            EmbedImages(worksheet, rowIndex, 10, record.Images, images);
            
            // 创建时间
            SetCellValue(worksheet, rowIndex, 11, record.CreateTime?.ToString("yyyy-MM-dd HH:mm:ss") ?? "");
            
            // 更新时间
            SetCellValue(worksheet, rowIndex, 12, record.UpdateTime?.ToString("yyyy-MM-dd HH:mm:ss") ?? "");

            // 设置行高（根据图片数量调整）
            int imageCount = record.Images.Count;
            if (imageCount > 0)
            {
                // 每张图片高度 + 间距
                double rowHeight = Math.Max(20, imageCount * (ImageHeight + 5));
                worksheet.Row(rowIndex).Height = rowHeight;
            }
            else
            {
                worksheet.Row(rowIndex).Height = 20;
            }

            // 设置边框
            for (int col = 1; col <= Headers.Length; col++)
            {
                worksheet.Cells[rowIndex, col].Style.Border.BorderAround(ExcelBorderStyle.Thin);
                worksheet.Cells[rowIndex, col].Style.VerticalAlignment = ExcelVerticalAlignment.Center;
            }
        }

        /// <summary>
        /// 设置单元格值
        /// </summary>
        private void SetCellValue(ExcelWorksheet worksheet, int row, int col, object value)
        {
            worksheet.Cells[row, col].Value = value;
        }

        /// <summary>
        /// 嵌入图片到单元格
        /// </summary>
        private void EmbedImages(
            ExcelWorksheet worksheet,
            int rowIndex,
            int colIndex,
            List<string> imageUrls,
            Dictionary<string, byte[]> images)
        {
            if (imageUrls.Count == 0)
            {
                SetCellValue(worksheet, rowIndex, colIndex, "无图片");
                return;
            }

            int imageOffset = 0;
            int successCount = 0;

            foreach (var url in imageUrls)
            {
                if (!images.TryGetValue(url, out var imageData) || imageData == null)
                {
                    continue;
                }

                try
                {
                    // 压缩和调整图片大小
                    var processedImage = ProcessImage(imageData);
                    if (processedImage == null) continue;

                    // 添加图片到 Excel
                    using var stream = new MemoryStream(processedImage);
                    var picture = worksheet.Drawings.AddPicture(
                        $"img_{rowIndex}_{colIndex}_{successCount}",
                        stream);

                    // 设置图片位置
                    picture.SetPosition(rowIndex - 1, imageOffset, colIndex - 1, 2);
                    picture.SetSize(ImageWidth, ImageHeight);

                    imageOffset += ImageHeight + 5;
                    successCount++;
                }
                catch
                {
                    // 忽略单张图片处理失败
                }
            }

            // 如果没有成功嵌入任何图片，显示文本
            if (successCount == 0)
            {
                SetCellValue(worksheet, rowIndex, colIndex, $"共{imageUrls.Count}张图片(加载失败)");
            }
        }

        /// <summary>
        /// 处理图片（调整大小和压缩）
        /// </summary>
        private byte[]? ProcessImage(byte[] imageData)
        {
            try
            {
                using var image = SixLabors.ImageSharp.Image.Load(imageData);
                
                // 调整大小
                image.Mutate(x => x.Resize(new ResizeOptions
                {
                    Size = new SixLabors.ImageSharp.Size(ImageWidth, ImageHeight),
                    Mode = ResizeMode.Max
                }));

                // 压缩为 JPEG
                using var outputStream = new MemoryStream();
                var encoder = new JpegEncoder
                {
                    Quality = JpegQuality
                };
                image.Save(outputStream, encoder);
                
                return outputStream.ToArray();
            }
            catch
            {
                return null;
            }
        }

        /// <summary>
        /// 设置列宽
        /// </summary>
        private void SetColumnWidths(ExcelWorksheet worksheet)
        {
            for (int i = 0; i < ColumnWidths.Length; i++)
            {
                worksheet.Column(i + 1).Width = ColumnWidths[i];
            }
        }
    }
}