using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Nop.Core.Domain.Catalog;
using Nop.Plugin.Misc.FruitBankPlugin.Domains.DataLayer;
using Nop.Plugin.Misc.FruitBankPlugin.Services;
using Nop.Services.Catalog;
using Nop.Services.Security;
using Nop.Web.Framework;
using Nop.Web.Framework.Controllers;
using Nop.Web.Framework.Mvc.Filters;
using PDFtoImage;
using SkiaSharp;


namespace Nop.Plugin.Misc.FruitBank.Controllers
{
    [AuthorizeAdmin]
    [Area(AreaNames.ADMIN)]
    [AutoValidateAntiforgeryToken]
    public class FileManagerController : BasePluginController
    {
        private readonly IPermissionService _permissionService;
        private readonly OpenAIApiService _aiApiService;
        private readonly IProductService _productService;
        private readonly FruitBankDbContext _dbContext;
        private readonly PdfToImageService _pdfToImageService;

        public FileManagerController(
            IPermissionService permissionService,
            OpenAIApiService aiApiService,
            IProductService productService,
            FruitBankDbContext fruitBankDbContext,
            PdfToImageService pdfToImageService)
        {
            _permissionService = permissionService;
            _aiApiService = aiApiService;
            _productService = productService;
            _dbContext = fruitBankDbContext;
            _pdfToImageService = pdfToImageService;
        }

        /// <summary>
        /// Display the image text extraction page
        /// </summary>
        public async Task<IActionResult> ImageTextExtraction()
        {
            if (!await _permissionService.AuthorizeAsync(StandardPermission.Security.ACCESS_ADMIN_PANEL))
                return AccessDeniedView();

            return View("~/Plugins/Misc.FruitBankPlugin/Areas/Admin/Views/Extras/ImageTextExtraction.cshtml");
        }

        /// <summary>
        /// Endpoint to extract text from uploaded image
        /// </summary>
        [HttpPost]
        public async Task<IActionResult> ExtractTextFromImage(IFormFile imageFile, string customPrompt = null)
        {
            if (!await _permissionService.AuthorizeAsync(StandardPermission.Security.ACCESS_ADMIN_PANEL))
                return Json(new { success = false, message = "Access denied" });

            if (imageFile == null || imageFile.Length == 0)
            {
                return Json(new { success = false, message = "No file received" });
            }

            // Validate file type - now including PDF
            var extension = Path.GetExtension(imageFile.FileName).ToLowerInvariant();
            if (extension != ".jpg" && extension != ".jpeg" && extension != ".png" &&
                extension != ".gif" && extension != ".webp" && extension != ".pdf")
            {
                return Json(new { success = false, message = "Invalid file type. Please upload JPG, PNG, GIF, WebP, or PDF." });
            }

            try
            {
                // Define the uploads folder
                var uploadsFolder = Path.Combine(Directory.GetCurrentDirectory(), "wwwroot", "uploads", "ocr");

                // Create directory if it doesn't exist
                if (!Directory.Exists(uploadsFolder))
                {
                    Directory.CreateDirectory(uploadsFolder);
                }

                string processedFilePath;
                string processedFileName;

                // Handle PDF conversion
                if (extension == ".pdf")
                {
                    // Save the PDF temporarily
                    var tempPdfFileName = $"temp_pdf_{DateTime.Now:yyyyMMdd_HHmmss}.pdf";
                    var tempPdfPath = Path.Combine(uploadsFolder, tempPdfFileName);

                    using (var stream = new FileStream(tempPdfPath, FileMode.Create))
                    {
                        await imageFile.CopyToAsync(stream);
                    }

                    // Convert PDF to JPG using our service                    
                    var convertedImages = await _pdfToImageService.ConvertPdfToJpgAsync(tempPdfPath, uploadsFolder);

                    if (convertedImages == null || convertedImages.Count == 0)
                    {
                        // Clean up temp PDF
                        if (System.IO.File.Exists(tempPdfPath))
                            System.IO.File.Delete(tempPdfPath);

                        return Json(new { success = false, message = "Failed to convert PDF or PDF is empty" });
                    }

                    // Use the first page
                    processedFilePath = convertedImages[0];
                    processedFileName = Path.GetFileName(processedFilePath);

                    // Clean up temp PDF
                    if (System.IO.File.Exists(tempPdfPath))
                        System.IO.File.Delete(tempPdfPath);
                }
                else
                {
                    // Handle regular image files
                    processedFileName = $"ocr_image_{DateTime.Now:yyyyMMdd_HHmmss}{extension}";
                    processedFilePath = Path.Combine(uploadsFolder, processedFileName);

                    using (var stream = new FileStream(processedFilePath, FileMode.Create))
                    {
                        await imageFile.CopyToAsync(stream);
                    }
                }

                // Extract text from the processed image using OpenAI Vision API
                string extractedText;
                using (var imageStream = new FileStream(processedFilePath, FileMode.Open, FileAccess.Read))
                {
                    extractedText = await _aiApiService.ExtractTextFromImageAsync(
                        imageStream,
                        processedFileName,
                        customPrompt
                    );
                }

                if (string.IsNullOrEmpty(extractedText))
                {
                    return Json(new
                    {
                        success = false,
                        message = "Failed to extract text. The API may have returned an empty response."
                    });
                }

                return Json(new
                {
                    success = true,
                    message = extension == ".pdf"
                        ? "PDF converted and text extracted successfully"
                        : "Text extracted successfully",
                    extractedText = extractedText,
                    fileName = processedFileName,
                    filePath = processedFilePath,
                    fileSize = imageFile.Length,
                    wasConverted = extension == ".pdf"
                });
            }
            catch (Exception ex)
            {
                Console.Error.WriteLine($"Error in ExtractTextFromImage: {ex}");
                return Json(new
                {
                    success = false,
                    message = $"Error processing file: {ex.Message}"
                });
            }
        }
    }
}