// Copyright (C) 2003-2026, Foxit Software Inc..
// All Rights Reserved.
//
// http://www.foxitsoftware.com
//
// The following code is copyrighted and contains proprietary information and trade secrets of Foxit Software Inc..
// You cannot distribute any part of Foxit PDF SDK to any third party or general public,
// unless there is a separate license agreement with Foxit Software Inc. which explicitly grants you such rights.
//
// This file contains an example to demonstrate how to use Foxit PDF SDK to do OCR for a PDF page or PDF document.

using System;
using foxit.common;
using foxit.pdf;
using foxit.addon.ocr;

namespace ocrCS
{
    class ocr
    {
        public static string output_path = "../output_files/ocr/";
        public static string input_path = "../input_files/ocr/";

        static void Main(String[] args)
        {
            System.IO.Directory.CreateDirectory(output_path);
            // Initialize library
            string sn = "Rew1vB0TqoMIxX444UcpScARWdhgJpsJfzmyMLR32a0+EgrCjp2NaQ==";
            string key = "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";
            ErrorCode error_code = Library.Initialize(sn, key);
            if (error_code != ErrorCode.e_ErrSuccess)
            {
                Console.WriteLine("Library Initialize Error: {0}\n", error_code);
                return;
            }

            try
            {
                // "ocr_resource_path" is the path of ocr resources. Please refer to Developer Guide for more details.
                string ocr_resource_path = "";

                if (ocr_resource_path == "")
                {
                    Console.WriteLine("ocr_resource_path is still empty. Please set it with a valid path to OCR resource path.");
                    return;
                }

                // Initialize OCR engine.
                error_code = OCREngine.Initialize(ocr_resource_path);
                if (error_code != ErrorCode.e_ErrSuccess)
                {
                    switch (error_code)
                    {
                        case ErrorCode.e_ErrInvalidLicense:
                            Console.WriteLine("[Failed] OCR module is not contained in current Foxit PDF SDK keys.");
                            break;
                        default:
                            Console.WriteLine("Fail to initialize OCR engine. Error: " + error_code);
                            break;
                    }
                    return;
                }
                Console.WriteLine("OCREngine is initialized.");

                // Set log for OCREngine. (This can be opened to set log file if necessary)
                //OCREngine.SetLogFile(output_path+"ocr.log");
                // Set languages.
                OCREngine.SetLanguages("English");

                // OCR PDF document, only for search, not editable.
                String input_file = input_path + "AboutFoxit_ocr.pdf";
                // Load a document
                using (PDFDoc doc = new PDFDoc(input_file))
                using (OCR ocr_operator = new OCR())
                {
                    ErrorCode doc_error_code = doc.Load(null);
                    if (doc_error_code != ErrorCode.e_ErrSuccess)
                    {
                        Console.WriteLine("The Doc [" + input_file + "] Error: " + doc_error_code);
                        return;
                    }
                    ocr_operator.OCRPDFDocument(doc, false, null);

                    String save_pdf_path = output_path + "ocr_doc_searchable.pdf";
                    doc.SaveAs(save_pdf_path, (int)PDFDoc.SaveFlags.e_SaveFlagNoOriginal);
                }

                // OCR PDF document, editable.
                using (PDFDoc doc = new PDFDoc(input_file))
                using (OCR ocr_operator = new OCR())
                {
                    ErrorCode doc_error_code = doc.Load(null);
                    if (doc_error_code != ErrorCode.e_ErrSuccess)
                    {
                        Console.WriteLine("The Doc [" + input_file + "] Error: " + doc_error_code);
                        return;
                    }
                    ocr_operator.OCRPDFDocument(doc, true, null);

                    String save_pdf_path = output_path + "ocr_doc_editable.pdf";
                    doc.SaveAs(save_pdf_path, (int)PDFDoc.SaveFlags.e_SaveFlagNoOriginal);
                }

                // OCR PDF page, only for search, not editable.
                using (PDFDoc doc = new PDFDoc(input_file))
                using (OCR ocr_operator = new OCR())
                {
                    ErrorCode doc_error_code = doc.Load(null);
                    if (doc_error_code != ErrorCode.e_ErrSuccess)
                    {
                        Console.WriteLine("The Doc [" + input_file + "] Error: " + doc_error_code);
                        return;
                    }
                    using (PDFPage page = doc.GetPage(0)) {
                        page.StartParse((int)PDFPage.ParseFlags.e_ParsePageNormal, null, false);
                        ocr_operator.OCRPDFPage(page, false, null);
                    }

                    String save_pdf_path = output_path + "ocr_page_searchable.pdf";
                    doc.SaveAs(save_pdf_path, (int)PDFDoc.SaveFlags.e_SaveFlagNoOriginal);
                }
                // OCR PDF document, editable.
                using (PDFDoc doc = new PDFDoc(input_file))
                using (OCR ocr_operator = new OCR())
                {
                    ErrorCode doc_error_code = doc.Load(null);
                    if (doc_error_code != ErrorCode.e_ErrSuccess)
                    {
                        Console.WriteLine("The Doc [" + input_file + "] Error: " + doc_error_code);
                        return;
                    }
                    using (PDFPage page = doc.GetPage(0))
                    {
                        page.StartParse((int)PDFPage.ParseFlags.e_ParsePageNormal, null, false);
                        ocr_operator.OCRPDFPage(page, true, null);
                    }

                    String save_pdf_path = output_path + "ocr_page_editable.pdf";
                    doc.SaveAs(save_pdf_path, (int)PDFDoc.SaveFlags.e_SaveFlagNoOriginal);
                }
                OCREngine.Release();
                Console.WriteLine("END: OCR demo.");
            }
            catch (System.Exception e)
            {
                Console.WriteLine(e.Message);
            }
            Library.Release();
        }
    }
}
