using iTextSharp.text.pdf;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Document = iTextSharp.text.Document;
using CliWrap;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(/*string[] args*/)
        {
            string[] fileExtension = { ".xlsx", ".xls", ".ods", ".odt", ".doc", ".docx", ".pdf" };
            Console.WriteLine($"start convert");
            var inputFiles = new List<string>();
            var resultFile = "C:\\Test\\result.pdf";
            inputFiles.Add("11112222.docx");
            inputFiles.Add("11117777.pdf");
            inputFiles.Add("22223333.xls");
            inputFiles.Add("33334444.xlsx");

            var listOutNames = new List<string>();
            var filteredFilesNames = inputFiles
                .Distinct()
                .Where(f => fileExtension.Any(fe => f.ToLower().EndsWith(fe)))
                .ToList();
            foreach (var FileName in inputFiles)
            {
                var outputFile = Path.ChangeExtension(FileName, ".pdf");
                var outFile = StartConvertProcessAsync(FileName, outputFile);
                Console.WriteLine($"convert file - {FileName}");
                Console.ReadLine();
                listOutNames.Add(outFile.Result.ToString());
            }
            Console.WriteLine("merged files");
            Console.ReadLine();
            DoMerged(listOutNames, resultFile);
        }

        public static void DoMerged(IEnumerable<string> inputFiles, string outFile)
        {
            using (FileStream stream = new FileStream(outFile, FileMode.Create))
            using (Document doc = new Document())
            using (PdfCopy pdf = new PdfCopy(doc, stream))
            {
                doc.Open();
                PdfReader? reader = null;
                PdfImportedPage? page = null;
                inputFiles.ToList().ForEach(file =>
                {
                    reader = new PdfReader(file);
                    for (int i = 0; i < reader.NumberOfPages; i++)
                    {
                        page = pdf.GetImportedPage(reader, i + 1);
                        pdf.AddPage(page);
                    }
                    pdf.FreeReader(reader);
                    reader.Close();
                    File.Delete(file);
                });
            }
        }

        //public static void StartConvertProcess(string inputFileName, string outFileName)
        //{
        //    using (Process pdfprocess = new Process())
        //    {
        //        pdfprocess.StartInfo.UseShellExecute = true;
        //        //pdfprocess.StartInfo.LoadUserProfile = true;
        //        pdfprocess.StartInfo.FileName = "soffice";
        //        pdfprocess.StartInfo.Arguments = $"--headless --convert-to pdf {inputFileName} --outdir {outFileName}";
        //        pdfprocess.StartInfo.WorkingDirectory = "/usr/bin";
        //        pdfprocess.StartInfo.WindowStyle = ProcessWindowStyle.Hidden;
        //        pdfprocess.Start();
        //        if (!pdfprocess.WaitForExit(1000 * 60 * 1))
        //        {
        //            pdfprocess.Kill();
        //        }
        //        pdfprocess.Close();
        //    }
        //}
        private static async Task<string> StartConvertProcessAsync(string inputFileName, string outFileName)
        {
            //string outPath = "/home/eddie/Test/OutFiles";
            string outPath = "C:\\Test\\OutFiles";
            var result = Cli.Wrap("C:\\Program Files\\LibreOffice\\program\\soffice.exe")
                .WithArguments($"-headless -convert-to pdf C:\\Test\\InFiles\\{inputFileName} -outdir {outPath}");
            await result.ExecuteAsync();
            var outFile = $"{outPath}\\{outFileName}";
            return outFile;
        }

        public static async Task GetConverteAndMergedFileAsync(IEnumerable<string> filesNames, string resultPath)
        {
            string[] fileExtension = { ".xlsx", ".xls", ".ods", ".odt", ".doc", ".docx", ".pdf" };
            //var filteredFilesNames = filesNames.Distinct();
            var filteredFilesNames = filesNames
                .Distinct()
                .Where(f => fileExtension.Any(fe => f.ToLower().EndsWith(fe)))
                .ToList();
            var listFileNames = filteredFilesNames
                .ToList()
                .Select(o => new {
                    inputFile = o,
                    convertedFile = Path.ChangeExtension(o, ".pdf")
                });
            foreach (var excelFileName in listFileNames)
            {
                await StartConvertProcessAsync(excelFileName.inputFile, excelFileName.convertedFile);
                Console.WriteLine($"convert file - {excelFileName.inputFile}");
                Console.ReadLine();
            }

            Console.WriteLine("merged files");
            Console.ReadLine();
            DoMerged(listFileNames.Select(c => c.convertedFile), resultPath);

        }
    }
}