using System;
using System.IO;
using System.Threading.Tasks;
using Plugin.Media;
using Syncfusion.Drawing;
using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Pdf.Parsing;


namespace InABox.Mobile
{
    
    public abstract class MobileDocumentSource
    {
        public abstract Task<MobileDocument> GetDocument();
        
    }

    public class MobileDocumentCameraSource : MobileDocumentSource
    {
        public override async Task<MobileDocument> GetDocument()
        {
            await CrossMedia.Current.Initialize();

            if (!CrossMedia.Current.IsCameraAvailable || !CrossMedia.Current.IsTakePhotoSupported)
            {
                throw new Exception("No Camera Available");
            }

            String filename = $"{DateTime.Now:yyyy-MM-dd HH:mm:ss.fff}.png";

            var file = await CrossMedia.Current.TakePhotoAsync(new Plugin.Media.Abstractions.StoreCameraMediaOptions
            {
                Name = filename,
                CompressionQuality = 5,
                PhotoSize = Plugin.Media.Abstractions.PhotoSize.Large
            });

            if (file == null)
                return null;

            byte[] data;
            await using (var stream = file.GetStream())
            {
                BinaryReader br = new BinaryReader(stream);
                data = br.ReadBytes((int)stream.Length);
            }
            return new MobileDocument(filename, data);
        }
    }

    public class MobileDocumentLibrarySource : MobileDocumentSource
    {
        public override async Task<MobileDocument> GetDocument() 
        {
            await CrossMedia.Current.Initialize();
        
            if (!CrossMedia.Current.IsPickPhotoSupported)
                throw new Exception("No Photo Library available");

            var file = await CrossMedia.Current.PickPhotoAsync(new Plugin.Media.Abstractions.PickMediaOptions()
            {
                CompressionQuality = 5,
                PhotoSize = Plugin.Media.Abstractions.PhotoSize.Large
            });
    
            if (file == null)
                return null;
            
            byte[] data;
            await using (var stream = file.GetStream())
            {
                BinaryReader br = new BinaryReader(stream);
                data = br.ReadBytes((int)stream.Length);
            }
            return new MobileDocument(file.OriginalFilename ?? Path.GetFileName(file.Path),data);
            
        }
    }
    
    public static class MobileDocumentExtensions
    {
        public static MobileDocument ToPDF(this MobileDocument document)
        {
            byte[] result;
            using (var img = new MemoryStream(document.Data))
            {
                var image = new PdfBitmap(img);

                var pdfDoc = new PdfDocument();

                var section = pdfDoc.Sections.Add();
                section.PageSettings.Margins.All = 0;
                section.PageSettings.Width = image.Width;
                section.PageSettings.Height = image.Height;

                var page = section.Pages.Add();
                page.Graphics.DrawImage(image, 0, 0, page.Size.Width, page.Size.Height);

                using (var ms = new MemoryStream())
                {
                    pdfDoc.Save(ms);
                    document.Data = ms.GetBuffer();
                    document.FileName = Path.ChangeExtension(document.FileName, "pdf");                
                }
            }

            return document;
        }
    }
    
    public class MobileDocument
    {
        public string FileName { get; set; }
        public byte[] Data { get; set; }

        public MobileDocument(string filename, byte[] data)
        {
            FileName = filename;
            Data = data;
        }

        public bool IsPDF() => FileName.ToUpper().EndsWith(".PDF");

        public static async Task<MobileDocument> From<T>() 
            where T : MobileDocumentSource, new()
        {
            return await new T().GetDocument();
        }
    }
}