ObservableImageField.cs

using System;
using System.IO;
using System.Threading.Tasks;
using Microsoft.Maui.Storage;
using NeuroAccessMaui.Resources.Languages;
using NeuroAccessMaui.UI.Pages.Utility.Images;
using System.Collections.Generic;
using Microsoft.Maui.Controls;
using CommunityToolkit.Mvvm.Input;
using NeuroAccessMaui.Services.Kyc.Models;
using CommunityToolkit.Mvvm.ComponentModel;
 
namespace NeuroAccessMaui.Services.Kyc.ViewModels
{
    public partial class ObservableImageField : ObservableFileField
    {
        public override string? StringValue
        {
            get => this.RawValue as string;
            set {
                this.RawValue = value;
                this.ImageSource = ImageSource.FromStream(() => new MemoryStream(Convert.FromBase64String(this.RawValue as string ?? string.Empty)));
            }
        }
 
        public int? TargetWidth
        {
            get
            {
                object? Value;
                return this.Metadata.TryGetValue("TargetWidth", out Value) ? Value as int? : null;
            }
        }
        public int? TargetHeight
        {
            get
            {
                object? Value;
                return this.Metadata.TryGetValue("TargetHeight", out Value) ? Value as int? : null;
            }
        }
        public double? AspectRatio
        {
            get
            {
                object? Value;
                return this.Metadata.TryGetValue("AspectRatio", out Value) ? Value as double? : null;
            }
        }
        public bool? ShouldCrop
        {
            get
            {
                object? Value;
                return this.Metadata.TryGetValue("ShouldCrop", out Value) ? Value as bool? : null;
            }
        }
 
        [ObservableProperty]
        private ImageSource? imageSource;
 
        [ObservableProperty]
        private bool allowUpload = true;
 
        [RelayCommand]
        private async Task PickPhoto()
        {
            try
            {
                FileResult? FileResult = await MediaPicker.Default.PickPhotoAsync(new MediaPickerOptions()
                {
                    Title = ServiceRef.Localizer[nameof(AppResources.PickPhotoOfYourself)]
                });
 
                if (FileResult is null)
                    return;
 
                Stream FileStream = await FileResult.OpenReadAsync();
                byte[] InputBin = await ToByteArrayAsync(FileStream) ?? throw new Exception("Failed to read photo stream");
 
                TaskCompletionSource<byte[]?> Tcs = new();
                await ServiceRef.NavigationService.GoToAsync(
                    nameof(ImageCroppingPage),
                    new ImageCroppingNavigationArgs(ImageSource.FromStream(() => new MemoryStream(InputBin)), Tcs)
                );
 
                byte[] OutputBin = await Tcs.Task ?? throw new Exception("Failed to crop photo");
                this.RawValue = Convert.ToBase64String(OutputBin);
 
                this.ImageSource = ImageSource.FromStream(() => new MemoryStream(Convert.FromBase64String(this.RawValue as string ?? string.Empty)));
            }
            catch (Exception Ex)
            {
                ServiceRef.LogService.LogException(Ex);
                await ServiceRef.UiService.DisplayException(Ex);
            }
        }
 
        [RelayCommand]
        private async Task TakePhoto()
        {
            bool Permitted = await ServiceRef.PermissionService.CheckCameraPermissionAsync();
 
            if (!Permitted)
                return;
 
            try
            {
                FileResult? FileResult = await MediaPicker.Default.CapturePhotoAsync(new MediaPickerOptions()
                {
                    Title = ServiceRef.Localizer[nameof(AppResources.TakePhotoOfYourself)]
                });
 
                if (FileResult is null)
                    return;
 
                Stream FileStream = await FileResult.OpenReadAsync();
 
                byte[] InputBin = await ToByteArrayAsync(FileStream) ?? throw new Exception("Failed to read photo stream");
 
                TaskCompletionSource<byte[]?> Tcs = new();
                await ServiceRef.NavigationService.GoToAsync(nameof(ImageCroppingPage), new ImageCroppingNavigationArgs(ImageSource.FromStream(() => new MemoryStream(InputBin)), Tcs));
 
                byte[] OutputBin = await Tcs.Task ?? throw new Exception("Failed to crop photo");
 
                this.RawValue = Convert.ToBase64String(OutputBin);
 
                this.ImageSource = ImageSource.FromStream(() => new MemoryStream(Convert.FromBase64String(this.RawValue as string ?? string.Empty)));
            }
            catch (Exception Ex)
            {
                ServiceRef.LogService.LogException(Ex);
                await ServiceRef.UiService.DisplayAlert(
                    ServiceRef.Localizer[nameof(AppResources.ErrorTitle)],
                    ServiceRef.Localizer[nameof(AppResources.FailedToLoadPhoto)]);
            }
        }
 
        private static async Task<byte[]?> ToByteArrayAsync(System.IO.Stream stream)
        {
            if (stream is null)
                return null;
            using (System.IO.MemoryStream MemoryStream = new System.IO.MemoryStream())
            {
                await stream.CopyToAsync(MemoryStream);
                return MemoryStream.ToArray();
            }
        }
    }
}