using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using UnityEngine;

namespace Crowdin.Plugin.Views
{
    using Helpers;

    public class TakeScreenshotForCrowdin
    {
        private Texture2D screenshot;

        public event Action<string, Texture2D> OnScreenshotTacked;

        public void TakeScreenshot(CancellationToken cancellationToken = default)
        {
            ProcessTakeScreenshot(cancellationToken)
                .ContinueWith(task =>
                {
                    if (task.Exception is not null)
                    {
                        Debug.Log($"Error: {task.Exception.Message}");
                    }
                });
        }

        private async Task ProcessTakeScreenshot(CancellationToken cancellationToken)
        {
            var epochStart = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
            var key = $"{Application.productName}_{(DateTime.UtcNow - epochStart).TotalSeconds}";
            var imageName = $"{FolderHelper.screenshotsDirectory}/{key}.png";

            try
            {
                // Take the screenshot
                ScreenCapture.CaptureScreenshot(imageName);

                // Wait because CaptureScreenshot execution may not be completed
                await Task.Delay(500, cancellationToken);

                // Read the data from the file
                byte[] data = await File.ReadAllBytesAsync(imageName, cancellationToken);

                // Create the texture
                var screenshotTexture = new Texture2D(Screen.width, Screen.height);

                // Load the image
                screenshotTexture.LoadImage(data);

                // Fire event captured
                OnScreenshotTacked?.Invoke(imageName, screenshotTexture);
            }
            catch (OperationCanceledException)
            {
                // Popup closed mid-capture: don't let the capture finish and still fire
                // OnScreenshotTacked (which would go on to upload the screenshot).
                if (File.Exists(imageName))
                {
                    File.Delete(imageName);
                }

                throw;
            }
        }
    }
}