using System;
using System.IO;
using System.Linq;
using NUnit.Framework;
using QuestPDF.Drawing.Exceptions;
using QuestPDF.Examples.Engine;
using QuestPDF.Fluent;
using QuestPDF.Helpers;
using QuestPDF.Infrastructure;
using SkiaSharp;

namespace QuestPDF.Examples
{
    public class ImageExamples
    {
        [Test]
        public void LoadingImage()
        {
            RenderingTest
                .Create()
                .PageSize(PageSizes.A5)
                .ProducePdf()
                .ShowResults()
                .Render(page =>
                {
                    page.Padding(25).Column(column =>
                    {
                        column.Spacing(25);
                        
                        column.Item().Image("logo.png");

                        var binaryData = File.ReadAllBytes("logo.png");
                        column.Item().Image(binaryData);
                        
                        using var stream = new FileStream("logo.png", FileMode.Open);
                        column.Item().Image(stream);
                    });
                });
        }
        
        [Test]
        public void DynamicImage()
        {
            RenderingTest
                .Create()
                .PageSize(450, 350)
                .ProducePdf()
                .ShowResults()
                .Render(page =>
                {
                    page.Padding(25)
                        .Image(Placeholders.Image);
                });
        }
        
        [Test]
        public void ScalingImageWithAlpha()
        {
            RenderingTest
                .Create()
                .PageSize(PageSizes.A4)
                .ProducePdf()
                .ShowResults()
                .Render(page =>
                {
                    page.Padding(25).Layers(layers =>
                    {
                        layers.Layer().Image(Placeholders.Image);
                        layers.PrimaryLayer().Padding(25).Image("multilingual.png");
                    });
                });
        }

        [Test]
        public void DpiSetting()
        {
            RenderingTest
                .Create()
                .PageSize(400, 600)
                .ProducePdf()
                .ShowResults()
                .Render(page =>
                {
                    page.Padding(15).Column(column =>
                    {
                        column.Spacing(15);
                        
                        column.Item().Image("photo.jpg").WithRasterDpi(16);
                        column.Item().Image("photo.jpg").WithRasterDpi(72);
                    });
                });
        }
        
        [Test]
        public void CompressionSetting()
        {
            RenderingTest
                .Create()
                .PageSize(400, 600)
                .ProducePdf()
                .ShowResults()
                .Render(page =>
                {
                    page.Padding(15).Column(column =>
                    {
                        column.Spacing(15);
                        
                        column.Item().Image("photo.jpg").WithCompressionQuality(ImageCompressionQuality.VeryLow).WithRasterDpi(72);
                        column.Item().Image("photo.jpg").WithCompressionQuality(ImageCompressionQuality.VeryHigh).WithRasterDpi(72);
                    });
                });
        }
        
        [Test]
        public void ReusingImage_With()
        {
            RenderingTest
                .Create()
                .PageSize(400, 600)
                .ProduceImages()
                .ShowResults()
                .Render(page =>
                {
                    page.Padding(15).Column(column =>
                    {
                        column.Spacing(15);

                        var image = Image.FromFile("checkbox.png");
                        
                        foreach (var i in Enumerable.Range(0, 5))
                        {
                            column.Item().Row(row =>
                            {
                                row.AutoItem().Width(24).Image(image);
                                row.RelativeItem().PaddingLeft(8).AlignMiddle().Text(Placeholders.Label()).FontSize(16);
                            });
                        }
                    });
                });
        }
        
        [Test]
        public void FitUnproportionally()
        {
            RenderingTest
                .Create()
                .PageSize(400, 600)
                .ProduceImages()
                .ShowResults()
                .Render(page =>
                {
                    page.Padding(15).MinimalBox().Background(Colors.Grey.Lighten3).Row(row =>
                    {
                        row.RelativeItem().Padding(5).Text(Placeholders.LoremIpsum());
                        row.RelativeItem().Image("photo.jpg").FitUnproportionally();
                    });
                });
        }
        
        [Test]
        public void Exception()
        {
            Assert.Throws<DocumentComposeException>(() =>
            {
                RenderingTest
                    .Create()
                    .PageSize(PageSizes.A2)
                    .ProducePdf()
                    .ShowResults()
                    .Render(page => page.Image("non_existent.png"));
            });
        }

        [Test]
        public void DrawingImageWithTransparency()
        {
            RenderingTest
                .Create()
                .PageSize(PageSizes.A4)
                .ProducePdf()
                .ShowResults()
                .RenderDocument(document =>
                {
                    document.Page(page =>
                    {
                        page.Content()
                            .AlignCenter()
                            .Text("Test")
                            .FontSize(192)
                            .FontColor(Colors.Blue.Medium)
                            .Bold();

                        var image = LoadImageWithTransparency("photo.jpg", 0.75f);
                        page.Foreground().Image(image);
                    });
                });

            QuestPDF.Infrastructure.Image LoadImageWithTransparency(string fileName, float transparency)
            {
                using var originalImage = SKImage.FromEncodedData(fileName);

                using var surface = SKSurface.Create(originalImage.Width, originalImage.Height, SKColorType.Rgba8888, SKAlphaType.Premul);
                using var canvas = surface.Canvas;

                using var transparencyPaint = new SKPaint
                {
                    ColorFilter = SKColorFilter.CreateBlendMode(SKColors.White.WithAlpha((byte)(transparency * 255)), SKBlendMode.DstIn)
                };

                canvas.DrawImage(originalImage, new SKPoint(0, 0), transparencyPaint);

                var encodedImage = surface.Snapshot().Encode(SKEncodedImageFormat.Png, 100).ToArray();
                return Image.FromBinaryData(encodedImage);
            }
        }

        [Test]
        public void ImageFilesShouldBeDisposableImmediatelyAfterDocumentGeneration()
        {
            var files = Enumerable.Range(0, 100).Select(x => $"temp_{x}.jpg").ToList();

            foreach (var file in files)
                File.Copy("photo.jpg", file);

            var document = Document.Create(document =>
            {
                document.Page(page =>
                {
                    page.Margin(24);

                    page.Content().Column(column =>
                    {
                        column.Spacing(24);

                        foreach (var file in files)
                            column.Item().Image(file).UseOriginalImage();
                    });
                });
            });

            document.GeneratePdfAndShow();

            foreach (var file in files)
                File.Delete(file);
        }
    }
}