StitchATon2/App/Controllers/ImageController.cs

using System.Text.Json;
using StitchATon2.App.Models;
using StitchATon2.Domain;

namespace StitchATon2.App.Controllers;

public static class ImageController
{
    public static async Task GenerateImage(
        HttpResponse response,
        GenerateImageDto dto,
        TileManager tileManager,
        CancellationToken cancellationToken)
    {
        if (dto.GetErrors() is { Count: > 0 } errors)
        {
            response.StatusCode = 422;
            response.ContentType = "text/json";
            var errorBody = JsonSerializer.Serialize(errors, AppJsonSerializerContext.Default.DictionaryStringListString);
            response.ContentLength = errorBody.Length;
            await response.WriteAsync(errorBody, cancellationToken: cancellationToken);
            await response.CompleteAsync();
            return;
        }
        
        response.StatusCode = 200;
        response.ContentType = "image/png";
        
        Console.WriteLine($"Generate image for {dto}");

        await tileManager
            .CreateSection(dto)
            .DangerousWriteToPipe(response.BodyWriter, dto.OutputScale, cancellationToken);
        
        await response.CompleteAsync();
    }
    
    public static async Task GenerateRandomImage(
        HttpResponse response,
        TileManager tileManager,
        CancellationToken cancellationToken)
    {
        response.StatusCode = 200;
        response.ContentType = "image/png";

        var maxId = tileManager.Configuration.Rows * tileManager.Configuration.Columns;
        var id0 = Random.Shared.Next(maxId);
        var id1 = Random.Shared.Next(maxId);
        
        var tile0 = tileManager.GetTile(id0);
        var tile1 = tileManager.GetTile(id1);
        var coordinatePair = $"{tile0.Coordinate}:{tile1.Coordinate}";
        
        var section = tileManager.CreateSection(coordinatePair, 0, 0, 1, 1);
        
        var scale = float.Clamp(480f / int.Max(section.Width, section.Height), 0.01f, 1f);
        Console.WriteLine($"Generate random image for {coordinatePair} scale: {scale}");
        
        await section.DangerousWriteToPipe(response.BodyWriter, scale, cancellationToken);
        await response.CompleteAsync();
    }
}