using System.Text;
using AvParser.ImgTestService;

var builder = WebApplication.CreateBuilder(args);

var options = builder.Configuration.GetSection("ImgTest").Get<ImgTestOptions>() ?? new ImgTestOptions();
var endpoints = options.BuildLookup();

var app = builder.Build();

// A plain index so opening the host in a browser explains what is here.
app.MapGet(
    "/",
    () =>
    {
        var text = new StringBuilder();
        text.AppendLine("AvParser image test service");
        text.AppendLine();
        text.AppendLine($"miss rate: {options.MissRate:0.###}");
        text.AppendLine("endpoints:");
        foreach (var endpoint in endpoints.Values)
        {
            var ext = endpoint.Extensions.Length == 0 ? "(none)" : string.Join(" ", endpoint.Extensions);
            text.AppendLine(
                $"  /{endpoint.Path}/{{id}}  length {endpoint.MinLength}-{endpoint.MaxLength}, "
                    + $"{endpoint.Allowed.Count} chars, ext {ext}"
            );
        }

        return Results.Text(text.ToString(), "text/plain; charset=utf-8");
    }
);

app.MapGet("/healthz", () => Results.Text("ok", "text/plain"));

// One handler for every configured endpoint: the first segment selects the config, the second is
// the id (optionally with an extension). A miss and an unknown endpoint are both a plain 404.
app.MapGet(
    "/{endpoint}/{id}",
    (string endpoint, string id) =>
    {
        if (!endpoints.TryGetValue(endpoint, out var config))
        {
            return Results.NotFound();
        }

        var core = config.StripExtension(id);
        if (!config.Matches(core) || ImgTestOptions.IsMiss(core, options.MissRate))
        {
            return Results.NotFound();
        }

        return Results.Bytes(Identicon.Render(core), "image/png");
    }
);

app.Run();