using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Diagnostics.HealthChecks;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Diagnostics.HealthChecks;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.ServiceDiscovery;
using OpenTelemetry;
using OpenTelemetry.Metrics;
using OpenTelemetry.Trace;

namespace Microsoft.Extensions.Hosting;

// Adds common .NET Aspire services: service discovery, resilience, health checks, and OpenTelemetry.
// This project should be referenced by each service project in your solution.
// To learn more about using this project, see https://aka.ms/dotnet/aspire/service-defaults
public static class Extensions
{
    public static TBuilder AddServiceDefaults<TBuilder>(this TBuilder builder) where TBuilder : IHostApplicationBuilder
    {
        builder.ConfigureOpenTelemetry();
        
        builder.Services.AddServiceDiscovery();

        builder.Services.ConfigureHttpClientDefaults(http =>
        {
            // Turn on resilience by default
            http.AddStandardResilienceHandler();

            // Turn on service discovery by default
            http.AddServiceDiscovery();
        });

        // Uncomment the following to restrict the allowed schemes for service discovery.
        // builder.Services.Configure<ServiceDiscoveryOptions>(options =>
        // {
        //     options.AllowedSchemes = ["https"];
        // });

        return builder;
    }

    public static TBuilder ConfigureOpenTelemetry<TBuilder>(this TBuilder builder) where TBuilder : IHostApplicationBuilder
    {
        builder.Logging.AddOpenTelemetry(logging =>
        {
            logging.IncludeFormattedMessage = true;
            logging.IncludeScopes = true;
        });

        builder.Services.AddOpenTelemetry()
            .WithMetrics(metrics =>
            {
                metrics.AddAspNetCoreInstrumentation()
                    .AddHttpClientInstrumentation()
                    .AddRuntimeInstrumentation();
            })
            .WithTracing(tracing =>
            {
                tracing.AddSource(builder.Environment.ApplicationName)
                    .AddAspNetCoreInstrumentation()
                    // Uncomment the following line to enable gRPC instrumentation (requires the OpenTelemetry.Instrumentation.GrpcNetClient package)
                    //.AddGrpcClientInstrumentation()
                    .AddHttpClientInstrumentation();
            });

        builder.AddOpenTelemetryExporters();

        return builder;
    }

    private static TBuilder AddOpenTelemetryExporters<TBuilder>(this TBuilder builder) where TBuilder : IHostApplicationBuilder
    {
        var useOtlpExporter = !string.IsNullOrWhiteSpace(builder.Configuration["OTEL_EXPORTER_OTLP_ENDPOINT"]);

        if (useOtlpExporter)
        {
            builder.Services.AddOpenTelemetry().UseOtlpExporter();
        }

        // Uncomment the following lines to enable the Azure Monitor exporter (requires the Azure.Monitor.OpenTelemetry.AspNetCore package)
        //if (!string.IsNullOrEmpty(builder.Configuration["APPLICATIONINSIGHTS_CONNECTION_STRING"]))
        //{
        //    builder.Services.AddOpenTelemetry()
        //       .UseAzureMonitor();
        //}

        return builder;
    }
}
