package httpapi

import (
	"errors"
	"net/http"

	"github.com/go-chi/chi/v5"
	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
	"go.opentelemetry.io/otel/metric"
	"go.opentelemetry.io/otel/propagation"
	"go.opentelemetry.io/otel/trace"
)

type Endpoints struct {
	Metadata http.Handler
	Token    http.Handler
	JWKS     http.Handler
	Health   http.Handler
	Ready    http.Handler
}

type Telemetry struct {
	TracerProvider trace.TracerProvider
	MeterProvider  metric.MeterProvider
	Propagators    propagation.TextMapPropagator
}

func NewRouter(endpoints Endpoints, telemetry Telemetry) (http.Handler, error) {
	if endpoints.Metadata == nil || endpoints.Token == nil || endpoints.JWKS == nil || endpoints.Health == nil || endpoints.Ready == nil {
		return nil, errors.New("all HTTP endpoints are required")
	}

	router := chi.NewRouter()
	router.Get("/.well-known/oauth-authorization-server", endpoints.Metadata.ServeHTTP)
	router.Post("/oauth2/token", endpoints.Token.ServeHTTP)
	router.Get("/oauth2/jwks", endpoints.JWKS.ServeHTTP)
	router.Get("/healthz", endpoints.Health.ServeHTTP)
	router.Get("/readyz", endpoints.Ready.ServeHTTP)

	options := make([]otelhttp.Option, 0, 3)
	if telemetry.TracerProvider != nil {
		options = append(options, otelhttp.WithTracerProvider(telemetry.TracerProvider))
	}
	if telemetry.MeterProvider != nil {
		options = append(options, otelhttp.WithMeterProvider(telemetry.MeterProvider))
	}
	if telemetry.Propagators != nil {
		options = append(options, otelhttp.WithPropagators(telemetry.Propagators))
	}
	return otelhttp.NewHandler(router, "workload-sts.http", options...), nil
}