// This provides a shim between HTTP GET requests sent
// by ambient devices, and the providers that may be
// configured (awn, wunderground)
package ambient

import (
	"context"
	"fmt"
	"net/http"

	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/otel"
	"github.com/rs/zerolog"
	"go.opentelemetry.io/otel/attribute"
	"go.opentelemetry.io/otel/codes"

	"gitea.libretechconsulting.com/rmcguire/ambient-weather-local-exporter/pkg/provider"
	"gitea.libretechconsulting.com/rmcguire/ambient-weather-local-exporter/pkg/provider/awn"
	"gitea.libretechconsulting.com/rmcguire/ambient-weather-local-exporter/pkg/provider/wunderground"
)

// These providers implement support for the update sent
// when either "AmbientWeather" or "Wunderground" are selected
// in the "Custom" section of the AWNet app, or the web UI
// of an Ambient WeatherHub
var (
	awnProvider = &awn.AWNProvider{}
	wuProvider  = &wunderground.WUProvider{}
)

func GetAWNHandlerFunc(appCtx context.Context) func(http.ResponseWriter, *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		handleProviderRequest(appCtx, awnProvider, w, r)
	}
}

func GetWundergroundHandlerFunc(appCtx context.Context) func(http.ResponseWriter, *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		handleProviderRequest(appCtx, wuProvider, w, r)
	}
}

// Takes an HTTP requests and convers it to a
// stable type. Enrich is called on the type to complete
// any missing fields as the two providers supported by Ambient
// devices (awn/wunderground) produce different fields
func handleProviderRequest(
	appCtx context.Context,
	p provider.AmbientProvider,
	w http.ResponseWriter,
	r *http.Request,
) {
	l := zerolog.Ctx(appCtx)
	tracer := otel.GetTracer(appCtx, p.Name()+".http.handler")

	ctx, span := tracer.Start(r.Context(), p.Name()+".update")
	span.SetAttributes(attribute.String("provider", p.Name()))
	defer span.End()

	l.Trace().Str("p", p.Name()).
		Any("query", r.URL.Query()).Send()

	// Convert to WeatherUpdate
	update, err := p.ReqToWeather(ctx, r)
	if err != nil {
		l.Err(err).Send()
		span.RecordError(err)
		span.SetStatus(codes.Error,
			fmt.Sprintf("failed to handle %s update: %s",
				p.Name(), err.Error()))

		w.WriteHeader(http.StatusInternalServerError)
		w.Write([]byte(err.Error()))
	}

	// Calculate any fields that may be missing
	// such as dew point and wind chill
	update.Enrich()

	l.Debug().
		Str("provider", p.Name()).
		Any("update", update).
		Msg("successfully handled update")
	w.Write([]byte("ok"))
}