package httpapi

import (
	"context"
	"net/http"

	"gitea.maximumdirect.net/ejr/feedapi/bind"
	"gitea.maximumdirect.net/ejr/feedapi/endpoint"
	"gitea.maximumdirect.net/ejr/feedapi/render"
	"gitea.maximumdirect.net/ejr/feedapi/response"
	"gitea.maximumdirect.net/ejr/weatherfeeder/model"
)

// Service describes the weather use-cases needed by the HTTP adapter.
type Service interface {
	LatestObservation(ctx context.Context) (*model.WeatherObservation, error)
	LatestHourlyForecast(ctx context.Context) (*model.WeatherForecastRun, error)
	LatestActiveAlerts(ctx context.Context) (*model.WeatherAlertRun, error)
}

type emptyRequest struct{}

func Definitions(svc Service) []endpoint.Definition {
	return []endpoint.Definition{
		endpoint.GET(
			"/observations",
			bindFormatOnly,
			func(ctx context.Context, _ emptyRequest) (any, error) {
				obs, err := svc.LatestObservation(ctx)
				if err != nil {
					return nil, err
				}
				return response.Envelope{Data: obs}, nil
			},
			endpoint.WithProduces(render.FormatJSON, render.FormatXML, render.FormatText),
			endpoint.WithTemplate("observations.txt.tmpl"),
		),
		endpoint.GET(
			"/forecast/hourly",
			bindFormatOnly,
			func(ctx context.Context, _ emptyRequest) (any, error) {
				run, err := svc.LatestHourlyForecast(ctx)
				if err != nil {
					return nil, err
				}
				return response.Envelope{Data: run}, nil
			},
			endpoint.WithProduces(render.FormatJSON, render.FormatXML, render.FormatText),
			endpoint.WithTemplate("forecast_hourly.txt.tmpl"),
		),
		endpoint.GET(
			"/alerts/active",
			bindFormatOnly,
			func(ctx context.Context, _ emptyRequest) (any, error) {
				run, err := svc.LatestActiveAlerts(ctx)
				if err != nil {
					return nil, err
				}
				return response.Envelope{Data: run}, nil
			},
			endpoint.WithProduces(render.FormatJSON, render.FormatXML, render.FormatText),
			endpoint.WithTemplate("alerts_active.txt.tmpl"),
		),
	}
}

func bindFormatOnly(r *http.Request) (emptyRequest, error) {
	_, err := bind.CommonQueryParams(r, bind.QueryPolicy{
		AllowFormat:   true,
		RejectUnknown: true,
	})
	if err != nil {
		return emptyRequest{}, err
	}
	return emptyRequest{}, nil
}