package nws

import (
	"context"
	"time"

	"gitea.maximumdirect.net/ejr/feedkit/config"
	"gitea.maximumdirect.net/ejr/feedkit/event"
	fksources "gitea.maximumdirect.net/ejr/feedkit/sources"
	nwscommon "gitea.maximumdirect.net/ejr/weatherfeeder/internal/providers/nws"
	"gitea.maximumdirect.net/ejr/weatherfeeder/standards"
)

// ForecastDiscussionSource polls an NWS forecast discussion HTML page and emits a RAW discussion Event.
//
// Output schema:
//   - standards.SchemaRawNWSForecastDiscussionV1
type ForecastDiscussionSource struct {
	http *fksources.HTTPSource
}

func NewForecastDiscussionSource(cfg config.SourceConfig) (*ForecastDiscussionSource, error) {
	const driver = "nws_forecast_discussion"

	hs, err := fksources.NewHTTPSource(driver, cfg, "text/html, application/xhtml+xml")
	if err != nil {
		return nil, err
	}

	return &ForecastDiscussionSource{http: hs}, nil
}

func (s *ForecastDiscussionSource) Name() string { return s.http.Name }

func (s *ForecastDiscussionSource) Kinds() []event.Kind {
	return []event.Kind{event.Kind("forecast_discussion")}
}

func (s *ForecastDiscussionSource) Poll(ctx context.Context) ([]event.Event, error) {
	body, changed, err := s.http.FetchBytesIfChanged(ctx)
	if err != nil {
		return nil, err
	}
	if !changed {
		return nil, nil
	}

	rawHTML := string(body)
	parsed, err := nwscommon.ParseForecastDiscussionHTML(rawHTML)
	if err != nil {
		return nil, err
	}

	issuedAt := parsed.IssuedAt.UTC()
	effectiveAt := &issuedAt
	emittedAt := time.Now().UTC()
	eventID := fksources.DefaultEventID("", s.http.Name, effectiveAt, emittedAt)

	return fksources.SingleEvent(
		event.Kind("forecast_discussion"),
		s.http.Name,
		standards.SchemaRawNWSForecastDiscussionV1,
		eventID,
		emittedAt,
		effectiveAt,
		rawHTML,
	)
}