package conditions

import (
	"context"
	"fmt"
	"time"

	"gitea.maximumdirect.net/ejr/weatherapi/internal/application/units"
	"gitea.maximumdirect.net/ejr/weatherapi/internal/core/ports"
	"gitea.maximumdirect.net/ejr/weatherapi/internal/platform/constants"
	"gitea.maximumdirect.net/ejr/weatherfeeder/model"
	"gitea.maximumdirect.net/ejr/weatherfeeder/standards"
)

type Service struct {
	repo     ports.ObservationRepository
	registry *units.Registry
	window   time.Duration
}

func NewService(repo ports.ObservationRepository, registry *units.Registry, window time.Duration) *Service {
	return &Service{repo: repo, registry: registry, window: window}
}

type Response struct {
	TemperatureC         *float64 `json:"temperatureC,omitempty"`
	TemperatureF         *float64 `json:"temperatureF,omitempty"`
	ApparentTemperatureC *float64 `json:"apparentTemperatureC,omitempty"`
	ApparentTemperatureF *float64 `json:"apparentTemperatureF,omitempty"`
	DewpointC            *float64 `json:"dewpointC,omitempty"`
	DewpointF            *float64 `json:"dewpointF,omitempty"`
	RelativeHumidity     *float64 `json:"relativeHumidityPercent,omitempty"`
	WindSpeedKmh         *float64 `json:"windSpeedKmh,omitempty"`
	WindSpeedMph         *float64 `json:"windSpeedMph,omitempty"`
	WindDirectionDegrees *float64 `json:"windDirectionDegrees,omitempty"`
	ConditionText        *string  `json:"conditionText,omitempty"`
	IsDay                *bool    `json:"isDay,omitempty"`
}

func (s *Service) GetCurrent(ctx context.Context, unitSystem string) (Response, error) {
	if s == nil {
		return Response{}, fmt.Errorf("conditions service is nil")
	}

	converter, err := s.registry.Resolve(unitSystem)
	if err != nil {
		return Response{}, err
	}

	summary, err := s.repo.GetCurrentConditionsSummary(ctx, s.window)
	if err != nil {
		return Response{}, err
	}

	resp := Response{
		RelativeHumidity:     summary.RelativeHumidity,
		WindDirectionDegrees: summary.WindDirectionDegrees,
		IsDay:                summary.IsDay,
	}
	if summary.ConditionCode != nil {
		resp.ConditionText = ptrString(standards.WMOText(model.WMOCode(*summary.ConditionCode), summary.IsDay))
	}

	switch converter.System() {
	case constants.UnitSystemUS:
		resp.TemperatureF = converter.TemperatureCToOutput(summary.TemperatureC)
		resp.ApparentTemperatureF = converter.TemperatureCToOutput(summary.ApparentTemperatureC)
		resp.DewpointF = converter.TemperatureCToOutput(summary.DewpointC)
		resp.WindSpeedMph = converter.SpeedKmhToOutput(summary.WindSpeedKmh)
	default:
		resp.TemperatureC = converter.TemperatureCToOutput(summary.TemperatureC)
		resp.ApparentTemperatureC = converter.TemperatureCToOutput(summary.ApparentTemperatureC)
		resp.DewpointC = converter.TemperatureCToOutput(summary.DewpointC)
		resp.WindSpeedKmh = converter.SpeedKmhToOutput(summary.WindSpeedKmh)
	}

	return resp, nil
}

func ptrString(v string) *string {
	return &v
}