package observations

import (
	"context"
	"fmt"
	"time"

	"gitea.maximumdirect.net/ejr/weatherapi/internal/application/units"
	"gitea.maximumdirect.net/ejr/weatherapi/internal/core/ports"
)

type Service struct {
	repo      ports.ObservationRepository
	converter units.Converter
	window    time.Duration
}

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

type CurrentResponse struct {
	Summary             SummaryResponse     `json:"summary"`
	Conditions          []ConditionResponse `json:"conditions"`
	PrecipitationEvents []string            `json:"precipitationEvents"`
}

type SummaryResponse struct {
	TemperatureF         *float64 `json:"temperatureF"`
	ApparentTemperatureF *float64 `json:"apparentTemperatureF"`
	WindowMinutes        int      `json:"windowMinutes"`
}

type ConditionResponse struct {
	StationID              *string   `json:"stationId"`
	ObservedAt             time.Time `json:"observedAt"`
	TemperatureF           *float64  `json:"temperatureF"`
	TextDescription        *string   `json:"textDescription"`
	ProviderRawDescription *string   `json:"providerRawDescription"`
	ConditionText          *string   `json:"conditionText"`
}

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

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

	conditionsMetric, err := s.repo.ListCurrentConditions(ctx, s.window)
	if err != nil {
		return CurrentResponse{}, err
	}

	precip, err := s.repo.ListCurrentPrecipitationEvents(ctx, s.window)
	if err != nil {
		return CurrentResponse{}, err
	}

	conditions := make([]ConditionResponse, 0, len(conditionsMetric))
	for _, c := range conditionsMetric {
		conditions = append(conditions, ConditionResponse{
			StationID:              c.StationID,
			ObservedAt:             c.ObservedAt,
			TemperatureF:           s.converter.TemperatureCToOutput(c.TemperatureC),
			TextDescription:        c.TextDescription,
			ProviderRawDescription: c.ProviderRawDescription,
			ConditionText:          c.ConditionText,
		})
	}

	return CurrentResponse{
		Summary: SummaryResponse{
			TemperatureF:         s.converter.TemperatureCToOutput(summary.TemperatureC),
			ApparentTemperatureF: s.converter.TemperatureCToOutput(summary.ApparentTemperatureC),
			WindowMinutes:        int(s.window / time.Minute),
		},
		Conditions:          conditions,
		PrecipitationEvents: precip,
	}, nil
}