package diyanetcalc

import (
	"context"
	"errors"
	"fmt"
	"math"
	"time"

	"prayertimes/pkg/prayer"
)

var errNotSupported = errors.New("not supported in calculation provider")

type Provider struct{}

func New() Provider {
	return Provider{}
}

func (Provider) SearchLocations(_ context.Context, _ string) ([]prayer.Location, error) {
	return nil, fmt.Errorf("failed to search locations: %w", errNotSupported)
}

func (Provider) Get(_ context.Context, _ string) (prayer.TimesResult, error) {
	return prayer.TimesResult{}, fmt.Errorf("failed to get prayer times by location id: %w", errNotSupported)
}

func (Provider) GetByCoords(_ context.Context, coords prayer.Coordinates) (prayer.TimesResult, error) {
	seq := CalculatePrayerTimes(CalculateParams{
		Latitude:    coords.Latitude,
		Longitude:   coords.Longitude,
		StartingDay: time.Now().UTC().Truncate(24 * time.Hour),
	})

	times := make([]prayer.Times, 0, daysToGenerate)
	for item := range seq {
		times = append(times, prayer.Times{
			Date:      item.Date,
			DateHijri: item.DateHijri,
			Fajr:      item.Fajr,
			Sunrise:   item.Sunrise,
			Dhuhr:     item.Dhuhr,
			Asr:       item.Asr,
			Sunset:    item.Sunset,
			Maghrib:   item.Maghrib,
			Isha:      item.Isha,
		})

		if len(times) == daysToGenerate {
			break
		}
	}

	return prayer.TimesResult{
		Location: prayer.Location{
			Latitude:  coords.Latitude,
			Longitude: coords.Longitude,
			Timezone:  fmt.Sprintf("UTC%+d", int(math.Round(coords.Longitude/degPerHour))),
		},
		Times: times,
	}, nil
}