91 lines
2.3 KiB
Go
91 lines
2.3 KiB
Go
package model
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import (
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"encoding/json"
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"math"
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"net/http"
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"net/url"
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"strconv"
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"github.com/ceticamarco/zephyr/types"
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)
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func getMoonPhase(moonValue float64) (string, string) {
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// 0 and 1 are 'new moon',
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// 0.25 is 'first quarter moon',
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// 0.5 is 'full moon' and 0.75 is 'last quarter moon'.
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// The periods in between are called 'waxing crescent',
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// 'waxing gibbous', 'waning gibbous' and 'waning crescent', respectively.
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switch {
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case moonValue == 0, moonValue == 1:
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return "🌑", "New Moon"
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case moonValue > 0 && moonValue < 0.25:
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return "🌒", "Waxing Crescent"
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case moonValue == 0.25:
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return "🌓", "First Quarter"
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case moonValue > 0.25 && moonValue < 0.5:
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return "🌔", "Waxing Gibbous"
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case moonValue == 0.5:
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return "🌕", "Full Moon"
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case moonValue > 0.5 && moonValue < 0.75:
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return "🌖", "Waning Gibbous"
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case moonValue == 0.75:
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return "🌗", "Last Quarter"
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case moonValue > 0.75 && moonValue < 1:
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return "🌘", "Waning Crescent"
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}
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return "❓", "Unknown moon phase"
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}
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func GetMoon(apiKey string) (types.Moon, error) {
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url, err := url.Parse(WTR_URL)
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if err != nil {
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return types.Moon{}, err
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}
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params := url.Query()
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params.Set("lat", "41.8933203") // Rome latitude
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params.Set("lon", "12.4829321") // Rome longitude
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params.Set("appid", apiKey)
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params.Set("units", "metric")
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params.Set("exclude", "current,hourly,alerts")
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url.RawQuery = params.Encode()
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res, err := http.Get(url.String())
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if err != nil {
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return types.Moon{}, err
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}
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defer res.Body.Close()
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// Structure representing the JSON response
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type MoonRes struct {
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Daily []struct {
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Value float64 `json:"moon_phase"`
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} `json:"daily"`
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}
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var moonRes MoonRes
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if err := json.NewDecoder(res.Body).Decode(&moonRes); err != nil {
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return types.Moon{}, err
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}
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// Retrieve moon icon and moon phase(description) from moon phase(value)
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icon, phase := getMoonPhase(moonRes.Daily[0].Value)
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getMoonPercentage := func(moonVal float64) int {
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// Approximate moon illumination percentage using moon phase
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// by computing \sin(\pi * moonValue)^2
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res := math.Pow(math.Sin(math.Pi*moonVal), 2)
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return int(math.Round(res * 100))
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}
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return types.Moon{
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Icon: icon,
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Phase: phase,
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Percentage: strconv.Itoa(getMoonPercentage(moonRes.Daily[0].Value)),
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}, nil
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}
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