nws: add Forecast

2 files changed, 117 insertions, 0 deletions

diff --git a/nws/nws.go b/nws/nws.go
index a3155ab..b939d2a 100644
--- a/nws/nws.go
+++ b/nws/nws.go
@@ -24,6 +24,29 @@ type NWSPoint struct {
 	Properties NWSPointProperties
 }
 
+type NWSForecastPeriod struct {
+	Number           int
+	Name             string
+	StartTime        string
+	EndTime          string
+	IsDayTime        bool
+	Temperature      int
+	TemperatureUnit  string
+	TemperatureTrend string
+	WindSpeed        string
+	WindDirection    string
+	ShortForecast    string
+	DetailedForecast string
+}
+
+type NWSForecastProperties struct {
+	Periods []NWSForecastPeriod
+}
+
+type NWSForecast struct {
+	Properties NWSForecastProperties
+}
+
 type NWSError struct {
 	Title  string
 	Type   string
@@ -74,3 +97,45 @@ func Points(lat, lng float32) (*NWSPoint, error) {
 	return point, nil
 }
 
+// NWS forecast endpoint.
+func Forecast(point *NWSPoint) (*NWSForecast, error) {
+	if point == nil {
+		return nil, fmt.Errorf("forecast: point nil")
+	}
+	if len(point.Properties.Forecast) == 0 {
+		return nil, fmt.Errorf("forecast: link empty")
+	}
+
+	// Get the forecast
+	resp, err := client.Get(point.Properties.Forecast)
+	if err != nil {
+		return nil, fmt.Errorf("forecast: get: %v", err)
+	}
+
+	// Parse response body.
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("forecast: body: %v", err)
+	}
+
+	// Check if the request failed.
+	if resp.StatusCode != 200 {
+		perr := new(NWSError)
+		err := json.Unmarshal(body, perr)
+		if err != nil {
+			return nil, fmt.Errorf("forecast: json: %v", err)
+		}
+		return nil, fmt.Errorf("forecast: %v", perr)
+	}
+
+	// Unmarshal.
+	forecast := new(NWSForecast)
+	err = json.Unmarshal(body, forecast)
+	if err != nil {
+		return nil, fmt.Errorf("forecast: decode: %v", err)
+	}
+	if len(forecast.Properties.Periods) == 0 {
+		return nil, fmt.Errorf("forecast: periods empty")
+	}
+	return forecast, nil
+}
diff --git a/nws/nws_test.go b/nws/nws_test.go
index 97dd184..ea47188 100644
--- a/nws/nws_test.go
+++ b/nws/nws_test.go
@@ -33,3 +33,55 @@ func TestPoints(t *testing.T) {
 		t.Errorf("points: %v", np)
 	}
 }
+
+func TestForecast(t *testing.T) {
+	// Get point.
+	np, err := Points(41.115, -83.177)
+	if err != nil {
+		t.Errorf("error: %v", err)
+	}
+
+	// Get forecast.
+	fc, err := Forecast(np)
+	if err != nil {
+		t.Errorf("error: %v", err)
+	}
+
+	// Verify periods.
+	for i, period := range fc.Properties.Periods {
+		if period.Number < 1 {
+			t.Errorf("period: %d: number invalid: %v", i, period.Number)
+		}
+		if len(period.Name) < 1 {
+			t.Errorf("period: %d: name invalid: %v", i, period.Name)
+		}
+		if len(period.StartTime) < 1 {
+			t.Errorf("period: %d: start time invalid: %v", i,
+				period.StartTime)
+		}
+		if len(period.EndTime) < 1 {
+			t.Errorf("period: %d: end time invalid: %v", i,
+				period.EndTime)
+		}
+		if len(period.TemperatureUnit) < 1 {
+			t.Errorf("period: %d: temperature unit invalid: %v",
+				i, period.TemperatureUnit)
+		}
+		if len(period.WindSpeed) < 1 {
+			t.Errorf("period: %d: wind speed invalid: %v",
+				i, period.WindSpeed)
+		}
+		if len(period.WindDirection) < 1 {
+			t.Errorf("period: %d: wind direction invalid: %v",
+				i, period.WindDirection)
+		}
+		if len(period.ShortForecast) < 1 {
+			t.Errorf("period: %d: short forecast invalid: %v",
+				i, period.ShortForecast)
+		}
+		if len(period.DetailedForecast) < 1 {
+			t.Errorf("period: %d: detailed forecast invalid: %v",
+				i, period.DetailedForecast)
+		}
+	}
+}