init

backend/internal/client/openmeteo.go

@@ -0,0 +1,168 @@
+package client
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"time"
+
+	"github.com/scottyah/paragliding/internal/model"
+)
+
+const (
+	openMeteoBaseURL = "https://api.open-meteo.com/v1/forecast"
+)
+
+// OpenMeteoClient is a client for the Open-Meteo weather API
+type OpenMeteoClient struct {
+	httpClient *http.Client
+	latitude   float64
+	longitude  float64
+	timezone   string
+}
+
+// OpenMeteoConfig contains configuration for the Open-Meteo client
+type OpenMeteoConfig struct {
+	Latitude  float64
+	Longitude float64
+	Timezone  string // IANA timezone (e.g., "America/Los_Angeles")
+}
+
+// NewOpenMeteoClient creates a new Open-Meteo API client
+func NewOpenMeteoClient(config OpenMeteoConfig) *OpenMeteoClient {
+	return &OpenMeteoClient{
+		httpClient: &http.Client{
+			Timeout: 10 * time.Second,
+		},
+		latitude:  config.Latitude,
+		longitude: config.Longitude,
+		timezone:  config.Timezone,
+	}
+}
+
+// openMeteoResponse represents the JSON response from Open-Meteo API
+type openMeteoResponse struct {
+	Latitude  float64 `json:"latitude"`
+	Longitude float64 `json:"longitude"`
+	Timezone  string  `json:"timezone"`
+	Hourly    struct {
+		Time          []string  `json:"time"`
+		WindSpeed10m  []float64 `json:"wind_speed_10m"`
+		WindDir10m    []int     `json:"wind_direction_10m"`
+		WindGusts10m  []float64 `json:"wind_gusts_10m"`
+	} `json:"hourly"`
+}
+
+// GetWeatherForecast fetches weather data from Open-Meteo API
+// It retrieves 1 day of past data and 2 days of forecast data
+func (c *OpenMeteoClient) GetWeatherForecast(ctx context.Context) ([]model.WeatherPoint, error) {
+	// Build request URL with query parameters
+	reqURL, err := url.Parse(openMeteoBaseURL)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse base URL: %w", err)
+	}
+
+	query := reqURL.Query()
+	query.Set("latitude", fmt.Sprintf("%.4f", c.latitude))
+	query.Set("longitude", fmt.Sprintf("%.4f", c.longitude))
+	query.Set("hourly", "wind_speed_10m,wind_direction_10m,wind_gusts_10m")
+	query.Set("wind_speed_unit", "mph")
+	query.Set("timezone", c.timezone)
+	query.Set("forecast_days", "2")
+	query.Set("past_days", "1")
+	reqURL.RawQuery = query.Encode()
+
+	// Create HTTP request with context
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, reqURL.String(), nil)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create request: %w", err)
+	}
+
+	// Execute request
+	resp, err := c.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch weather data: %w", err)
+	}
+	defer resp.Body.Close()
+
+	// Check status code
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("API returned status %d: %s", resp.StatusCode, string(body))
+	}
+
+	// Parse JSON response
+	var apiResp openMeteoResponse
+	if err := json.NewDecoder(resp.Body).Decode(&apiResp); err != nil {
+		return nil, fmt.Errorf("failed to decode response: %w", err)
+	}
+
+	// Convert to WeatherPoint slice
+	points, err := c.parseWeatherPoints(apiResp)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse weather points: %w", err)
+	}
+
+	return points, nil
+}
+
+// parseWeatherPoints converts the API response into a slice of WeatherPoint
+func (c *OpenMeteoClient) parseWeatherPoints(resp openMeteoResponse) ([]model.WeatherPoint, error) {
+	if len(resp.Hourly.Time) == 0 {
+		return nil, fmt.Errorf("no hourly data in response")
+	}
+
+	// Validate that all arrays have the same length
+	dataLen := len(resp.Hourly.Time)
+	if len(resp.Hourly.WindSpeed10m) != dataLen ||
+		len(resp.Hourly.WindDir10m) != dataLen ||
+		len(resp.Hourly.WindGusts10m) != dataLen {
+		return nil, fmt.Errorf("inconsistent data array lengths in response")
+	}
+
+	// Load timezone location
+	loc, err := time.LoadLocation(resp.Timezone)
+	if err != nil {
+		// Fallback to UTC if timezone can't be loaded
+		loc = time.UTC
+	}
+
+	points := make([]model.WeatherPoint, 0, dataLen)
+
+	for i := 0; i < dataLen; i++ {
+		// Parse timestamp - API returns ISO8601 format without timezone (e.g., "2026-01-01T00:00")
+		// Try RFC3339 first, then fall back to ISO8601 without timezone
+		var t time.Time
+		var err error
+		
+		// Try RFC3339 format first (with timezone)
+		t, err = time.Parse(time.RFC3339, resp.Hourly.Time[i])
+		if err != nil {
+			// Try ISO8601 format without timezone (e.g., "2006-01-02T15:04")
+			t, err = time.Parse("2006-01-02T15:04", resp.Hourly.Time[i])
+			if err != nil {
+				// Try with seconds if present
+				t, err = time.Parse("2006-01-02T15:04:05", resp.Hourly.Time[i])
+				if err != nil {
+					return nil, fmt.Errorf("failed to parse time at index %d: %w", i, err)
+				}
+			}
+			// Apply timezone to parsed time
+			t = time.Date(t.Year(), t.Month(), t.Day(), t.Hour(), t.Minute(), t.Second(), t.Nanosecond(), loc)
+		}
+
+		point := model.WeatherPoint{
+			Time:          t,
+			WindSpeedMPH:  resp.Hourly.WindSpeed10m[i],
+			WindDirection: resp.Hourly.WindDir10m[i],
+			WindGustMPH:   resp.Hourly.WindGusts10m[i],
+		}
+
+		points = append(points, point)
+	}
+
+	return points, nil
+}