Initial commit

4 files changed, 224 insertions, 0 deletions

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..e0485a4
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020 Ben Burwell
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..4f4d0fa
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module bnbl.io/wx
+
+go 1.13
diff --git a/metar/metar.go b/metar/metar.go
new file mode 100644
index 0000000..1bb57f5
--- /dev/null
+++ b/metar/metar.go
@@ -0,0 +1,198 @@
+package metar
+
+import (
+	"context"
+	"encoding/xml"
+	"errors"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type Client struct {
+	hc http.Client
+}
+
+const (
+	MostRecentConstraint = "constraint"
+	MostRecentPostFilter = "postfilter"
+	MostRecentTrue       = "true"
+)
+
+type Response struct {
+	RequestIndex int `xml:"request_index"`
+	DataSource   struct {
+		Name string `xml:"name,attr"`
+	} `xml:"data_source"`
+	Request struct {
+		Type string `xml:"type,attr"`
+	} `xml:"request"`
+	Errors      []string `xml:"errors>error"`
+	Warnings    []string `xml:"warnings>warning"`
+	TimeTakenMs int      `xml:"time_taken_ms"`
+	Data        struct {
+		NumResults int     `xml:"num_results,attr"`
+		METARs     []METAR `xml:"METAR"`
+	} `xml:"data"`
+}
+
+type METAR struct {
+	RawText             string  `xml:"raw_text"`
+	StationID           string  `xml:"station_id"`
+	ObservationTime     string  `xml:"observation_time"`
+	Latitude            float32 `xml:"latitude"`
+	Longitude           float32 `xml:"longitude"`
+	TempC               float32 `xml:"temp_c"`
+	DewpointC           float32 `xml:"dewpoint_c"`
+	WindDirDegrees      int     `xml:"wind_dir_degress"`
+	WindSpeedKt         int     `xml:"wind_speed_kt"`
+	WindGustKt          int     `xml:"wind_gust_kt"`
+	VisibilityStatuteMi float32 `xml:"visibility_statute_mi"`
+	AltimInHg           float32 `xml:"altim_in_hg"`
+	SeaLevelPressureMb  float32 `xml:"sea_level_pressure_mb"`
+	QualityControlFlags struct {
+		Corrected               string `xml:"corrected"`
+		Auto                    string `xml:"auto"`
+		AutoStation             string `xml:"auto_station"`
+		MaintenanceIndicatorOn  string `xml:"maintenance_indicator_on"`
+		NoSignal                string `xml:"no_signal"`
+		LightningSensorOff      string `xml:"lightning_sensor_off"`
+		FreezingRainSensorOff   string `xml:"freezing_rain_sensor_off"`
+		PresentWeatherSensorOff string `xml:"present_weather_sensor_off"`
+	} `xml:"quality_control_flags"`
+	WxString                  string         `xml:"wx_string"`
+	SkyConditions             []SkyCondition `xml:"sky_condition"`
+	FlightCategory            string         `xml:"flight_category"`
+	ThreeHrPressureTendencyMb float32        `xml:"three_hr_pressure_tendency_mb"`
+	MaxTC                     float32        `xml:"maxT_c"`
+	MinTC                     float32        `xml:"minT_c"`
+	MaxT24HrC                 float32        `xml:"maxT24hr_c"`
+	MinT24HrC                 float32        `xml:"minT24hr_c"`
+	PrecipIn                  float32        `xml:"precip_in"`
+	Pcp3HrIn                  float32        `xml:"pcp3hr_in"`
+	Pcp6HrIn                  float32        `xml:"pcp6hr_in"`
+	Pcp24HrIn                 float32        `xml:"pcp24hr_in"`
+	SnowIn                    float32        `xml:"snow_in"`
+	VertVisFt                 int            `xml:"vert_vis_ft"`
+	METARType                 string         `xml:"metar_type"`
+	ElevationM                float32        `xml:"elevation_m"`
+}
+
+type SkyCondition struct {
+	SkyCover       string `xml:"sky_cover,attr"`
+	CloudBaseFtAGL int    `xml:"cloud_base_ft_agl,attr"`
+}
+
+type Request struct {
+	v url.Values
+}
+
+type requestArg func(*Request)
+
+func NewRequest(args ...requestArg) *Request {
+	var r Request
+	for _, arg := range args {
+		arg(&r)
+	}
+	return &r
+}
+
+func StationString(s string) requestArg {
+	return func(r *Request) {
+		r.v.Add("stationString", s)
+	}
+}
+
+func TimeRange(from, to time.Time) requestArg {
+	return func(r *Request) {
+		r.v.Add("startTime", string(from.Unix()))
+		r.v.Add("endTime", string(to.Unix()))
+	}
+}
+
+func HoursBeforeNow(h float64) requestArg {
+	return func(r *Request) {
+		r.v.Add("hoursBeforeNow", strconv.FormatFloat(h, 'f', 64, -1))
+	}
+}
+
+func MostRecent(mr bool) requestArg {
+	return func(r *Request) {
+		r.v.Add("mostRecent", strconv.FormatBool(mr))
+	}
+}
+
+func MostRecentForEachStation(s string) requestArg {
+	return func(r *Request) {
+		r.v.Add("mostRecentForEachStation", s)
+	}
+}
+
+func LatLongRect(minLat, minLon, maxLat, maxLon float64) requestArg {
+	return func(r *Request) {
+		r.v.Add("minLat", strconv.FormatFloat(minLat, 'f', 64, -1))
+		r.v.Add("minLon", strconv.FormatFloat(minLon, 'f', 64, -1))
+		r.v.Add("maxLat", strconv.FormatFloat(maxLat, 'f', 64, -1))
+		r.v.Add("maxLon", strconv.FormatFloat(maxLon, 'f', 64, -1))
+	}
+}
+
+func RadialDistance(s string) requestArg {
+	return func(r *Request) {
+		r.v.Add("radialDistance", s)
+	}
+}
+
+func FlightPath(s string) requestArg {
+	return func(r *Request) {
+		r.v.Add("flightPath", s)
+	}
+}
+
+func MinDegreeDistance(d float64) requestArg {
+	return func(r *Request) {
+		r.v.Add("minDegreeDistance", strconv.FormatFloat(d, 'f', 64, -1))
+	}
+}
+
+func Fields(ss ...string) requestArg {
+	return func(r *Request) {
+		r.v.Add("fields", strings.Join(ss, ","))
+	}
+}
+
+func requestToQueryString(m *Request) string {
+	m.v.Add("dataSource", "metars")
+	m.v.Add("requestType", "retrieve")
+	m.v.Add("format", "xml")
+	return m.v.Encode()
+}
+
+func (c *Client) GetMETARs(ctx context.Context, req *Request) (*Response, error) {
+	u := url.URL{
+		Scheme:   "https",
+		Host:     "www.aviationweather.gov",
+		Path:     "/adds/dataserver_current/httpparam",
+		RawQuery: requestToQueryString(req),
+	}
+	hr, err := http.NewRequestWithContext(ctx, "GET", u.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+	hr.Header.Add("user-agent", "wxbot/1.0 +bnbl.io/wx")
+	resp, err := c.hc.Do(hr)
+	if err != nil {
+		return nil, err
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, errors.New(resp.Status)
+	}
+	defer resp.Body.Close()
+	var r Response
+	if err := xml.NewDecoder(resp.Body).Decode(&r); err != nil {
+		return nil, err
+	}
+	return &r, nil
+}
diff --git a/wx.go b/wx.go
new file mode 100644
index 0000000..648bc4f
--- /dev/null
+++ b/wx.go
@@ -0,0 +1,2 @@
+// Package wx communicates with NOAA's Aviation Weather Center
+package wx