1 files changed, 223 insertions, 0 deletions
diff --git a/cmd/metar.go b/cmd/metar.go
new file mode 100644
index 0000000..6355105
--- /dev/null
+++ b/cmd/metar.go
@@ -0,0 +1,223 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"strings"
+	"time"
+
+	"bnbl.io/wx/metar"
+	"github.com/spf13/cobra"
+)
+
+// wx metar --past 1h kbos
+// wx metar --past 3h kbos kbed
+// wx metar --past 1h @MA
+// wx metar --since yesterday --until now kbos
+// wx metar --since yesterday --until now --rect 0,0,1,1
+// wx metar --past 1h --rect 0,0,1,1
+// wx metar --past 1h --radial 90,0,0
+// wx metar --past 6h --most-recent-by-station=constraint --path-dist 50 --waypoint ksea --waypoint kbos --min-dist 3
+
+type relTime struct {
+	t time.Time
+}
+
+func (t *relTime) String() string {
+	return t.t.String()
+}
+
+func (t *relTime) Set(s string) (err error) {
+	// first, see if s is a duration that we can use relative to now, e.g.
+	// "--since 3d" means since 3 days ago.
+	if d, err := time.ParseDuration(s); err == nil {
+		t.t = time.Now().Add(-1 * d)
+		return nil
+	}
+
+	// next, try to parse it in a series of formats
+	t.t, err = time.Parse("2006-01-02T15:04:05", s)
+	return
+}
+
+func (t *relTime) Type() string {
+	return "relative time"
+}
+
+type rectangle struct {
+	minLat, minLon, maxLat, maxLon float64
+}
+
+func (r *rectangle) String() string {
+	return fmt.Sprintf("%f,%f,%f,%f", r.minLat, r.minLon, r.maxLat, r.maxLon)
+}
+
+func (r *rectangle) Set(s string) error {
+	n, err := fmt.Sscanf(s, "%f,%f,%f,%f", &r.minLat, &r.minLon, &r.maxLat, &r.maxLon)
+	if err != nil {
+		return err
+	}
+	if n != 4 {
+		return fmt.Errorf("excpected 4 values but got %d", n)
+	}
+	return nil
+}
+
+func (r *rectangle) Type() string {
+	return "rect"
+}
+
+func (r *rectangle) IsZero() bool {
+	return r.minLat == 0 && r.minLon == 0 && r.maxLat == 0 && r.maxLon == 0
+}
+
+type ring struct {
+	radius, lat, lon float64
+}
+
+func (r *ring) String() string {
+	return fmt.Sprintf("%f,%f,%f", r.radius, r.lat, r.lon)
+}
+
+func (r *ring) Set(s string) error {
+	n, err := fmt.Sscanf(s, "%f,%f,%f", &r.radius, &r.lat, &r.lon)
+	if err != nil {
+		return err
+	}
+	if n != 3 {
+		return fmt.Errorf("expected a radius, lat, and lon, but got %d values", n)
+	}
+	return nil
+}
+
+func (r *ring) Type() string {
+	return "radial"
+}
+
+func (r *ring) IsZero() bool {
+	return r.radius == 0 && r.lat == 0 && r.lon == 0
+}
+
+var (
+	since, until        relTime
+	past                time.Duration
+	mostRecentByStation string
+	mostRecent          bool
+	rect                rectangle
+	radial              ring
+	pathDist            float64
+	waypoints           []string
+	minDist             float64
+)
+
+func init() {
+	rootCmd.AddCommand(metarCmd)
+
+	// time constraints
+	metarCmd.Flags().Var(
+		&since, "since",
+		`Starting time for METARs (e.g. "2020-01-01T01:31:00" or "3h"), used in
+conjunction with --until`)
+	metarCmd.Flags().Var(
+		&until, "until",
+		`Ending time for METARs (e.g. "2020-01-01T01:31:00" or "3h"), used in
+conjunction with --since`)
+	metarCmd.Flags().DurationVar(
+		&past, "past", 0,
+		`Duration to retrieve METARs since (e.g. "3h")`)
+
+	// location constraints
+	metarCmd.Flags().Var(
+		&rect, "rect",
+		`A lat-lon rect to search within (minLat,minLon,maxLat,maxLon) e.g.
+"40,-71,41,-70"`)
+	metarCmd.Flags().Var(
+		&radial, "radial",
+		`A distance around a radius to search within (dist,centerLat,centerLon)
+e.g. "3.5,40,-71"`)
+	metarCmd.Flags().Float64Var(
+		&pathDist, "path-dist", 0,
+		"The distance along the flight path to search METARs for")
+	metarCmd.Flags().StringSliceVar(
+		&waypoints, "waypoint", []string{},
+		`Multiple waypoint arguments specify the waypoints that make up a flight
+path, ordered from origin to destination. They may be specified as ICAO
+identifiers e.g. "KBOS", or as lon-lat pairs, e.g. "-71,40".`)
+	metarCmd.Flags().Float64Var(
+		&minDist, "min-dist", 0,
+		`The minimum distance in degrees latitude or longitude between stations
+reported. A higher value results in less dense results.`)
+
+	// result count limiting
+	metarCmd.Flags().StringVar(
+		&mostRecentByStation, "most-recent-by-station", "constraint",
+		`Method for fetching most recent for each station ("constraint",
+"postfilter", "false")`)
+	metarCmd.Flags().BoolVarP(
+		&mostRecent, "one", "1", false,
+		`Only fetch the single most recently-issued METAR of all the selected
+stations`)
+}
+
+var metarCmd = &cobra.Command{
+	Use:   "metar",
+	Short: "Fetch METARs",
+	Long:  "Fetch METARs matching the supplied criteria from the TDS",
+	Run: func(cmd *cobra.Command, args []string) {
+		reqArgs := []func(*metar.Request){}
+
+		if len(args) > 0 {
+			reqArgs = append(reqArgs, metar.StationString(strings.Join(args, " ")))
+		}
+
+		if !since.t.IsZero() || !until.t.IsZero() {
+			reqArgs = append(reqArgs, metar.TimeRange(since.t, until.t))
+		}
+
+		dur, _ := cmd.Flags().GetDuration("past")
+		if dur > 0 {
+			reqArgs = append(reqArgs, metar.HoursBeforeNow(dur.Hours()))
+		}
+
+		if mostRecentByStation != "" {
+			reqArgs = append(reqArgs, metar.MostRecentForEachStation(mostRecentByStation))
+		}
+
+		if mostRecent {
+			reqArgs = append(reqArgs, metar.MostRecent(true))
+		}
+
+		if !rect.IsZero() {
+			reqArgs = append(reqArgs, metar.LonLatRect(rect.minLat, rect.minLon, rect.maxLat, rect.maxLon))
+		}
+
+		if !radial.IsZero() {
+			reqArgs = append(reqArgs, metar.RadialDistance(radial.radius, radial.lat, radial.lon))
+		}
+
+		if pathDist > 0 && len(waypoints) > 0 {
+			reqArgs = append(reqArgs, metar.FlightPath(pathDist, waypoints...))
+		}
+
+		if minDist > 0 {
+			reqArgs = append(reqArgs, metar.MinDegreeDistance(minDist))
+		}
+
+		var mc metar.Client
+		res, err := mc.GetMETARs(context.Background(), metar.NewRequest(reqArgs...))
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "could not get metar: %v\n", err)
+			os.Exit(1)
+		}
+		if len(res.Errors) > 0 {
+			for _, err := range res.Errors {
+				fmt.Fprintf(os.Stderr, "error: %s\n", err)
+			}
+			os.Exit(2)
+		}
+		for _, m := range res.Data.METARs {
+			fmt.Printf("%s\n", strings.TrimSpace(m.RawText))
+		}
+	},
+}