package aprs

import (
	"strconv"
	"strings"
)

type Query struct {
	Type      string `json:"type"`
	Latitude  float64
	Longitude float64
	Radius    float64 // radius in meters
}

func (q Query) String() string {
	return q.Type
}

type queryDecoder struct{}

func (queryDecoder) CanDecode(frame *Frame) bool {
	return len(frame.Raw) >= 3 && frame.Raw.Type() == '?'
}

func (queryDecoder) Decode(frame *Frame) (data Data, err error) {
	var (
		kind = string(frame.Raw[1:])
		args string
		i    int
	)
	if i = strings.IndexByte(kind, '?'); i == -1 {
		return &Query{
			Type: kind,
		}, nil
	} else {
		kind, args = kind[:i], kind[i+1:]
	}

	query := &Query{Type: kind}

	if part := strings.SplitN(strings.TrimSpace(args), ",", 3); len(part) == 3 {
		var radius int
		query.Latitude, _ = strconv.ParseFloat(part[0], 64)
		query.Longitude, _ = strconv.ParseFloat(part[1], 64)
		radius, _ = strconv.Atoi(part[2])
		query.Radius = milesToMeters(float64(radius))
	}

	return query, nil
}