/* Go program to read data from the Velostar <https://www.levelostar.fr/>
service */

package main

import (
	"fmt"
	"flag"
	"os"
	"http"
	"xml"
	"bytes"
)

const (
	key string = "XXXXXXXXXXX" // Get your own key at
	// <http://data.keolis-rennes.com/>
	url     string = "http://data.keolis-rennes.com/xml/"
	maxsize int    = 65536
)

type Station struct {
	Id             int
	Number         int
	State          int
	Latitude       float
	Longitude      float
	Name           string
	Slotsavailable int
	Bikesavailable int
	District       string
	Lastupdate     string
}

type Data struct {
	Station Station
}

type Answer struct {
	// Status
	Data Data
}

type ApiKR struct {
	Request string
	Answer  Answer
}

func main() {
	if flag.NArg() != 1 {
		fmt.Printf("Usage: gostar query\n")
		os.Exit(1)
	}
	query := flag.Arg(0)
	completeurl := url + "?version=1.0&key=" + http.URLEscape(key) +
		"&cmd=getstation&param[request]=number&param[value]=" +
		http.URLEscape(query)
	response, _, error := http.Get(completeurl)
	if error == nil {
		// TODO: test response.Status?
		body := make([]byte, maxsize)
		n, _ := response.Body.Read(body)
		buffer := bytes.NewBuffer(body[0:n])
		result := ApiKR{}
		error := xml.Unmarshal(buffer, &result)
		if error == nil {
			fmt.Printf("Station %s\nBikes available: %d\nSlots available: %d\n", result.Answer.Data.Station.Name,
				result.Answer.Data.Station.Bikesavailable,
				result.Answer.Data.Station.Slotsavailable)
		} else {
			fmt.Printf("XML error %s\n", error)
		}
	} else {
		fmt.Printf("HTTP error %s\n", error)
	}
}