go-cmw/main.go

443 lines
11 KiB
Go

package main
import (
"fmt"
"io"
"io/ioutil"
"log"
"net/http"
"os"
"strings"
kingpin "gopkg.in/alecthomas/kingpin.v2"
)
// VERSION The version release
const VERSION = "0.0.5"
// AUTHOR The author name
const AUTHOR = "Elia el Lazkani"
// Create a list of constants to figure out
// the command line flags and translate them
// into uri flags.
const (
METRIC = 1 << iota
USCS
METERSECOND
ZERO
ONE
TWO
IGNOREUSERAGENT
FOLLOWLINK
NARROW
QUIET
SUPERQUIET
NOCOLORS
ADDFRAME
MIDTRANSPARENCY
FORMAT
ONELINER
LOCATION
LANGUAGE
PNG
VTWO
)
// Create a list of constants to define
// uri switches by flag.
const (
MetricSwitch = "m"
UscsSwitch = "u"
MeterSecondSwitch = "M"
ZeroSwitch = "0"
OneSwitch = "1"
TwoSwitch = "2"
IgnoreUserAgentSwitch = "A"
FollowLinkSwitch = "F"
NarrowSwitch = "n"
QuietSwitch = "q"
SuperQuietSwitch = "Q"
NoColorsSwitch = "T"
AddFrameSwitch = "p"
MidTransparencySwitch = "T"
)
// We create a weather struct with the url
type weather struct {
url string
}
// `weather` method to handle creating new requests with proper headers
func (w weather) newRequest(headers map[string]string) *http.Request {
req, err := http.NewRequest("GET", w.url, nil)
if err != nil {
log.Fatal("Error reading request. ", err)
}
return w.formatHeader(req, headers)
}
// `weather` method to format the headers and inject required ones
func (w weather) formatHeader(req *http.Request, headers map[string]string) *http.Request {
req.Header.Set("Content-Type", "text/plain; charset=utf-8")
// I had to read the wttr.in code to figure this one out.
// It wasn't Golang, it was 2 wasted hours that I won't be getting back.
req.Header.Set("User-Agent", "curl")
for key, value := range headers {
req.Header.Add(key, value)
}
return req
}
// `weather` method to create a client and get a weather response
// This method handles printing or downloading the weather
func (w weather) get(req *http.Request, download bool) {
client := &http.Client{}
client.Jar = nil
resp, err := client.Do(req)
if err != nil {
log.Fatal("Error reading response. ", err)
}
defer resp.Body.Close()
if download {
w.download(resp)
} else {
w.print(resp)
}
}
// `weather` method to print the weather
func (w weather) print(resp *http.Response) {
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
log.Fatal("Error reading body. ", err)
}
fmt.Printf("%s", body)
}
// `weather` method to download the weather
func (w weather) download(resp *http.Response) {
splitURL := strings.Split(w.url, "/")
filename := splitURL[len(splitURL)-1]
f, err := os.Create(filename)
if err != nil {
return
}
defer f.Close()
_, err = io.Copy(f, resp.Body)
}
// Wraper function around the weather struct
func getWheather(url string, headers map[string]string, download bool) {
w := weather{url}
req := w.newRequest(headers)
w.get(req, download)
}
// Define a command parameters struct.
// This will hold all the configurations
// set by the command line parameters provided.
type cmdParams struct {
Flags int
Transparency int
Format string
Location string
Language string
}
// Create a method to figure out the command parameters
// provided and translate them into uri parameters.
// This will figure out if we need to download the PNG image
// as well.
func (cmdP *cmdParams) generateParamFormat() (string, bool, error) {
var params []string
var affix []string
var download bool
affix = append(affix, "?")
// If --format is specified, let's not bother and simply return it
// If --one-liner is specified, we know the format is set so let's return it
if cmdP.Flags&FORMAT == FORMAT || cmdP.Flags&ONELINER == ONELINER {
return cmdP.Format, false, nil
}
if cmdP.Flags&METRIC == METRIC {
params = append(params, MetricSwitch)
}
if cmdP.Flags&USCS == USCS {
params = append(params, UscsSwitch)
}
if cmdP.Flags&METERSECOND == METERSECOND {
params = append(params, MeterSecondSwitch)
}
if cmdP.Flags&ZERO == ZERO {
params = append(params, ZeroSwitch)
}
if cmdP.Flags&ONE == ONE {
params = append(params, OneSwitch)
}
if cmdP.Flags&TWO == TWO {
params = append(params, TwoSwitch)
}
if cmdP.Flags&IGNOREUSERAGENT == IGNOREUSERAGENT {
params = append(params, IgnoreUserAgentSwitch)
}
if cmdP.Flags&FOLLOWLINK == FOLLOWLINK {
params = append(params, FollowLinkSwitch)
}
if cmdP.Flags&NARROW == NARROW {
params = append(params, NarrowSwitch)
}
if cmdP.Flags&QUIET == QUIET {
params = append(params, QuietSwitch)
}
if cmdP.Flags&SUPERQUIET == SUPERQUIET {
params = append(params, SuperQuietSwitch)
}
if cmdP.Flags&NOCOLORS == NOCOLORS {
params = append(params, NoColorsSwitch)
}
if cmdP.Flags&ADDFRAME == ADDFRAME {
params = append(params, AddFrameSwitch)
}
if cmdP.Flags&PNG == PNG {
affix[0] = "_"
if cmdP.Flags&MIDTRANSPARENCY == MIDTRANSPARENCY {
params = append(params, MidTransparencySwitch)
}
if cmdP.Transparency >= 0 && cmdP.Transparency <= 100 {
params = append(params, strings.Join([]string{"_transparency=", string(cmdP.Transparency)}, ""))
}
params = append(params, ".png")
download = true
}
params = append(affix, strings.Join(params, ""))
return strings.Join(params, ""), download, nil
}
// Defining the command-line interface
var (
app = kingpin.New("go-cmw", "A small terminal wrapper around the wttr.in weather endpoint.")
metric = app.Flag("metric", "Display weather in metric").Short('m').Default("false").Bool()
uscs = app.Flag("uscs", "Display weather in imperial").Short('u').Default("false").Bool()
meterSecond = app.Flag("meter-second", "Display wind in m/s").Short('M').Default("false").Bool()
zero = app.Flag("zero", "Show the weather now").Short('z').Default("false").Bool()
one = app.Flag("one", "Show the weather for one day").Short('o').Default("false").Bool()
two = app.Flag("two", "Show the weather for two days").Short('w').Default("false").Bool()
ignoreUserAgent = app.Flag("ignore-user-agent", "Request ignoring the user agent").Short('A').Default("false").Bool()
followLink = app.Flag("follow-link", "Follow link redirect").Short('F').Default("true").Bool()
narrow = app.Flag("narrow", "Display weather in narrow view").Short('n').Default("false").Bool()
quiet = app.Flag("quiet", "Add the quiet flag").Short('q').Default("false").Bool()
superQuiet = app.Flag("super-quiet", "Add the super quiet flag").Short('Q').Default("false").Bool()
noColors = app.Flag("no-colors", "Disable displaying colors (always enabled on windows").Short('N').Default("false").Bool()
addFrame = app.Flag("add-frame", "Add a frame to the output").Short('p').Default("false").Bool()
midTransparency = app.Flag("mid-transparency", "Enable mid-transparency (PNG only)").Short('T').Default("false").Bool()
png = app.Flag("png", "Download a weather PNG image").Short('P').Default("false").Bool()
v2 = app.Flag("v2", "Use the v2 endpoint").Default("false").Bool()
transparency = app.Flag("transparency", "Set transparency level (0-100) (PNG only)").Short('t').Default("0").Int()
format = app.Flag("format", "Query format (overrides everything else)").Short('f').OverrideDefaultFromEnvar("GO_CMW_FORMAT").String()
location = app.Flag("location", "Specify explicite location").Short('L').OverrideDefaultFromEnvar("GO_CMW_LOCATION").String()
language = app.Flag("language", "Specify explicite language").Short('l').OverrideDefaultFromEnvar("GO_CMW_LANGUAGE").String()
oneLiner = app.Flag("one-liner", "One liner outpet (for the terminal multiplexer lovers out there)").Short('O').Default("false").Bool()
extraInformation = app.Flag("extra-information", "Print extra information").Default("false").Bool()
)
// Special help menu
func printExtraInformation() {
eInfo := `
Supported Location Types
------------------------
City name: Paris
Unicode name: Москва
Airport code (3 letters): muc
Domain name: @stackoverflow.com
Area code: 94107
GPS coordinates: -78.46,106.79
Special Location
----------------
Moon phase (add ,+US or
,+France for these cities): moon
Moon phase for a date: moon@2016-10-25
Supported languages
-------------------
Supported: af da de el et fr fa hu id it nb nl
pl pt-br ro ru tr uk vi
`
println(eInfo)
}
// Create a function to parse all the command line parameters
// provided and save them in the parameter struct.
func flagParser(cmdP *cmdParams) {
app.Version(VERSION)
app.Author(AUTHOR)
kingpin.MustParse(app.Parse(os.Args[1:]))
if *extraInformation {
printExtraInformation()
os.Exit(0)
}
// Windows does not have color encoding
// so let's make sure windows users are happy
term := os.Getenv("TERM")
if term == "" {
*noColors = true
}
if *metric {
cmdP.Flags += METRIC
}
if *uscs {
cmdP.Flags += USCS
}
if *meterSecond {
cmdP.Flags += METERSECOND
}
if *zero {
cmdP.Flags += ZERO
}
if *one {
cmdP.Flags += ONE
}
if *two {
cmdP.Flags += TWO
}
if *ignoreUserAgent {
cmdP.Flags += IGNOREUSERAGENT
}
if *followLink {
cmdP.Flags += FOLLOWLINK
}
if *narrow {
cmdP.Flags += NARROW
}
if *quiet {
cmdP.Flags += QUIET
}
if *superQuiet {
cmdP.Flags += SUPERQUIET
}
if *noColors {
cmdP.Flags += NOCOLORS
}
if *addFrame {
cmdP.Flags += ADDFRAME
}
if *midTransparency {
cmdP.Flags += MIDTRANSPARENCY
}
if *transparency >= 0 && *transparency <= 100 {
cmdP.Transparency = *transparency
}
if *png {
cmdP.Flags += PNG
}
if *v2 {
cmdP.Flags += VTWO
}
if *format != "" {
cmdP.Flags += FORMAT
cmdP.Format = *format
}
if *location != "" {
cmdP.Flags += LOCATION
cmdP.Location = *location
}
if *language != "" {
cmdP.Flags += LANGUAGE
cmdP.Language = *language
}
if *oneLiner {
cmdP.Flags += ONELINER
cmdP.Format = "?format=3"
}
}
// Create a function to generate the url that we'll be calling shortly.
func generateURL(domain string, v2 bool, location string, lang string, affix string) ([]string, map[string]string) {
var link []string
var headers = make(map[string]string)
link = append(link, "https://")
if v2 {
link = append(link, "v2.")
}
link = append(link, domain, "/")
if location != "" {
link = append(link, location)
}
if affix != "" {
link = append(link, affix)
}
if lang != "" {
headers["Accept-Language"] = lang
}
return link, headers
}
// This is the main function that glues everything together.
func main() {
var params cmdParams = cmdParams{}
var domain string = "wttr.in"
flagParser(&params)
affix, download, _ := params.generateParamFormat()
link, headers := generateURL(domain, params.Flags&VTWO == VTWO, params.Location, params.Language, affix)
getWheather(strings.Join(link, ""), headers, download)
}