weather/main.go

/*
 Copyright 2019 Adrien Waksberg

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

     https://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
*/

package main

import (
  "fmt"
  "flag"
  "os"
  "time"
)

// Options and OpenWeatherMap URI
var (
  URI = "https://api.openweathermap.org/data/2.5"
  CONFIG = flag.String("config", "", "config file path")
  DAEMON = flag.Bool("daemon", false, "run in daemon mode")
  HELP   = flag.Bool("help", false, "print this help message")
)

func init() {
  flag.Parse()
}

func main() {
  var w Weather

  if *HELP {
    flag.PrintDefaults()
    os.Exit(1)
  }

  if *CONFIG == "" {
    fmt.Println("you must specify a config file with -config option")
    os.Exit(1)
  }

  err := w.Config.Load(*CONFIG)
  if err != nil {
    fmt.Printf("%s\n", err)
    os.Exit(2)
  }

  for {
    startTime := time.Now().Unix()

    w.FetchData()
    err = w.SendToInfluxDB()
    if err != nil {
      fmt.Printf("%s\n", err)
    }

    if *DAEMON == false {
      if err == nil {
        os.Exit(0)
      } else {
        os.Exit(2)
      }
    }

    sleepTime := time.Now().Unix() - startTime + w.Config.Interval
    if sleepTime > 0 {
      time.Sleep(time.Duration(sleepTime) * time.Second)
    }
  }
}