root.go

// Copyright © 2018 Sven Agneessens <sven.agneessens@gmail.com>
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package cmd

import (
	"fmt"
	"os"
	"path"
	"path/filepath"

	"github.com/apex/log"
	cliHandler "github.com/apex/log/handlers/cli"
	textHandler "github.com/apex/log/handlers/logfmt"
	multiHandler "github.com/apex/log/handlers/multi"
	homedir "github.com/mitchellh/go-homedir"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

var (
	cfgFile string
	logFile *os.File
	verbose bool
	debug   bool
)

// RootCmd represents the base command when called without any subcommands
var RootCmd = &cobra.Command{
	Use:   "lora-mapper",
	Short: "Tool to create coverage maps for LoRa network",
	Long:  `lora-mapper is a tool to create coverage maps for existing LoRa networks`,
	PersistentPreRun: func(cmd *cobra.Command, args []string) {
		var logLevel = log.InfoLevel
		var logHandlers []log.Handler

		if verbose {
			logHandlers = append(logHandlers, cliHandler.Default)
		}

		if debug {
			logLevel = log.DebugLevel
		}

		absLogFileLocation, err := filepath.Abs("lora-mapper.log")
		if err != nil {
			panic(err)
		}
		logFile, err = os.OpenFile(absLogFileLocation, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0644)
		if err != nil {
			panic(err)
		}
		if err == nil {
			logHandlers = append(logHandlers, textHandler.New(logFile))
		}

		log.SetHandler(multiHandler.New(logHandlers...))
		log.SetLevel(logLevel)
	},
	// Uncomment the following line if your bare application
	// has an action associated with it:
	//	Run: func(cmd *cobra.Command, args []string) { },
	PersistentPostRun: func(cmd *cobra.Command, args []string) {
		if logFile != nil {
			logFile.Close()
		}
	},
}

// Execute adds all child commands to the root command and sets flags appropriately.
// This is called by main.main(). It only needs to happen once to the rootCmd.
func Execute() {
	if err := RootCmd.Execute(); err != nil {
		fmt.Println(err)
		os.Exit(1)
	}
}

func init() {
	cobra.OnInitialize(initConfig)

	// Here you will define your flags and configuration settings.
	// Cobra supports persistent flags, which, if defined here,
	// will be global for your application.
	RootCmd.PersistentFlags().StringVar(&cfgFile, "config", "", "config file (default is $HOME/.lora-mapper.yaml)")
	RootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "print everything to standard output")
	RootCmd.PersistentFlags().BoolVarP(&debug, "debug", "d", false, "enable debug logs")

	// Cobra also supports local flags, which will only run
	// when this action is called directly.
	//RootCmd.Flags().BoolP("toggle", "t", false, "Help message for toggle")
}

// initConfig reads in config file and ENV variables if set.
func initConfig() {
	if cfgFile != "" {
		// Use config file from the flag.
		viper.SetConfigFile(cfgFile)
	} else {
		// Find home directory.
		home, err := homedir.Dir()
		if err != nil {
			fmt.Println(err)
			os.Exit(1)
		}

		configName := ".lora-mapper"

		// Search config in home directory with name ".lora-mapper" (without extension).
		viper.AddConfigPath(home)
		viper.SetConfigName(configName)

		// Add standard path to config file
		cfgFile = path.Join(home, string(append([]byte(configName), []byte(".yaml")...)))
	}

	viper.AutomaticEnv() // read in environment variables that match

	// If a config file is found, read it in.
	if err := viper.ReadInConfig(); err == nil {
		fmt.Println("Using config file:", viper.ConfigFileUsed())
	}
}