parse_args.go

package main

import (
	"flag"
	"fmt"
	"strconv"
	"strings"
)

var (
	help = flag.Bool(
		"help",
		false,
		"Show usage help",
	)
	token = flag.String(
		"token",
		"",
		"The oauth admin token which authorizes this application to connect to github",
	)
	org = flag.String(
		"org",
		"",
		"The name of the GitHub organization",
	)
	repos = flag.String(
		"repos",
		"",
		"The list of student repositories, delimited by commas",
	)
	labs = flag.String(
		"labs",
		"",
		"The list of labs to check, delimited by commas",
	)
	languages = flag.String(
		"languages",
		"",
		"The list of languages of the labs, delimited by commas. 0 = Java, 1 = Go, 2 = C++, 3 = C",
	)
	endpoint = flag.String(
		"endpoint",
		"",
		"The endpoint to listen on.",
	)
)

func usage() {
	flag.PrintDefaults()
	fmt.Printf("Example: ./antiplagiarism -token=0123456789ABCDEF -org=DAT320 ")
	fmt.Printf("-repos=Student1,Student2,Student3 -labs=LabA,LabB,LabC -languages=0,1,0\n")
	fmt.Printf("Example: ./antiplagiarism -endpoint=localhost:11111\n")
}

// parseArgs() parses the command line arguments.
// The return argument indicates whether or not the function was successful.
func parseArgs(args *commandLineArgs) bool {
	flag.Usage = usage
	flag.Parse()
	if *help {
		flag.Usage()
		return false
	}

	if *endpoint != "" {
		args.endpoint = *endpoint
		// The other values are not needed, so just return.
		return true
	}

	if *org == "" {
		fmt.Printf("No GitHub organization provided.\n")
		return false
	}
	args.githubOrg = *org

	if *labs == "" {
		fmt.Printf("No lab names provided.\n")
		return false
	}
	args.labNames = strings.Split(*labs, ",")

	if *token == "" {
		fmt.Printf("No token provided.\n")
		return false
	}
	args.githubToken = *token

	if *repos == "" {
		fmt.Printf("No student repositories provided.\n")
		return false
	}
	args.studentRepos = strings.Split(*repos, ",")

	if *languages == "" {
		fmt.Printf("No languages provided.\n")
		return false
	}
	langStr := strings.Split(*languages, ",")

	if len(args.labNames) != len(langStr) {
		fmt.Printf("The number of labs does not equal the number of languages provided.\n")
		return false
	}

	for _, lang := range langStr {
		langNum, err := strconv.Atoi(lang)
		if err != nil {
			fmt.Printf("Error parsing languages: %v.\n", err)
			return false
		}
		args.labLanguages = append(args.labLanguages, langNum)
	}

	return true
}