main.go

package main

import (
	"encoding/csv"
	"flag"
	"fmt"
	"math/rand"
	"os"
	"strings"
	"time"
)

type problem struct {
	q string
	a string
}

func main() {
	// Get the csv file name from command line
	csvFilename := flag.String("csv", "problems.csv", "a csv file in a format of 'question,answer'")
	timeLimit := flag.Int("limit", 30, "the time limit for the quiz in seconds")
	shuffle := flag.Bool("shuffle", true, "shuffle the order of the questions")
	flag.Parse()

	// Open the csv file in read mode
	file, err := os.Open(*csvFilename)
	if err != nil {
		exit(fmt.Sprintf("Failed to open the CSV file: %s\n", *csvFilename))
	}
	r := csv.NewReader(file)
	// Read from the csv file using Reader created in line above
	lines, err := r.ReadAll()
	if err != nil {
		exit("Failed to parse the lines from csv file")
	}
	// Parse the lines as slice of struct
	problems := parseLines(lines)

	// Shuffle the quiz questions
	if *shuffle {
		problems = shuffleQuiz(problems)
	}

	// Start the quiz
	startQuiz(problems, timeLimit)
}

func startQuiz(problems []problem, timeLimit *int) {
	timer := time.NewTimer(time.Duration(*timeLimit) * time.Second)
	correct := 0
	for i, p := range problems {
		fmt.Printf("Problem #%d: %s = \n", i+1, p.q)
		answerCh := make(chan string)
		go func() {
			var answer string
			fmt.Scanf("%s\n", &answer)
			answerCh <- answer
		}()
		select {
		case <-timer.C:
			fmt.Printf("You scored %d out of %d.\n", correct, len(problems))
			return
		case answer := <-answerCh:
			if answer == p.a {
				correct++
			}
		}
	}
	fmt.Printf("You scored %d out of %d.\n", correct, len(problems))
}

func shuffleQuiz(problems []problem) []problem {
	rand.Shuffle(len(problems), func(i, j int) {
		problems[i], problems[j] = problems[j], problems[i]
	})
	return problems
}

func parseLines(lines [][]string) []problem {
	ret := make([]problem, len(lines))
	for i, line := range lines {
		ret[i] = problem{
			q: line[0],
			a: strings.TrimSpace(line[1]),
		}
	}
	return ret
}

func exit(msg string) {
	fmt.Println(msg)
	os.Exit(1)
}