feat: add obinna quiz implementation

Author: obi2na

students/obinna/go.mod

@@ -0,0 +1,5 @@
+module gophersizeEx1
+
+go 1.24.3
+
+require github.com/google/go-cmp v0.7.0 // indirect

students/obinna/main.go

@@ -0,0 +1,178 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"encoding/csv"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+func main() {
+	var file string // flag -f for file
+	flag.StringVar(&file, "f", "problems.csv", "file location of quiz")
+
+	var timeLimit int
+	flag.IntVar(&timeLimit, "t", 30, "time limit for the quiz")
+
+	//parse the flag
+	flag.Parse()
+
+	// validate correct file is used
+	if err := validatePath(file); err != nil {
+		log.Fatal(err)
+		os.Exit(1)
+	}
+
+	problems := NewProblemSheet()
+	err := problems.populateSheet(file)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	problems.StartQuiz(time.Duration(timeLimit)*time.Second, os.Stdin, os.Stdout)
+	problems.DisplayResults(os.Stdout)
+}
+
+func validatePath(path string) error {
+	// validate extension is correct
+	if filepath.Ext(path) != ".csv" {
+		return fmt.Errorf("malformed file path: %s contains no csv extension", path)
+	}
+
+	//check that file exists
+	_, err := os.Stat(path)
+	if os.IsNotExist(err) {
+		return fmt.Errorf("path does not exist: %w", err)
+	} else if err != nil {
+		return fmt.Errorf("error getting file info: %w", err)
+	}
+
+	return nil
+}
+
+type Problem struct {
+	Question string
+	Answer   string
+}
+
+type ProblemSheet struct {
+	Questions         []Problem
+	CorrectlyAnswered int
+}
+
+func (p *ProblemSheet) populateSheet(file string) error {
+	//open file
+	f, err := os.Open(file)
+	if err != nil {
+		return fmt.Errorf("failed to open file: %w", err)
+	}
+	defer f.Close()
+
+	reader := csv.NewReader(f)
+	lines, err := reader.ReadAll()
+	if err != nil {
+		return fmt.Errorf("failed to read csv: %w", err)
+	}
+
+	if len(lines) == 0 {
+		return fmt.Errorf("empty csv file loaded")
+	}
+
+	for i, line := range lines {
+		if len(line) != 2 {
+			fmt.Printf("csv row %d has %d cell(s). Skipping to next line", i, len(line))
+			continue
+		}
+
+		newProblem := Problem{
+			Question: line[0],
+			Answer:   line[1],
+		}
+
+		p.Questions = append(p.Questions, newProblem)
+	}
+	return nil
+}
+
+func NewProblemSheet() *ProblemSheet {
+	return &ProblemSheet{}
+}
+
+func (p *ProblemSheet) StartQuiz(limit time.Duration, r io.Reader, w io.Writer) {
+
+	reader := bufio.NewReader(r)
+
+	fmt.Println(w, "Press Enter to begin quiz")
+	reader.ReadString('\n')
+
+	ctx, cancel := context.WithTimeout(context.Background(), limit)
+	defer cancel()
+
+	for _, problem := range p.Questions {
+		answerCh := make(chan string, 1)
+
+		go func(q string) {
+			fmt.Fprintf(w, "\n\nQuestion: %s\n", q)
+			fmt.Fprint(w, "answer: ")
+			userAns, _ := reader.ReadString('\n')
+			answerCh <- strings.TrimSpace(userAns)
+		}(problem.Question)
+
+		select {
+		case userAnswer := <-answerCh:
+			if userAnswer == problem.Answer {
+				p.CorrectlyAnswered++
+			}
+		case <-ctx.Done():
+			fmt.Fprintln(w, "\nquiz not completed before timeout")
+			return
+		}
+	}
+}
+
+func (p *ProblemSheet) DisplayResults(w io.Writer) {
+	fmt.Fprintln(w, "Quiz has ended")
+	fmt.Fprintf(w, "You answered %d/%d questions\n", p.CorrectlyAnswered, len(p.Questions))
+}
+
+//type workerFunc func() string
+//
+//func timeLimit(worker workerFunc, limit time.Duration) (string, error) {
+//	out := make(chan string, 1)
+//	ctx, cancel := context.WithTimeout(context.Background(), limit)
+//	defer cancel()
+//
+//	go func() {
+//		fmt.Println("goroutine started")
+//		out <- worker()
+//	}()
+//
+//	select {
+//	case result := <-out:
+//		return result, nil
+//	case <-ctx.Done():
+//		return "quiz not completed before timeout", errors.New("work timed out")
+//	}
+//}
+
+//func (p *problemSheet) StartQuiz() string {
+//	for _, problem := range p.questions {
+//		fmt.Printf("\n\nQuestion: %s\n", problem.question)
+//		fmt.Print("answer: ")
+//		var answer string
+//		fmt.Scanln(&answer)
+//
+//		if answer == problem.answer {
+//			p.correctlyAnswered++
+//		}
+//	}
+//
+//	return "Quiz completed before timeout"
+//}