Go を使用して OTP ベースの認証サーバーを構築する: パート 3

<code class="language-go">func (app *application) sendOTPViaTwilio(otp, phoneNumber string) error {
    client := twilio.NewRestClientWithParams(twilio.ClientParams{
        Username: os.Getenv("TWILIO_SID"),
        Password: os.Getenv("TWILIO_API_KEY"),
    })

    params := &api.CreateMessageParams{}
    params.SetBody(fmt.Sprintf(
        "Thank you for choosing Cheershare! Your one-time password is %v.",
        otp,
    ))
    params.SetFrom(os.Getenv("TWILIO_PHONE_NUMBER"))
    params.SetTo(fmt.Sprintf("+91%v", phoneNumber))

    const maxRetries = 3
    var lastErr error

    for attempt := 1; attempt <= maxRetries; attempt++ {
        resp, err := client.SendSms(params)
        if err == nil {
            app.logger.Printf("Message SID: %s", resp.Sid)
            return nil
        }
        lastErr = err
        time.Sleep(time.Duration(attempt) * 100 * time.Millisecond)
    }

    return fmt.Errorf("failed to send OTP after %d retries: %w", maxRetries, lastErr)
}</code>

<code class="language-go">type application struct {
    wg     sync.WaitGroup
    config config
    models data.Models
    logger *log.Logger
    cache  *redis.Client
}</code>

<code class="language-go">func (app *application) background(fn func()) {
    app.wg.Add(1)
    go func() {
        defer app.wg.Done()
        defer func() {
            if err := recover(); err != nil {
                app.logger.Printf("Error in background function: %v\n", err)
            }
        }()
        fn()
    }()
}</code>

<code class="language-sql">-- 000002_create-token.up.sql
CREATE TABLE IF NOT EXISTS tokens (
    hash bytea PRIMARY KEY,
    user_id bigint NOT NULL REFERENCES users ON DELETE CASCADE,
    expiry timestamp(0) with time zone NOT NULL,
    scope text NOT NULL
);

-- 000002_create-token.down.sql
DROP TABLE IF EXISTS tokens;</code>

<code class="language-go">// ... (other imports) ...

package data

// ... (other code) ...

func generateToken(userId int64, ttl time.Duration, scope string) (*Token, error) {
    // ... (token generation logic) ...
}

func (m TokenModel) Insert(token *Token) error {
    // ... (database insertion logic) ...
}

func (m TokenModel) DeleteAllForUser(scope string, userID int64) error {
    // ... (database deletion logic) ...
}

func (m TokenModel) New(userId int64, ttl time.Duration, scope string) (*Token, error) {
    // ... (token creation and insertion logic) ...
}</code>

<code class="language-go">// ... (other functions) ...

func (app *application) handleUserSignupAndVerification(w http.ResponseWriter, r *http.Request) {
    // ... (input parsing and validation) ...

    // ... (OTP generation and sending logic) ...

    // ... (OTP verification logic) ...

    // ... (user creation or retrieval) ...

    token, err := app.generateTokenForUser(user.ID)
    if err != nil {
        // ... (error handling) ...
    }

    // ... (success response with token) ...
}</code>