Temporal workflow versioning by chatgpt.go

package main

import (
	"context"
	"go.temporal.io/sdk/client"
	"go.temporal.io/sdk/temporal"
	"go.temporal.io/sdk/workflow"
	"time"
)

// Define the sendEmail activity interface
func sendEmail(ctx context.Context, email string) error {
	// TODO: Replace this with actual email sending logic
	workflow.GetLogger(ctx).Info("Sending email to:", email)

	// Return nil to indicate successful completion of the activity
	return nil
}

// Define the workflow interface
func helloWorkflow(ctx workflow.Context, email1 string, email2 string) error {
	// Print a message to the console
	workflow.GetLogger(ctx).Info("Hello, world!")

	// Send the first email
	err := workflow.ExecuteActivity(ctx, sendEmail, email1).Get(ctx, nil)
	if err != nil {
		workflow.GetLogger(ctx).Error("Failed to send email:", err)
	}

	// Create a timer that waits for one day
	timer := workflow.NewTimer(ctx, time.Hour*24)
	selector := workflow.NewSelector(ctx)
	var timerFired bool
	selector.AddFuture(timer, func(f workflow.Future) {
		timerFired = true
	})

	// Wait for either the timer to fire or the workflow to be cancelled
	selector.Select(ctx)

	if timerFired {
		// Send the second email after the timer fires
		err := workflow.ExecuteActivity(ctx, sendEmail, email2).Get(ctx, nil)
		if err != nil {
			workflow.GetLogger(ctx).Error("Failed to send email:", err)
		}
	}

	// Return nil to indicate successful completion of the workflow
	return nil
}

func main() {
	// Set up the Temporal client
	c, err := client.NewClient(client.Options{})
	if err != nil {
		panic(err)
	}

	// Register the workflow with the versioning API
	// This should be done once per version of the workflow
	workflow.RegisterWithOptions(helloWorkflow, workflow.RegisterOptions{Name: "hello-workflow", EnableSessionWorker: true})

	// Get the workflow client and start a new workflow execution
	workflowClient := c.NewWorkflowClient()
	options := client.StartWorkflowOptions{
		TaskQueue: "default",
	}
	we, err := workflowClient.ExecuteWorkflow(context.Background(), options, "hello-workflow", "example1@example.com", "example2@example.com")
	if err != nil {
		panic(err)
	}

	// Wait for the workflow to complete
	var result string
	err = we.Get(context.Background(), &result)
	if err != nil {
		panic(err)
	}

	// Print the workflow result to the console
	workflow.GetLogger(context.Background()).Info("Workflow result:", result)

	// Signal the workflow to run the new version
	// This can be done at any time after the initial workflow execution has started
	err = we.SignalWorkflow(context.Background(), "upgrade", "example1@example.com", "example2@example.com")
	if err != nil {
		panic(err)
	}

	// Wait for the upgraded workflow to complete
	err = we.Get(context.Background(), &result)
	if err != nil {
		panic(err)
	}

	// Print the upgraded workflow result to the console
	workflow.GetLogger(context.Background()).Info("Upgraded workflow result:", result)
}

// Define the upgrade function
func upgradeWorkflow(ctx workflow.Context, email string) error {