ynab-portfolio-monitor/main.go

package main

import (
	"log"
	"os"
	"time"

	"deadbeef.codes/steven/ynab-portfolio-monitor/ynab"
)

var (
	configuredProviders []AccountProvider // Any account providers that are successfully configured get added to this slice
	ynabClient          *ynab.Client      // YNAB HTTP client
)

// Called at program startup or if SIGHUP is received
func init() {
	log.Printf("ynab-portfolio-monitor init")

	// Load mandatory application configuration from environment variables
	envVars := make(map[string]string)
	envVars["ynab_secret"] = os.Getenv("ynab_secret")
	envVars["ynab_budget_id"] = os.Getenv("ynab_budget_id")

	// Validate that all required environment variables are set
	for key, value := range envVars {
		if value == "" {
			log.Fatalf("shell environment variable %s is not set", key)
		}
	}

	// Loop through all account providers and attempt to configure them
	// if configuration fails, the provider will not be used
	configuredProviders = make([]AccountProvider, 0)
	for _, p := range allProviders {
		err := p.Configure()
		if err != nil {
			log.Printf("skipping provider '%s': %v", p.Name(), err)
			continue
		}
		configuredProviders = append(configuredProviders, p)
		log.Printf("enabled provider '%s'", p.Name())
	}

	// ynab client is static and has no persistent data so is initialized here and not in main program loop
	var err error
	ynabClient, err = ynab.NewClient(envVars["ynab_budget_id"], envVars["ynab_secret"])
	if err != nil {
		log.Fatalf("failed to create ynab client: %v", err)
	}
}

// Main program loop
func main() {
	for {
		// Loop through each configured account provider and attempt to get the account balances, and update YNAB
		for _, p := range configuredProviders {
			balances, accountIDs, err := p.GetBalances()
			if err != nil {
				log.Printf("failed to get balances with provider '%s': %v", p.Name(), err)
				continue
			}
			if len(balances) != len(accountIDs) {
				log.Printf("'%s' provider data validation error: mismatched balance and accountID slice lengths - expected the same: balances length = %d, accountIDs length = %d", p.Name(), len(balances), len(accountIDs))
				continue
			}
			for i := range balances {
				err = ynabClient.SetAccountBalance(accountIDs[i], balances[i])
				if err != nil {
					log.Printf("failed to update ynab account '%s' balance: %v", accountIDs[i], err)
				}
			}
		}
		log.Print("Sleeping for 6 hours...")
		time.Sleep(time.Hour * 6)
	}
}