homelab-deploy/internal/cli/aliases.go

// Package cli provides the deploy command logic.
package cli

import (
	"os"
	"strings"
)

const aliasEnvPrefix = "HOMELAB_DEPLOY_ALIAS_"

// ResolveAlias resolves a subject alias to a full NATS subject.
// If the input looks like a NATS subject (contains dots), it is returned as-is.
// Otherwise, it checks for an environment variable HOMELAB_DEPLOY_ALIAS_<NAME>.
// Alias names are case-insensitive and hyphens are converted to underscores.
func ResolveAlias(input string) string {
	// If it contains dots, it's already a subject
	if strings.Contains(input, ".") {
		return input
	}

	// Convert to uppercase and replace hyphens with underscores
	envName := aliasEnvPrefix + strings.ToUpper(strings.ReplaceAll(input, "-", "_"))

	if alias := os.Getenv(envName); alias != "" {
		return alias
	}

	// Return as-is if no alias found (will likely fail later)
	return input
}

// IsAlias returns true if the input looks like an alias (no dots).
func IsAlias(input string) bool {
	return !strings.Contains(input, ".")
}

// GetAliasEnvVar returns the environment variable name for a given alias.
func GetAliasEnvVar(alias string) string {
	return aliasEnvPrefix + strings.ToUpper(strings.ReplaceAll(alias, "-", "_"))
}