implement econet exporter

pkg/config/custom.go

@@ -5,12 +5,30 @@
 package config
 
 import (
+	"time"
+
+	"github.com/caarlos0/env/v11"
+
 	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/config"
 )
 
+// DefaultUsageInterval is used when UsageInterval is unset. Rheem's
+// energy/water history only updates hourly, so polling faster is wasteful.
+const DefaultUsageInterval = 5 * time.Minute
+
 type ServiceConfig struct {
-	Timezone string    `yaml:"timezone" json:"timezone,omitempty" default:"UTC"`
-	Opts     *DemoOpts `yaml:"opts" json:"opts,omitempty"`
+	// Rheem EcoNet cloud credentials. Prefer supplying the password via
+	// the ECONET_PASSWORD environment variable rather than config.yaml.
+	EconetEmail    string `yaml:"econetEmail"    json:"econetEmail,omitempty"    env:"ECONET_EMAIL"`
+	EconetPassword string `yaml:"econetPassword" json:"econetPassword,omitempty" env:"ECONET_PASSWORD"`
+
+	// CostPerKWH is the electricity price in US dollars per kWh (e.g. 0.18
+	// means 18 cents/kWh, NOT 18). It derives the econet_energy_cost_dollars
+	// metric from kWh energy usage.
+	CostPerKWH float64 `yaml:"costPerKWH" json:"costPerKWH,omitempty" env:"ECONET_COST_PER_KWH"`
+
+	// UsageInterval controls how often energy/water usage history is polled.
+	UsageInterval time.Duration `yaml:"usageInterval" json:"usageInterval,omitempty" env:"ECONET_USAGE_INTERVAL"`
 
 	// Embeds go-app config, used by go-app to
 	// merge custom config into go-app config, and to produce
@@ -18,14 +36,21 @@ type ServiceConfig struct {
 	*config.AppConfig
 }
 
-type DemoOpts struct {
-	FactLang string   `yaml:"factLang" json:"factLang,omitempty" default:"en"`
-	FactType FactType `yaml:"factType" json:"factType,omitempty" default:"random" enum:"today,random"`
+// LoadEnv applies environment-variable overrides to the custom ServiceConfig
+// fields. go-app's MustLoadConfigInto only handles env for the embedded
+// AppConfig, so the caller must apply env for custom fields. The embedded
+// AppConfig is skipped here to preserve go-app's own env/yaml precedence.
+func (c *ServiceConfig) LoadEnv() error {
+	appConfig := c.AppConfig
+	c.AppConfig = nil
+	defer func() { c.AppConfig = appConfig }()
+	return env.Parse(c)
 }
 
-type FactType string
-
-const (
-	TypeToday  FactType = "today"
-	TypeRandom FactType = "random"
-)
+// GetUsageInterval returns the configured usage poll interval or the default.
+func (c *ServiceConfig) GetUsageInterval() time.Duration {
+	if c.UsageInterval <= 0 {
+		return DefaultUsageInterval
+	}
+	return c.UsageInterval
+}