Function resolveUsageQty

internal/estimate/estimator.go:642–691

resolveUsageQty returns the monthly quantity to use for a resource. Priority: usageMap (user-supplied) > rawType key > service/subLabel key > service key > global default. All keys are looked up in serviceUsageDefaults — rawType (e.g. "aws:cloudwatch/metricAlarm:MetricAlarm"), "Service/SubLabel", an

(resourceName, service, subLabel, rawType string, usageMap map[string]float64)

// All keys are looked up in serviceUsageDefaults — rawType (e.g. "aws:cloudwatch/metricAlarm:MetricAlarm"),
// "Service/SubLabel", and bare "Service" are all valid keys in that map.
func resolveUsageQty(resourceName, service, subLabel, rawType string, usageMap map[string]float64) (qty float64, isDefault bool) {
	// 1. User-supplied value takes highest priority.
	if usageMap != nil {
		// 1a. Exact name/SubLabel match — most specific, for 1:N resources
		//     e.g. --usage my-lambda/Requests=5000000
		if subLabel != "" {
			if v, ok := usageMap[resourceName+"/"+subLabel]; ok && v > 0 {
				return v, false
			}
		}
		// 1b. Bare name match — applies to all sub-labels of this resource
		//     e.g. --usage my-lambda=5000000
		if v, ok := usageMap[resourceName]; ok && v > 0 {
			return v, false
		}
	}
	// 2. rawType exact match (e.g. "aws:cloudwatch/metricAlarm:MetricAlarm" → 1).
	if rawType != "" {
		if v, ok := serviceUsageDefaults[rawType]; ok {
			return v, true
		}
	}
	// 3. Per-service/subLabel default — try exact then case-insensitive.
	if subLabel != "" {
		key := service + "/" + subLabel
		if v, ok := serviceUsageDefaults[key]; ok {
			return v, true
		}
		keyLower := strings.ToLower(key)
		for k, v := range serviceUsageDefaults {
			if strings.ToLower(k) == keyLower {
				return v, true
			}
		}
	}
	// 4. Per-service default — try exact then case-insensitive.
	if service != "" {
		if v, ok := serviceUsageDefaults[service]; ok {
			return v, true
		}
		serviceLower := strings.ToLower(service)
		for k, v := range serviceUsageDefaults {
			if strings.ToLower(k) == serviceLower {
				return v, true
			}
		}
	}
	// 5. Global fallback.
	return defaultUsageQty, true
}

// calcUsageMonthlyCost computes the monthly cost for a usage-based resource
// given a monthly quantity. It uses the OnDemand entry's tiers when available,