package environment

import "sync"

// Defines the current resource usage for a given server instance. If a server is offline you
// should obviously expect memory and CPU usage to be 0. However, disk will always be returned
// since that is not dependent on the server being running to collect that data.
type Stats struct {
	mu sync.RWMutex

	// The total amount of memory, in bytes, that this server instance is consuming. This is
	// calculated slightly differently than just using the raw Memory field that the stats
	// return from the container, so please check the code setting this value for how that
	// is calculated.
	Memory uint64 `json:"memory_bytes"`

	// The total amount of memory this container or resource can use. Inside Docker this is
	// going to be higher than you'd expect because we're automatically allocating overhead
	// abilities for the container, so its not going to be a perfect match.
	MemoryLimit uint64 `json:"memory_limit_bytes"`

	// The absolute CPU usage is the amount of CPU used in relation to the entire system and
	// does not take into account any limits on the server process itself.
	CpuAbsolute float64 `json:"cpu_absolute"`

	// The current disk space being used by the server. This is cached to prevent slow lookup
	// issues on frequent refreshes.
	// Disk int64 `json:"disk_bytes"`

	// Current network transmit in & out for a container.
	Network struct {
		RxBytes uint64 `json:"rx_bytes"`
		TxBytes uint64 `json:"tx_bytes"`
	} `json:"network"`
}

// Resets the usages values to zero, used when a server is stopped to ensure we don't hold
// onto any values incorrectly.
func (s *Stats) Empty() {
	s.mu.Lock()
	defer s.mu.Unlock()

	s.Memory = 0
	s.CpuAbsolute = 0
	s.Network.TxBytes = 0
	s.Network.RxBytes = 0
}