package stats

import (
	"path/filepath"
	"time"

	"linkfog.com/public/lib/cgroup"
	"linkfog.com/public/lib/cgroup/fs"
	"linkfog.com/public/lib/cgroup/fs2"
	"linkfog.com/public/lib/cgroup/types"
)

// GetMemoryWorkingSet return memory.usage_in_bytes - total_inactive_file
func GetMemoryWorkingSet(cgroupDir string) (usage float64, err error) {
	var memStats types.MemoryStats
	memStats, err = GetMemoryStats(cgroupDir)
	if err != nil {
		return
	}

	usage = float64(memStats.WorkingSet)
	return
}

// GetMemoryUsage return memory.usage_in_bytes
func GetMemoryUsage(cgroupDir string) (usage float64, err error) {
	var memStats types.MemoryStats
	memStats, err = GetMemoryStats(cgroupDir)
	if err != nil {
		return
	}

	usage = float64(memStats.Usage)
	return
}

func GetMemoryStats(cgroupDir string) (stats types.MemoryStats, err error) {
	if cgroup.IsCgroup2() {
		stats.Usage, stats.WorkingSet, err = fs2.GetMemoryUsage(cgroupDir)
	} else {
		stats.Usage, stats.WorkingSet, err = fs.GetMemoryUsage(cgroupDir)
	}
	if err != nil {
		return
	}

	stats.Timestamp = time.Now()
	return
}

func GetKernelMemoryUsage(cgroupDir string) (usage float64, err error) {
	var kmemUsage uint64
	if cgroup.IsCgroup2() {
		kmemUsage, err = fs2.GetKernelMemoryUsage(cgroupDir)
	} else {
		kmemUsage, err = fs.GetKernelMemoryUsage(cgroupDir)
	}
	if err != nil {
		return
	}

	usage = float64(kmemUsage)
	return
}

func GetMemoryStatFields(cgroupDir string) (activeFile, inactiveFile, activeAnon, inactiveAnon uint64, err error) {
	var stats map[string]uint64
	stats, err = fs.ParseMemoryStat(filepath.Join(cgroupDir, "memory.stat"))
	if err != nil {
		return
	}

	if cgroup.IsCgroup2() {
		if v, ok := stats["active_file"]; ok {
			activeFile = v
		}
		if v, ok := stats["inactive_file"]; ok {
			inactiveFile = v
		}
		if v, ok := stats["active_anon"]; ok {
			activeAnon = v
		}
		if v, ok := stats["inactive_anon"]; ok {
			inactiveAnon = v
		}
	} else {
		if v, ok := stats["total_active_file"]; ok {
			activeFile = v
		}
		if v, ok := stats["total_inactive_file"]; ok {
			inactiveFile = v
		}
		if v, ok := stats["total_active_anon"]; ok {
			activeAnon = v
		}
		if v, ok := stats["total_inactive_anon"]; ok {
			inactiveAnon = v
		}
	}
	return
}

func GetKernelMemorySlabInfo(cgroupDir string) (slabInfo fs.SlabInfo, err error) {
	if cgroup.IsCgroup2() {
		return fs2.GetKernelMemorySlabInfo(cgroupDir)
	} else {
		return fs.GetKernelMemorySlabInfo(cgroupDir)
	}
}