package system

import (
	"fmt"
	gonet "net"
	"strings"

	dc "github.com/fsouza/go-dockerclient"
	"github.com/influxdb/tivan/plugins"
	"github.com/influxdb/tivan/plugins/system/ps/common"
	"github.com/influxdb/tivan/plugins/system/ps/cpu"
	"github.com/influxdb/tivan/plugins/system/ps/disk"
	"github.com/influxdb/tivan/plugins/system/ps/docker"
	"github.com/influxdb/tivan/plugins/system/ps/load"
	"github.com/influxdb/tivan/plugins/system/ps/mem"
	"github.com/influxdb/tivan/plugins/system/ps/net"
)

type DockerContainerStat struct {
	Id      string
	Name    string
	Command string
	CPU     *cpu.CPUTimesStat
	Mem     *docker.CgroupMemStat
}

type PS interface {
	LoadAvg() (*load.LoadAvgStat, error)
	CPUTimes() ([]cpu.CPUTimesStat, error)
	DiskUsage() ([]*disk.DiskUsageStat, error)
	NetIO() ([]net.NetIOCountersStat, error)
	DiskIO() (map[string]disk.DiskIOCountersStat, error)
	VMStat() (*mem.VirtualMemoryStat, error)
	SwapStat() (*mem.SwapMemoryStat, error)
	DockerStat() ([]*DockerContainerStat, error)
}

func add(acc plugins.Accumulator,
	name string, val float64, tags map[string]string) {
	if val >= 0 {
		acc.Add(name, val, tags)
	}
}

type CPUStats struct {
	ps PS
}

func (_ *CPUStats) Description() string {
	return "Read metrics about cpu usage"
}

func (_ *CPUStats) SampleConfig() string { return "" }

func (s *CPUStats) Gather(acc plugins.Accumulator) error {
	times, err := s.ps.CPUTimes()
	if err != nil {
		return fmt.Errorf("error getting CPU info: %s", err)
	}

	for _, cts := range times {
		tags := map[string]string{
			"cpu": cts.CPU,
		}

		add(acc, "user", cts.User, tags)
		add(acc, "system", cts.System, tags)
		add(acc, "idle", cts.Idle, tags)
		add(acc, "nice", cts.Nice, tags)
		add(acc, "iowait", cts.Iowait, tags)
		add(acc, "irq", cts.Irq, tags)
		add(acc, "softirq", cts.Softirq, tags)
		add(acc, "steal", cts.Steal, tags)
		add(acc, "guest", cts.Guest, tags)
		add(acc, "guestNice", cts.GuestNice, tags)
		add(acc, "stolen", cts.Stolen, tags)
	}

	return nil
}

type DiskStats struct {
	ps PS
}

func (_ *DiskStats) Description() string {
	return "Read metrics about disk usage by mount point"
}

func (_ *DiskStats) SampleConfig() string { return "" }

func (s *DiskStats) Gather(acc plugins.Accumulator) error {
	disks, err := s.ps.DiskUsage()
	if err != nil {
		return fmt.Errorf("error getting disk usage info: %s", err)
	}

	for _, du := range disks {
		tags := map[string]string{
			"path": du.Path,
		}

		acc.Add("total", du.Total, tags)
		acc.Add("free", du.Free, tags)
		acc.Add("used", du.Total-du.Free, tags)
		acc.Add("inodes_total", du.InodesTotal, tags)
		acc.Add("inodes_free", du.InodesFree, tags)
		acc.Add("inodes_used", du.InodesTotal-du.InodesFree, tags)
	}

	return nil
}

type DiskIOStats struct {
	ps PS
}

func (_ *DiskIOStats) Description() string {
	return "Read metrics about disk IO by device"
}

func (_ *DiskIOStats) SampleConfig() string { return "" }

func (s *DiskIOStats) Gather(acc plugins.Accumulator) error {
	diskio, err := s.ps.DiskIO()
	if err != nil {
		return fmt.Errorf("error getting disk io info: %s", err)
	}

	for _, io := range diskio {
		tags := map[string]string{
			"name":   io.Name,
			"serial": io.SerialNumber,
		}

		acc.Add("reads", io.ReadCount, tags)
		acc.Add("writes", io.WriteCount, tags)
		acc.Add("read_bytes", io.ReadBytes, tags)
		acc.Add("write_bytes", io.WriteBytes, tags)
		acc.Add("read_time", io.ReadTime, tags)
		acc.Add("write_time", io.WriteTime, tags)
		acc.Add("io_time", io.IoTime, tags)
	}

	return nil
}

type NetIOStats struct {
	ps PS

	Interfaces []string
}

func (_ *NetIOStats) Description() string {
	return "Read metrics about network interface usage"
}

var netSampleConfig = `
# By default, tivan gathers stats from any up interface (excluding loopback)
# Setting interfaces will tell it to gather these explicit interfaces,
# regardless of status.
#
# interfaces = ["eth0", ... ]
`

func (_ *NetIOStats) SampleConfig() string {
	return netSampleConfig
}

func (s *NetIOStats) Gather(acc plugins.Accumulator) error {
	netio, err := s.ps.NetIO()
	if err != nil {
		return fmt.Errorf("error getting net io info: %s", err)
	}

	for _, io := range netio {
		if len(s.Interfaces) != 0 {
			var found bool

			for _, name := range s.Interfaces {
				if name == io.Name {
					found = true
					break
				}
			}

			if !found {
				continue
			}
		} else {
			iface, err := gonet.InterfaceByName(io.Name)
			if err != nil {
				continue
			}

			if iface.Flags&gonet.FlagLoopback == gonet.FlagLoopback {
				continue
			}

			if iface.Flags&gonet.FlagUp == 0 {
				continue
			}
		}

		tags := map[string]string{
			"interface": io.Name,
		}

		acc.Add("bytes_sent", io.BytesSent, tags)
		acc.Add("bytes_recv", io.BytesRecv, tags)
		acc.Add("packets_sent", io.PacketsSent, tags)
		acc.Add("packets_recv", io.PacketsRecv, tags)
		acc.Add("err_in", io.Errin, tags)
		acc.Add("err_out", io.Errout, tags)
		acc.Add("drop_in", io.Dropin, tags)
		acc.Add("drop_out", io.Dropout, tags)
	}

	return nil
}

type MemStats struct {
	ps PS
}

func (_ *MemStats) Description() string {
	return "Read metrics about memory usage"
}

func (_ *MemStats) SampleConfig() string { return "" }

func (s *MemStats) Gather(acc plugins.Accumulator) error {
	vm, err := s.ps.VMStat()
	if err != nil {
		return fmt.Errorf("error getting virtual memory info: %s", err)
	}

	vmtags := map[string]string(nil)

	acc.Add("total", vm.Total, vmtags)
	acc.Add("available", vm.Available, vmtags)
	acc.Add("used", vm.Used, vmtags)
	acc.Add("used_prec", vm.UsedPercent, vmtags)
	acc.Add("free", vm.Free, vmtags)
	acc.Add("active", vm.Active, vmtags)
	acc.Add("inactive", vm.Inactive, vmtags)
	acc.Add("buffers", vm.Buffers, vmtags)
	acc.Add("cached", vm.Cached, vmtags)
	acc.Add("wired", vm.Wired, vmtags)
	acc.Add("shared", vm.Shared, vmtags)

	return nil
}

type SwapStats struct {
	ps PS
}

func (_ *SwapStats) Description() string {
	return "Read metrics about swap memory usage"
}

func (_ *SwapStats) SampleConfig() string { return "" }

func (s *SwapStats) Gather(acc plugins.Accumulator) error {
	swap, err := s.ps.SwapStat()
	if err != nil {
		return fmt.Errorf("error getting swap memory info: %s", err)
	}

	swaptags := map[string]string(nil)

	acc.Add("total", swap.Total, swaptags)
	acc.Add("used", swap.Used, swaptags)
	acc.Add("free", swap.Free, swaptags)
	acc.Add("used_perc", swap.UsedPercent, swaptags)
	acc.Add("in", swap.Sin, swaptags)
	acc.Add("out", swap.Sout, swaptags)

	return nil
}

type DockerStats struct {
	ps PS
}

func (_ *DockerStats) Description() string {
	return "Read metrics about docker containers"
}

func (_ *DockerStats) SampleConfig() string { return "" }

func (s *DockerStats) Gather(acc plugins.Accumulator) error {
	containers, err := s.ps.DockerStat()
	if err != nil {
		return fmt.Errorf("error getting docker info: %s", err)
	}

	for _, cont := range containers {
		tags := map[string]string{
			"id":      cont.Id,
			"name":    cont.Name,
			"command": cont.Command,
		}

		cts := cont.CPU

		acc.Add("user", cts.User, tags)
		acc.Add("system", cts.System, tags)
		acc.Add("idle", cts.Idle, tags)
		acc.Add("nice", cts.Nice, tags)
		acc.Add("iowait", cts.Iowait, tags)
		acc.Add("irq", cts.Irq, tags)
		acc.Add("softirq", cts.Softirq, tags)
		acc.Add("steal", cts.Steal, tags)
		acc.Add("guest", cts.Guest, tags)
		acc.Add("guestNice", cts.GuestNice, tags)
		acc.Add("stolen", cts.Stolen, tags)

		acc.Add("cache", cont.Mem.Cache, tags)
		acc.Add("rss", cont.Mem.RSS, tags)
		acc.Add("rss_huge", cont.Mem.RSSHuge, tags)
		acc.Add("mapped_file", cont.Mem.MappedFile, tags)
		acc.Add("swap_in", cont.Mem.Pgpgin, tags)
		acc.Add("swap_out", cont.Mem.Pgpgout, tags)
		acc.Add("page_fault", cont.Mem.Pgfault, tags)
		acc.Add("page_major_fault", cont.Mem.Pgmajfault, tags)
		acc.Add("inactive_anon", cont.Mem.InactiveAnon, tags)
		acc.Add("active_anon", cont.Mem.ActiveAnon, tags)
		acc.Add("inactive_file", cont.Mem.InactiveFile, tags)
		acc.Add("active_file", cont.Mem.ActiveFile, tags)
		acc.Add("unevictable", cont.Mem.Unevictable, tags)
		acc.Add("memory_limit", cont.Mem.HierarchicalMemoryLimit, tags)
		acc.Add("total_cache", cont.Mem.TotalCache, tags)
		acc.Add("total_rss", cont.Mem.TotalRSS, tags)
		acc.Add("total_rss_huge", cont.Mem.TotalRSSHuge, tags)
		acc.Add("total_mapped_file", cont.Mem.TotalMappedFile, tags)
		acc.Add("total_swap_in", cont.Mem.TotalPgpgIn, tags)
		acc.Add("total_swap_out", cont.Mem.TotalPgpgOut, tags)
		acc.Add("total_page_fault", cont.Mem.TotalPgFault, tags)
		acc.Add("total_page_major_fault", cont.Mem.TotalPgMajFault, tags)
		acc.Add("total_inactive_anon", cont.Mem.TotalInactiveAnon, tags)
		acc.Add("total_active_anon", cont.Mem.TotalActiveAnon, tags)
		acc.Add("total_inactive_file", cont.Mem.TotalInactiveFile, tags)
		acc.Add("total_active_file", cont.Mem.TotalActiveFile, tags)
		acc.Add("total_unevictable", cont.Mem.TotalUnevictable, tags)
	}

	return nil
}

type SystemStats struct {
	ps PS
}

func (_ *SystemStats) Description() string {
	return "Read metrics about system load"
}

func (_ *SystemStats) SampleConfig() string { return "" }

func (s *SystemStats) add(acc plugins.Accumulator,
	name string, val float64, tags map[string]string) {
	if val >= 0 {
		acc.Add(name, val, tags)
	}
}

func (s *SystemStats) Gather(acc plugins.Accumulator) error {
	lv, err := s.ps.LoadAvg()
	if err != nil {
		return err
	}

	acc.Add("load1", lv.Load1, nil)
	acc.Add("load5", lv.Load5, nil)
	acc.Add("load15", lv.Load15, nil)

	return nil
}

type systemPS struct {
	dockerClient *dc.Client
}

func (s *systemPS) LoadAvg() (*load.LoadAvgStat, error) {
	return load.LoadAvg()
}

func (s *systemPS) CPUTimes() ([]cpu.CPUTimesStat, error) {
	return cpu.CPUTimes(true)
}

func (s *systemPS) DiskUsage() ([]*disk.DiskUsageStat, error) {
	parts, err := disk.DiskPartitions(true)
	if err != nil {
		return nil, err
	}

	var usage []*disk.DiskUsageStat

	for _, p := range parts {
		du, err := disk.DiskUsage(p.Mountpoint)
		if err != nil {
			return nil, err
		}

		usage = append(usage, du)
	}

	return usage, nil
}

func (s *systemPS) NetIO() ([]net.NetIOCountersStat, error) {
	return net.NetIOCounters(true)
}

func (s *systemPS) DiskIO() (map[string]disk.DiskIOCountersStat, error) {
	m, err := disk.DiskIOCounters()
	if err == common.NotImplementedError {
		return nil, nil
	}

	return m, err
}

func (s *systemPS) VMStat() (*mem.VirtualMemoryStat, error) {
	return mem.VirtualMemory()
}

func (s *systemPS) SwapStat() (*mem.SwapMemoryStat, error) {
	return mem.SwapMemory()
}

func (s *systemPS) DockerStat() ([]*DockerContainerStat, error) {
	if s.dockerClient == nil {
		c, err := dc.NewClient("unix:///var/run/docker.sock")
		if err != nil {
			return nil, err
		}

		s.dockerClient = c
	}

	opts := dc.ListContainersOptions{}

	list, err := s.dockerClient.ListContainers(opts)
	if err != nil {
		if _, ok := err.(*gonet.OpError); ok {
			return nil, nil
		}

		return nil, err
	}

	var stats []*DockerContainerStat

	for _, cont := range list {
		ctu, err := docker.CgroupCPUDocker(cont.ID)
		if err != nil {
			return nil, err
		}

		mem, err := docker.CgroupMemDocker(cont.ID)
		if err != nil {
			return nil, err
		}

		name := strings.Join(cont.Names, " ")

		stats = append(stats, &DockerContainerStat{
			Id:      cont.ID,
			Name:    name,
			Command: cont.Command,
			CPU:     ctu,
			Mem:     mem,
		})
	}

	return stats, nil
}

func init() {
	plugins.Add("cpu", func() plugins.Plugin {
		return &CPUStats{ps: &systemPS{}}
	})

	plugins.Add("disk", func() plugins.Plugin {
		return &DiskStats{ps: &systemPS{}}
	})

	plugins.Add("io", func() plugins.Plugin {
		return &DiskIOStats{ps: &systemPS{}}
	})

	plugins.Add("net", func() plugins.Plugin {
		return &NetIOStats{ps: &systemPS{}}
	})

	plugins.Add("mem", func() plugins.Plugin {
		return &MemStats{ps: &systemPS{}}
	})

	plugins.Add("swap", func() plugins.Plugin {
		return &SwapStats{ps: &systemPS{}}
	})

	plugins.Add("docker", func() plugins.Plugin {
		return &DockerStats{ps: &systemPS{}}
	})

	plugins.Add("system", func() plugins.Plugin {
		return &SystemStats{ps: &systemPS{}}
	})
}