package docker

import (
	"fmt"
	"strings"
	"sync"
	"time"

	"github.com/influxdata/telegraf"

	api "k8s.io/kubernetes/pkg/api"
	kube "k8s.io/kubernetes/pkg/client/unversioned"

	godocker "github.com/fsouza/go-dockerclient"
)

// CreateClient sets the client value in the Docker struct
func CreateClient(endpoint string) (*godocker.Client, error) {
	var c *godocker.Client
	var err error
	if endpoint == "ENV" {
		c, err = godocker.NewClientFromEnv()
	} else if endpoint == "" {
		c, err = godocker.NewClient("unix:///var/run/docker.sock")
	} else {
		c, err = godocker.NewClient(endpoint)
	}
	return c, err
}

func GatherContainerMetrics(client *godocker.Client, kubeClient *kube.Client, containerNames []string, acc telegraf.Accumulator) error {
	opts := godocker.ListContainersOptions{}
	containers, err := client.ListContainers(opts)
	if err != nil {
		return err
	}

	var wg sync.WaitGroup
	wg.Add(len(containers))
	for _, container := range containers {
		go func(c godocker.APIContainers) {
			defer wg.Done()
			err := gatherContainer(client, kubeClient, c, containerNames, acc)
			if err != nil {
				fmt.Println(err.Error())
			}
		}(container)
	}
	wg.Wait()
	return nil
}

func gatherContainer(
	client *godocker.Client,
	kubeClient *kube.Client,
	container godocker.APIContainers,
	containerNames []string,
	acc telegraf.Accumulator,
) error {
	// Parse container name
	cname := "unknown"
	if len(container.Names) > 0 {
		// Not sure what to do with other names, just take the first.
		cname = strings.TrimPrefix(container.Names[0], "/")
	}

	tags := map[string]string{
		"container_id":    container.ID,
		"container_name":  cname,
		"container_image": container.Image,
	}

	if kubeClient != nil {
		tags = gatherKubernetesLabels(kubeClient, container.ID, tags)
	}

	if len(containerNames) > 0 {
		if !sliceContains(cname, containerNames) {
			return nil
		}
	}

	statChan := make(chan *godocker.Stats)
	done := make(chan bool)
	statOpts := godocker.StatsOptions{
		Stream:  false,
		ID:      container.ID,
		Stats:   statChan,
		Done:    done,
		Timeout: time.Duration(time.Second * 5),
	}

	go func() {
		client.Stats(statOpts)
	}()

	stat := <-statChan
	close(done)

	// Add labels to tags
	for k, v := range container.Labels {
		tags[k] = v
	}

	gatherContainerStats(stat, acc, tags)

	return nil
}

func gatherContainerStats(
	stat *godocker.Stats,
	acc telegraf.Accumulator,
	tags map[string]string,
) {
	now := stat.Read

	memfields := map[string]interface{}{
		"max_usage":                 stat.MemoryStats.MaxUsage,
		"usage":                     stat.MemoryStats.Usage,
		"fail_count":                stat.MemoryStats.Failcnt,
		"limit":                     stat.MemoryStats.Limit,
		"total_pgmafault":           stat.MemoryStats.Stats.TotalPgmafault,
		"cache":                     stat.MemoryStats.Stats.Cache,
		"mapped_file":               stat.MemoryStats.Stats.MappedFile,
		"total_inactive_file":       stat.MemoryStats.Stats.TotalInactiveFile,
		"pgpgout":                   stat.MemoryStats.Stats.Pgpgout,
		"rss":                       stat.MemoryStats.Stats.Rss,
		"total_mapped_file":         stat.MemoryStats.Stats.TotalMappedFile,
		"writeback":                 stat.MemoryStats.Stats.Writeback,
		"unevictable":               stat.MemoryStats.Stats.Unevictable,
		"pgpgin":                    stat.MemoryStats.Stats.Pgpgin,
		"total_unevictable":         stat.MemoryStats.Stats.TotalUnevictable,
		"pgmajfault":                stat.MemoryStats.Stats.Pgmajfault,
		"total_rss":                 stat.MemoryStats.Stats.TotalRss,
		"total_rss_huge":            stat.MemoryStats.Stats.TotalRssHuge,
		"total_writeback":           stat.MemoryStats.Stats.TotalWriteback,
		"total_inactive_anon":       stat.MemoryStats.Stats.TotalInactiveAnon,
		"rss_huge":                  stat.MemoryStats.Stats.RssHuge,
		"hierarchical_memory_limit": stat.MemoryStats.Stats.HierarchicalMemoryLimit,
		"total_pgfault":             stat.MemoryStats.Stats.TotalPgfault,
		"total_active_file":         stat.MemoryStats.Stats.TotalActiveFile,
		"active_anon":               stat.MemoryStats.Stats.ActiveAnon,
		"total_active_anon":         stat.MemoryStats.Stats.TotalActiveAnon,
		"total_pgpgout":             stat.MemoryStats.Stats.TotalPgpgout,
		"total_cache":               stat.MemoryStats.Stats.TotalCache,
		"inactive_anon":             stat.MemoryStats.Stats.InactiveAnon,
		"active_file":               stat.MemoryStats.Stats.ActiveFile,
		"pgfault":                   stat.MemoryStats.Stats.Pgfault,
		"inactive_file":             stat.MemoryStats.Stats.InactiveFile,
		"total_pgpgin":              stat.MemoryStats.Stats.TotalPgpgin,
	}
	acc.AddFields("docker_mem", memfields, tags, now)

	cpufields := map[string]interface{}{
		"usage_total":                  stat.CPUStats.CPUUsage.TotalUsage,
		"usage_in_usermode":            stat.CPUStats.CPUUsage.UsageInUsermode,
		"usage_in_kernelmode":          stat.CPUStats.CPUUsage.UsageInKernelmode,
		"usage_system":                 stat.CPUStats.SystemCPUUsage,
		"throttling_periods":           stat.CPUStats.ThrottlingData.Periods,
		"throttling_throttled_periods": stat.CPUStats.ThrottlingData.ThrottledPeriods,
		"throttling_throttled_time":    stat.CPUStats.ThrottlingData.ThrottledTime,
	}
	cputags := copyTags(tags)
	cputags["cpu"] = "cpu-total"
	acc.AddFields("docker_cpu", cpufields, cputags, now)

	for i, percpu := range stat.CPUStats.CPUUsage.PercpuUsage {
		percputags := copyTags(tags)
		percputags["cpu"] = fmt.Sprintf("cpu%d", i)
		acc.AddFields("docker_cpu", map[string]interface{}{"usage_total": percpu}, percputags, now)
	}

	for network, netstats := range stat.Networks {
		netfields := map[string]interface{}{
			"rx_dropped": netstats.RxDropped,
			"rx_bytes":   netstats.RxBytes,
			"rx_errors":  netstats.RxErrors,
			"tx_packets": netstats.TxPackets,
			"tx_dropped": netstats.TxDropped,
			"rx_packets": netstats.RxPackets,
			"tx_errors":  netstats.TxErrors,
			"tx_bytes":   netstats.TxBytes,
		}
		// Create a new network tag dictionary for the "network" tag
		nettags := copyTags(tags)
		nettags["network"] = network
		acc.AddFields("docker_net", netfields, nettags, now)
	}

	gatherBlockIOMetrics(stat, acc, tags, now)
}

func gatherBlockIOMetrics(
	stat *godocker.Stats,
	acc telegraf.Accumulator,
	tags map[string]string,
	now time.Time,
) {
	blkioStats := stat.BlkioStats
	// Make a map of devices to their block io stats
	deviceStatMap := make(map[string]map[string]interface{})

	for _, metric := range blkioStats.IOServiceBytesRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		_, ok := deviceStatMap[device]
		if !ok {
			deviceStatMap[device] = make(map[string]interface{})
		}

		field := fmt.Sprintf("io_service_bytes_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IOServicedRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		_, ok := deviceStatMap[device]
		if !ok {
			deviceStatMap[device] = make(map[string]interface{})
		}

		field := fmt.Sprintf("io_serviced_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IOQueueRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("io_queue_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IOServiceTimeRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("io_service_time_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IOWaitTimeRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("io_wait_time_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IOMergedRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("io_merged_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.IOTimeRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("io_time_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for _, metric := range blkioStats.SectorsRecursive {
		device := fmt.Sprintf("%d:%d", metric.Major, metric.Minor)
		field := fmt.Sprintf("sectors_recursive_%s", strings.ToLower(metric.Op))
		deviceStatMap[device][field] = metric.Value
	}

	for device, fields := range deviceStatMap {
		iotags := copyTags(tags)
		iotags["device"] = device
		acc.AddFields("docker_blkio", fields, iotags, now)
	}
}

func copyTags(in map[string]string) map[string]string {
	out := make(map[string]string)
	for k, v := range in {
		out[k] = v
	}
	return out
}

func gatherKubernetesLabels(kubeClient *kube.Client, containerID string, tags map[string]string) map[string]string {
	podClient := kubeClient.Pods(api.NamespaceAll)
	pods, _ := podClient.List(api.ListOptions{})

	for _, pod := range pods.Items {
		for _, containerStatus := range pod.Status.ContainerStatuses {
			podContainerID := strings.TrimPrefix(containerStatus.ContainerID, "docker://")
			if podContainerID == containerID {
				for k, v := range pod.ObjectMeta.Labels {
					tags[k] = v
				}
				return tags
			}
		}
	}
	return tags
}

func sliceContains(in string, sl []string) bool {
	for _, str := range sl {
		if str == in {
			return true
		}
	}
	return false
}