package metric

import (
	"fmt"
	influxdb "github.com/influxdata/influxdb1-client"
	"net/url"
	"os"
	"sort"
	"strings"
	"time"
)

type metric struct {
	Type      string            `json:"type"`
	Timestamp int64             `json:"timestamp"`
	Metric    string            `json:"metric"`
	Count     int64             `json:"count"`
	Value     int64             `json:"value"`
	Max       int64             `json:"max"`
	Min       int64             `json:"min"`
	Tags      map[string]string `json:"tags"`
}

type service struct {
	hostname    string
	serviceName string
	hostIp      string
	podIp       string
	metrics     chan *metric
	megers      map[string]*metric
	config      *Config
	client      *influxdb.Client
}

func NewService(c *Config) *service {
	hostname, _ := os.Hostname()

	infUrl, _ := url.Parse(c.Address)
	infCfg := influxdb.NewConfig()
	infCfg.Username = c.Username
	infCfg.Password = c.Password
	infCfg.URL = *infUrl

	client, _ := influxdb.NewClient(infCfg)

	return &service{
		metrics:     make(chan *metric, 100000),
		hostname:    hostname,
		serviceName: os.Getenv("SERVICE_NAME"),
		podIp:       os.Getenv("POD_IP"),
		hostIp:      os.Getenv("HOST_IP"),
		config:      c,
		client:      client,
	}
}

func (s *service) run() {
	timer := time.NewTicker(time.Duration(s.config.Interval) * time.Second)
	for {
		select {
		case m := <-s.metrics:
			s.process(m)

		case <-timer.C:
			s.report()
		}
	}
}

func (s *service) sortMap(tag map[string]string) string {
	arr := make([]string, 0)
	for k, v := range tag {
		arr = append(arr, fmt.Sprintf("%s=%s", k, v))
	}
	sort.Strings(arr)
	return strings.Join(arr, ":")
}

func (s *service) process(m *metric) {
	if s.megers == nil {
		s.megers = make(map[string]*metric)
	}
	key := m.Metric
	if m.Tags != nil {
		key += "_" + s.sortMap(m.Tags)
	}

	if v, ok := s.megers[key]; ok {
		v.Value += m.Value
		v.Count += m.Count
		v.Timestamp = m.Timestamp
		if m.Value > v.Max {
			v.Max = m.Value
		}
		if m.Value < v.Min {
			v.Value = m.Min
		}
		return
	}

	m.Max = m.Value
	m.Min = m.Value
	s.megers[key] = m
}

func (s *service) defaultTags() map[string]string {
	return map[string]string{
		"hostname":     s.hostname,
		"host_ip":      s.hostIp,
		"pod_ip":       s.podIp,
		"service_name": s.serviceName,
	}
}

func (s *service) report() {
	if s.megers == nil {
		return
	}

	var bp influxdb.BatchPoints
	for _, v := range s.megers {
		var p influxdb.Point
		p.Measurement = v.Metric
		p.Tags = v.Tags
		p.Fields = s.getField(v)
		p.Time = time.Unix(v.Timestamp, 0)
		bp.Points = append(bp.Points, p)
	}

	bp.Database = s.config.Database
	bp.Tags = s.defaultTags()

	s.client.Write(bp)
	s.megers = nil
}

func (s *service) add(m *metric) {
	select {
	case s.metrics <- m:
	default:
		fmt.Println("chan is full")
	}
}

func (s *service) getField(m *metric) map[string]interface{} {

	if m.Type == TypeCount {
		return map[string]interface{}{
			"count": m.Value,
		}
	}

	if m.Type == TypeDuration {
		avgMs := int64(float64(m.Value) / float64(m.Count))
		return map[string]interface{}{
			"avg":   avgMs,
			"count": m.Count,
			"max":   m.Max,
			"min":   m.Min,
		}
	}

	return nil
}