package main

import (
	"encoding/json"
	"errors"
	"os"
	"time"

	"labix.org/v2/mgo/bson"
)

type PublisherType struct {
	name           string
	disabled       bool
	Index          string
	Output         []OutputInterface
	TopologyOutput OutputInterface

	RefreshTopologyTimer <-chan time.Time
}

type OutputInterface interface {
	PublishIPs(name string, localAddrs []string) error
	GetNameByIP(ip string) string
	PublishEvent(event *Event) error
}

var Publisher PublisherType

// Config
type tomlAgent struct {
	Name                  string
	Refresh_topology_freq int
	Ignore_outgoing       bool
	Topology_expire       int
}
type tomlMothership struct {
	Enabled            bool
	Save_topology      bool
	Host               string
	Port               int
	Protocol           string
	Username           string
	Password           string
	Index              string
	Path               string
	Db                 int
	Db_topology        int
	Timeout            int
	Reconnect_interval int
	Filename           string
	Rotate_every_kb    int
	Number_of_files    int
	DataType           string
}

const (
	ElasticsearchOutputName = "elasticsearch"
	RedisOutputName         = "redis"
	FileOutputName          = "file"
)

var outputTypes = []string{ElasticsearchOutputName, RedisOutputName, FileOutputName}

type Event struct {
	Timestamp    time.Time `json:"@timestamp"`
	Type         string    `json:"type"`
	Agent        string    `json:"agent"`
	Src_ip       string    `json:"src_ip"`
	Src_port     uint16    `json:"src_port"`
	Src_proc     string    `json:"src_proc"`
	Src_country  string    `json:"src_country"`
	Src_server   string    `json:"src_server"`
	Dst_ip       string    `json:"dst_ip"`
	Dst_port     uint16    `json:"dst_port"`
	Dst_proc     string    `json:"dst_proc"`
	Dst_server   string    `json:"dst_server"`
	ResponseTime int32     `json:"responsetime"`
	Status       string    `json:"status"`
	RequestRaw   string    `json:"request_raw"`
	ResponseRaw  string    `json:"response_raw"`

	Mysql  bson.M `json:"mysql"`
	Http   bson.M `json:"http"`
	Redis  bson.M `json:"redis"`
	Pgsql  bson.M `json:"pgsql"`
	Thrift bson.M `json:"thrift"`
}

type Topology struct {
	Name string `json:"name"`
	Ip   string `json:"ip"`
}

func PrintPublishEvent(event *Event) {
	json, err := json.MarshalIndent(event, "", "  ")
	if err != nil {
		ERR("json.Marshal: %s", err)
	} else {
		DEBUG("publish", "Publish: %s", string(json))
	}
}

const (
	OK_STATUS    = "OK"
	ERROR_STATUS = "Error"
)

func (publisher *PublisherType) GetServerName(ip string) string {
	// in case the IP is localhost, return current agent name
	islocal, err := IsLoopback(ip)
	if err != nil {
		ERR("Parsing IP %s fails with: %s", ip, err)
		return ""
	} else {
		if islocal {
			return publisher.name
		}
	}
	// find the agent with the desired IP
	if publisher.TopologyOutput != nil {
		return publisher.TopologyOutput.GetNameByIP(ip)
	} else {
		return ""
	}
}

func (publisher *PublisherType) PublishHttpTransaction(t *HttpTransaction) error {

	event := Event{}

	event.Type = "http"
	response := t.Http["response"].(bson.M)
	code := response["code"].(uint16)
	if code < 400 {
		event.Status = OK_STATUS
	} else {
		event.Status = ERROR_STATUS
	}
	event.ResponseTime = t.ResponseTime
	event.RequestRaw = t.Request_raw
	event.ResponseRaw = t.Response_raw
	event.Http = t.Http

	return publisher.PublishEvent(t.ts, &t.Src, &t.Dst, &event)

}

func (publisher *PublisherType) PublishMysqlTransaction(t *MysqlTransaction) error {

	event := Event{}
	event.Type = "mysql"

	if t.Mysql["iserror"].(bool) {
		event.Status = ERROR_STATUS
	} else {
		event.Status = OK_STATUS
	}

	event.ResponseTime = t.ResponseTime
	event.RequestRaw = t.Request_raw
	event.ResponseRaw = t.Response_raw
	event.Mysql = t.Mysql

	return publisher.PublishEvent(t.ts, &t.Src, &t.Dst, &event)
}

func (publisher *PublisherType) PublishRedisTransaction(t *RedisTransaction) error {

	event := Event{}
	event.Type = "redis"
	event.Status = OK_STATUS
	event.ResponseTime = t.ResponseTime
	event.RequestRaw = t.Request_raw
	event.ResponseRaw = t.Response_raw
	event.Redis = t.Redis

	return publisher.PublishEvent(t.ts, &t.Src, &t.Dst, &event)
}

func (publisher *PublisherType) PublishEvent(ts time.Time, src *Endpoint, dst *Endpoint, event *Event) error {

	event.Src_server = publisher.GetServerName(src.Ip)
	event.Dst_server = publisher.GetServerName(dst.Ip)

	if _Config.Agent.Ignore_outgoing && event.Dst_server != "" &&
		event.Dst_server != publisher.name {
		// duplicated transaction -> ignore it
		DEBUG("publish", "Ignore duplicated REDIS transaction on %s: %s -> %s", publisher.name, event.Src_server, event.Dst_server)
		return nil
	}

	event.Timestamp = ts
	event.Agent = publisher.name
	event.Src_ip = src.Ip
	event.Src_port = src.Port
	event.Src_proc = src.Proc
	event.Dst_ip = dst.Ip
	event.Dst_port = dst.Port
	event.Dst_proc = dst.Proc

	// set src_country if no src_server is set
	event.Src_country = ""
	if _GeoLite != nil {
		if len(event.Src_server) == 0 { // only for external IP addresses
			loc := _GeoLite.GetLocationByIP(src.Ip)
			if loc != nil {
				event.Src_country = loc.CountryCode
			}
		}
	}

	if IS_DEBUG("publish") {
		PrintPublishEvent(event)
	}

	// add transaction
	has_error := false
	if !publisher.disabled {
		for i := 0; i < len(publisher.Output); i++ {
			err := publisher.Output[i].PublishEvent(event)
			if err != nil {
				ERR("Fail to publish event type on output %s: %s", publisher.Output, err)
				has_error = true
			}
		}
	}

	if has_error {
		return errors.New("Fail to publish event")
	}
	return nil
}
func (publisher *PublisherType) PublishPgsqlTransaction(t *PgsqlTransaction) error {

	event := Event{}

	event.Type = "pgsql"
	if t.Pgsql["iserror"].(bool) {
		event.Status = ERROR_STATUS
	} else {
		event.Status = OK_STATUS
	}
	event.ResponseTime = t.ResponseTime
	event.RequestRaw = t.Request_raw
	event.ResponseRaw = t.Response_raw
	event.Pgsql = t.Pgsql

	return publisher.PublishEvent(t.ts, &t.Src, &t.Dst, &event)
}

func (publisher *PublisherType) UpdateTopologyPeriodically() {
	for _ = range publisher.RefreshTopologyTimer {
		publisher.PublishTopology()
	}
}

func (publisher *PublisherType) PublishTopology(params ...string) error {

	var localAddrs []string = params

	if len(params) == 0 {
		addrs, err := LocalIpAddrsAsStrings(false)
		if err != nil {
			ERR("Getting local IP addresses fails with: %s", err)
			return err
		}
		localAddrs = addrs
	}

	if publisher.TopologyOutput != nil {
		DEBUG("publish", "Add topology entry for %s: %s", publisher.name, localAddrs)

		err := publisher.TopologyOutput.PublishIPs(publisher.name, localAddrs)
		if err != nil {
			return err
		}
	}

	return nil
}

func (publisher *PublisherType) Init(publishDisabled bool) error {
	var err error

	publisher.disabled = publishDisabled
	if publisher.disabled {
		INFO("Dry run mode. All output types except the file based one are disabled.")
	}

	for i := 0; i < len(outputTypes); i++ {
		output, exists := _Config.Output[outputTypes[i]]
		if exists {
			switch outputTypes[i] {
			case ElasticsearchOutputName:
				if output.Enabled && !publisher.disabled {
					err := ElasticsearchOutput.Init(output)
					if err != nil {
						ERR("Fail to initialize Elasticsearch as output: %s", err)
						return err
					}
					publisher.Output = append(publisher.Output, OutputInterface(&ElasticsearchOutput))

					if output.Save_topology {
						if publisher.TopologyOutput != nil {
							ERR("Multiple outputs defined to store topology. Please add save_topology = true option only for one output.")
							return errors.New("Multiple outputs defined to store topology")
						}
						publisher.TopologyOutput = OutputInterface(&ElasticsearchOutput)
						INFO("Using Elasticsearch to store the topology")
					}
				}
				break

			case RedisOutputName:
				if output.Enabled && !publisher.disabled {
					err := RedisOutput.Init(output)
					if err != nil {
						ERR("Fail to initialize Redis as output: %s", err)
						return err
					}
					publisher.Output = append(publisher.Output, OutputInterface(&RedisOutput))

					if output.Save_topology {
						if publisher.TopologyOutput != nil {
							ERR("Multiple outputs defined to store topology. Please add save_topology = true option only for one output.")
							return errors.New("Multiple outputs defined to store topology")
						}
						publisher.TopologyOutput = OutputInterface(&RedisOutput)
						INFO("Using Redis to store the topology")
					}
				}
				break

			case FileOutputName:
				if output.Enabled {
					err := FileOutput.Init(output)
					if err != nil {
						ERR("Fail to initialize file output: %s", err)
						return err
					}
					publisher.Output = append(publisher.Output, OutputInterface(&FileOutput))

					// topology saving not supported by this one
				}
				break
			}
		}
	}

	if !publisher.disabled {
		if len(publisher.Output) == 0 {
			INFO("No outputs are defined. Please define one under [output]")
			return errors.New("No outputs are define")
		}

		if publisher.TopologyOutput == nil {
			WARN("No output is defined to store the topology. The server fields might not be filled.")
		}
	}

	publisher.name = _Config.Agent.Name
	if len(publisher.name) == 0 {
		// use the hostname
		publisher.name, err = os.Hostname()
		if err != nil {
			return err
		}

		INFO("No agent name configured, using hostname '%s'", publisher.name)
	}

	if !publisher.disabled && publisher.TopologyOutput != nil {
		RefreshTopologyFreq := 10 * time.Second
		if _Config.Agent.Refresh_topology_freq != 0 {
			RefreshTopologyFreq = time.Duration(_Config.Agent.Refresh_topology_freq) * time.Second
		}
		publisher.RefreshTopologyTimer = time.Tick(RefreshTopologyFreq)
		INFO("Topology map refreshed every %s", RefreshTopologyFreq)

		// register agent and its public IP addresses
		err = publisher.PublishTopology()
		if err != nil {
			ERR("Failed to publish topology: %s", err)
			return err
		}

		// update topology periodically
		go publisher.UpdateTopologyPeriodically()
	}

	return nil
}