package i2es

import (
	"bytes"
	"encoding/json"
	"errors"
	"io/ioutil"
	"net/http"
	"strings"

	log "github.com/Sirupsen/logrus"
	"github.com/google/uuid"
)

// ESDoc Elasticsearch document structure
type ESDoc struct {
	Echo    string `json:"echo"`
	Subg    string `json:"subg"`
	To      string `json:"to"`
	Author  string `json:"author"`
	Message string `json:"message"`
	Date    string `json:"date"`
	MsgID   string `json:"msgid"`
	Tags    string `json:"tags"`
	Repto   string `json:"repto"`
	Address string `json:"address"`
	TopicID string `json:"topicid"`
}

// ESConf ES connection settings
type ESConf struct {
	Host  string
	Index string
	Type  string
}

type topicid struct {
	es ESConf
}

// doPostRequest ...
func doRequest(uri, data, method string) ([]byte, error) {
	req, err := http.NewRequest(method, uri, bytes.NewBuffer([]byte(data)))
	req.Header.Add("Content-Type", "application/json")
	if err != nil {
		return []byte(""), err
	}

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return []byte(""), err
	}

	defer resp.Body.Close()

	body, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return []byte(""), err
	}

	return body, nil
}

// findTopicID for msgid
func (t topicid) findTopicID(msgid string, enter int) (string, error) {
	searchURI := strings.Join([]string{t.es.Host, t.es.Index, t.es.Type, "_search"}, "/")
	searchQ := strings.Join([]string{`{"sort": [{"date": {"order": "desc"}}, {"_score": { "order": "desc" }}], "query": { "query_string" : {"fields": ["msgid"], "query": "msgid.keyword:` + msgid + ` "}}, "size":' + show_rows + ', "from":' + from + '}`}, "")

	body, err := doRequest(searchURI, searchQ, "POST")
	if err != nil {
		return "", err
	}

	var res ESRes
	err = json.Unmarshal(body, &res)
	if err != nil {
		return "", err
	}

	if res.Hits.Total == 0 {
		e := errors.New("MSGID " + msgid + " not found ")
		return "", e
	}

	if res.Hits.Hits[0].Source.TopicID != "" {
		topicid := res.Hits.Hits[0].Source.TopicID
		return topicid, nil
	}

	if res.Hits.Hits[0].Source.Repto != "" && res.Hits.Hits[0].Source.TopicID == "" {
		if enter > 25 {
			topicid := uuid.New().String()
			log.Error("Maximum recurse depth. Top message not in index? Forse assign new topicID " + topicid)
			return topicid, nil
		} else {
			t.findTopicID(res.Hits.Hits[0].Source.Repto, enter+1)
		}
	} else if res.Hits.Hits[0].Source.Repto == "" && res.Hits.Hits[0].Source.TopicID != "" {
		return res.Hits.Hits[0].Source.TopicID, nil
	}

	if res.Hits.Hits[0].Source.Repto == "" && res.Hits.Hits[0].Source.TopicID == "" {
		// This is a old message without topicid => generate new topicid and update a top document
		topicid := uuid.New().String()
		log.Warn(topicid)
		log.Warn("Top message " + res.Hits.Hits[0].Source.MsgID + " found but it is doesn not have a topicID")
		log.Warn("Generated new topicID " + topicid)
		log.Warn("Update top message")

		updateDoc := res.Hits.Hits[0].Source
		updateDoc.TopicID = topicid

		updateDocPlain, err := json.Marshal(updateDoc)
		if err != nil {
			e := errors.New("Cant serialize document: " + err.Error())
			return "", e
		}

		postURI := strings.Join([]string{t.es.Host, t.es.Index, t.es.Type, updateDoc.MsgID}, "/")
		_, err = doRequest(postURI, string(updateDocPlain), "PUT")
		if err != nil {
			e := errors.New("Cant update document: " + err.Error())
			return "", e
		}

		log.Info(string(updateDocPlain))
		return topicid, nil
	}
	return "", errors.New("Something went wrong")
}

// check if
func (t topicid) checkTopicID(msg *ESDoc) func() string {
	if msg.TopicID != "" {
		return func() string { return msg.TopicID }
	}

	if msg.Repto == "" {
		var genTopicID = func() string {
			topicid := uuid.New().String()
			log.Warn("New start message for topic " + topicid + " found")
			return topicid
		}
		return genTopicID
	}

	if msg.Repto != "" {
		var findAndSetTopicID = func() string {
			topicid, err := t.findTopicID(msg.Repto, 0)
			if err != nil {
				log.Error(err.Error())
				return ""
			}
			log.Info("Topic ID " + topicid + " found for message " + msg.MsgID)
			return topicid
		}
		return findAndSetTopicID
	}

	return func() string { return "" }
}

// getorcreate topicID. Generate new unique topicID if message is start message
// Find top message and get it topicid if ESDoc.Repto is not empty
func (t topicid) getOrCreate(msg *ESDoc) string {
	f := t.checkTopicID(msg)
	return f()
}

// PutToIndex ...
func (es ESConf) PutToIndex(msg ESDoc) error {
	putURI := strings.Join([]string{es.Host, es.Index, es.Type, msg.MsgID}, "/")
	log.Print(putURI)

	// Assign topicID
	var t topicid
	t.es = es
	topic := t.getOrCreate(&msg)
	if msg.TopicID == "" && topic != "" {
		msg.TopicID = topic
	}

	doc, err := json.Marshal(msg)
	if err != nil {
		return err
	}

	req, err := http.NewRequest("PUT", putURI, bytes.NewBuffer(doc))
	req.Header.Add("Content-Type", "application/json")

	client := &http.Client{}
	resp, err := client.Do(req)
	if err != nil {
		return err
	}

	defer resp.Body.Close()

	return err
}

// ESRes ES response structure
type ESRes struct {
	Took     int  `json:"took"`
	TimedOut bool `json:"timed_out"`
	Hits     Hits `json:"hits"`
}

// Hits Founded documents
type Hits struct {
	Total    int     `json:"total"`
	MaxScore float32 `json:"max_score"`
	Hits     []Hit   `json:"hits"`
}

// ES Document
type Hit struct {
	Index  string  `json:"_index"`
	Type   string  `json:"_type"`
	ID     string  `json:"_id"`
	Score  float32 `json:"_score"`
	Source ESDoc   `json:"_source"`
}

// CheckID ...
func (es ESConf) CheckID(id string) (bool, error) {
	searchURI := strings.Join([]string{es.Host, es.Index, es.Type, "_search"}, "/")

	searchQ := strings.Join([]string{`{"query": {"match": {"_id": "`, id, `"}}}`}, "")

	body, err := doRequest(searchURI, searchQ, "POST")
	if err != nil {
		return false, err
	}

	var e ESRes
	err = json.Unmarshal(body, &e)
	if err != nil {
		return false, err
	}

	if e.Hits.Total > 0 {
		err = errors.New(strings.Join([]string{"Message ", id, " already in index"}, ""))
		return false, err
	}

	if e.TimedOut {
		err = errors.New("Request time out")
		return false, err
	}

	return false, nil
}