blog_backend_api/db/elasticEngine.go

package db

import (
	"background/utils"
	"encoding/json"
	"reflect"

	"github.com/pkg/errors"
	"golang.org/x/net/context"
	"gopkg.in/olivere/elastic.v7"
	"qiniupkg.com/x/log.v7"
)

const (
	ERROR_PTR        = "null pointer error"
	INPUT_TYPE_ERROR = "wrong input parameter: "
	CREATED_ERROR    = "create error"
	DELETE_ERROR     = "delete error"
	INDEX_EXISTED    = "index existed"
)

type ElkEngine struct {
	cli *elastic.Client
}

func (p *ElkEngine) Create(index string, types string, id string, data interface{}) error {
	if nil != p {
		if (reflect.TypeOf(data).Kind() == reflect.String) || (reflect.TypeOf(data).Kind() == reflect.Struct) {
			resp, err := p.cli.Index().
				Index(index).
				BodyJson(data).
				Do(context.Background())
			if err != nil {
				log.Print("create error", err)
				return err
			}
			log.Print(resp)
		} else {
			log.Print(reflect.TypeOf(data).Kind())
			return errors.New(INPUT_TYPE_ERROR)
		}
	} else {
		return errors.New(ERROR_PTR)
	}
	return nil
}

func (p *ElkEngine) Delete(query elastic.Query, index string) error {
	if nil != p {
		_, err := p.cli.DeleteByQuery().Index(index).Query(query).
			Do(context.Background())
		if err != nil {
			log.Print(err)
			return err
		}

	} else {
		return errors.New(ERROR_PTR)
	}
	return nil
}


func (p *ElkEngine) QueryHighlight(index string, query elastic.Query, v interface{},hightlight *elastic.Highlight,
	limit int, offset int) ([]string, error) {

	if reflect.ValueOf(v).Kind() != reflect.Ptr {
		return nil, errors.New(INPUT_TYPE_ERROR + "shoulbe be Ptr")
	}
	if reflect.ValueOf(v).Elem().Kind() != reflect.Slice {
		return nil, errors.New(INPUT_TYPE_ERROR + "shoulbe be Slice")
	}
	if reflect.ValueOf(v).Elem().Type().Elem().Kind() != reflect.Struct {
		return nil, errors.New(INPUT_TYPE_ERROR + "shoulbe be Struct")
	}
	eletype := reflect.ValueOf(v).Elem().Type().Elem()
	obj := reflect.ValueOf(v).Elem()
	objAdd := make([]reflect.Value, 0)

	if nil != p {
		if limit == 0 {
			res, err := p.cli.Search().Index(index).Query(query).Highlight(hightlight).Do(context.TODO())
			if err != nil {
				print(err)
				return nil, err
			}
			id := []string{}
			for _, vs := range res.Hits.Hits {
				id = append(id, vs.Id)
				data, e := vs.Source.MarshalJSON()
				if nil != e {
					log.Print(e.Error())
				}
				mapobj := map[string]interface{}{}
				mapobj["highlight"] = vs.Highlight["content"]
				e = json.Unmarshal(data, &mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				obj, e := utils.UnmarshalJson2StructGen(eletype, mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				objAdd = append(objAdd, reflect.ValueOf(obj))
			}
			return id, nil
		} else {
			res, err := p.cli.Search(index).Query(query).Highlight(hightlight).Size(limit).From(limit * offset).Do(context.TODO())
			if err != nil {
				print(err)
				return nil, err
			}
			id := []string{}
			for _, vs := range res.Hits.Hits {
				id = append(id, vs.Id)
				data, e := vs.Source.MarshalJSON()
				// log.Print(string(data))
				if nil != e {
					log.Print(e.Error())
				}
				mapobj := map[string]interface{}{}
				e = json.Unmarshal(data, &mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				mapobj["content"] = ""
				mapobj["highlight"] = vs.Highlight["content"]
				obj, e := utils.UnmarshalJson2StructGen(eletype, mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				objAdd = append(objAdd, reflect.ValueOf(obj))
			}
			addOp := reflect.Append(obj, objAdd...)
			obj.Set(addOp)
			return id, nil
		}
	} else {
		return nil, errors.New(ERROR_PTR)
	}
}

func (p *ElkEngine) Query(index string, query elastic.Query, v interface{},
	limit int, offset int) ([]string, error) {

	if reflect.ValueOf(v).Kind() != reflect.Ptr {
		return nil, errors.New(INPUT_TYPE_ERROR + "shoulbe be Ptr")
	}
	if reflect.ValueOf(v).Elem().Kind() != reflect.Slice {
		return nil, errors.New(INPUT_TYPE_ERROR + "shoulbe be Slice")
	}
	if reflect.ValueOf(v).Elem().Type().Elem().Kind() != reflect.Struct {
		return nil, errors.New(INPUT_TYPE_ERROR + "shoulbe be Struct")
	}
	eletype := reflect.ValueOf(v).Elem().Type().Elem()
	obj := reflect.ValueOf(v).Elem()
	objAdd := make([]reflect.Value, 0)

	if nil != p {
		if limit == 0 {
			res, err := p.cli.Search(index).Query(query).Do(context.Background())
			if err != nil {
				print(err)
				return nil, err
			}

			id := []string{}
			for _, vs := range res.Hits.Hits {
				id = append(id, vs.Id)
				data, e := vs.Source.MarshalJSON()
				if nil != e {
					log.Print(e.Error())
				}
				mapobj := map[string]interface{}{}
				e = json.Unmarshal(data, &mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				obj, e := utils.UnmarshalJson2StructGen(eletype, mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				objAdd = append(objAdd, reflect.ValueOf(obj))
			}
			return id, nil
		} else {
			res, err := p.cli.Search(index).Query(query).Size(limit).From(limit * offset).Do(context.Background())
			if err != nil {
				print(err)
				return nil, err
			}
			id := []string{}
			for _, vs := range res.Hits.Hits {
				id = append(id, vs.Id)
				data, e := vs.Source.MarshalJSON()
				log.Print(string(data))
				if nil != e {
					log.Print(e.Error())
				}
				mapobj := map[string]interface{}{}
				e = json.Unmarshal(data, &mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				obj, e := utils.UnmarshalJson2StructGen(eletype, mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				objAdd = append(objAdd, reflect.ValueOf(obj))
			}
			addOp := reflect.Append(obj, objAdd...)
			obj.Set(addOp)
			return id, nil
		}
	} else {
		return nil, errors.New(ERROR_PTR)
	}
}

func (p *ElkEngine) QueryGen(index string, query elastic.Query, typ reflect.Type,
	limit int, offset int) ([]interface{}, []string, error) {
	rets := []interface{}{}
	if nil != p {
		if limit == 0 {
			res, err := p.cli.Search(index).Query(query).Do(context.Background())
			if err != nil {
				print(err)
				return nil, nil, err
			}

			id := []string{}
			for _, vs := range res.Hits.Hits {
				id = append(id, vs.Id)
			}
			return rets, id, nil
		} else {
			res, err := p.cli.Search(index).Query(query).Size(limit).From(limit * offset).Do(context.Background())
			if err != nil {
				print(err)
				return nil, nil, err
			}
			id := []string{}
			for _, vs := range res.Hits.Hits {
				id = append(id, vs.Id)
				data, e := vs.Source.MarshalJSON()
				if nil != e {
					log.Print(e.Error())
				}
				mapobj := map[string]interface{}{}
				e = json.Unmarshal(data, &mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				obj, e := utils.UnmarshalJson2StructGen(typ, mapobj)
				if nil != e {
					log.Print(e.Error())
				}
				rets = append(rets, obj)
			}
			return rets, id, nil
		}
	} else {
		return nil, nil, errors.New(ERROR_PTR)
	}
}

func (p *ElkEngine) Update(index string, types string, id string, data map[string]interface{}) error {
	if nil != p {
		_, err := p.cli.Update().
			Index(index).
			Id(id).
			Doc(data).
			Do(context.Background())
		if err != nil {
			println(err.Error())
			return err
		}
	}
	return errors.New(ERROR_PTR)
}

func (p *ElkEngine) CreateIndex(index string, typemaping string) error {
	if nil != p {
		exists, err := p.cli.IndexExists(index).Do(context.Background())
		if err != nil {
			// Handle error
			log.Print(err)
			return err
		}
		if exists {
			return errors.New(INDEX_EXISTED)
		}
		createIndex, err := p.cli.CreateIndex(index).Body(typemaping).Do(context.Background())
		if err != nil {
			log.Print(err)
			return err
		}
		if !createIndex.Acknowledged {
			return errors.New("create index error")
			// Not acknowledged
		}
		return nil
	}
	return errors.New(ERROR_PTR)
}

func (p *ElkEngine) IndexExisted(index string) (bool, error) {
	if nil != p {
		exists, err := p.cli.IndexExists(index).Do(context.Background())
		if exists {
			return true, nil
		}
		if err != nil {
			// Handle error
			log.Print(err)
			return false, err
		}
		return false, nil
	}
	return false, nil
}