type Config struct {
	//google cloud credential
	ClientEmail  string `json:"client_email,omitempty"`
	TokenURL     string `json:"token_uri,omitempty"`
	PrivateKey   string `json:"private_key,omitempty"`
	PrivateKeyID string `json:"private_key_id,omitempty"`
	ProjectID  string `json:"project_id,omitempty"`
}

package main

import (
    "github.com/viant/bgc"
    "github.com/viant/dsc"
    "time"
    "fmt"
    "log"
)


type MostLikedCity struct {
	City      string
	Visits    int
	Souvenirs []string
}

type  Traveler struct {
	Id            int
	Name          string
	LastVisitTime time.Time
	Achievements  []string
	MostLikedCity MostLikedCity
	VisitedCities []struct {
		City   string
		Visits int
	}
}


func main() {

    config, err := dsc.NewConfigWithParameters("bigquery", "",
    	    "bq", // google cloud secret placed in ~/.secret/bg.json
            map[string]string{
                "datasetId":"MyDataset",
            })

    if err != nil {
        log.Fatal(err)
    }

		
    factory := dsc.NewManagerFactory()
    manager, err := factory.Create(config)
    if err != nil {
        log.Fatalf("Failed to create manager %v", err)
    }
   

    traveler := Traveler{}
    success, err := manager.ReadSingle(&traveler, " SELECT id, name, lastVisitTime, visitedCities, achievements, mostLikedCity FROM travelers WHERE id = ?", []interface{}{4}, nil)
    if err != nil {
        panic(err.Error())
    }

    travelers :=  make([]Traveler, 0)
    err:= manager.ReadAll(&interest, "SELECT iid, name, lastVisitTime, visitedCities, achievements, mostLikedCity",nil, nil)
    if err != nil {
        panic(err.Error())
    }

   // ...

    inserted, updated, err := manager.PersistAll(&travelers, "travelers", nil)
    if err != nil {
           panic(err.Error())
    }
    // ...
    




   //Custom reading handler with reading query info type to get CacheHit, TotalRows, TotalBytesProcessed

   var resultInfo = &bgc.QueryResultInfo{}
   var perf = make(map[string]int)  
   	err = manager.ReadAllWithHandler(`SELECT DATE(date), COUNT(*) FROM performance_agg WHERE DATE(date) = ?  GROUP BY 1`, []interface{}{
   		"2018-05-03",
   		resultInfo,
   	}, func(scanner dsc.Scanner) (toContinue bool, err error) {
   	        var date string
   	        var count int
   	        err = scanner.Scan(&date, &count)
   	        if err != nil {
   	        	return false, err
   	        }
   	        perf[date] = count
   		return true, nil
   	})
   	log.Printf("cache: %v,  rows: %v, bytes: %v", resultInfo.CacheHit, resultInfo.TotalRows, resultInfo.TotalBytesProcessed)

   
    dialect := dsc.GetDatastoreDialect(config.DriverName)
    DDL, err := dialect.ShowCreateTable(manager, "performance_agg")
    fmt.Printf("%v %v\n", DDL, err)
   
}