query-orchestration/internal/jsonExtractor/service.go

package jsonextractor

import (
	"context"
	"encoding/json"
	"fmt"
	"queryorchestration/internal/database"
	"queryorchestration/internal/database/repository"
	queryprocessor "queryorchestration/internal/queryProcessor"
	"queryorchestration/internal/result"

	"github.com/tidwall/gjson"
)

type Extractor struct {
	db *database.Connection
}

type Config struct {
	Path string `json:"path"`
}

func NewExtractor(db *database.Connection) Extractor {
	return Extractor{db}
}

func (e Extractor) Process(ctx context.Context, query queryprocessor.Query, values *[]result.Value) (string, error) {
	if len(*values) != 1 {
		return "", fmt.Errorf("JSON Extraction requires 1 result")
	}

	value, err := (*values)[0].GetValue(ctx)
	if err != nil {
		return "", err
	}

	byteConfig, err := e.db.Queries.GetQueryConfig(ctx, repository.GetQueryConfigParams{
		Queryid:      database.MustToDBUUID(query.ID),
		Addedversion: query.Version,
	})
	if err != nil {
		return "", err
	}

	var config Config
	err = json.Unmarshal(byteConfig.Config, &config)
	if err != nil {
		return "", err
	}

	return e.extract(value, config.Path)
}

func (e *Extractor) extract(jsonString string, path string) (string, error) {
	value := gjson.Get(jsonString, path)

	if !value.Exists() {
		return "", fmt.Errorf("JSON path does not exist: %s", path)
	}

	return value.String(), nil
}