backend/plugins/customize/tasks/customized_fields_extractor.go

/*
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements.  See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
the License.  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package tasks

import (
	"context"
	"fmt"
	"strings"

	"github.com/apache/devlake/core/dal"
	"github.com/apache/devlake/core/errors"
	"github.com/apache/devlake/core/models/common"
	"github.com/apache/devlake/core/models/domainlayer/ticket"
	"github.com/apache/devlake/core/plugin"
	"github.com/apache/devlake/plugins/customize/models"
	"github.com/tidwall/gjson"
)

var _ plugin.SubTaskEntryPoint = ExtractCustomizedFields

var ExtractCustomizedFieldsMeta = plugin.SubTaskMeta{Name: "extractCustomizedFields",
	EntryPoint:       ExtractCustomizedFields,
	EnabledByDefault: true,
	Description:      "extract customized fields",
}

// ExtractCustomizedFields extracts fields from raw data tables and assigns to domain layer tables
func ExtractCustomizedFields(taskCtx plugin.SubTaskContext) errors.Error {
	data := taskCtx.GetData().(*TaskData)
	if data == nil || data.Options == nil {
		return nil
	}
	d := taskCtx.GetDal()
	logger := taskCtx.GetLogger()
	for _, rule := range data.Options.TransformationRules {
		orphaned, err := extractCustomizedFields(taskCtx.GetContext(), d, rule.Table, rule.RawDataTable, rule.RawDataParams, rule.Mapping)
		if err != nil {
			return errors.Default.Wrap(err, "error extracting customized fields")
		}
		if orphaned > 0 {
			logger.Warn(nil,
				"skipped %d row(s) of table %s: the raw record referenced by _raw_data_id no longer exists in %s",
				orphaned, rule.Table, rule.RawDataTable)
		}
	}
	return nil
}

// extractCustomizedFields walks the domain layer table and copies configured JSON paths out of the
// raw record behind each row. It returns the number of rows skipped because no raw record backed
// them, so the caller can report that rather than leaving it invisible.
func extractCustomizedFields(ctx context.Context, d dal.Dal, table, rawTable, rawDataParams string, extractor map[string]string) (int, error) {
	pkFields, err := dal.GetPrimarykeyColumns(d, &models.Table{Name: table})
	if err != nil {
		return 0, err
	}
	rawDataField := fmt.Sprintf("%s.data", rawTable)
	// `fields` only include `_raw_data_id` and primary keys coming from the domain layer table, and `data` coming from the raw layer
	fields := []string{fmt.Sprintf("%s.%s", table, "_raw_data_id")}
	fields = append(fields, rawDataField)
	for _, field := range pkFields {
		fields = append(fields, fmt.Sprintf("%s.%s", table, field.Name()))
	}
	clauses := []dal.Clause{
		dal.Select(strings.Join(fields, ", ")),
		dal.From(table),
		dal.Join(fmt.Sprintf(" LEFT JOIN %s ON %s._raw_data_id = %s.id", rawTable, table, rawTable)),
		dal.Where("_raw_data_table = ? AND _raw_data_params LIKE ?", rawTable, rawDataParams),
	}
	rows, err := d.Cursor(clauses...)
	if err != nil {
		return 0, err
	}
	defer rows.Close()

	orphaned := 0
	for rows.Next() {
		select {
		case <-ctx.Done():
			return orphaned, ctx.Err()
		default:
		}
		row := make(map[string]interface{})
		updates := make(map[string]interface{})
		err = d.Fetch(rows, &row)
		if err != nil {
			return orphaned, err
		}
		switch blob := row["data"].(type) {
		case []byte:
			for field, path := range extractor {
				result := gjson.GetBytes(blob, path)
				fillInUpdates(result, field, updates)
			}
		case string:
			for field, path := range extractor {
				result := gjson.Get(blob, path)
				// special case for issues custom_fields
				rawDataId, ok := row["_raw_data_id"].(int64)
				if !ok {
					return orphaned, errors.Default.New("_raw_data_id is not int64")
				}
				if table == "issues" && result.IsArray() {
					issueId := row["id"].(string)
					fieldId := field
					// Delete existing records for the given issue and field
					err = d.Delete(
						&ticket.IssueCustomArrayField{},
						dal.Where("issue_id = ? AND field_id = ?", issueId, fieldId),
					)
					if err != nil {
						return orphaned, err
					}

					result.ForEach(func(_, v gjson.Result) bool {
						err1 := d.Create(&ticket.IssueCustomArrayField{
							IssueId:    issueId,
							FieldId:    fieldId,
							FieldValue: v.String(),
							NoPKModel: common.NoPKModel{
								RawDataOrigin: common.RawDataOrigin{
									RawDataParams: rawDataParams,
									RawDataTable:  rawTable,
									RawDataId:     uint64(rawDataId),
								},
							},
						})
						if err1 != nil {
							err = err1
							return false
						}
						return true
					})
				} else {
					fillInUpdates(result, field, updates)
				}
			}
		default:
			// The cursor LEFT JOINs the raw table, so a domain row whose _raw_data_id points at a
			// raw record that has since been deleted comes back with a NULL data column. There is
			// nothing to extract from it, but the rows after it are usually fine, so skip this one
			// instead of ending the scan.
			orphaned++
			continue
		}

		if len(updates) > 0 {
			// remove columns that are not primary key
			delete(row, "_raw_data_id")
			delete(row, "data")
			query, params, err := mkUpdate(table, updates, row)
			if err != nil {
				return orphaned, err
			}
			err = d.Exec(query, params...)
			if err != nil {
				return orphaned, errors.Default.Wrap(err, "Exec SQL error")
			}
		}
	}
	return orphaned, rows.Err()
}

// fillInUpdates fills in the updates map with the result of the gjson query
func fillInUpdates(result gjson.Result, field string, updates map[string]interface{}) {
	if result.Type == gjson.Null {
		updates[field] = nil
	} else {
		updates[field] = result.String()
	}
}

// mkUpdate generates SQL statement and parameters for updating a record
func mkUpdate(table string, updates map[string]interface{}, pk map[string]interface{}) (string, []interface{}, error) {
	if err := dal.ValidateTableName(table); err != nil {
		return "", nil, err
	}
	var params []interface{}
	stat := fmt.Sprintf("UPDATE %s SET ", table)
	var uu []string
	for field, value := range updates {
		if err := dal.ValidateColumnName(field); err != nil {
			return "", nil, err
		}
		uu = append(uu, fmt.Sprintf("%s = ?", field))
		params = append(params, value)
	}
	var ww []string
	for field, value := range pk {
		if err := dal.ValidateColumnName(field); err != nil {
			return "", nil, err
		}
		ww = append(ww, fmt.Sprintf("%s = ?", field))
		params = append(params, value)
	}
	return stat + strings.Join(uu, ", ") + " WHERE " + strings.Join(ww, " AND "), params, nil
}