create.go

package event

import (
	"encoding/json"
	"strings"
	"time"

	cloudevents "github.com/cloudevents/sdk-go/v2"
	"github.com/wavesoftware/go-ensure"
)

// NewDefault creates a default CloudEvent.
func NewDefault() *cloudevents.Event {
	e := cloudevents.NewEvent()
	e.SetType(DefaultType)
	e.SetID(NewID())
	ensure.NoError(e.SetData(cloudevents.ApplicationJSON, map[string]string{}))
	e.SetSource(DefaultSource())
	e.SetTime(time.Now())
	ensure.NoError(e.Validate())
	return &e
}

// CreateFromSpec will create an event by parsing given args.
func CreateFromSpec(spec *Spec) (*cloudevents.Event, error) {
	e := NewDefault()
	e.SetID(spec.ID)
	e.SetSource(spec.Source)
	e.SetType(spec.Type)
	m := map[string]interface{}{}
	for _, fieldSpec := range spec.Fields {
		updateMapWithSpec(m, fieldSpec)
	}
	err := e.SetData(cloudevents.ApplicationJSON, m)
	if err != nil {
		return nil, err
	}
	return e, nil
}

func updateMapWithSpec(m map[string]interface{}, spec FieldSpec) {
	paths := strings.Split(spec.Path, ".")
	curr := m
	for i, p := range paths {
		if i < len(paths)-1 {
			if _, ok := curr[p]; !ok {
				curr[p] = map[string]interface{}{}
			}
			curr = curr[p].(map[string]interface{})
		} else {
			curr[p] = spec.Value
		}
	}
}

// UnmarshalData will take bytes and unmarshall it as JSON to map structure.
func UnmarshalData(bytes []byte) (map[string]interface{}, error) {
	m := map[string]interface{}{}
	err := json.Unmarshal(bytes, &m)
	if err != nil {
		return nil, err
	}
	return m, nil
}

// AddField will add a field to the spec.
func (s *Spec) AddField(path string, val interface{}) {
	s.Fields = append(s.Fields, FieldSpec{
		Path: path, Value: val,
	})
}