1package entity
 2
 3import (
 4	"fmt"
 5)
 6
 7// MergeStatus represent the result of a merge operation of an entity
 8type MergeStatus int
 9
10const (
11	_                  MergeStatus = iota
12	MergeStatusNew                 // a new Entity was created locally
13	MergeStatusInvalid             // the remote data is invalid
14	MergeStatusUpdated             // a local Entity has been updated
15	MergeStatusNothing             // no changes were made to a local Entity (already up to date)
16	MergeStatusError               // a terminal error happened
17)
18
19// MergeResult hold the result of a merge operation on an Entity.
20type MergeResult struct {
21	// Err is set when a terminal error occur in the process
22	Err error
23
24	Id     Id
25	Status MergeStatus
26
27	// Only set for invalid status
28	Reason string
29
30	// Not set for invalid status
31	Entity Interface
32}
33
34func (mr MergeResult) String() string {
35	switch mr.Status {
36	case MergeStatusNew:
37		return "new"
38	case MergeStatusInvalid:
39		return fmt.Sprintf("invalid data: %s", mr.Reason)
40	case MergeStatusUpdated:
41		return "updated"
42	case MergeStatusNothing:
43		return "nothing to do"
44	case MergeStatusError:
45		return fmt.Sprintf("merge error on %s: %s", mr.Id, mr.Err.Error())
46	default:
47		panic("unknown merge status")
48	}
49}
50
51func NewMergeError(err error, id Id) MergeResult {
52	return MergeResult{
53		Err:    err,
54		Id:     id,
55		Status: MergeStatusError,
56	}
57}
58
59// TODO: Interface --> *Entity ?
60func NewMergeStatus(status MergeStatus, id Id, entity Interface) MergeResult {
61	return MergeResult{
62		Id:     id,
63		Status: status,
64
65		// Entity is not set for an invalid merge result
66		Entity: entity,
67	}
68}
69
70func NewMergeInvalidStatus(id Id, reason string) MergeResult {
71	return MergeResult{
72		Id:     id,
73		Status: MergeStatusInvalid,
74		Reason: reason,
75	}
76}