1package bug
2
3import (
4 "crypto/sha256"
5 "encoding/json"
6 "fmt"
7 "time"
8
9 "github.com/MichaelMure/git-bug/util/git"
10 "github.com/pkg/errors"
11)
12
13// OperationType is an operation type identifier
14type OperationType int
15
16const (
17 _ OperationType = iota
18 CreateOp
19 SetTitleOp
20 AddCommentOp
21 SetStatusOp
22 LabelChangeOp
23 EditCommentOp
24)
25
26// Operation define the interface to fulfill for an edit operation of a Bug
27type Operation interface {
28 // base return the OpBase of the Operation, for package internal use
29 base() *OpBase
30 // Hash return the hash of the operation, to be used for back references
31 Hash() (git.Hash, error)
32 // Time return the time when the operation was added
33 Time() time.Time
34 // GetUnixTime return the unix timestamp when the operation was added
35 GetUnixTime() int64
36 // GetFiles return the files needed by this operation
37 GetFiles() []git.Hash
38 // Apply the operation to a Snapshot to create the final state
39 Apply(snapshot *Snapshot)
40 // Validate check if the operation is valid (ex: a title is a single line)
41 Validate() error
42 // SetMetadata store arbitrary metadata about the operation
43 SetMetadata(key string, value string)
44 // GetMetadata retrieve arbitrary metadata about the operation
45 GetMetadata(key string) (string, bool)
46}
47
48func hashRaw(data []byte) git.Hash {
49 hasher := sha256.New()
50 hasher.Write(data)
51 return git.Hash(fmt.Sprintf("%x", hasher.Sum(nil)))
52}
53
54// hash compute the hash of the serialized operation
55func hashOperation(op Operation) (git.Hash, error) {
56 base := op.base()
57
58 if base.hash != "" {
59 return base.hash, nil
60 }
61
62 data, err := json.Marshal(op)
63 if err != nil {
64 return "", err
65 }
66
67 base.hash = hashRaw(data)
68
69 return base.hash, nil
70}
71
72// OpBase implement the common code for all operations
73type OpBase struct {
74 OperationType OperationType `json:"type"`
75 Author Person `json:"author"`
76 UnixTime int64 `json:"timestamp"`
77 hash git.Hash
78 Metadata map[string]string `json:"metadata,omitempty"`
79}
80
81// newOpBase is the constructor for an OpBase
82func newOpBase(opType OperationType, author Person, unixTime int64) *OpBase {
83 return &OpBase{
84 OperationType: opType,
85 Author: author,
86 UnixTime: unixTime,
87 }
88}
89
90// Time return the time when the operation was added
91func (op *OpBase) Time() time.Time {
92 return time.Unix(op.UnixTime, 0)
93}
94
95// GetUnixTime return the unix timestamp when the operation was added
96func (op *OpBase) GetUnixTime() int64 {
97 return op.UnixTime
98}
99
100// GetFiles return the files needed by this operation
101func (op *OpBase) GetFiles() []git.Hash {
102 return nil
103}
104
105// Validate check the OpBase for errors
106func opBaseValidate(op Operation, opType OperationType) error {
107 if op.base().OperationType != opType {
108 return fmt.Errorf("incorrect operation type (expected: %v, actual: %v)", opType, op.base().OperationType)
109 }
110
111 if _, err := op.Hash(); err != nil {
112 return errors.Wrap(err, "op is not serializable")
113 }
114
115 if op.GetUnixTime() == 0 {
116 return fmt.Errorf("time not set")
117 }
118
119 if err := op.base().Author.Validate(); err != nil {
120 return errors.Wrap(err, "author")
121 }
122
123 for _, hash := range op.GetFiles() {
124 if !hash.IsValid() {
125 return fmt.Errorf("file with invalid hash %v", hash)
126 }
127 }
128
129 return nil
130}
131
132// SetMetadata store arbitrary metadata about the operation
133func (op *OpBase) SetMetadata(key string, value string) {
134 if op.Metadata == nil {
135 op.Metadata = make(map[string]string)
136 }
137
138 op.Metadata[key] = value
139}
140
141// GetMetadata retrieve arbitrary metadata about the operation
142func (op *OpBase) GetMetadata(key string) (string, bool) {
143 val, ok := op.Metadata[key]
144 return val, ok
145}