1package bug
2
3import (
4 "crypto/sha256"
5 "encoding/json"
6 "fmt"
7 "time"
8
9 "github.com/MichaelMure/git-bug/identity"
10
11 "github.com/MichaelMure/git-bug/util/git"
12 "github.com/pkg/errors"
13)
14
15// OperationType is an operation type identifier
16type OperationType int
17
18const (
19 _ OperationType = iota
20 CreateOp
21 SetTitleOp
22 AddCommentOp
23 SetStatusOp
24 LabelChangeOp
25 EditCommentOp
26 NoOpOp
27 SetMetadataOp
28)
29
30// Operation define the interface to fulfill for an edit operation of a Bug
31type Operation interface {
32 // base return the OpBase of the Operation, for package internal use
33 base() *OpBase
34 // Hash return the hash of the operation, to be used for back references
35 Hash() (git.Hash, error)
36 // Time return the time when the operation was added
37 Time() time.Time
38 // GetUnixTime return the unix timestamp when the operation was added
39 GetUnixTime() int64
40 // GetFiles return the files needed by this operation
41 GetFiles() []git.Hash
42 // Apply the operation to a Snapshot to create the final state
43 Apply(snapshot *Snapshot)
44 // Validate check if the operation is valid (ex: a title is a single line)
45 Validate() error
46 // SetMetadata store arbitrary metadata about the operation
47 SetMetadata(key string, value string)
48 // GetMetadata retrieve arbitrary metadata about the operation
49 GetMetadata(key string) (string, bool)
50 // AllMetadata return all metadata for this operation
51 AllMetadata() map[string]string
52}
53
54func hashRaw(data []byte) git.Hash {
55 hasher := sha256.New()
56 // Write can't fail
57 _, _ = hasher.Write(data)
58 return git.Hash(fmt.Sprintf("%x", hasher.Sum(nil)))
59}
60
61// hash compute the hash of the serialized operation
62func hashOperation(op Operation) (git.Hash, error) {
63 base := op.base()
64
65 if base.hash != "" {
66 return base.hash, nil
67 }
68
69 data, err := json.Marshal(op)
70 if err != nil {
71 return "", err
72 }
73
74 base.hash = hashRaw(data)
75
76 return base.hash, nil
77}
78
79// TODO: serialization with identity
80
81// OpBase implement the common code for all operations
82type OpBase struct {
83 OperationType OperationType
84 Author identity.Interface
85 UnixTime int64
86 Metadata map[string]string
87 // Not serialized. Store the op's hash in memory.
88 hash git.Hash
89 // Not serialized. Store the extra metadata in memory,
90 // compiled from SetMetadataOperation.
91 extraMetadata map[string]string
92}
93
94// newOpBase is the constructor for an OpBase
95func newOpBase(opType OperationType, author identity.Interface, unixTime int64) OpBase {
96 return OpBase{
97 OperationType: opType,
98 Author: author,
99 UnixTime: unixTime,
100 }
101}
102
103type opBaseJson struct {
104 OperationType OperationType `json:"type"`
105 UnixTime int64 `json:"timestamp"`
106 Metadata map[string]string `json:"metadata,omitempty"`
107}
108
109func (op *OpBase) MarshalJSON() ([]byte, error) {
110 return json.Marshal(opBaseJson{
111 OperationType: op.OperationType,
112 UnixTime: op.UnixTime,
113 Metadata: op.Metadata,
114 })
115}
116
117func (op *OpBase) UnmarshalJSON(data []byte) error {
118 aux := opBaseJson{}
119
120 if err := json.Unmarshal(data, &aux); err != nil {
121 return err
122 }
123
124 op.OperationType = aux.OperationType
125 op.UnixTime = aux.UnixTime
126 op.Metadata = aux.Metadata
127
128 return nil
129}
130
131// Time return the time when the operation was added
132func (op *OpBase) Time() time.Time {
133 return time.Unix(op.UnixTime, 0)
134}
135
136// GetUnixTime return the unix timestamp when the operation was added
137func (op *OpBase) GetUnixTime() int64 {
138 return op.UnixTime
139}
140
141// GetFiles return the files needed by this operation
142func (op *OpBase) GetFiles() []git.Hash {
143 return nil
144}
145
146// Validate check the OpBase for errors
147func opBaseValidate(op Operation, opType OperationType) error {
148 if op.base().OperationType != opType {
149 return fmt.Errorf("incorrect operation type (expected: %v, actual: %v)", opType, op.base().OperationType)
150 }
151
152 if _, err := op.Hash(); err != nil {
153 return errors.Wrap(err, "op is not serializable")
154 }
155
156 if op.GetUnixTime() == 0 {
157 return fmt.Errorf("time not set")
158 }
159
160 if op.base().Author == nil {
161 return fmt.Errorf("author not set")
162 }
163
164 if err := op.base().Author.Validate(); err != nil {
165 return errors.Wrap(err, "author")
166 }
167
168 for _, hash := range op.GetFiles() {
169 if !hash.IsValid() {
170 return fmt.Errorf("file with invalid hash %v", hash)
171 }
172 }
173
174 return nil
175}
176
177// SetMetadata store arbitrary metadata about the operation
178func (op *OpBase) SetMetadata(key string, value string) {
179 if op.Metadata == nil {
180 op.Metadata = make(map[string]string)
181 }
182
183 op.Metadata[key] = value
184 op.hash = ""
185}
186
187// GetMetadata retrieve arbitrary metadata about the operation
188func (op *OpBase) GetMetadata(key string) (string, bool) {
189 val, ok := op.Metadata[key]
190
191 if ok {
192 return val, true
193 }
194
195 // extraMetadata can't replace the original operations value if any
196 val, ok = op.extraMetadata[key]
197
198 return val, ok
199}
200
201// AllMetadata return all metadata for this operation
202func (op *OpBase) AllMetadata() map[string]string {
203 result := make(map[string]string)
204
205 for key, val := range op.extraMetadata {
206 result[key] = val
207 }
208
209 // Original metadata take precedence
210 for key, val := range op.Metadata {
211 result[key] = val
212 }
213
214 return result
215}