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 NoOpOp
25 SetMetadataOp
26)
27
28// Operation define the interface to fulfill for an edit operation of a Bug
29type Operation interface {
30 // base return the OpBase of the Operation, for package internal use
31 base() *OpBase
32 // Hash return the hash of the operation, to be used for back references
33 Hash() (git.Hash, error)
34 // Time return the time when the operation was added
35 Time() time.Time
36 // GetUnixTime return the unix timestamp when the operation was added
37 GetUnixTime() int64
38 // GetFiles return the files needed by this operation
39 GetFiles() []git.Hash
40 // Apply the operation to a Snapshot to create the final state
41 Apply(snapshot *Snapshot)
42 // Validate check if the operation is valid (ex: a title is a single line)
43 Validate() error
44 // SetMetadata store arbitrary metadata about the operation
45 SetMetadata(key string, value string)
46 // GetMetadata retrieve arbitrary metadata about the operation
47 GetMetadata(key string) (string, bool)
48 // AllMetadata return all metadata for this operation
49 AllMetadata() map[string]string
50}
51
52func hashRaw(data []byte) git.Hash {
53 hasher := sha256.New()
54 // Write can't fail
55 _, _ = hasher.Write(data)
56 return git.Hash(fmt.Sprintf("%x", hasher.Sum(nil)))
57}
58
59// hash compute the hash of the serialized operation
60func hashOperation(op Operation) (git.Hash, error) {
61 base := op.base()
62
63 if base.hash != "" {
64 return base.hash, nil
65 }
66
67 data, err := json.Marshal(op)
68 if err != nil {
69 return "", err
70 }
71
72 base.hash = hashRaw(data)
73
74 return base.hash, nil
75}
76
77// OpBase implement the common code for all operations
78type OpBase struct {
79 OperationType OperationType `json:"type"`
80 Author Person `json:"author"`
81 UnixTime int64 `json:"timestamp"`
82 Metadata map[string]string `json:"metadata,omitempty"`
83 // Not serialized. Store the op's hash in memory.
84 hash git.Hash
85 // Not serialized. Store the extra metadata compiled from SetMetadataOperation
86 // in memory.
87 extraMetadata map[string]string
88}
89
90// newOpBase is the constructor for an OpBase
91func newOpBase(opType OperationType, author Person, unixTime int64) OpBase {
92 return OpBase{
93 OperationType: opType,
94 Author: author,
95 UnixTime: unixTime,
96 }
97}
98
99// Time return the time when the operation was added
100func (op *OpBase) Time() time.Time {
101 return time.Unix(op.UnixTime, 0)
102}
103
104// GetUnixTime return the unix timestamp when the operation was added
105func (op *OpBase) GetUnixTime() int64 {
106 return op.UnixTime
107}
108
109// GetFiles return the files needed by this operation
110func (op *OpBase) GetFiles() []git.Hash {
111 return nil
112}
113
114// Validate check the OpBase for errors
115func opBaseValidate(op Operation, opType OperationType) error {
116 if op.base().OperationType != opType {
117 return fmt.Errorf("incorrect operation type (expected: %v, actual: %v)", opType, op.base().OperationType)
118 }
119
120 if _, err := op.Hash(); err != nil {
121 return errors.Wrap(err, "op is not serializable")
122 }
123
124 if op.GetUnixTime() == 0 {
125 return fmt.Errorf("time not set")
126 }
127
128 if err := op.base().Author.Validate(); err != nil {
129 return errors.Wrap(err, "author")
130 }
131
132 for _, hash := range op.GetFiles() {
133 if !hash.IsValid() {
134 return fmt.Errorf("file with invalid hash %v", hash)
135 }
136 }
137
138 return nil
139}
140
141// SetMetadata store arbitrary metadata about the operation
142func (op *OpBase) SetMetadata(key string, value string) {
143 if op.Metadata == nil {
144 op.Metadata = make(map[string]string)
145 }
146
147 op.Metadata[key] = value
148 op.hash = ""
149}
150
151// GetMetadata retrieve arbitrary metadata about the operation
152func (op *OpBase) GetMetadata(key string) (string, bool) {
153 val, ok := op.Metadata[key]
154
155 if ok {
156 return val, true
157 }
158
159 // extraMetadata can't replace the original operations value if any
160 val, ok = op.extraMetadata[key]
161
162 return val, ok
163}
164
165// AllMetadata return all metadata for this operation
166func (op *OpBase) AllMetadata() map[string]string {
167 result := make(map[string]string)
168
169 for key, val := range op.extraMetadata {
170 result[key] = val
171 }
172
173 // Original metadata take precedence
174 for key, val := range op.Metadata {
175 result[key] = val
176 }
177
178 return result
179}