aboutsummaryrefslogtreecommitdiffstats
path: root/bug/operation.go
blob: 91b77e56bf6342ea22cbb4cdd8c373c71e93f889 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
package bug

import (
	"crypto/sha256"
	"encoding/json"
	"fmt"
	"time"

	"github.com/MichaelMure/git-bug/util/git"
	"github.com/pkg/errors"
)

// OperationType is an operation type identifier
type OperationType int

const (
	_ OperationType = iota
	CreateOp
	SetTitleOp
	AddCommentOp
	SetStatusOp
	LabelChangeOp
	EditCommentOp
)

// Operation define the interface to fulfill for an edit operation of a Bug
type Operation interface {
	// base return the OpBase of the Operation, for package internal use
	base() *OpBase
	// Hash return the hash of the operation, to be used for back references
	Hash() (git.Hash, error)
	// Time return the time when the operation was added
	Time() time.Time
	// GetUnixTime return the unix timestamp when the operation was added
	GetUnixTime() int64
	// GetFiles return the files needed by this operation
	GetFiles() []git.Hash
	// Apply the operation to a Snapshot to create the final state
	Apply(snapshot *Snapshot)
	// Validate check if the operation is valid (ex: a title is a single line)
	Validate() error
	// SetMetadata store arbitrary metadata about the operation
	SetMetadata(key string, value string)
	// GetMetadata retrieve arbitrary metadata about the operation
	GetMetadata(key string) (string, bool)
}

func hashRaw(data []byte) git.Hash {
	hasher := sha256.New()
	// Write can't fail
	_, _ = hasher.Write(data)
	return git.Hash(fmt.Sprintf("%x", hasher.Sum(nil)))
}

// hash compute the hash of the serialized operation
func hashOperation(op Operation) (git.Hash, error) {
	base := op.base()

	if base.hash != "" {
		return base.hash, nil
	}

	data, err := json.Marshal(op)
	if err != nil {
		return "", err
	}

	base.hash = hashRaw(data)

	return base.hash, nil
}

// OpBase implement the common code for all operations
type OpBase struct {
	OperationType OperationType `json:"type"`
	Author        Person        `json:"author"`
	UnixTime      int64         `json:"timestamp"`
	hash          git.Hash
	Metadata      map[string]string `json:"metadata,omitempty"`
}

// newOpBase is the constructor for an OpBase
func newOpBase(opType OperationType, author Person, unixTime int64) *OpBase {
	return &OpBase{
		OperationType: opType,
		Author:        author,
		UnixTime:      unixTime,
	}
}

// Time return the time when the operation was added
func (op *OpBase) Time() time.Time {
	return time.Unix(op.UnixTime, 0)
}

// GetUnixTime return the unix timestamp when the operation was added
func (op *OpBase) GetUnixTime() int64 {
	return op.UnixTime
}

// GetFiles return the files needed by this operation
func (op *OpBase) GetFiles() []git.Hash {
	return nil
}

// Validate check the OpBase for errors
func opBaseValidate(op Operation, opType OperationType) error {
	if op.base().OperationType != opType {
		return fmt.Errorf("incorrect operation type (expected: %v, actual: %v)", opType, op.base().OperationType)
	}

	if _, err := op.Hash(); err != nil {
		return errors.Wrap(err, "op is not serializable")
	}

	if op.GetUnixTime() == 0 {
		return fmt.Errorf("time not set")
	}

	if err := op.base().Author.Validate(); err != nil {
		return errors.Wrap(err, "author")
	}

	for _, hash := range op.GetFiles() {
		if !hash.IsValid() {
			return fmt.Errorf("file with invalid hash %v", hash)
		}
	}

	return nil
}

// SetMetadata store arbitrary metadata about the operation
func (op *OpBase) SetMetadata(key string, value string) {
	if op.Metadata == nil {
		op.Metadata = make(map[string]string)
	}

	op.Metadata[key] = value
}

// GetMetadata retrieve arbitrary metadata about the operation
func (op *OpBase) GetMetadata(key string) (string, bool) {
	val, ok := op.Metadata[key]
	return val, ok
}