package bug
import (
"crypto/sha256"
"encoding/json"
"fmt"
"time"
"github.com/MichaelMure/git-bug/identity"
"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
NoOpOp
SetMetadataOp
)
const unsetIDMarker = "unset"
// 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
// ID return the identifier of the operation, to be used for back references
ID() string
// 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)
// AllMetadata return all metadata for this operation
AllMetadata() map[string]string
// GetAuthor return the author identity
GetAuthor() identity.Interface
}
func hashRaw(data []byte) string {
hasher := sha256.New()
// Write can't fail
_, _ = hasher.Write(data)
return fmt.Sprintf("%x", hasher.Sum(nil))
}
func idOperation(op Operation) string {
base := op.base()
if base.id == "" {
// something went really wrong
panic("op's id not set")
}
if base.id == "unset" {
// This means we are trying to get the op's ID *before* it has been stored, for instance when
// adding multiple ops in one go in an OperationPack.
// As the ID is computed based on the actual bytes written on the disk, we are going to predict
// those and then get the ID. This is safe as it will be the exact same code writing on disk later.
data, err := json.Marshal(op)
if err != nil {
panic(err)
}
base.id = hashRaw(data)
}
return base.id
}
func IDIsValid(id string) bool {
// IDs have the same format as a git hash
if len(id) != 40 && len(id) != 64 {
return false
}
for _, r := range id {
if (r < 'a' || r > 'z') && (r < '0' || r > '9') {
return false
}
}
return true
}
// OpBase implement the common code for all operations
type OpBase struct {
OperationType OperationType
Author identity.Interface
UnixTime int64
Metadata map[string]string
// Not serialized. Store the op's id in memory.
id string
// Not serialized. Store the extra metadata in memory,
// compiled from SetMetadataOperation.
extraMetadata map[string]string
}
// newOpBase is the constructor for an OpBase
func newOpBase(opType OperationType, author identity.Interface, unixTime int64) OpBase {
return OpBase{
OperationType: opType,
Author: author,
UnixTime: unixTime,
id: unsetIDMarker,
}
}
func (op OpBase) MarshalJSON() ([]byte, error) {
return json.Marshal(struct {
OperationType OperationType `json:"type"`
Author identity.Interface `json:"author"`
UnixTime int64 `json:"timestamp"`
Metadata map[string]string `json:"metadata,omitempty"`
}{
OperationType: op.OperationType,
Author: op.Author,
UnixTime: op.UnixTime,
Metadata: op.Metadata,
})
}
func (op *OpBase) UnmarshalJSON(data []byte) error {
// Compute the ID when loading the op from disk.
op.id = hashRaw(data)
aux := struct {
OperationType OperationType `json:"type"`
Author json.RawMessage `json:"author"`
UnixTime int64 `json:"timestamp"`
Metadata map[string]string `json:"metadata,omitempty"`
}{}
if err := json.Unmarshal(data, &aux); err != nil {
return err
}
// delegate the decoding of the identity
author, err := identity.UnmarshalJSON(aux.Author)
if err != nil {
return err
}
op.OperationType = aux.OperationType
op.Author = author
op.UnixTime = aux.UnixTime
op.Metadata = aux.Metadata
return nil
}
// 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 op.GetUnixTime() == 0 {
return fmt.Errorf("time not set")
}
if op.base().Author == nil {
return fmt.Errorf("author 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
op.id = unsetIDMarker
}
// GetMetadata retrieve arbitrary metadata about the operation
func (op *OpBase) GetMetadata(key string) (string, bool) {
val, ok := op.Metadata[key]
if ok {
return val, true
}
// extraMetadata can't replace the original operations value if any
val, ok = op.extraMetadata[key]
return val, ok
}
// AllMetadata return all metadata for this operation
func (op *OpBase) AllMetadata() map[string]string {
result := make(map[string]string)
for key, val := range op.extraMetadata {
result[key] = val
}
// Original metadata take precedence
for key, val := range op.Metadata {
result[key] = val
}
return result
}
// GetAuthor return author identity
func (op *OpBase) GetAuthor() identity.Interface {
return op.Author
}
