1// Package identity contains the identity data model and low-level related functions
2package identity
3
4import (
5 "encoding/json"
6 "fmt"
7 "os"
8 "reflect"
9 "strings"
10 "time"
11
12 "github.com/pkg/errors"
13
14 "github.com/MichaelMure/git-bug/entity"
15 "github.com/MichaelMure/git-bug/repository"
16 "github.com/MichaelMure/git-bug/util/git"
17 "github.com/MichaelMure/git-bug/util/lamport"
18 "github.com/MichaelMure/git-bug/util/timestamp"
19)
20
21const identityRefPattern = "refs/identities/"
22const identityRemoteRefPattern = "refs/remotes/%s/identities/"
23const versionEntryName = "version"
24const identityConfigKey = "git-bug.identity"
25
26var ErrNonFastForwardMerge = errors.New("non fast-forward identity merge")
27var ErrNoIdentitySet = errors.New("No identity is set.\n" +
28 "To interact with bugs, an identity first needs to be created using " +
29 "\"git bug user create\"")
30var ErrMultipleIdentitiesSet = errors.New("multiple user identities set")
31
32var _ Interface = &Identity{}
33var _ entity.Interface = &Identity{}
34
35type Identity struct {
36 // Id used as unique identifier
37 id entity.Id
38
39 // all the successive version of the identity
40 versions []*Version
41
42 // not serialized
43 lastCommit git.Hash
44}
45
46func NewIdentity(name string, email string) *Identity {
47 return &Identity{
48 id: entity.UnsetId,
49 versions: []*Version{
50 {
51 name: name,
52 email: email,
53 nonce: makeNonce(20),
54 },
55 },
56 }
57}
58
59func NewIdentityFull(name string, email string, login string, avatarUrl string) *Identity {
60 return &Identity{
61 id: entity.UnsetId,
62 versions: []*Version{
63 {
64 name: name,
65 email: email,
66 login: login,
67 avatarURL: avatarUrl,
68 nonce: makeNonce(20),
69 },
70 },
71 }
72}
73
74// MarshalJSON will only serialize the id
75func (i *Identity) MarshalJSON() ([]byte, error) {
76 return json.Marshal(&IdentityStub{
77 id: i.id,
78 })
79}
80
81// UnmarshalJSON will only read the id
82// Users of this package are expected to run Load() to load
83// the remaining data from the identities data in git.
84func (i *Identity) UnmarshalJSON(data []byte) error {
85 panic("identity should be loaded with identity.UnmarshalJSON")
86}
87
88// ReadLocal load a local Identity from the identities data available in git
89func ReadLocal(repo repository.Repo, id entity.Id) (*Identity, error) {
90 ref := fmt.Sprintf("%s%s", identityRefPattern, id)
91 return read(repo, ref)
92}
93
94// ReadRemote load a remote Identity from the identities data available in git
95func ReadRemote(repo repository.Repo, remote string, id string) (*Identity, error) {
96 ref := fmt.Sprintf(identityRemoteRefPattern, remote) + id
97 return read(repo, ref)
98}
99
100// read will load and parse an identity from git
101func read(repo repository.Repo, ref string) (*Identity, error) {
102 refSplit := strings.Split(ref, "/")
103 id := entity.Id(refSplit[len(refSplit)-1])
104
105 if err := id.Validate(); err != nil {
106 return nil, errors.Wrap(err, "invalid ref")
107 }
108
109 hashes, err := repo.ListCommits(ref)
110
111 // TODO: this is not perfect, it might be a command invoke error
112 if err != nil {
113 return nil, ErrIdentityNotExist
114 }
115
116 i := &Identity{
117 id: id,
118 }
119
120 for _, hash := range hashes {
121 entries, err := repo.ListEntries(hash)
122 if err != nil {
123 return nil, errors.Wrap(err, "can't list git tree entries")
124 }
125
126 if len(entries) != 1 {
127 return nil, fmt.Errorf("invalid identity data at hash %s", hash)
128 }
129
130 entry := entries[0]
131
132 if entry.Name != versionEntryName {
133 return nil, fmt.Errorf("invalid identity data at hash %s", hash)
134 }
135
136 data, err := repo.ReadData(entry.Hash)
137 if err != nil {
138 return nil, errors.Wrap(err, "failed to read git blob data")
139 }
140
141 var version Version
142 err = json.Unmarshal(data, &version)
143
144 if err != nil {
145 return nil, errors.Wrapf(err, "failed to decode Identity version json %s", hash)
146 }
147
148 // tag the version with the commit hash
149 version.commitHash = hash
150 i.lastCommit = hash
151
152 i.versions = append(i.versions, &version)
153 }
154
155 return i, nil
156}
157
158type StreamedIdentity struct {
159 Identity *Identity
160 Err error
161}
162
163// ReadAllLocalIdentities read and parse all local Identity
164func ReadAllLocalIdentities(repo repository.ClockedRepo) <-chan StreamedIdentity {
165 return readAllIdentities(repo, identityRefPattern)
166}
167
168// ReadAllRemoteIdentities read and parse all remote Identity for a given remote
169func ReadAllRemoteIdentities(repo repository.ClockedRepo, remote string) <-chan StreamedIdentity {
170 refPrefix := fmt.Sprintf(identityRemoteRefPattern, remote)
171 return readAllIdentities(repo, refPrefix)
172}
173
174// Read and parse all available bug with a given ref prefix
175func readAllIdentities(repo repository.ClockedRepo, refPrefix string) <-chan StreamedIdentity {
176 out := make(chan StreamedIdentity)
177
178 go func() {
179 defer close(out)
180
181 refs, err := repo.ListRefs(refPrefix)
182 if err != nil {
183 out <- StreamedIdentity{Err: err}
184 return
185 }
186
187 for _, ref := range refs {
188 b, err := read(repo, ref)
189
190 if err != nil {
191 out <- StreamedIdentity{Err: err}
192 return
193 }
194
195 out <- StreamedIdentity{Identity: b}
196 }
197 }()
198
199 return out
200}
201
202// NewFromGitUser will query the repository for user detail and
203// build the corresponding Identity
204func NewFromGitUser(repo repository.Repo) (*Identity, error) {
205 name, err := repo.GetUserName()
206 if err != nil {
207 return nil, err
208 }
209 if name == "" {
210 return nil, errors.New("user name is not configured in git yet. Please use `git config --global user.name \"John Doe\"`")
211 }
212
213 email, err := repo.GetUserEmail()
214 if err != nil {
215 return nil, err
216 }
217 if email == "" {
218 return nil, errors.New("user name is not configured in git yet. Please use `git config --global user.email johndoe@example.com`")
219 }
220
221 return NewIdentity(name, email), nil
222}
223
224// SetUserIdentity store the user identity's id in the git config
225func SetUserIdentity(repo repository.RepoConfig, identity *Identity) error {
226 return repo.LocalConfig().StoreString(identityConfigKey, identity.Id().String())
227}
228
229// GetUserIdentity read the current user identity, set with a git config entry
230func GetUserIdentity(repo repository.Repo) (*Identity, error) {
231 configs, err := repo.LocalConfig().ReadAll(identityConfigKey)
232 if err != nil {
233 return nil, err
234 }
235
236 if len(configs) == 0 {
237 return nil, ErrNoIdentitySet
238 }
239
240 if len(configs) > 1 {
241 return nil, ErrMultipleIdentitiesSet
242 }
243
244 var id entity.Id
245 for _, val := range configs {
246 id = entity.Id(val)
247 }
248
249 if err := id.Validate(); err != nil {
250 return nil, err
251 }
252
253 i, err := ReadLocal(repo, id)
254 if err == ErrIdentityNotExist {
255 innerErr := repo.LocalConfig().RemoveAll(identityConfigKey)
256 if innerErr != nil {
257 _, _ = fmt.Fprintln(os.Stderr, errors.Wrap(innerErr, "can't clear user identity").Error())
258 }
259 return nil, err
260 }
261
262 return i, nil
263}
264
265// IsUserIdentitySet say if the user has set his identity
266func IsUserIdentitySet(repo repository.Repo) (bool, error) {
267 configs, err := repo.LocalConfig().ReadAll(identityConfigKey)
268 if err != nil {
269 return false, err
270 }
271
272 return len(configs) == 1, nil
273}
274
275// Mutate allow to create a new version of the Identity
276func (i *Identity) Mutate(f func(orig VersionMutator) VersionMutator) {
277 orig := VersionMutator{
278 Name: i.Name(),
279 Email: i.Email(),
280 Login: i.Login(),
281 AvatarUrl: i.AvatarUrl(),
282 Keys: i.Keys(),
283 }
284 mutated := f(orig)
285 if reflect.DeepEqual(orig, mutated) {
286 return
287 }
288 i.versions = append(i.versions, &Version{
289 name: mutated.Name,
290 email: mutated.Email,
291 login: mutated.Login,
292 avatarURL: mutated.AvatarUrl,
293 keys: mutated.Keys,
294 })
295}
296
297// Write the identity into the Repository. In particular, this ensure that
298// the Id is properly set.
299func (i *Identity) Commit(repo repository.ClockedRepo) error {
300 // Todo: check for mismatch between memory and commit data
301
302 if !i.NeedCommit() {
303 return fmt.Errorf("can't commit an identity with no pending version")
304 }
305
306 if err := i.Validate(); err != nil {
307 return errors.Wrap(err, "can't commit an identity with invalid data")
308 }
309
310 for _, v := range i.versions {
311 if v.commitHash != "" {
312 i.lastCommit = v.commitHash
313 // ignore already commit versions
314 continue
315 }
316
317 // get the times where new versions starts to be valid
318 v.time = repo.EditTime()
319 v.unixTime = time.Now().Unix()
320
321 blobHash, err := v.Write(repo)
322 if err != nil {
323 return err
324 }
325
326 // Make a git tree referencing the blob
327 tree := []repository.TreeEntry{
328 {ObjectType: repository.Blob, Hash: blobHash, Name: versionEntryName},
329 }
330
331 treeHash, err := repo.StoreTree(tree)
332 if err != nil {
333 return err
334 }
335
336 var commitHash git.Hash
337 if i.lastCommit != "" {
338 commitHash, err = repo.StoreCommitWithParent(treeHash, i.lastCommit)
339 } else {
340 commitHash, err = repo.StoreCommit(treeHash)
341 }
342
343 if err != nil {
344 return err
345 }
346
347 i.lastCommit = commitHash
348 v.commitHash = commitHash
349
350 // if it was the first commit, use the commit hash as the Identity id
351 if i.id == "" || i.id == entity.UnsetId {
352 i.id = entity.Id(commitHash)
353 }
354 }
355
356 if i.id == "" {
357 panic("identity with no id")
358 }
359
360 ref := fmt.Sprintf("%s%s", identityRefPattern, i.id)
361 err := repo.UpdateRef(ref, i.lastCommit)
362
363 if err != nil {
364 return err
365 }
366
367 return nil
368}
369
370func (i *Identity) CommitAsNeeded(repo repository.ClockedRepo) error {
371 if !i.NeedCommit() {
372 return nil
373 }
374 return i.Commit(repo)
375}
376
377func (i *Identity) NeedCommit() bool {
378 for _, v := range i.versions {
379 if v.commitHash == "" {
380 return true
381 }
382 }
383
384 return false
385}
386
387// Merge will merge a different version of the same Identity
388//
389// To make sure that an Identity history can't be altered, a strict fast-forward
390// only policy is applied here. As an Identity should be tied to a single user, this
391// should work in practice but it does leave a possibility that a user would edit his
392// Identity from two different repo concurrently and push the changes in a non-centralized
393// network of repositories. In this case, it would result in some of the repo accepting one
394// version and some other accepting another, preventing the network in general to converge
395// to the same result. This would create a sort of partition of the network, and manual
396// cleaning would be required.
397//
398// An alternative approach would be to have a determinist rebase:
399// - any commits present in both local and remote version would be kept, never changed.
400// - newer commits would be merged in a linear chain of commits, ordered based on the
401// Lamport time
402//
403// However, this approach leave the possibility, in the case of a compromised crypto keys,
404// of forging a new version with a bogus Lamport time to be inserted before a legit version,
405// invalidating the correct version and hijacking the Identity. There would only be a short
406// period of time where this would be possible (before the network converge) but I'm not
407// confident enough to implement that. I choose the strict fast-forward only approach,
408// despite it's potential problem with two different version as mentioned above.
409func (i *Identity) Merge(repo repository.Repo, other *Identity) (bool, error) {
410 if i.id != other.id {
411 return false, errors.New("merging unrelated identities is not supported")
412 }
413
414 if i.lastCommit == "" || other.lastCommit == "" {
415 return false, errors.New("can't merge identities that has never been stored")
416 }
417
418 modified := false
419 for j, otherVersion := range other.versions {
420 // if there is more version in other, take them
421 if len(i.versions) == j {
422 i.versions = append(i.versions, otherVersion)
423 i.lastCommit = otherVersion.commitHash
424 modified = true
425 }
426
427 // we have a non fast-forward merge.
428 // as explained in the doc above, refusing to merge
429 if i.versions[j].commitHash != otherVersion.commitHash {
430 return false, ErrNonFastForwardMerge
431 }
432 }
433
434 if modified {
435 err := repo.UpdateRef(identityRefPattern+i.id.String(), i.lastCommit)
436 if err != nil {
437 return false, err
438 }
439 }
440
441 return false, nil
442}
443
444// Validate check if the Identity data is valid
445func (i *Identity) Validate() error {
446 lastTime := lamport.Time(0)
447
448 if len(i.versions) == 0 {
449 return fmt.Errorf("no version")
450 }
451
452 for _, v := range i.versions {
453 if err := v.Validate(); err != nil {
454 return err
455 }
456
457 if v.commitHash != "" && v.time < lastTime {
458 return fmt.Errorf("non-chronological version (%d --> %d)", lastTime, v.time)
459 }
460
461 lastTime = v.time
462 }
463
464 // The identity Id should be the hash of the first commit
465 if i.versions[0].commitHash != "" && string(i.versions[0].commitHash) != i.id.String() {
466 return fmt.Errorf("identity id should be the first commit hash")
467 }
468
469 return nil
470}
471
472func (i *Identity) lastVersion() *Version {
473 if len(i.versions) <= 0 {
474 panic("no version at all")
475 }
476
477 return i.versions[len(i.versions)-1]
478}
479
480// Id return the Identity identifier
481func (i *Identity) Id() entity.Id {
482 if i.id == "" {
483 // simply panic as it would be a coding error
484 // (using an id of an identity not stored yet)
485 panic("no id yet")
486 }
487 return i.id
488}
489
490// Name return the last version of the name
491func (i *Identity) Name() string {
492 return i.lastVersion().name
493}
494
495// Email return the last version of the email
496func (i *Identity) Email() string {
497 return i.lastVersion().email
498}
499
500// Login return the last version of the login
501func (i *Identity) Login() string {
502 return i.lastVersion().login
503}
504
505// AvatarUrl return the last version of the Avatar URL
506func (i *Identity) AvatarUrl() string {
507 return i.lastVersion().avatarURL
508}
509
510// Keys return the last version of the valid keys
511func (i *Identity) Keys() []Key {
512 return i.lastVersion().keys
513}
514
515// ValidKeysAtTime return the set of keys valid at a given lamport time
516func (i *Identity) ValidKeysAtTime(time lamport.Time) []Key {
517 var result []Key
518
519 for _, v := range i.versions {
520 if v.time > time {
521 return result
522 }
523
524 result = v.keys
525 }
526
527 return result
528}
529
530// DisplayName return a non-empty string to display, representing the
531// identity, based on the non-empty values.
532func (i *Identity) DisplayName() string {
533 switch {
534 case i.Name() == "" && i.Login() != "":
535 return i.Login()
536 case i.Name() != "" && i.Login() == "":
537 return i.Name()
538 case i.Name() != "" && i.Login() != "":
539 return fmt.Sprintf("%s (%s)", i.Name(), i.Login())
540 }
541
542 panic("invalid person data")
543}
544
545// IsProtected return true if the chain of git commits started to be signed.
546// If that's the case, only signed commit with a valid key for this identity can be added.
547func (i *Identity) IsProtected() bool {
548 // Todo
549 return false
550}
551
552// LastModificationLamportTime return the Lamport time at which the last version of the identity became valid.
553func (i *Identity) LastModificationLamport() lamport.Time {
554 return i.lastVersion().time
555}
556
557// LastModification return the timestamp at which the last version of the identity became valid.
558func (i *Identity) LastModification() timestamp.Timestamp {
559 return timestamp.Timestamp(i.lastVersion().unixTime)
560}
561
562// SetMetadata store arbitrary metadata along the last defined Version.
563// If the Version has been commit to git already, it won't be overwritten.
564func (i *Identity) SetMetadata(key string, value string) {
565 i.lastVersion().SetMetadata(key, value)
566}
567
568// ImmutableMetadata return all metadata for this Identity, accumulated from each Version.
569// If multiple value are found, the first defined takes precedence.
570func (i *Identity) ImmutableMetadata() map[string]string {
571 metadata := make(map[string]string)
572
573 for _, version := range i.versions {
574 for key, value := range version.metadata {
575 if _, has := metadata[key]; !has {
576 metadata[key] = value
577 }
578 }
579 }
580
581 return metadata
582}
583
584// MutableMetadata return all metadata for this Identity, accumulated from each Version.
585// If multiple value are found, the last defined takes precedence.
586func (i *Identity) MutableMetadata() map[string]string {
587 metadata := make(map[string]string)
588
589 for _, version := range i.versions {
590 for key, value := range version.metadata {
591 metadata[key] = value
592 }
593 }
594
595 return metadata
596}