iterator.go

  1package github
  2
  3import (
  4	"context"
  5	"time"
  6
  7	"github.com/shurcooL/githubv4"
  8)
  9
 10type indexer struct{ index int }
 11
 12type issueEditIterator struct {
 13	index     int
 14	query     issueEditQuery
 15	variables map[string]interface{}
 16}
 17
 18type commentEditIterator struct {
 19	index     int
 20	query     commentEditQuery
 21	variables map[string]interface{}
 22}
 23
 24type timelineIterator struct {
 25	index     int
 26	query     issueTimelineQuery
 27	variables map[string]interface{}
 28
 29	issueEdit   indexer
 30	commentEdit indexer
 31
 32	// lastEndCursor cache the timeline end cursor for one iteration
 33	lastEndCursor githubv4.String
 34}
 35
 36type iterator struct {
 37	// github graphql client
 38	gc *githubv4.Client
 39
 40	// if since is given the iterator will query only the updated
 41	// and created issues after this date
 42	since time.Time
 43
 44	// number of timelines/userEditcontent/issueEdit to query
 45	// at a time, more capacity = more used memory = less queries
 46	// to make
 47	capacity int
 48
 49	// sticky error
 50	err error
 51
 52	// timeline iterator
 53	timeline timelineIterator
 54
 55	// issue edit iterator
 56	issueEdit issueEditIterator
 57
 58	// comment edit iterator
 59	commentEdit commentEditIterator
 60}
 61
 62// NewIterator create and initalize a new iterator
 63func NewIterator(owner, project, token string, since time.Time) *iterator {
 64	i := &iterator{
 65		gc:       buildClient(token),
 66		since:    since,
 67		capacity: 10,
 68		timeline: timelineIterator{
 69			index:       -1,
 70			issueEdit:   indexer{-1},
 71			commentEdit: indexer{-1},
 72			variables: map[string]interface{}{
 73				keyOwner: githubv4.String(owner),
 74				"name":   githubv4.String(project),
 75			},
 76		},
 77		commentEdit: commentEditIterator{
 78			index: -1,
 79			variables: map[string]interface{}{
 80				keyOwner: githubv4.String(owner),
 81				"name":   githubv4.String(project),
 82			},
 83		},
 84		issueEdit: issueEditIterator{
 85			index: -1,
 86			variables: map[string]interface{}{
 87				keyOwner: githubv4.String(owner),
 88				"name":   githubv4.String(project),
 89			},
 90		},
 91	}
 92
 93	i.initTimelineQueryVariables()
 94	return i
 95}
 96
 97// init issue timeline variables
 98func (i *iterator) initTimelineQueryVariables() {
 99	i.timeline.variables["issueFirst"] = githubv4.Int(1)
100	i.timeline.variables["issueAfter"] = (*githubv4.String)(nil)
101	i.timeline.variables["issueSince"] = githubv4.DateTime{Time: i.since}
102	i.timeline.variables["timelineFirst"] = githubv4.Int(i.capacity)
103	i.timeline.variables["timelineAfter"] = (*githubv4.String)(nil)
104	// Fun fact, github provide the comment edition in reverse chronological
105	// order, because haha. Look at me, I'm dying of laughter.
106	i.timeline.variables["issueEditLast"] = githubv4.Int(i.capacity)
107	i.timeline.variables["issueEditBefore"] = (*githubv4.String)(nil)
108	i.timeline.variables["commentEditLast"] = githubv4.Int(i.capacity)
109	i.timeline.variables["commentEditBefore"] = (*githubv4.String)(nil)
110}
111
112// init issue edit variables
113func (i *iterator) initIssueEditQueryVariables() {
114	i.issueEdit.variables["issueFirst"] = githubv4.Int(1)
115	i.issueEdit.variables["issueAfter"] = i.timeline.variables["issueAfter"]
116	i.issueEdit.variables["issueSince"] = githubv4.DateTime{Time: i.since}
117	i.issueEdit.variables["issueEditLast"] = githubv4.Int(i.capacity)
118	i.issueEdit.variables["issueEditBefore"] = (*githubv4.String)(nil)
119}
120
121// init issue comment variables
122func (i *iterator) initCommentEditQueryVariables() {
123	i.commentEdit.variables["issueFirst"] = githubv4.Int(1)
124	i.commentEdit.variables["issueAfter"] = i.timeline.variables["issueAfter"]
125	i.commentEdit.variables["issueSince"] = githubv4.DateTime{Time: i.since}
126	i.commentEdit.variables["timelineFirst"] = githubv4.Int(1)
127	i.commentEdit.variables["timelineAfter"] = (*githubv4.String)(nil)
128	i.commentEdit.variables["commentEditLast"] = githubv4.Int(i.capacity)
129	i.commentEdit.variables["commentEditBefore"] = (*githubv4.String)(nil)
130}
131
132// reverse UserContentEdits arrays in both of the issue and
133// comment timelines
134func (i *iterator) reverseTimelineEditNodes() {
135	node := i.timeline.query.Repository.Issues.Nodes[0]
136	reverseEdits(node.UserContentEdits.Nodes)
137	for index, ce := range node.Timeline.Edges {
138		if ce.Node.Typename == "IssueComment" && len(node.Timeline.Edges) != 0 {
139			reverseEdits(node.Timeline.Edges[index].Node.IssueComment.UserContentEdits.Nodes)
140		}
141	}
142}
143
144// Error return last encountered error
145func (i *iterator) Error() error {
146	return i.err
147}
148
149func (i *iterator) queryIssue() bool {
150	if err := i.gc.Query(context.TODO(), &i.timeline.query, i.timeline.variables); err != nil {
151		i.err = err
152		return false
153	}
154
155	if len(i.timeline.query.Repository.Issues.Nodes) == 0 {
156		return false
157	}
158
159	i.reverseTimelineEditNodes()
160	return true
161}
162
163// NextIssue try to query the next issue and return true. Only one issue is
164// queried at each call.
165func (i *iterator) NextIssue() bool {
166	// if $issueAfter variable is nil we can directly make the first query
167	if i.timeline.variables["issueAfter"] == (*githubv4.String)(nil) {
168		nextIssue := i.queryIssue()
169		// prevent from infinite loop by setting a non nil cursor
170		i.timeline.variables["issueAfter"] = i.timeline.query.Repository.Issues.PageInfo.EndCursor
171		return nextIssue
172	}
173
174	if i.err != nil {
175		return false
176	}
177
178	if !i.timeline.query.Repository.Issues.PageInfo.HasNextPage {
179		return false
180	}
181
182	// if we have more issues, query them
183	i.timeline.variables["timelineAfter"] = (*githubv4.String)(nil)
184	i.timeline.variables["issueAfter"] = i.timeline.query.Repository.Issues.PageInfo.EndCursor
185	i.timeline.index = -1
186
187	// store cursor for future use
188	i.timeline.lastEndCursor = i.timeline.query.Repository.Issues.Nodes[0].Timeline.PageInfo.EndCursor
189
190	// query issue block
191	return i.queryIssue()
192}
193
194// IssueValue return the actual issue value
195func (i *iterator) IssueValue() issueTimeline {
196	return i.timeline.query.Repository.Issues.Nodes[0]
197}
198
199// NextTimelineItem return true if there is a next timeline item and increments the index by one.
200// It is used iterates over all the timeline items. Extra queries are made if it is necessary.
201func (i *iterator) NextTimelineItem() bool {
202	if i.err != nil {
203		return false
204	}
205
206	if len(i.timeline.query.Repository.Issues.Nodes[0].Timeline.Edges) == 0 {
207		return false
208	}
209
210	if i.timeline.index < min(i.capacity, len(i.timeline.query.Repository.Issues.Nodes[0].Timeline.Edges))-1 {
211		i.timeline.index++
212		return true
213	}
214
215	if !i.timeline.query.Repository.Issues.Nodes[0].Timeline.PageInfo.HasNextPage {
216		return false
217	}
218
219	i.timeline.lastEndCursor = i.timeline.query.Repository.Issues.Nodes[0].Timeline.PageInfo.EndCursor
220
221	// more timelines, query them
222	i.timeline.variables["timelineAfter"] = i.timeline.query.Repository.Issues.Nodes[0].Timeline.PageInfo.EndCursor
223	if err := i.gc.Query(context.TODO(), &i.timeline.query, i.timeline.variables); err != nil {
224		i.err = err
225		return false
226	}
227
228	i.reverseTimelineEditNodes()
229	i.timeline.index = 0
230	return true
231}
232
233// TimelineItemValue return the actual timeline item value
234func (i *iterator) TimelineItemValue() timelineItem {
235	return i.timeline.query.Repository.Issues.Nodes[0].Timeline.Edges[i.timeline.index].Node
236}
237
238func (i *iterator) queryIssueEdit() bool {
239	if err := i.gc.Query(context.TODO(), &i.issueEdit.query, i.issueEdit.variables); err != nil {
240		i.err = err
241		//i.timeline.issueEdit.index = -1
242		return false
243	}
244
245	// reverse issue edits because github
246	reverseEdits(i.issueEdit.query.Repository.Issues.Nodes[0].UserContentEdits.Nodes)
247
248	// this is not supposed to happen
249	if len(i.issueEdit.query.Repository.Issues.Nodes[0].UserContentEdits.Nodes) == 0 {
250		i.timeline.issueEdit.index = -1
251		return false
252	}
253
254	i.issueEdit.index = 0
255	i.timeline.issueEdit.index = -2
256	return i.nextValidIssueEdit()
257}
258
259func (i *iterator) nextValidIssueEdit() bool {
260	// issueEdit.Diff == nil happen if the event is older than early 2018, Github doesn't have the data before that.
261	// Best we can do is to ignore the event.
262	if issueEdit := i.IssueEditValue(); issueEdit.Diff == nil || string(*issueEdit.Diff) == "" {
263		return i.NextIssueEdit()
264	}
265	return true
266}
267
268// NextIssueEdit return true if there is a next issue edit and increments the index by one.
269// It is used iterates over all the issue edits. Extra queries are made if it is necessary.
270func (i *iterator) NextIssueEdit() bool {
271	if i.err != nil {
272		return false
273	}
274
275	// this mean we looped over all available issue edits in the timeline.
276	// now we have to use i.issueEditQuery
277	if i.timeline.issueEdit.index == -2 {
278		if i.issueEdit.index < min(i.capacity, len(i.issueEdit.query.Repository.Issues.Nodes[0].UserContentEdits.Nodes))-1 {
279			i.issueEdit.index++
280			return i.nextValidIssueEdit()
281		}
282
283		if !i.issueEdit.query.Repository.Issues.Nodes[0].UserContentEdits.PageInfo.HasPreviousPage {
284			i.timeline.issueEdit.index = -1
285			i.issueEdit.index = -1
286			return false
287		}
288
289		// if there is more edits, query them
290		i.issueEdit.variables["issueEditBefore"] = i.issueEdit.query.Repository.Issues.Nodes[0].UserContentEdits.PageInfo.StartCursor
291		return i.queryIssueEdit()
292	}
293
294	// if there is no edit, the UserContentEdits given by github is empty. That
295	// means that the original message is given by the issue message.
296	//
297	// if there is edits, the UserContentEdits given by github contains both the
298	// original message and the following edits. The issue message give the last
299	// version so we don't care about that.
300	//
301	// the tricky part: for an issue older than the UserContentEdits API, github
302	// doesn't have the previous message version anymore and give an edition
303	// with .Diff == nil. We have to filter them.
304	if len(i.timeline.query.Repository.Issues.Nodes[0].UserContentEdits.Nodes) == 0 {
305		return false
306	}
307
308	// loop over them timeline comment edits
309	if i.timeline.issueEdit.index < min(i.capacity, len(i.timeline.query.Repository.Issues.Nodes[0].UserContentEdits.Nodes))-1 {
310		i.timeline.issueEdit.index++
311		return i.nextValidIssueEdit()
312	}
313
314	if !i.timeline.query.Repository.Issues.Nodes[0].UserContentEdits.PageInfo.HasPreviousPage {
315		i.timeline.issueEdit.index = -1
316		return false
317	}
318
319	// if there is more edits, query them
320	i.initIssueEditQueryVariables()
321	i.issueEdit.variables["issueEditBefore"] = i.timeline.query.Repository.Issues.Nodes[0].UserContentEdits.PageInfo.StartCursor
322	return i.queryIssueEdit()
323}
324
325// IssueEditValue return the actual issue edit value
326func (i *iterator) IssueEditValue() userContentEdit {
327	// if we are using issue edit query
328	if i.timeline.issueEdit.index == -2 {
329		return i.issueEdit.query.Repository.Issues.Nodes[0].UserContentEdits.Nodes[i.issueEdit.index]
330	}
331
332	// else get it from timeline issue edit query
333	return i.timeline.query.Repository.Issues.Nodes[0].UserContentEdits.Nodes[i.timeline.issueEdit.index]
334}
335
336func (i *iterator) queryCommentEdit() bool {
337	if err := i.gc.Query(context.TODO(), &i.commentEdit.query, i.commentEdit.variables); err != nil {
338		i.err = err
339		return false
340	}
341
342	// this is not supposed to happen
343	if len(i.commentEdit.query.Repository.Issues.Nodes[0].Timeline.Nodes[0].IssueComment.UserContentEdits.Nodes) == 0 {
344		i.timeline.commentEdit.index = -1
345		return false
346	}
347
348	reverseEdits(i.commentEdit.query.Repository.Issues.Nodes[0].Timeline.Nodes[0].IssueComment.UserContentEdits.Nodes)
349
350	i.commentEdit.index = 0
351	i.timeline.commentEdit.index = -2
352	return i.nextValidCommentEdit()
353}
354
355func (i *iterator) nextValidCommentEdit() bool {
356	// if comment edit diff is a nil pointer or points to an empty string look for next value
357	if commentEdit := i.CommentEditValue(); commentEdit.Diff == nil || string(*commentEdit.Diff) == "" {
358		return i.NextCommentEdit()
359	}
360	return true
361}
362
363// NextCommentEdit return true if there is a next comment edit and increments the index by one.
364// It is used iterates over all the comment edits. Extra queries are made if it is necessary.
365func (i *iterator) NextCommentEdit() bool {
366	if i.err != nil {
367		return false
368	}
369
370	// same as NextIssueEdit
371	if i.timeline.commentEdit.index == -2 {
372
373		if i.commentEdit.index < min(i.capacity, len(i.commentEdit.query.Repository.Issues.Nodes[0].Timeline.Nodes[0].IssueComment.UserContentEdits.Nodes))-1 {
374			i.commentEdit.index++
375			return i.nextValidCommentEdit()
376		}
377
378		if !i.commentEdit.query.Repository.Issues.Nodes[0].Timeline.Nodes[0].IssueComment.UserContentEdits.PageInfo.HasPreviousPage {
379			i.timeline.commentEdit.index = -1
380			i.commentEdit.index = -1
381			return false
382		}
383
384		// if there is more comment edits, query them
385		i.commentEdit.variables["commentEditBefore"] = i.commentEdit.query.Repository.Issues.Nodes[0].Timeline.Nodes[0].IssueComment.UserContentEdits.PageInfo.StartCursor
386		return i.queryCommentEdit()
387	}
388
389	// if there is no comment edits
390	if len(i.timeline.query.Repository.Issues.Nodes[0].Timeline.Edges[i.timeline.index].Node.IssueComment.UserContentEdits.Nodes) == 0 {
391		return false
392	}
393
394	// loop over them timeline comment edits
395	if i.timeline.commentEdit.index < min(i.capacity, len(i.timeline.query.Repository.Issues.Nodes[0].Timeline.Edges[i.timeline.index].Node.IssueComment.UserContentEdits.Nodes))-1 {
396		i.timeline.commentEdit.index++
397		return i.nextValidCommentEdit()
398	}
399
400	if !i.timeline.query.Repository.Issues.Nodes[0].Timeline.Edges[i.timeline.index].Node.IssueComment.UserContentEdits.PageInfo.HasPreviousPage {
401		i.timeline.commentEdit.index = -1
402		return false
403	}
404
405	i.initCommentEditQueryVariables()
406	if i.timeline.index == 0 {
407		i.commentEdit.variables["timelineAfter"] = i.timeline.lastEndCursor
408	} else {
409		i.commentEdit.variables["timelineAfter"] = i.timeline.query.Repository.Issues.Nodes[0].Timeline.Edges[i.timeline.index-1].Cursor
410	}
411
412	i.commentEdit.variables["commentEditBefore"] = i.timeline.query.Repository.Issues.Nodes[0].Timeline.Edges[i.timeline.index].Node.IssueComment.UserContentEdits.PageInfo.StartCursor
413
414	return i.queryCommentEdit()
415}
416
417// CommentEditValue return the actual comment edit value
418func (i *iterator) CommentEditValue() userContentEdit {
419	if i.timeline.commentEdit.index == -2 {
420		return i.commentEdit.query.Repository.Issues.Nodes[0].Timeline.Nodes[0].IssueComment.UserContentEdits.Nodes[i.commentEdit.index]
421	}
422
423	return i.timeline.query.Repository.Issues.Nodes[0].Timeline.Edges[i.timeline.index].Node.IssueComment.UserContentEdits.Nodes[i.timeline.commentEdit.index]
424}
425
426func min(a, b int) int {
427	if a > b {
428		return b
429	}
430
431	return a
432}
433
434func reverseEdits(edits []userContentEdit) {
435	for i, j := 0, len(edits)-1; i < j; i, j = i+1, j-1 {
436		edits[i], edits[j] = edits[j], edits[i]
437	}
438}