Add issue edit iterator

2 files changed, 97 insertions, 13 deletions

diff --git a/bridge/github/import_query.go b/bridge/github/import_query.go
index a791a88b..f159882e 100644
--- a/bridge/github/import_query.go
+++ b/bridge/github/import_query.go
@@ -124,7 +124,7 @@ type timelineItemsQuery struct {
 			TimelineItems struct {
 				Edges []struct {
 					Cursor githubv4.String
-					Node timelineItem
+					Node   timelineItem
 				}
 				PageInfo pageInfo
 			} `graphql:"timelineItems(first: $timelineFirst, after: $timelineAfter)"`
@@ -205,18 +205,31 @@ type loginQuery struct {
 }
 
 type issueQuery struct {
-        Repository struct {
-                Issues struct {
-                        Nodes    []issue
-                        PageInfo pageInfo
-                } `graphql:"issues(first: $issueFirst, after: $issueAfter, orderBy: {field: CREATED_AT, direction: ASC})"` //, filterBy: {since: $issueSince})"`
-        } `graphql:"repository(owner: $owner, name: $name)"`
+	Repository struct {
+		Issues struct {
+			Nodes    []issue
+			PageInfo pageInfo
+		} `graphql:"issues(first: $issueFirst, after: $issueAfter, orderBy: {field: CREATED_AT, direction: ASC})"` //, filterBy: {since: $issueSince})"`
+	} `graphql:"repository(owner: $owner, name: $name)"`
 }
 
 type issue struct {
-        authorEvent
-        Title  string
-        Number githubv4.Int
-        Body   githubv4.String
-        Url    githubv4.URI
+	authorEvent
+	Title  string
+	Number githubv4.Int
+	Body   githubv4.String
+	Url    githubv4.URI
+}
+
+type issueEditQuery_A struct {
+	Node struct {
+		Typename githubv4.String `graphql:"__typename"`
+		Issue    struct {
+			UserContentEdits struct {
+				Nodes      []userContentEdit
+				TotalCount githubv4.Int
+				PageInfo   pageInfo
+			} `graphql:"userContentEdits(last: $issueEditLast, before: $issueEditBefore)"`
+		} `graphql:"... on Issue"`
+	} `graphql:"node(id: $gqlNodeId)"`
 }
diff --git a/bridge/github/iterator.go b/bridge/github/iterator.go
index 1f84d86f..60964ee5 100644
--- a/bridge/github/iterator.go
+++ b/bridge/github/iterator.go
@@ -19,10 +19,15 @@ type iterator_A struct {
 type issueIter struct {
         iterVars
         query         issueQuery
-        // issueEditIter []issueEditIter
+        issueEditIter []issueEditIter
         // timelineIter  []timelineIter
 }
 
+type issueEditIter struct {
+        iterVars
+        query issueEditQuery_A
+}
+
 type iterVars struct {
         index     int
         capacity  int
@@ -62,6 +67,14 @@ func (i *iterator_A) currIssueItem() *issue {
         return &i.issueIter.query.Repository.Issues.Nodes[i.issueIter.index]
 }
 
+func (i *iterator_A) currIssueEditIter() *issueEditIter {
+        return &i.issueIter.issueEditIter[i.issueIter.index]
+}
+
+func (i *iterator_A) currIssueGqlNodeId() githubv4.ID {
+        return i.currIssueItem().Id
+}
+
 // Error return last encountered error
 func (i *iterator_A) Error() error {
         if i.err != nil {
@@ -118,6 +131,64 @@ func (i *iterator_A) queryIssue() bool {
         return true
 }
 
+func (i *iterator_A) NextIssueEdit() bool {
+        if i.HasError() {
+                return false
+        }
+        ieIter := i.currIssueEditIter()
+        ieIdx := &ieIter.index
+        ieItems := ieIter.query.Node.Issue.UserContentEdits
+        if 0 <= *ieIdx && *ieIdx < len(ieItems.Nodes)-1 {
+                *ieIdx += 1
+                return i.nextValidIssueEdit()
+        }
+        if !ieItems.PageInfo.HasNextPage {
+                return false
+        }
+        querySucc := i.queryIssueEdit()
+        if !querySucc {
+                return false
+        }
+        return i.nextValidIssueEdit()
+}
+
+func (i *iterator_A) nextValidIssueEdit() bool {
+        // issueEdit.Diff == nil happen if the event is older than early 2018, Github doesn't have the data before that.
+        // Best we can do is to ignore the event.
+        if issueEdit := i.IssueEditValue(); issueEdit.Diff == nil || string(*issueEdit.Diff) == "" {
+                return i.NextIssueEdit()
+        }
+        return true
+}
+
+func (i *iterator_A) IssueEditValue() userContentEdit {
+        iei := i.currIssueEditIter()
+        return iei.query.Node.Issue.UserContentEdits.Nodes[iei.index]
+}
+
+func (i *iterator_A) queryIssueEdit() bool {
+        ctx, cancel := context.WithTimeout(i.ctx, defaultTimeout)
+        defer cancel()
+        iei := i.currIssueEditIter()
+        if endCursor := iei.query.Node.Issue.UserContentEdits.PageInfo.EndCursor; endCursor != "" {
+                iei.variables["issueEditBefore"] = endCursor
+        }
+        iei.variables["gqlNodeId"] = i.currIssueGqlNodeId()
+        if err := i.gc.Query(ctx, &iei.query, iei.variables); err != nil {
+                i.err = err
+                return false
+        }
+        issueEditItems := iei.query.Node.Issue.UserContentEdits.Nodes
+        if len(issueEditItems) <= 0 {
+                iei.index = -1
+                return false
+        }
+        // The UserContentEditConnection in the Github API serves its elements in reverse chronological
+        // order. For our purpose we have to reverse the edits.
+        reverseEdits(issueEditItems)
+        iei.index = 0
+        return true
+}