Fix MR Selection, Go Code Refactor (#358)

refactor: Refactors the Go codebase into a more modular and idiomatic approach
fix: require selection of specific MR when there are multiple targets for a given source branch
feat: Allows for the passing of Gitlab's filter options when choosing an MR, improves MR selection
feat: API to choose an MR from a list based on the provided username's involvement as an assignee/reviewer/author

This is a #MINOR release

cmd/app/comment.go

@@ -0,0 +1,215 @@
+package app
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/xanzy/go-gitlab"
+)
+
+type PostCommentRequest struct {
+	Comment string `json:"comment"`
+	PositionData
+}
+
+type DeleteCommentRequest struct {
+	NoteId       int    `json:"note_id"`
+	DiscussionId string `json:"discussion_id"`
+}
+
+type EditCommentRequest struct {
+	Comment      string `json:"comment"`
+	NoteId       int    `json:"note_id"`
+	DiscussionId string `json:"discussion_id"`
+	Resolved     bool   `json:"resolved"`
+}
+
+type CommentResponse struct {
+	SuccessResponse
+	Comment    *gitlab.Note       `json:"note"`
+	Discussion *gitlab.Discussion `json:"discussion"`
+}
+
+/* CommentWithPosition is a comment with an (optional) position data value embedded in it. The position data will be non-nil for range-based comments. */
+type CommentWithPosition struct {
+	PositionData PositionData
+}
+
+func (comment CommentWithPosition) GetPositionData() PositionData {
+	return comment.PositionData
+}
+
+type CommentManager interface {
+	CreateMergeRequestDiscussion(pid interface{}, mergeRequest int, opt *gitlab.CreateMergeRequestDiscussionOptions, options ...gitlab.RequestOptionFunc) (*gitlab.Discussion, *gitlab.Response, error)
+	UpdateMergeRequestDiscussionNote(pid interface{}, mergeRequest int, discussion string, note int, opt *gitlab.UpdateMergeRequestDiscussionNoteOptions, options ...gitlab.RequestOptionFunc) (*gitlab.Note, *gitlab.Response, error)
+	DeleteMergeRequestDiscussionNote(pid interface{}, mergeRequest int, discussion string, note int, options ...gitlab.RequestOptionFunc) (*gitlab.Response, error)
+}
+
+type commentService struct {
+	data
+	client CommentManager
+}
+
+/* commentHandler creates, edits, and deletes discussions (comments, multi-line comments) */
+func (a commentService) handler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
+	switch r.Method {
+	case http.MethodPost:
+		a.postComment(w, r)
+	case http.MethodPatch:
+		a.editComment(w, r)
+	case http.MethodDelete:
+		a.deleteComment(w, r)
+	default:
+		w.Header().Set("Access-Control-Allow-Methods", fmt.Sprintf("%s, %s, %s", http.MethodDelete, http.MethodPost, http.MethodPatch))
+		handleError(w, InvalidRequestError{}, "Expected DELETE, POST or PATCH", http.StatusMethodNotAllowed)
+	}
+}
+
+/* deleteComment deletes a note, multiline comment, or comment, which are all considered discussion notes. */
+func (a commentService) deleteComment(w http.ResponseWriter, r *http.Request) {
+	body, err := io.ReadAll(r.Body)
+	if err != nil {
+		handleError(w, err, "Could not read request body", http.StatusBadRequest)
+		return
+	}
+
+	defer r.Body.Close()
+
+	var deleteCommentRequest DeleteCommentRequest
+	err = json.Unmarshal(body, &deleteCommentRequest)
+	if err != nil {
+		handleError(w, err, "Could not read JSON from request", http.StatusBadRequest)
+		return
+	}
+
+	res, err := a.client.DeleteMergeRequestDiscussionNote(a.projectInfo.ProjectId, a.projectInfo.MergeId, deleteCommentRequest.DiscussionId, deleteCommentRequest.NoteId)
+
+	if err != nil {
+		handleError(w, err, "Could not delete comment", http.StatusInternalServerError)
+		return
+	}
+
+	if res.StatusCode >= 300 {
+		handleError(w, GenericError{endpoint: "/mr/comment"}, "Could not delete comment", res.StatusCode)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	response := SuccessResponse{
+		Message: "Comment deleted successfully",
+		Status:  http.StatusOK,
+	}
+
+	err = json.NewEncoder(w).Encode(response)
+	if err != nil {
+		handleError(w, err, "Could not encode response", http.StatusInternalServerError)
+	}
+}
+
+/* postComment creates a note, multiline comment, or comment. */
+func (a commentService) postComment(w http.ResponseWriter, r *http.Request) {
+	body, err := io.ReadAll(r.Body)
+	if err != nil {
+		handleError(w, err, "Could not read request body", http.StatusBadRequest)
+		return
+	}
+
+	defer r.Body.Close()
+
+	var postCommentRequest PostCommentRequest
+	err = json.Unmarshal(body, &postCommentRequest)
+	if err != nil {
+		handleError(w, err, "Could not unmarshal data from request body", http.StatusBadRequest)
+		return
+	}
+
+	opt := gitlab.CreateMergeRequestDiscussionOptions{
+		Body: &postCommentRequest.Comment,
+	}
+
+	/* If we are leaving a comment on a line, leave position. Otherwise,
+	we are leaving a note (unlinked comment) */
+
+	if postCommentRequest.FileName != "" {
+		commentWithPositionData := CommentWithPosition{postCommentRequest.PositionData}
+		opt.Position = buildCommentPosition(commentWithPositionData)
+	}
+
+	discussion, res, err := a.client.CreateMergeRequestDiscussion(a.projectInfo.ProjectId, a.projectInfo.MergeId, &opt)
+
+	if err != nil {
+		handleError(w, err, "Could not create discussion", http.StatusInternalServerError)
+		return
+	}
+
+	if res.StatusCode >= 300 {
+		handleError(w, GenericError{endpoint: "/mr/comment"}, "Could not create discussion", res.StatusCode)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	response := CommentResponse{
+		SuccessResponse: SuccessResponse{
+			Message: "Comment created successfully",
+			Status:  http.StatusOK,
+		},
+		Comment:    discussion.Notes[0],
+		Discussion: discussion,
+	}
+
+	err = json.NewEncoder(w).Encode(response)
+	if err != nil {
+		handleError(w, err, "Could not encode response", http.StatusInternalServerError)
+	}
+}
+
+/* editComment changes the text of a comment or changes it's resolved status. */
+func (a commentService) editComment(w http.ResponseWriter, r *http.Request) {
+	body, err := io.ReadAll(r.Body)
+
+	if err != nil {
+		handleError(w, err, "Could not read request body", http.StatusBadRequest)
+		return
+	}
+
+	defer r.Body.Close()
+
+	var editCommentRequest EditCommentRequest
+	err = json.Unmarshal(body, &editCommentRequest)
+	if err != nil {
+		handleError(w, err, "Could not unmarshal data from request body", http.StatusBadRequest)
+		return
+	}
+
+	options := gitlab.UpdateMergeRequestDiscussionNoteOptions{}
+	options.Body = gitlab.Ptr(editCommentRequest.Comment)
+
+	note, res, err := a.client.UpdateMergeRequestDiscussionNote(a.projectInfo.ProjectId, a.projectInfo.MergeId, editCommentRequest.DiscussionId, editCommentRequest.NoteId, &options)
+
+	if err != nil {
+		handleError(w, err, "Could not update comment", http.StatusInternalServerError)
+		return
+	}
+
+	if res.StatusCode >= 300 {
+		handleError(w, GenericError{endpoint: "/mr/comment"}, "Could not update comment", res.StatusCode)
+		return
+	}
+
+	w.WriteHeader(http.StatusOK)
+	response := CommentResponse{
+		SuccessResponse: SuccessResponse{
+			Message: "Comment updated successfully",
+			Status:  http.StatusOK,
+		},
+		Comment: note,
+	}
+
+	err = json.NewEncoder(w).Encode(response)
+	if err != nil {
+		handleError(w, err, "Could not encode response", http.StatusInternalServerError)
+	}
+}