1 files changed, 119 insertions, 0 deletions
diff --git a/gerrit/client.go b/gerrit/client.go
new file mode 100644
index 000000000000..5a13befe5463
--- /dev/null
+++ b/gerrit/client.go
@@ -0,0 +1,119 @@
+package gerrit
+
+import (
+	goGerrit "github.com/andygrunwald/go-gerrit"
+
+	"net/url"
+)
+
+// passed to gerrit when retrieving changesets
+var additionalFields = []string{"LABELS", "CURRENT_REVISION", "CURRENT_COMMIT", "DETAILED_ACCOUNTS"}
+
+// IClient defines the gerrit.Client interface
+type IClient interface {
+	SearchChangesets(queryString string) (changesets []*Changeset, Error error)
+	GetHEAD(projectName string, branchName string) (string, error)
+	GetChangeset(changeID string) (*Changeset, error)
+	SubmitChangeset(changeset *Changeset) (*Changeset, error)
+	RebaseChangeset(changeset *Changeset, ref string) (*Changeset, error)
+	RemoveTag(changeset *Changeset, tag string) (*Changeset, error)
+}
+
+var _ IClient = &Client{}
+
+// Client provides some ways to interact with a gerrit instance
+type Client struct {
+	client *goGerrit.Client
+}
+
+// NewClient initializes a new gerrit client
+func NewClient(URL, username, password string) (*Client, error) {
+	urlParsed, err := url.Parse(URL)
+	if err != nil {
+		return nil, err
+	}
+	urlParsed.User = url.UserPassword(username, password)
+
+	goGerritClient, err := goGerrit.NewClient(urlParsed.String(), nil)
+	if err != nil {
+		return nil, err
+	}
+	return &Client{client: goGerritClient}, nil
+}
+
+// SearchChangesets fetches a list of changesets matching a passed query string
+func (gerrit *Client) SearchChangesets(queryString string) (changesets []*Changeset, Error error) {
+	opt := &goGerrit.QueryChangeOptions{}
+	opt.Query = []string{
+		queryString,
+	}
+	opt.AdditionalFields = additionalFields //TODO: check DETAILED_ACCOUNTS is needed
+	changes, _, err := gerrit.client.Changes.QueryChanges(opt)
+	if err != nil {
+		return nil, err
+	}
+
+	changesets = make([]*Changeset, 0)
+	for _, change := range *changes {
+		changesets = append(changesets, MakeChangeset(&change))
+	}
+
+	return changesets, nil
+}
+
+// GetHEAD returns the commit ID of a selected branch
+func (gerrit *Client) GetHEAD(projectName string, branchName string) (string, error) {
+	branchInfo, _, err := gerrit.client.Projects.GetBranch(projectName, branchName)
+	if err != nil {
+		return "", err
+	}
+	return branchInfo.Revision, nil
+}
+
+// GetChangeset downloads an existing Changeset from gerrit, by its ID
+// Gerrit's API is a bit sparse, and only returns what you explicitly ask it
+// This is used to refresh an existing changeset with more data.
+func (gerrit *Client) GetChangeset(changeID string) (*Changeset, error) {
+	opt := goGerrit.ChangeOptions{}
+	opt.AdditionalFields = []string{"LABELS", "DETAILED_ACCOUNTS"}
+	changeInfo, _, err := gerrit.client.Changes.GetChange(changeID, &opt)
+	if err != nil {
+		return nil, err
+	}
+	return MakeChangeset(changeInfo), nil
+}
+
+// SubmitChangeset submits a given changeset, and returns a changeset afterwards.
+func (gerrit *Client) SubmitChangeset(changeset *Changeset) (*Changeset, error) {
+	changeInfo, _, err := gerrit.client.Changes.SubmitChange(changeset.ChangeID, &goGerrit.SubmitInput{})
+	if err != nil {
+		return nil, err
+	}
+	return gerrit.GetChangeset(changeInfo.ChangeID)
+}
+
+// RebaseChangeset rebases a given changeset on top of a given ref
+func (gerrit *Client) RebaseChangeset(changeset *Changeset, ref string) (*Changeset, error) {
+	changeInfo, _, err := gerrit.client.Changes.RebaseChange(changeset.ChangeID, &goGerrit.RebaseInput{
+		Base: ref,
+	})
+	if err != nil {
+		return changeset, err
+	}
+	return gerrit.GetChangeset(changeInfo.ChangeID)
+}
+
+// RemoveTag removes the submit queue tag from a changeset and updates gerrit
+// we never add, that's something users should do in the GUI.
+func (gerrit *Client) RemoveTag(changeset *Changeset, tag string) (*Changeset, error) {
+	hashTags := changeset.HashTags
+	newHashTags := []string{}
+	for _, hashTag := range hashTags {
+		if hashTag != tag {
+			newHashTags = append(newHashTags, hashTag)
+		}
+	}
+	// TODO: implement set hashtags api in go-gerrit and use here
+	// https://gerrit-review.googlesource.com/Documentation/rest-api-changes.html#set-hashtags
+	return changeset, nil
+}