1 files changed, 81 insertions, 0 deletions
diff --git a/lib/pama/rebase.go b/lib/pama/rebase.go
new file mode 100644
index 00000000..8f316b7e
--- /dev/null
+++ b/lib/pama/rebase.go
@@ -0,0 +1,81 @@
+package pama
+
+import (
+	"fmt"
+
+	"git.sr.ht/~rjarry/aerc/lib/pama/models"
+)
+
+// RebaseCommits fetches the commits between baseID and HEAD. The tags from the
+// current project will be mapped onto the fetched commits based on either the
+// commit hash or the commit subject.
+func (m PatchManager) RebaseCommits(p models.Project, baseID string) ([]models.Commit, error) {
+	rc, err := m.rc(p.RevctrlID, p.Root)
+	if err != nil {
+		return nil, revErr(err)
+	}
+
+	if !rc.Exists(baseID) {
+		return nil, fmt.Errorf("cannot rebase on %s. "+
+			"commit does not exist", baseID)
+	}
+
+	commitIDs, err := rc.History(baseID)
+	if err != nil {
+		return nil, err
+	}
+
+	commits := make([]models.Commit, len(commitIDs))
+	for i := 0; i < len(commitIDs); i++ {
+		commits[i] = models.NewCommit(
+			rc,
+			commitIDs[i],
+			models.Untracked,
+		)
+	}
+
+	// map tags from the commits from the project p
+	for i, r := range commits {
+		for _, c := range p.Commits {
+			if c.ID == r.ID || c.Subject == r.Subject {
+				commits[i].MessageId = c.MessageId
+				commits[i].Tag = c.Tag
+				break
+			}
+		}
+	}
+
+	return commits, nil
+}
+
+// SaveRebased checks if the commits actually exist in the repo, repopulate the
+// info fields and saves the baseID for project p.
+func (m PatchManager) SaveRebased(p models.Project, baseID string, commits []models.Commit) error {
+	rc, err := m.rc(p.RevctrlID, p.Root)
+	if err != nil {
+		return revErr(err)
+	}
+
+	exist := make([]models.Commit, 0, len(commits))
+	for _, c := range commits {
+		if !rc.Exists(c.ID) {
+			continue
+		}
+		exist = append(exist, c)
+	}
+
+	for i, c := range exist {
+		exist[i].Subject = rc.Subject(c.ID)
+		exist[i].Author = rc.Author(c.ID)
+		exist[i].Date = rc.Date(c.ID)
+	}
+
+	p.Commits = exist
+
+	if rc.Exists(baseID) {
+		p.Base = models.NewCommit(rc, baseID, "")
+	}
+
+	err = m.store().StoreProject(p, true)
+	return storeErr(err)
+}