1 files changed, 252 insertions, 0 deletions
diff --git a/rebase.go b/rebase.go
new file mode 100644
index 0000000..8553e25
--- /dev/null
+++ b/rebase.go
@@ -0,0 +1,252 @@
+package git
+
+/*
+#include <git2.h>
+*/
+import "C"
+import (
+	"runtime"
+	"unsafe"
+)
+
+// RebaseOperationType is the type of rebase operation
+type RebaseOperationType uint
+
+const (
+	// RebaseOperationPick The given commit is to be cherry-picked.  The client should commit the changes and continue if there are no conflicts.
+	RebaseOperationPick RebaseOperationType = C.GIT_REBASE_OPERATION_PICK
+	// RebaseOperationEdit The given commit is to be cherry-picked, but the client should stop to allow the user to edit the changes before committing them.
+	RebaseOperationEdit RebaseOperationType = C.GIT_REBASE_OPERATION_EDIT
+	// RebaseOperationSquash The given commit is to be squashed into the previous commit.  The commit message will be merged with the previous message.
+	RebaseOperationSquash RebaseOperationType = C.GIT_REBASE_OPERATION_SQUASH
+	// RebaseOperationFixup No commit will be cherry-picked.  The client should run the given command and (if successful) continue.
+	RebaseOperationFixup RebaseOperationType = C.GIT_REBASE_OPERATION_FIXUP
+	// RebaseOperationExec No commit will be cherry-picked.  The client should run the given command and (if successful) continue.
+	RebaseOperationExec RebaseOperationType = C.GIT_REBASE_OPERATION_EXEC
+)
+
+// RebaseOperation describes a single instruction/operation to be performed during the rebase.
+type RebaseOperation struct {
+	Type RebaseOperationType
+	Id   *Oid
+	Exec string
+}
+
+func newRebaseOperationFromC(c *C.git_rebase_operation) *RebaseOperation {
+	operation := &RebaseOperation{}
+	operation.Type = RebaseOperationType(c._type)
+	operation.Id = newOidFromC(&c.id)
+	operation.Exec = C.GoString(c.exec)
+
+	return operation
+}
+
+// RebaseOptions are used to tell the rebase machinery how to operate
+type RebaseOptions struct {
+	Version         uint
+	Quiet           int
+	InMemory        int
+	RewriteNotesRef string
+	MergeOptions    MergeOptions
+	CheckoutOptions CheckoutOpts
+}
+
+// DefaultRebaseOptions returns a RebaseOptions with default values.
+func DefaultRebaseOptions() (RebaseOptions, error) {
+	opts := C.git_rebase_options{}
+
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	ecode := C.git_rebase_init_options(&opts, C.GIT_REBASE_OPTIONS_VERSION)
+	if ecode < 0 {
+		return RebaseOptions{}, MakeGitError(ecode)
+	}
+	return rebaseOptionsFromC(&opts), nil
+}
+
+func rebaseOptionsFromC(opts *C.git_rebase_options) RebaseOptions {
+	return RebaseOptions{
+		Version:         uint(opts.version),
+		Quiet:           int(opts.quiet),
+		InMemory:        int(opts.inmemory),
+		RewriteNotesRef: C.GoString(opts.rewrite_notes_ref),
+		MergeOptions:    mergeOptionsFromC(&opts.merge_options),
+		CheckoutOptions: checkoutOptionsFromC(&opts.checkout_options),
+	}
+}
+
+func (ro *RebaseOptions) toC() *C.git_rebase_options {
+	if ro == nil {
+		return nil
+	}
+	return &C.git_rebase_options{
+		version:           C.uint(ro.Version),
+		quiet:             C.int(ro.Quiet),
+		inmemory:          C.int(ro.InMemory),
+		rewrite_notes_ref: mapEmptyStringToNull(ro.RewriteNotesRef),
+		merge_options:     *ro.MergeOptions.toC(),
+		checkout_options:  *ro.CheckoutOptions.toC(),
+	}
+}
+
+func mapEmptyStringToNull(ref string) *C.char {
+	if ref == "" {
+		return nil
+	}
+	return C.CString(ref)
+}
+
+// Rebase is the struct representing a Rebase object.
+type Rebase struct {
+	ptr *C.git_rebase
+}
+
+// InitRebase initializes a rebase operation to rebase the changes in branch relative to upstream onto another branch.
+func (r *Repository) InitRebase(branch *AnnotatedCommit, upstream *AnnotatedCommit, onto *AnnotatedCommit, opts *RebaseOptions) (*Rebase, error) {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	if branch == nil {
+		branch = &AnnotatedCommit{ptr: nil}
+	}
+
+	if upstream == nil {
+		upstream = &AnnotatedCommit{ptr: nil}
+	}
+
+	if onto == nil {
+		onto = &AnnotatedCommit{ptr: nil}
+	}
+
+	var ptr *C.git_rebase
+	err := C.git_rebase_init(&ptr, r.ptr, branch.ptr, upstream.ptr, onto.ptr, opts.toC())
+	if err < 0 {
+		return nil, MakeGitError(err)
+	}
+
+	return newRebaseFromC(ptr), nil
+}
+
+// OpenRebase opens an existing rebase that was previously started by either an invocation of InitRebase or by another client.
+func (r *Repository) OpenRebase(opts *RebaseOptions) (*Rebase, error) {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	var ptr *C.git_rebase
+	err := C.git_rebase_open(&ptr, r.ptr, opts.toC())
+	if err < 0 {
+		return nil, MakeGitError(err)
+	}
+
+	return newRebaseFromC(ptr), nil
+}
+
+// OperationAt gets the rebase operation specified by the given index.
+func (rebase *Rebase) OperationAt(index uint) *RebaseOperation {
+	operation := C.git_rebase_operation_byindex(rebase.ptr, C.size_t(index))
+	
+	return newRebaseOperationFromC(operation)
+}
+
+// CurrentOperationIndex gets the index of the rebase operation that is currently being applied.
+// Returns an error if no rebase operation is currently applied.
+func (rebase *Rebase) CurrentOperationIndex() (uint, error) {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	operationIndex := int(C.git_rebase_operation_current(rebase.ptr))
+	if operationIndex == C.GIT_REBASE_NO_OPERATION {
+		return 0, MakeGitError(C.GIT_REBASE_NO_OPERATION)
+	}
+
+	return uint(operationIndex), nil
+}
+
+// OperationCount gets the count of rebase operations that are to be applied.
+func (rebase *Rebase) OperationCount() uint {
+	return uint(C.git_rebase_operation_entrycount(rebase.ptr))
+}
+
+// Next performs the next rebase operation and returns the information about it.
+// If the operation is one that applies a patch (which is any operation except RebaseOperationExec)
+// then the patch will be applied and the index and working directory will be updated with the changes.
+// If there are conflicts, you will need to address those before committing the changes.
+func (rebase *Rebase) Next() (*RebaseOperation, error) {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	var ptr *C.git_rebase_operation
+	err := C.git_rebase_next(&ptr, rebase.ptr)
+	if err < 0 {
+		return nil, MakeGitError(err)
+	}
+
+	return newRebaseOperationFromC(ptr), nil
+}
+
+// Commit commits the current patch.
+// You must have resolved any conflicts that were introduced during the patch application from the Next() invocation.
+func (rebase *Rebase) Commit(ID *Oid, author, committer *Signature, message string) error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	authorSig, err := author.toC()
+	if err != nil {
+		return err
+	}
+	defer C.git_signature_free(authorSig)
+
+	committerSig, err := committer.toC()
+	if err != nil {
+		return err
+	}
+	defer C.git_signature_free(committerSig)
+
+	cmsg := C.CString(message)
+	defer C.free(unsafe.Pointer(cmsg))
+
+	cerr := C.git_rebase_commit(ID.toC(), rebase.ptr, authorSig, committerSig, nil, cmsg)
+	if cerr < 0 {
+		return MakeGitError(cerr)
+	}
+
+	return nil
+}
+
+// Finish finishes a rebase that is currently in progress once all patches have been applied.
+func (rebase *Rebase) Finish() error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	err := C.git_rebase_finish(rebase.ptr, nil)
+	if err < 0 {
+		return MakeGitError(err)
+	}
+
+	return nil
+}
+
+// Abort aborts a rebase that is currently in progress, resetting the repository and working directory to their state before rebase began.
+func (rebase *Rebase) Abort() error {
+	runtime.LockOSThread()
+	defer runtime.UnlockOSThread()
+
+	err := C.git_rebase_abort(rebase.ptr)
+	if err < 0 {
+		return MakeGitError(err)
+	}
+	return nil
+}
+
+// Free frees the Rebase object.
+func (rebase *Rebase) Free() {
+	runtime.SetFinalizer(rebase, nil)
+	C.git_rebase_free(rebase.ptr)
+}
+
+func newRebaseFromC(ptr *C.git_rebase) *Rebase {
+	rebase := &Rebase{ptr: ptr}
+	runtime.SetFinalizer(rebase, (*Rebase).Free)
+	return rebase
+}