package difftree
import (
"bytes"
"fmt"
"strings"
"srcd.works/go-git.v4/plumbing/object"
"srcd.works/go-git.v4/utils/merkletrie"
)
// Change values represent a detected change between two git trees. For
// modifications, From is the original status of the node and To is its
// final status. For insertions, From is the zero value and for
// deletions To is the zero value.
type Change struct {
From ChangeEntry
To ChangeEntry
}
var empty = ChangeEntry{}
// Action returns the kind of action represented by the change, an
// insertion, a deletion or a modification.
func (c *Change) Action() (merkletrie.Action, error) {
if c.From == empty && c.To == empty {
return merkletrie.Action(0),
fmt.Errorf("malformed change: empty from and to")
}
if c.From == empty {
return merkletrie.Insert, nil
}
if c.To == empty {
return merkletrie.Delete, nil
}
return merkletrie.Modify, nil
}
// Files return the files before and after a change.
// For insertions from will be nil. For deletions to will be nil.
func (c *Change) Files() (from, to *object.File, err error) {
action, err := c.Action()
if err != nil {
return
}
if action == merkletrie.Insert || action == merkletrie.Modify {
to, err = c.To.Tree.TreeEntryFile(&c.To.TreeEntry)
if err != nil {
return
}
}
if action == merkletrie.Delete || action == merkletrie.Modify {
from, err = c.From.Tree.TreeEntryFile(&c.From.TreeEntry)
if err != nil {
return
}
}
return
}
func (c *Change) String() string {
action, err := c.Action()
if err != nil {
return fmt.Sprintf("malformed change")
}
return fmt.Sprintf("<Action: %s, Path: %s>", action, c.name())
}
func (c *Change) name() string {
if c.From != empty {
return c.From.Name
}
return c.To.Name
}
// ChangeEntry values represent a node that has suffered a change.
type ChangeEntry struct {
// Full path of the node using "/" as separator.
Name string
// Parent tree of the node that has changed.
Tree *object.Tree
// The entry of the node.
TreeEntry object.TreeEntry
}
// Changes represents a collection of changes between two git trees.
// Implements sort.Interface lexicographically over the path of the
// changed files.
type Changes []*Change
func (c Changes) Len() int {
return len(c)
}
func (c Changes) Swap(i, j int) {
c[i], c[j] = c[j], c[i]
}
func (c Changes) Less(i, j int) bool {
return strings.Compare(c[i].name(), c[j].name()) < 0
}
func (c Changes) String() string {
var buffer bytes.Buffer
buffer.WriteString("[")
comma := ""
for _, v := range c {
buffer.WriteString(comma)
buffer.WriteString(v.String())
comma = ", "
}
buffer.WriteString("]")
return buffer.String()
}
