1package git
  2
  3import (
  4	"fmt"
  5	"log"
  6	"strings"
  7
  8	"github.com/bluekeyes/go-gitdiff/gitdiff"
  9	"github.com/go-git/go-git/v5/plumbing/object"
 10)
 11
 12type TextFragment struct {
 13	Header string
 14	Lines  []gitdiff.Line
 15}
 16
 17type Diff struct {
 18	Name struct {
 19		Old string
 20		New string
 21	}
 22	TextFragments []TextFragment
 23	IsBinary      bool
 24	IsNew         bool
 25	IsDelete      bool
 26}
 27
 28// A nicer git diff representation.
 29type NiceDiff struct {
 30	Commit struct {
 31		Message string
 32		Author  object.Signature
 33		This    string
 34		Parent  string
 35	}
 36	Stat struct {
 37		FilesChanged int
 38		Insertions   int
 39		Deletions    int
 40	}
 41	Diff []Diff
 42}
 43
 44func (g *GitRepo) Diff() (*NiceDiff, error) {
 45	c, err := g.r.CommitObject(g.h)
 46	if err != nil {
 47		return nil, fmt.Errorf("commit object: %w", err)
 48	}
 49
 50	commitTree, err := c.Tree()
 51	if err != nil {
 52		return nil, fmt.Errorf("commit tree: %w", err)
 53	}
 54
 55	parentTree := &object.Tree{}
 56	var parent *object.Commit
 57	if c.NumParents() != 0 {
 58		parent, err = c.Parents().Next()
 59		if err != nil {
 60			return nil, fmt.Errorf("parent commit (is the repository shallow?): %w", err)
 61		}
 62		parentTree, err = parent.Tree()
 63		if err != nil {
 64			return nil, fmt.Errorf("parent tree: %w", err)
 65		}
 66	}
 67
 68	patch, err := parentTree.Patch(commitTree)
 69	if err != nil {
 70		return nil, fmt.Errorf("patch: %w", err)
 71	}
 72
 73	diffs, _, err := gitdiff.Parse(strings.NewReader(patch.String()))
 74	if err != nil {
 75		log.Println(err)
 76	}
 77
 78	nd := NiceDiff{}
 79	nd.Commit.This = c.Hash.String()
 80
 81	if parent == nil {
 82		nd.Commit.Parent = ""
 83	} else {
 84		nd.Commit.Parent = parent.Hash.String()
 85	}
 86	nd.Commit.Author = c.Author
 87	nd.Commit.Message = c.Message
 88
 89	for _, d := range diffs {
 90		ndiff := Diff{}
 91		ndiff.Name.New = d.NewName
 92		ndiff.Name.Old = d.OldName
 93		ndiff.IsBinary = d.IsBinary
 94		ndiff.IsNew = d.IsNew
 95		ndiff.IsDelete = d.IsDelete
 96
 97		for _, tf := range d.TextFragments {
 98			ndiff.TextFragments = append(ndiff.TextFragments, TextFragment{
 99				Header: tf.Header(),
100				Lines:  tf.Lines,
101			})
102			for _, l := range tf.Lines {
103				switch l.Op {
104				case gitdiff.OpAdd:
105					nd.Stat.Insertions += 1
106				case gitdiff.OpDelete:
107					nd.Stat.Deletions += 1
108				}
109			}
110		}
111
112		nd.Diff = append(nd.Diff, ndiff)
113	}
114
115	nd.Stat.FilesChanged = len(diffs)
116
117	return &nd, nil
118}