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	patch := &object.Patch{}
 51	commitTree, err := c.Tree()
 52	parent := &object.Commit{}
 53	if err == nil {
 54		parentTree := &object.Tree{}
 55		if c.NumParents() != 0 {
 56			parent, err = c.Parents().Next()
 57			if err == nil {
 58				parentTree, err = parent.Tree()
 59				if err == nil {
 60					patch, err = parentTree.Patch(commitTree)
 61					if err != nil {
 62						return nil, fmt.Errorf("patch: %w", err)
 63					}
 64				}
 65			}
 66		} else {
 67			patch, err = parentTree.Patch(commitTree)
 68			if err != nil {
 69				return nil, fmt.Errorf("patch: %w", err)
 70			}
 71		}
 72	}
 73
 74	diffs, _, err := gitdiff.Parse(strings.NewReader(patch.String()))
 75	if err != nil {
 76		log.Println(err)
 77	}
 78
 79	nd := NiceDiff{}
 80	nd.Commit.This = c.Hash.String()
 81
 82	if parent.Hash.IsZero() {
 83		nd.Commit.Parent = ""
 84	} else {
 85		nd.Commit.Parent = parent.Hash.String()
 86	}
 87	nd.Commit.Author = c.Author
 88	nd.Commit.Message = c.Message
 89
 90	for _, d := range diffs {
 91		ndiff := Diff{}
 92		ndiff.Name.New = d.NewName
 93		ndiff.Name.Old = d.OldName
 94		ndiff.IsBinary = d.IsBinary
 95		ndiff.IsNew = d.IsNew
 96		ndiff.IsDelete = d.IsDelete
 97
 98		for _, tf := range d.TextFragments {
 99			ndiff.TextFragments = append(ndiff.TextFragments, TextFragment{
100				Header: tf.Header(),
101				Lines:  tf.Lines,
102			})
103			for _, l := range tf.Lines {
104				switch l.Op {
105				case gitdiff.OpAdd:
106					nd.Stat.Insertions += 1
107				case gitdiff.OpDelete:
108					nd.Stat.Deletions += 1
109				}
110			}
111		}
112
113		nd.Diff = append(nd.Diff, ndiff)
114	}
115
116	nd.Stat.FilesChanged = len(diffs)
117
118	return &nd, nil
119}