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}
 24
 25// A nicer git diff representation.
 26type NiceDiff struct {
 27	Commit struct {
 28		Message string
 29		Author  object.Signature
 30		This    string
 31		Parent  string
 32	}
 33	Stat struct {
 34		FilesChanged int
 35		Insertions   int
 36		Deletions    int
 37	}
 38	Diff []Diff
 39}
 40
 41func (g *GitRepo) Diff() (*NiceDiff, error) {
 42	c, err := g.r.CommitObject(g.h)
 43	if err != nil {
 44		return nil, fmt.Errorf("commit object: %w", err)
 45	}
 46
 47	patch := &object.Patch{}
 48	commitTree, err := c.Tree()
 49	parent := &object.Commit{}
 50	if err == nil {
 51		parentTree := &object.Tree{}
 52		if c.NumParents() != 0 {
 53			parent, err = c.Parents().Next()
 54			if err == nil {
 55				parentTree, err = parent.Tree()
 56				if err == nil {
 57					patch, err = parentTree.Patch(commitTree)
 58					if err != nil {
 59						return nil, fmt.Errorf("patch: %w", err)
 60					}
 61				}
 62			}
 63		} else {
 64			patch, err = parentTree.Patch(commitTree)
 65			if err != nil {
 66				return nil, fmt.Errorf("patch: %w", err)
 67			}
 68		}
 69	}
 70
 71	diffs, _, err := gitdiff.Parse(strings.NewReader(patch.String()))
 72	if err != nil {
 73		log.Println(err)
 74	}
 75
 76	nd := NiceDiff{}
 77	nd.Commit.This = c.Hash.String()
 78
 79	if parent.Hash.IsZero() {
 80		nd.Commit.Parent = ""
 81	} else {
 82		nd.Commit.Parent = parent.Hash.String()
 83	}
 84	nd.Commit.Author = c.Author
 85	nd.Commit.Message = c.Message
 86
 87	for _, d := range diffs {
 88		ndiff := Diff{}
 89		ndiff.Name.New = d.NewName
 90		ndiff.Name.Old = d.OldName
 91
 92		for _, tf := range d.TextFragments {
 93			ndiff.TextFragments = append(ndiff.TextFragments, TextFragment{
 94				Header: tf.Header(),
 95				Lines:  tf.Lines,
 96			})
 97			for _, l := range tf.Lines {
 98				switch l.Op {
 99				case gitdiff.OpAdd:
100					nd.Stat.Insertions += 1
101				case gitdiff.OpDelete:
102					nd.Stat.Deletions += 1
103				}
104			}
105		}
106
107		nd.Diff = append(nd.Diff, ndiff)
108	}
109
110	nd.Stat.FilesChanged = len(diffs)
111
112	return &nd, nil
113}