b4nst/turbogit

package git

import (
    "os"
    "strings"

    git2go "github.com/libgit2/git2go/v33"
)

// Getrepo returns the repository in the current directory or an error.
func Getrepo() (*git2go.Repository, error) {
    wd, err := os.Getwd()
    if err != nil {
        return nil, err
    }
    rpath, err := git2go.Discover(wd, false, nil)
    if err != nil {
        return nil, err
    }
    repo, err := git2go.OpenRepository(rpath)
    if err != nil {
        return nil, err
    }
    return repo, nil
}

func StagedDiff(r *git2go.Repository) (*git2go.Diff, error) {
    var tree *git2go.Tree
    if obj, err := r.RevparseSingle("HEAD^{tree}"); err == nil {
        tree, err = obj.AsTree()
        if err != nil {
            return nil, err
        }
    }

    diff, err := r.DiffTreeToIndex(tree, nil, &git2go.DiffOptions{
        Flags:            git2go.DiffIgnoreWhitespace,
        IgnoreSubmodules: git2go.SubmoduleIgnoreAll,
    })
    if err != nil {
        return nil, err
    }

    return diff, nil
}

func PatchFromDiff(diff *git2go.Diff) (string, error) {
    numDeltas, err := diff.NumDeltas()
    if err != nil {
        return "", err
    }

    patches := make([]string, numDeltas)
    for i := 0; i < numDeltas; i++ {
        p, err := diff.Patch(i)
        if err != nil {
            return "", err
        }
        ps, err := p.String()
        if err != nil {
            return "", err
        }
        patches = append(patches, ps)
    }

    return strings.Join(patches, "\n"), nil
}