1 files changed, 84 insertions, 0 deletions
diff --git a/bug/git_tree.go b/bug/git_tree.go
new file mode 100644
index 00000000..a5583bda
--- /dev/null
+++ b/bug/git_tree.go
@@ -0,0 +1,84 @@
+package bug
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/pkg/errors"
+
+	"github.com/MichaelMure/git-bug/repository"
+	"github.com/MichaelMure/git-bug/util/lamport"
+)
+
+type gitTree struct {
+	opsEntry   repository.TreeEntry
+	createTime lamport.Time
+	editTime   lamport.Time
+}
+
+func readTree(repo repository.RepoData, hash repository.Hash) (*gitTree, error) {
+	tree := &gitTree{}
+
+	entries, err := repo.ReadTree(hash)
+	if err != nil {
+		return nil, errors.Wrap(err, "can't list git tree entries")
+	}
+
+	opsFound := false
+
+	for _, entry := range entries {
+		if entry.Name == opsEntryName {
+			tree.opsEntry = entry
+			opsFound = true
+			continue
+		}
+		if strings.HasPrefix(entry.Name, createClockEntryPrefix) {
+			n, err := fmt.Sscanf(entry.Name, createClockEntryPattern, &tree.createTime)
+			if err != nil {
+				return nil, errors.Wrap(err, "can't read create lamport time")
+			}
+			if n != 1 {
+				return nil, fmt.Errorf("could not parse create time lamport value")
+			}
+		}
+		if strings.HasPrefix(entry.Name, editClockEntryPrefix) {
+			n, err := fmt.Sscanf(entry.Name, editClockEntryPattern, &tree.editTime)
+			if err != nil {
+				return nil, errors.Wrap(err, "can't read edit lamport time")
+			}
+			if n != 1 {
+				return nil, fmt.Errorf("could not parse edit time lamport value")
+			}
+		}
+	}
+
+	if !opsFound {
+		return nil, errors.New("invalid tree, missing the ops entry")
+	}
+
+	return tree, nil
+}
+
+func makeMediaTree(pack OperationPack) []repository.TreeEntry {
+	var tree []repository.TreeEntry
+	counter := 0
+	added := make(map[repository.Hash]interface{})
+
+	for _, ops := range pack.Operations {
+		for _, file := range ops.GetFiles() {
+			if _, has := added[file]; !has {
+				tree = append(tree, repository.TreeEntry{
+					ObjectType: repository.Blob,
+					Hash:       file,
+					// The name is not important here, we only need to
+					// reference the blob.
+					Name: fmt.Sprintf("file%d", counter),
+				})
+				counter++
+				added[file] = struct{}{}
+			}
+		}
+	}
+
+	return tree
+}