1 files changed, 125 insertions, 0 deletions
diff --git a/entity/operation_pack.go b/entity/operation_pack.go
new file mode 100644
index 00000000..2377167f
--- /dev/null
+++ b/entity/operation_pack.go
@@ -0,0 +1,125 @@
+package entity
+
+import (
+	"encoding/json"
+	"strconv"
+	"strings"
+
+	"github.com/pkg/errors"
+
+	"github.com/MichaelMure/git-bug/repository"
+	"github.com/MichaelMure/git-bug/util/lamport"
+)
+
+const opsEntryName = "ops"
+const versionEntryPrefix = "version-"
+const createClockEntryPrefix = "create-clock-"
+const editClockEntryPrefix = "edit-clock-"
+
+type operationPack struct {
+	Operations []Operation
+	CreateTime lamport.Time
+	EditTime   lamport.Time
+}
+
+// func (opp *operationPack) MarshalJSON() ([]byte, error) {
+// 	return json.Marshal(struct {
+// 		Operations []Operation `json:"ops"`
+// 	}{
+// 		Operations: opp.Operations,
+// 	})
+// }
+
+func readOperationPack(def Definition, repo repository.RepoData, treeHash repository.Hash) (*operationPack, error) {
+	entries, err := repo.ReadTree(treeHash)
+	if err != nil {
+		return nil, err
+	}
+
+	// check the format version first, fail early instead of trying to read something
+	// var version uint
+	// for _, entry := range entries {
+	// 	if strings.HasPrefix(entry.Name, versionEntryPrefix) {
+	// 		v, err := strconv.ParseUint(strings.TrimPrefix(entry.Name, versionEntryPrefix), 10, 64)
+	// 		if err != nil {
+	// 			return nil, errors.Wrap(err, "can't read format version")
+	// 		}
+	// 		if v > 1<<12 {
+	// 			return nil, fmt.Errorf("format version too big")
+	// 		}
+	// 		version = uint(v)
+	// 		break
+	// 	}
+	// }
+	// if version == 0 {
+	// 	return nil, NewErrUnknowFormat(def.formatVersion)
+	// }
+	// if version != def.formatVersion {
+	// 	return nil, NewErrInvalidFormat(version, def.formatVersion)
+	// }
+
+	var ops []Operation
+	var createTime lamport.Time
+	var editTime lamport.Time
+
+	for _, entry := range entries {
+		if entry.Name == opsEntryName {
+			data, err := repo.ReadData(entry.Hash)
+			if err != nil {
+				return nil, errors.Wrap(err, "failed to read git blob data")
+			}
+
+			ops, err = unmarshallOperations(def, data)
+			if err != nil {
+				return nil, err
+			}
+			break
+		}
+
+		if strings.HasPrefix(entry.Name, createClockEntryPrefix) {
+			v, err := strconv.ParseUint(strings.TrimPrefix(entry.Name, createClockEntryPrefix), 10, 64)
+			if err != nil {
+				return nil, errors.Wrap(err, "can't read creation lamport time")
+			}
+			createTime = lamport.Time(v)
+		}
+
+		if strings.HasPrefix(entry.Name, editClockEntryPrefix) {
+			v, err := strconv.ParseUint(strings.TrimPrefix(entry.Name, editClockEntryPrefix), 10, 64)
+			if err != nil {
+				return nil, errors.Wrap(err, "can't read edit lamport time")
+			}
+			editTime = lamport.Time(v)
+		}
+	}
+
+	return &operationPack{
+		Operations: ops,
+		CreateTime: createTime,
+		EditTime:   editTime,
+	}, nil
+}
+
+func unmarshallOperations(def Definition, data []byte) ([]Operation, error) {
+	aux := struct {
+		Operations []json.RawMessage `json:"ops"`
+	}{}
+
+	if err := json.Unmarshal(data, &aux); err != nil {
+		return nil, err
+	}
+
+	ops := make([]Operation, 0, len(aux.Operations))
+
+	for _, raw := range aux.Operations {
+		// delegate to specialized unmarshal function
+		op, err := def.operationUnmarshaler(raw)
+		if err != nil {
+			return nil, err
+		}
+
+		ops = append(ops, op)
+	}
+
+	return ops, nil
+}