feat: initial Plutia release — verifiable high-performance PLC mirror (mirror + resolver modes)

1 files changed, 77 insertions, 0 deletions

diff --git a/internal/types/operation.go b/internal/types/operation.go
new file mode 100644
index 0000000..2facb82
--- /dev/null
+++ b/internal/types/operation.go
@@ -0,0 +1,77 @@
+package types
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+)
+
+// ExportRecord mirrors a line/event from plc.directory export stream.
+type ExportRecord struct {
+	Seq       uint64          `json:"seq"`
+	DID       string          `json:"did"`
+	CreatedAt string          `json:"createdAt,omitempty"`
+	CID       string          `json:"cid,omitempty"`
+	Nullified bool            `json:"nullified,omitempty"`
+	Operation json.RawMessage `json:"operation"`
+}
+
+type ParsedOperation struct {
+	DID            string
+	CanonicalBytes []byte
+	Payload        map[string]any
+	Sequence       uint64
+	CID            string
+	Prev           string
+	RawRecord      ExportRecord
+}
+
+func CanonicalizeJSON(raw []byte) ([]byte, error) {
+	trimmed := bytes.TrimSpace(raw)
+	if len(trimmed) == 0 {
+		return nil, fmt.Errorf("empty json payload")
+	}
+	if !json.Valid(trimmed) {
+		return nil, fmt.Errorf("invalid json payload")
+	}
+	var out bytes.Buffer
+	if err := json.Compact(&out, trimmed); err != nil {
+		return nil, fmt.Errorf("compact json: %w", err)
+	}
+	return out.Bytes(), nil
+}
+
+func ParseOperation(rec ExportRecord) (ParsedOperation, error) {
+	if rec.DID == "" {
+		return ParsedOperation{}, fmt.Errorf("missing did")
+	}
+	canonical, err := CanonicalizeJSON(rec.Operation)
+	if err != nil {
+		return ParsedOperation{}, err
+	}
+	payload := map[string]any{}
+	if err := json.Unmarshal(canonical, &payload); err != nil {
+		return ParsedOperation{}, fmt.Errorf("decode operation: %w", err)
+	}
+	prev, _ := payload["prev"].(string)
+	cid := rec.CID
+	if cid == "" {
+		cid = ComputeDigestCID(canonical)
+	}
+	return ParsedOperation{
+		DID:            rec.DID,
+		CanonicalBytes: canonical,
+		Payload:        payload,
+		Sequence:       rec.Seq,
+		CID:            cid,
+		Prev:           prev,
+		RawRecord:      rec,
+	}, nil
+}
+
+func ComputeDigestCID(payload []byte) string {
+	sum := sha256.Sum256(payload)
+	return "sha256:" + hex.EncodeToString(sum[:])
+}