also return the checksums for each element of the repository

2 files changed, 83 insertions, 10 deletions

diff --git a/internal/types/entry.go b/internal/types/entry.go
index a274e2c..067d849 100644
--- a/internal/types/entry.go
+++ b/internal/types/entry.go
@@ -4,31 +4,82 @@ import (
 	"crypto/sha256"
 	"encoding/json"
 	"fmt"
+	"os"
+	"strings"
+	"sync"
 )
 
+// Tells me whether the entry was shared to the sm platform named Name
 type Shared struct {
 	Name string `json:"id"`
 	Is   bool   `json:"is,omitempty"`
 }
 
+func (s Shared) String() string {
+	return fmt.Sprintf("Name:%s\nIs:%v\n", s.Name, s.Is)
+}
+
 type Entry struct {
-	Body   string   `json:"body"`
-	Shared []Shared `json:"shared,omitempty"`
-	Epoch  int      `json:"epoch,omitempty"`
-	ID     string   `json:"id,omitempty"`
+	Body     string   `json:"body"`
+	Shared   []Shared `json:"shared,omitempty"`
+	Epoch    int      `json:"epoch,omitempty"`
+	ID       string   `json:"id,omitempty"`
+	mu       *sync.Mutex
+	dirty    bool
+	checksum string
 }
 
 func NewEntry(bytes []byte) (Entry, error) {
-	var entry Entry
-	if err := json.Unmarshal(bytes, &entry); err != nil {
-		return entry, fmt.Errorf("unable to deserialise payload: %w", err)
+	var ent Entry
+	if err := json.Unmarshal(bytes, &ent); err != nil {
+		return ent, fmt.Errorf("unable to deserialise payload: %w", err)
 	}
-	if entry.ID == "" {
-		entry.ID = fmt.Sprintf("%x", sha256.Sum256(bytes))
+	ent.mu = &sync.Mutex{}
+	ent.dirty = true
+	if ent.ID == "" {
+		ent.ID = fmt.Sprintf("%x", sha256.Sum256(bytes))
+	}
+	return ent, nil
+}
+
+func NewEntryFromFile(filePath string) (Entry, error) {
+	bytes, err := os.ReadFile(filePath)
+	if err != err {
+		return Entry{}, err
 	}
-	return entry, nil
+	return NewEntry(bytes)
 }
 
 func (e Entry) Serialize() ([]byte, error) {
 	return json.Marshal(e)
 }
+
+func (e Entry) String() string {
+	var sb strings.Builder
+
+	sb.WriteString("ID:")
+	sb.WriteString(e.ID)
+	sb.WriteString("\n")
+	sb.WriteString(fmt.Sprintf("Epoch:%d\n", e.Epoch))
+	for _, shared := range e.Shared {
+		sb.WriteString(shared.String())
+	}
+	sb.WriteString("Body:")
+	sb.WriteString(e.Body)
+	sb.WriteString("\n")
+
+	return sb.String()
+}
+
+func (e *Entry) Checksum() string {
+	e.mu.Lock()
+	defer e.mu.Unlock()
+
+	if !e.dirty {
+		return e.checksum
+	}
+
+	e.checksum = fmt.Sprintf("%x", sha256.Sum256([]byte(e.String())))
+	e.dirty = false
+	return e.checksum
+}
diff --git a/internal/types/entry_test.go b/internal/types/entry_test.go
new file mode 100644
index 0000000..65e74a3
--- /dev/null
+++ b/internal/types/entry_test.go
@@ -0,0 +1,22 @@
+package types
+
+import "testing"
+
+func TestEntryChecksum(t *testing.T) {
+	t.Parallel()
+
+	ent, err := NewEntry([]byte(`{"Body": "Body text here"}`))
+	if err != nil {
+		t.Error(err)
+		return
+	}
+
+	expected := "8618a63380fe6d365422cae6ef143a88bb6bd78df567fea3822074cc748f52f8"
+	got := ent.Checksum()
+
+	if expected != got {
+		t.Errorf("expected checksum '%s' but got '%s'", expected, got)
+		return
+	}
+	t.Log(ent.Checksum())
+}