Init V4 community edition (#2265)

* Init V4 community edition

* Init V4 community edition

application/migrator/avatars.go

@@ -0,0 +1,47 @@
+package migrator
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"github.com/cloudreve/Cloudreve/v4/pkg/util"
+)
+
+func migrateAvatars(m *Migrator) error {
+	m.l.Info("Migrating avatars files...")
+	avatarRoot := util.RelativePath(m.state.V3AvatarPath)
+
+	for uid, _ := range m.state.UserIDs {
+		avatarPath := filepath.Join(avatarRoot, fmt.Sprintf("avatar_%d_2.png", uid))
+
+		// check if file exists
+		if util.Exists(avatarPath) {
+			m.l.Info("Migrating avatar for user %d", uid)
+			// Copy to v4 avatar path
+			v4Path := filepath.Join(util.DataPath("avatar"), fmt.Sprintf("avatar_%d.png", uid))
+
+			// copy
+			origin, err := os.Open(avatarPath)
+			if err != nil {
+				return fmt.Errorf("failed to open avatar file: %w", err)
+			}
+			defer origin.Close()
+
+			dest, err := util.CreatNestedFile(v4Path)
+			if err != nil {
+				return fmt.Errorf("failed to create avatar file: %w", err)
+			}
+			defer dest.Close()
+
+			_, err = io.Copy(dest, origin)
+
+			if err != nil {
+				m.l.Warning("Failed to copy avatar file: %s, skipping...", err)
+			}
+		}
+	}
+
+	return nil
+}