setmeta updates to support json files (or reading stdin). easier interop with getmeta (#1240)

cmd/wsh/cmd/wshcmd-setmeta.go

@@ -6,6 +6,8 @@ package cmd
 import (
 	"encoding/json"
 	"fmt"
+	"io"
+	"os"
 	"strconv"
 	"strings"
 
@@ -14,15 +16,46 @@ import (
 )
 
 var setMetaCmd = &cobra.Command{
-	Use:     "setmeta {blockid|blocknum|this} key=value ...",
+	Use:     "setmeta [-b {blockid|blocknum|this}] [--json file.json] key=value ...",
 	Short:   "set metadata for an entity",
-	Args:    cobra.MinimumNArgs(1),
+	Args:    cobra.MinimumNArgs(0),
 	Run:     setMetaRun,
 	PreRunE: preRunSetupRpcClient,
 }
 
+var setMetaJsonFilePath string
+
 func init() {
 	rootCmd.AddCommand(setMetaCmd)
+	setMetaCmd.Flags().StringVar(&setMetaJsonFilePath, "json", "", "JSON file containing metadata to apply (use '-' for stdin)")
+}
+
+func loadJSONFile(filepath string) (map[string]interface{}, error) {
+	var data []byte
+	var err error
+
+	if filepath == "-" {
+		data, err = io.ReadAll(os.Stdin)
+		if err != nil {
+			return nil, fmt.Errorf("reading from stdin: %v", err)
+		}
+	} else {
+		data, err = os.ReadFile(filepath)
+		if err != nil {
+			return nil, fmt.Errorf("reading JSON file: %v", err)
+		}
+	}
+
+	var result map[string]interface{}
+	if err := json.Unmarshal(data, &result); err != nil {
+		return nil, fmt.Errorf("parsing JSON file: %v", err)
+	}
+
+	if result == nil {
+		return nil, fmt.Errorf("JSON file must contain an object, not null")
+	}
+
+	return result, nil
 }
 
 func parseMetaSets(metaSets []string) (map[string]interface{}, error) {
@@ -39,7 +72,7 @@ func parseMetaSets(metaSets []string) (map[string]interface{}, error) {
 			meta[fields[0]] = true
 		} else if setVal == "false" {
 			meta[fields[0]] = false
-		} else if setVal[0] == '[' || setVal[0] == '{' {
+		} else if setVal[0] == '[' || setVal[0] == '{' || setVal[0] == '"' {
 			var val interface{}
 			err := json.Unmarshal([]byte(setVal), &val)
 			if err != nil {
@@ -63,31 +96,63 @@ func parseMetaSets(metaSets []string) (map[string]interface{}, error) {
 	return meta, nil
 }
 
+func simpleMergeMeta(meta map[string]interface{}, metaUpdate map[string]interface{}) map[string]interface{} {
+	for k, v := range metaUpdate {
+		if v == nil {
+			delete(meta, k)
+		} else {
+			meta[k] = v
+		}
+	}
+	return meta
+}
+
 func setMetaRun(cmd *cobra.Command, args []string) {
-	oref := blockArg
-	metaSetsStrs := args[:]
-	if oref == "" {
-		WriteStderr("[error] oref is required\n")
+	if blockArg == "" {
+		WriteStderr("[error] block (oref) is required\n")
 		return
 	}
-	err := validateEasyORef(oref)
+	err := validateEasyORef(blockArg)
 	if err != nil {
 		WriteStderr("[error] %v\n", err)
 		return
 	}
-	meta, err := parseMetaSets(metaSetsStrs)
+
+	var jsonMeta map[string]interface{}
+	if setMetaJsonFilePath != "" {
+		jsonMeta, err = loadJSONFile(setMetaJsonFilePath)
 		if err != nil {
 			WriteStderr("[error] %v\n", err)
 			return
 		}
-	fullORef, err := resolveSimpleId(oref)
+	}
+
+	cmdMeta, err := parseMetaSets(args)
+	if err != nil {
+		WriteStderr("[error] %v\n", err)
+		return
+	}
+
+	// Merge JSON metadata with command-line metadata, with command-line taking precedence
+	var fullMeta map[string]any
+	if len(jsonMeta) > 0 {
+		fullMeta = simpleMergeMeta(jsonMeta, cmdMeta)
+	} else {
+		fullMeta = cmdMeta
+	}
+	if len(fullMeta) == 0 {
+		WriteStderr("[error] no metadata keys specified\n")
+		return
+	}
+	fullORef, err := resolveSimpleId(blockArg)
 	if err != nil {
 		WriteStderr("[error] resolving oref: %v\n", err)
 		return
 	}
+
 	setMetaWshCmd := &wshrpc.CommandSetMetaData{
 		ORef: *fullORef,
-		Meta: meta,
+		Meta: fullMeta,
 	}
 	_, err = RpcClient.SendRpcRequest(wshrpc.Command_SetMeta, setMetaWshCmd, &wshrpc.RpcOpts{Timeout: 2000})
 	if err != nil {