add data command and utility functions for type assertion and map key access

cmd/strom/data/main.go

@@ -0,0 +1,118 @@
+package data
+
+import (
+	"encoding/json"
+	"fmt"
+	"maps"
+	"os"
+	"slices"
+
+	"github.com/admin-else/strom/data"
+	"github.com/admin-else/strom/proto_generated"
+	"github.com/admin-else/strom/util"
+)
+
+// strom data 1.21.11 blocks id 0 name => air
+//   {
+//    "id": 0,
+//    "name": "air",
+//    "displayName": "Air",
+//    "hardness": 0.0,
+//    "resistance": 0.0,
+//    "stackSize": 64,
+//    "diggable": false,
+//    "material": "default",
+//    "transparent": true,
+//    "emitLight": 0,
+//    "filterLight": 0,
+//    "defaultState": 0,
+//    "minStateId": 0,
+//    "maxStateId": 0,
+//    "states": [],
+//    "drops": [],
+//    "boundingBox": "empty"
+//  },
+
+func Run(args []string) (err error) {
+	var dataValues any
+	switch len(args) {
+	case 0: // print available versions
+		dataValues = proto_generated.SupportedVersions
+	case 1: // print available data for version
+		dataValues = slices.Collect(maps.Keys(data.Paths.Data[args[0]]))
+	case 2:
+		err = data.LoadVersionedJson(args[0], args[1], &dataValues)
+	case 3:
+		err = data.LoadVersionedJson(args[0], args[1], &dataValues)
+		if err != nil {
+			return
+		}
+		var dataSlices []any
+		dataSlices, err = util.AssertTypeError[[]any](dataValues)
+		if err != nil {
+			return
+		}
+		var result = make([]any, len(dataSlices))
+		for _, v := range dataSlices {
+			var dataMap map[string]any
+			dataMap, err = util.AssertTypeError[map[string]any](v)
+			if err != nil {
+				return
+			}
+			var vToAppend any
+			vToAppend, err = util.MapGetError(dataMap, args[2])
+			if err != nil {
+				return
+			}
+			result = append(result, vToAppend)
+		}
+		dataValues = result
+	case 4, 5:
+		err = data.LoadVersionedJson(args[0], args[1], &dataValues)
+		if err != nil {
+			return
+		}
+		var dataSlices []any
+		dataSlices, err = util.AssertTypeError[[]any](dataValues)
+		if err != nil {
+			return
+		}
+		found := false
+		for _, v := range dataSlices {
+			var dataMap map[string]any
+			dataMap, err = util.AssertTypeError[map[string]any](v)
+			if err != nil {
+				return
+			}
+			if v2, ok := dataMap[args[2]]; ok {
+				if args[3] != fmt.Sprint(v2) {
+					continue
+				}
+
+				dataValues = dataMap
+				found = true
+				if len(args) == 5 {
+					dataValues, err = util.MapGetError(dataMap, args[4])
+					if err != nil {
+						return
+					}
+				}
+				break
+			}
+		}
+		if !found {
+			err = fmt.Errorf("not found")
+			return
+		}
+	default:
+		err = fmt.Errorf("too many arguments")
+	}
+
+	if err == nil {
+		e := json.NewEncoder(os.Stdout)
+		e.SetIndent("", "  ")
+		err = e.Encode(dataValues)
+		return
+	}
+	return
+}

cmd/strom/main.go

@@ -10,6 +10,7 @@ import (
 	"slices"
 
 	"github.com/admin-else/strom/cmd/strom/api"
+	"github.com/admin-else/strom/cmd/strom/data"
 	"github.com/admin-else/strom/cmd/strom/extract_mca"
 	"github.com/admin-else/strom/cmd/strom/offline_uuid"
 	"github.com/admin-else/strom/cmd/strom/packet_inspector"
@@ -41,6 +42,7 @@ var subcommands = map[string]func(args []string) error{
 	"api":          api.Run,
 	"version":      Version,
 	"extract-mca":  extract_mca.Run,
+	"data":         data.Run,
 }
 
 func Help(args []string) (err error) {

util/must.go

@@ -1,5 +1,7 @@
 package util
 
+import "fmt"
+
 func MustOk[T any](v T, ok bool) T {
 	if !ok {
 		panic("not ok")
@@ -19,3 +21,20 @@ func Must(err error) {
 		panic(err)
 	}
 }
+
+func AssertTypeError[T any](v any) (T, error) {
+	var zero T
+	r, ok := v.(T)
+	if !ok {
+		return zero, fmt.Errorf("type assertion failed: %T cannot be asserted to %T", v, zero)
+	}
+	return r, nil
+}
+
+func MapGetError[K comparable, V any, M map[K]V](m M, k K) (V, error) {
+	v, ok := m[k]
+	if !ok {
+		return v, fmt.Errorf("key %v not found", k)
+	}
+	return v, nil
+}