Reverse metadata lookup

gistfile1.txt

func findCall(ext types.Extrinsic, m *types.Metadata) string {
	meta := m.AsMetadataV14
	call := ext.Method

	var sb strings.Builder

	for _, mod := range meta.Pallets {
		if !mod.HasCalls {
			continue
		}

		if mod.Index != types.U8(call.CallIndex.SectionIndex) {
			continue
		}

		if mod.Name != "Proxy" {
			continue
		}

		sb.WriteString("Pallet name - " + string(mod.Name))
		sb.WriteString("\n")

		callType := mod.Calls.Type.Int64()

		if typ, ok := meta.EfficientLookup[callType]; ok {
			if len(typ.Def.Variant.Variants) > 0 {
				for _, vars := range typ.Def.Variant.Variants {
					if vars.Name != "anonymous" {
						continue
					}

					sb.WriteString("Method name - " + string(vars.Name))
					sb.WriteString("\n")

					if vars.Index == types.U8(call.CallIndex.MethodIndex) {
						decoder := scale.NewDecoder(bytes.NewReader(call.Args))

						sb.WriteString("Args:\n")
						for _, field := range vars.Fields {
							switch fn := field.Name; fn {
							case "proxy_type":
								var pt types.ProxyType

								decoder.Decode(&pt)

								sb.WriteString(fmt.Sprintf("%s - %d\n", fn, pt))
							case "delay":
								var bn types.BlockNumber

								decoder.Decode(&bn)

								sb.WriteString(fmt.Sprintf("%s - %d\n", fn, bn))
							case "index":
								var index types.U16

								decoder.Decode(&index)

								sb.WriteString(fmt.Sprintf("%s - %d\n", fn, index))
							}
						}
					}
				}
			}
		}
	}

	return sb.String()
}