SEBA-767 Directory restructuring in accordance with best practices

Change-Id: Id651366a3545ad0141a7854e99fa46867e543295
diff --git a/internal/pkg/commands/command.go b/internal/pkg/commands/command.go
new file mode 100644
index 0000000..45ccd5d
--- /dev/null
+++ b/internal/pkg/commands/command.go
@@ -0,0 +1,277 @@
+/*
+ * Portions copyright 2019-present Open Networking Foundation
+ * Original copyright 2019-present Ciena Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package commands
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/opencord/cordctl/pkg/format"
+	"github.com/opencord/cordctl/pkg/order"
+	"google.golang.org/grpc"
+	"gopkg.in/yaml.v2"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"strings"
+	"time"
+	"net"
+)
+
+type OutputType uint8
+
+const (
+	OUTPUT_TABLE OutputType = iota
+	OUTPUT_JSON
+	OUTPUT_YAML
+
+	CORE_VERSION_CONSTRAINT = ">= 3, < 4" // Support XOS major version 3
+)
+
+// Make it easy to override output stream for testing
+var OutputStream io.Writer = os.Stdout
+
+var CharReplacer = strings.NewReplacer("\\t", "\t", "\\n", "\n")
+
+type GrpcConfigSpec struct {
+	Timeout time.Duration `yaml:"timeout"`
+}
+
+type TlsConfigSpec struct {
+	UseTls bool   `yaml:"useTls"`
+	CACert string `yaml:"caCert"`
+	Cert   string `yaml:"cert"`
+	Key    string `yaml:"key"`
+	Verify string `yaml:"verify"`
+}
+
+type GlobalConfigSpec struct {
+	Server   string        `yaml:"server"`
+	Username string        `yaml:"username"`
+	Password string        `yaml:"password"`
+	Protoset string        `yaml:"protoset"`
+	Tls      TlsConfigSpec `yaml:"tls"`
+	Grpc     GrpcConfigSpec
+}
+
+var GlobalConfig = GlobalConfigSpec{
+	Server: "localhost",
+	Tls: TlsConfigSpec{
+		UseTls: false,
+	},
+	Grpc: GrpcConfigSpec{
+		Timeout: time.Second * 10,
+	},
+}
+
+var GlobalOptions struct {
+	Config   string `short:"c" long:"config" env:"CORDCONFIG" value-name:"FILE" default:"" description:"Location of client config file"`
+	Server   string `short:"s" long:"server" default:"" value-name:"SERVER:PORT" description:"IP/Host and port of XOS"`
+	Username string `short:"u" long:"username" value-name:"USERNAME" default:"" description:"Username to authenticate with XOS"`
+	Password string `short:"p" long:"password" value-name:"PASSWORD" default:"" description:"Password to authenticate with XOS"`
+	Protoset string `long:"protoset" value-name:"FILENAME" description:"Load protobuf definitions from protoset instead of reflection api"`
+	Debug    bool   `short:"d" long:"debug" description:"Enable debug mode"`
+	UseTLS   bool   `long:"tls" description:"Use TLS"`
+	CACert   string `long:"tlscacert" value-name:"CA_CERT_FILE" description:"Trust certs signed only by this CA"`
+	Cert     string `long:"tlscert" value-name:"CERT_FILE" description:"Path to TLS vertificate file"`
+	Key      string `long:"tlskey" value-name:"KEY_FILE" description:"Path to TLS key file"`
+	Verify   bool   `long:"tlsverify" description:"Use TLS and verify the remote"`
+	Yes      bool   `short:"y" long:"yes" description:"answer yes to any confirmation prompts"`
+}
+
+type OutputOptions struct {
+	Format   string `long:"format" value-name:"FORMAT" default:"" description:"Format to use to output structured data"`
+	Quiet    bool   `short:"q" long:"quiet" description:"Output only the IDs of the objects"`
+	OutputAs string `short:"o" long:"outputas" default:"table" choice:"table" choice:"json" choice:"yaml" description:"Type of output to generate"`
+}
+
+type ListOutputOptions struct {
+	OutputOptions
+	OrderBy string `short:"r" long:"orderby" default:"" description:"Specify the sort order of the results"`
+}
+
+func toOutputType(in string) OutputType {
+	switch in {
+	case "table":
+		fallthrough
+	default:
+		return OUTPUT_TABLE
+	case "json":
+		return OUTPUT_JSON
+	case "yaml":
+		return OUTPUT_YAML
+	}
+}
+
+type CommandResult struct {
+	Format   format.Format
+	OrderBy  string
+	OutputAs OutputType
+	Data     interface{}
+}
+
+type config struct {
+	Server string `yaml:"server"`
+}
+
+func ProcessGlobalOptions() {
+	if len(GlobalOptions.Config) == 0 {
+		home, err := os.UserHomeDir()
+		if err != nil {
+			log.Printf("Unable to discover the users home directory: %s\n", err)
+		}
+		GlobalOptions.Config = fmt.Sprintf("%s/.cord/config", home)
+	}
+
+	info, err := os.Stat(GlobalOptions.Config)
+	if err == nil && !info.IsDir() {
+		configFile, err := ioutil.ReadFile(GlobalOptions.Config)
+		if err != nil {
+			log.Printf("configFile.Get err   #%v ", err)
+		}
+		err = yaml.Unmarshal(configFile, &GlobalConfig)
+		if err != nil {
+			log.Fatalf("Unmarshal: %v", err)
+		}
+	}
+
+	// Override from environment
+	//    in particualr, for passing env vars via `go test`
+	env_server, present := os.LookupEnv("CORDCTL_SERVER")
+	if present {
+		GlobalConfig.Server = env_server
+	}
+	env_username, present := os.LookupEnv("CORDCTL_USERNAME")
+	if present {
+		GlobalConfig.Username = env_username
+	}
+	env_password, present := os.LookupEnv("CORDCTL_PASSWORD")
+	if present {
+		GlobalConfig.Password = env_password
+	}
+	env_protoset, present := os.LookupEnv("CORDCTL_PROTOSET")
+	if present {
+		GlobalConfig.Protoset = env_protoset
+	}
+
+	// Override from command line
+	if GlobalOptions.Server != "" {
+		GlobalConfig.Server = GlobalOptions.Server
+	}
+	if GlobalOptions.Username != "" {
+		GlobalConfig.Username = GlobalOptions.Username
+	}
+	if GlobalOptions.Password != "" {
+		GlobalConfig.Password = GlobalOptions.Password
+	}
+	if GlobalOptions.Protoset != "" {
+		GlobalConfig.Protoset = GlobalOptions.Protoset
+	}
+
+	// Generate error messages for required settings
+	if GlobalConfig.Server == "" {
+		log.Fatal("Server is not set. Please update config file or use the -s option")
+	}
+	if GlobalConfig.Username == "" {
+		log.Fatal("Username is not set. Please update config file or use the -u option")
+	}
+	if GlobalConfig.Password == "" {
+		log.Fatal("Password is not set. Please update config file or use the -p option")
+	}
+	//Try to resolve hostname if provided for the server
+	if host, port, err := net.SplitHostPort(GlobalConfig.Server); err == nil {
+		if addrs, err := net.LookupHost(host); err == nil {
+			GlobalConfig.Server = net.JoinHostPort(addrs[0], port)
+		}
+	}
+}
+
+func NewConnection() (*grpc.ClientConn, error) {
+	ProcessGlobalOptions()
+	return grpc.Dial(GlobalConfig.Server, grpc.WithInsecure())
+}
+
+func GenerateOutput(result *CommandResult) {
+	if result != nil && result.Data != nil {
+		data := result.Data
+		if result.OrderBy != "" {
+			s, err := order.Parse(result.OrderBy)
+			if err != nil {
+				panic(err)
+			}
+			data, err = s.Process(data)
+			if err != nil {
+				panic(err)
+			}
+		}
+		if result.OutputAs == OUTPUT_TABLE {
+			tableFormat := format.Format(result.Format)
+			tableFormat.Execute(OutputStream, true, data)
+		} else if result.OutputAs == OUTPUT_JSON {
+			asJson, err := json.Marshal(&data)
+			if err != nil {
+				panic(err)
+			}
+			fmt.Fprintf(OutputStream, "%s", asJson)
+		} else if result.OutputAs == OUTPUT_YAML {
+			asYaml, err := yaml.Marshal(&data)
+			if err != nil {
+				panic(err)
+			}
+			fmt.Fprintf(OutputStream, "%s", asYaml)
+		}
+	}
+}
+
+// Applies common output options to format and generate output
+func FormatAndGenerateOutput(options *OutputOptions, default_format string, quiet_format string, data interface{}) {
+	outputFormat := CharReplacer.Replace(options.Format)
+	if outputFormat == "" {
+		outputFormat = default_format
+	}
+	if options.Quiet {
+		outputFormat = quiet_format
+	}
+
+	result := CommandResult{
+		Format:   format.Format(outputFormat),
+		OutputAs: toOutputType(options.OutputAs),
+		Data:     data,
+	}
+
+	GenerateOutput(&result)
+}
+
+// Applies common output options to format and generate output
+func FormatAndGenerateListOutput(options *ListOutputOptions, default_format string, quiet_format string, data interface{}) {
+	outputFormat := CharReplacer.Replace(options.Format)
+	if outputFormat == "" {
+		outputFormat = default_format
+	}
+	if options.Quiet {
+		outputFormat = quiet_format
+	}
+
+	result := CommandResult{
+		Format:   format.Format(outputFormat),
+		OutputAs: toOutputType(options.OutputAs),
+		Data:     data,
+		OrderBy:  options.OrderBy,
+	}
+
+	GenerateOutput(&result)
+}