env.go

package sellsword

import (
	"bufio"
	"fmt"
	"github.com/fatih/color"
	"gopkg.in/yaml.v2"
	"io/ioutil"
	"os"
	"path"
	"sort"
	"strings"
)

type Env struct {
	Name            string
	Path            string
	Current         bool
	EnvType         string
	ExportVariables map[string]string
	Variables       map[string]string
}

func NewEnv(name string, basePath string, exportVars map[string]string, vars []string,
	envType string) (*Env, error) {
	env := new(Env)
	env.Name = name
	env.EnvType = envType
	env.Path = path.Join(basePath, name)
	if envType == "environment" {
		env.ExportVariables = exportVars
		// load the Variables from file if they exist
		if _, err := os.Stat(env.Path); err == nil {
			if env.Variables, err = env.loadYaml(); err != nil {
				return env, err
			}
		} else {
			env.Variables = arrayToEmptyMap(vars)
		}
	}
	return env, nil
}

// NewEnvironmentEnv is a factory method that properly initializes the Env struct for the env type of Environment
func NewEnvironmentEnv(name string, basePath string, exportVars map[string]string, vars []string) (*Env, error) {
	return NewEnv(name, basePath, exportVars, vars, "environment")
}

// NewDirectoryEnv is a factory method that properly initializes the Env struct for the env type of Directory
func NewDirectoryEnv(name string, basePath string) (*Env, error) {
	return NewEnv(name, basePath, map[string]string{}, []string{}, "directory")
}

func (e *Env) Load() {
	if e.EnvType == "environment" {
		e.PopulateExportVars()
		e.PrintExports()
	}
}

func (e *Env) loadYaml() (map[string]string, error) {
	varMap := make(map[string]string)
	if d, err := ioutil.ReadFile(e.Path); err != nil {
		return varMap, err
	} else {
		err := yaml.Unmarshal(d, varMap)
		return varMap, err
	}
}

func (e *Env) Save() error {
	if e.EnvType != "environment" {
		Logger.Warnf("Environment type %s does not currently support the save operation", e.EnvType)
		return nil
	}
	if d, err := yaml.Marshal(&e.Variables); err != nil {
		return err
	} else {
		if err := ioutil.WriteFile(e.Path, d, 0775); err != nil {
			return err
		} else {
			green := GetTermPrinterF(color.FgGreen)
			fmt.Print(green("New environment created at %s\n", e.Path))
			return nil
		}
	}
}

func (e *Env) PopulateExportVars() error {
	if yamlVars, err := e.loadYaml(); err != nil {
		return err
	} else {
		for key, value := range e.ExportVariables {
			if v, ok := yamlVars[value]; ok {
				e.ExportVariables[key] = v
			} else {
				delete(e.ExportVariables, key)
			}
		}
		Logger.Debugf("env export vars are %v", e.ExportVariables)
		return nil
	}
}

// This is a separate function from PrintExports to make it easier to test
func (e *Env) MakeExportStatements() string {
	statements := make([]string, 0)
	for key, value := range e.ExportVariables {
		statements = append(statements, "export "+key+"="+value)
	}
	// We sort it so that the output is easier to test
	sort.Strings(statements)
	return strings.Join(statements, "\n")
}

func (e *Env) PrintExports() {
	fmt.Println(e.MakeExportStatements())
}

// *Constructs* a new environment, not to be confused w/ the Constructor NewEnv
// In case of environment type, queries user for values
// Not implemented for other types yet
func (e *Env) Construct() error {
	if e.EnvType == "environment" {
		for k, _ := range e.Variables {
			reader := bufio.NewReader(os.Stdin)
			fmt.Printf("%s: ", k)
			if text, err := reader.ReadString('\n'); err != nil {
				return err
			} else {
				e.Variables[k] = strings.TrimSpace(text)
			}
		}
		if err := e.Save(); err != nil {
			Logger.Errorf("error: %v", err)
			return err
		}
	} else {
		red := GetTermPrinterF(color.FgRed)
		fmt.Fprint(os.Stderr, red("new command not implemented for environment type %s", e.EnvType))
	}
	return nil
}