cpolis/cmd/backend/config.go

package backend

import (
	"flag"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/BurntSushi/toml"
)

type Config struct {
	DBName      string
	Description string
	Domain      string
	FirebaseKey string
	KeyFile     string
	Link        string
	LogFile     string
	PDFDir      string
	PicsDir     string
	Port        string
	RSSFile     string
	Title       string
	WebDir      string
}

func newConfig() *Config {
	return &Config{
		DBName:      "cpolis",
		FirebaseKey: "/var/www/cpolis/serviceAccountKey.json",
		KeyFile:     "/var/www/cpolis/cpolis.key",
		LogFile:     "/var/log/cpolis.log",
		PDFDir:      "/var/www/cpolis/pdfs",
		PicsDir:     "/var/www/cpolis/pics",
		RSSFile:     "/var/www/cpolis/cpolis.rss",
		WebDir:      "/var/www/cpolis/web",
	}
}

func (c *Config) readFile() error {
	cfgFile, err := filepath.Abs(os.Getenv("HOME") + "/.config/cpolis/config.toml")
	if err != nil {
		return fmt.Errorf("error getting absolute path for config file: %v", err)
	}

	_, err = os.Stat(cfgFile)
	if os.IsNotExist(err) {
		fileStrings := strings.Split(cfgFile, "/")

		dir := strings.Join(fileStrings[0:len(fileStrings)-1], "/")
		if err = os.MkdirAll(dir, 0755); err != nil {
			return fmt.Errorf("error creating config directory: %v", err)
		}

		fileName := fileStrings[len(fileStrings)-1]
		file, err := os.Create(dir + "/" + fileName)
		if err != nil {
			return fmt.Errorf("error creating config file: %v", err)
		}
		defer file.Close()
		if err = file.Chmod(0644); err != nil {
			return fmt.Errorf("error setting permissions for config file: %v", err)
		}
	} else {
		_, err = toml.DecodeFile(cfgFile, c)
		if err != nil {
			return fmt.Errorf("error reading config file: %v", err)
		}
	}

	return nil
}

func (c *Config) handleCliArgs() error {
	var err error
	port := 8080

	flag.StringVar(&c.DBName, "db", c.DBName, "DB name")
	flag.StringVar(&c.Description, "desc", c.Description, "channel description")
	flag.StringVar(&c.Domain, "domain", c.Domain, "domain name")
	flag.StringVar(&c.FirebaseKey, "firebase", c.FirebaseKey, "Firebase service account key file")
	flag.StringVar(&c.KeyFile, "key", c.KeyFile, "key file")
	flag.StringVar(&c.Link, "link", c.Link, "channel Link")
	flag.StringVar(&c.LogFile, "log", c.LogFile, "log file")
	flag.StringVar(&c.PDFDir, "pdfs", c.PDFDir, "pdf directory")
	flag.StringVar(&c.PicsDir, "pics", c.PicsDir, "pictures directory")
	flag.StringVar(&c.RSSFile, "rss", c.RSSFile, "RSS file")
	flag.StringVar(&c.Title, "title", c.Title, "channel title")
	flag.StringVar(&c.WebDir, "web", c.WebDir, "web directory")
	flag.IntVar(&port, "port", port, "port")
	flag.Parse()

	c.FirebaseKey, err = filepath.Abs(c.FirebaseKey)
	if err != nil {
		return fmt.Errorf("error finding absolute path for Firebase service account key file: %v", err)
	}

	c.KeyFile, err = filepath.Abs(c.KeyFile)
	if err != nil {
		return fmt.Errorf("error finding absolute path for key file: %v", err)
	}

	c.LogFile, err = filepath.Abs(c.LogFile)
	if err != nil {
		return fmt.Errorf("error finding absolute path for log file: %v", err)
	}

	c.PDFDir, err = filepath.Abs(c.PDFDir)
	if err != nil {
		return fmt.Errorf("error finding absolute path for pdfs dir: %v", err)
	}

	c.PicsDir, err = filepath.Abs(c.PicsDir)
	if err != nil {
		return fmt.Errorf("error finding absolute path for pics dir: %v", err)
	}

	c.Port = fmt.Sprint(":", port)

	c.RSSFile, err = filepath.Abs(c.RSSFile)
	if err != nil {
		return fmt.Errorf("error finding absolute path for RSS file: %v", err)
	}

	c.WebDir, err = filepath.Abs(c.WebDir)
	if err != nil {
		return fmt.Errorf("error finding absolute path for web dir: %v", err)
	}

	return nil
}

func HandleConfig() (*Config, error) {
	config := newConfig()

	if err := config.readFile(); err != nil {
		return nil, fmt.Errorf("error reading config file: %v", err)
	}

	if err := config.handleCliArgs(); err != nil {
		return nil, fmt.Errorf("error handling cli arguments: %v", err)
	}

	return config, nil
}