slideshow-api/internal/config/config.go

package config

import (
	"os"
	"os/exec"
	"strconv"
	"strings"
	"time"

	"git.velvettear.de/velvettear/loggo"
)

var ServerAddress string
var ServerPort int
var Directory string
var ScanInterval time.Duration
var Resolution string
var PaletteAlgorithm int
var PaletteColors int
var BufferSize int

// initialize the config
func Initialize() {
	loggo.SetLogLevelByName(os.Getenv("SLIDESHOW_LOGLEVEL"))
	ServerAddress = os.Getenv("SLIDESHOW_ADDRESS")
	tmpInt, _ := strconv.Atoi(os.Getenv("SLIDESHOW_PORT"))
	if tmpInt <= 0 {
		tmpInt = 3000
	}
	ServerPort = tmpInt
	Directory = os.Getenv("SLIDESHOW_DIRECTORY")
	if len(Directory) == 0 {
		tmp, error := os.UserHomeDir()
		if error != nil {
			loggo.Fatal("encountered an error getting the current user's home directory", error.Error())
		}
		Directory = tmp
	}
	stats, error := os.Stat(Directory)
	if error != nil {
		loggo.Fatal("encountered an error checking the directory '"+Directory+"'", error.Error())
	}
	if !stats.IsDir() {
		loggo.Fatal("configured directory '" + Directory + "' is not a valid directory")
	}
	tmpInt, _ = strconv.Atoi(os.Getenv("SLIDESHOW_SCANINTERVAL"))
	if tmpInt <= 0 {
		tmpInt = 60
	}
	ScanInterval = time.Duration(tmpInt) * time.Second
	Resolution = os.Getenv("SLIDESHOW_RESOLUTION")
	if len(Resolution) > 0 {
		width, height, found := strings.Cut(Resolution, "x")
		if !found {
			loggo.Fatal("encountered an error parsing the configured resolution, make sure to specify the format like '1920x1080'")
		}
		_, error = strconv.Atoi(width)
		if error != nil {
			loggo.Fatal("encountered an error parsing the configured width '" + width + "'")
		}
		_, error = strconv.Atoi(height)
		if error != nil {
			loggo.Fatal("encountered an error parsing the configured height '" + height + "'")
		}
	}
	tmpString := os.Getenv("SLIDESHOW_PALETTE_ALGORITHM")
	if strings.ToLower(tmpString) == "wu" {
		PaletteAlgorithm = 0
	} else {
		PaletteAlgorithm = 1
	}
	tmpInt, _ = strconv.Atoi(os.Getenv("SLIDESHOW_PALETTE_COLORS"))
	if tmpInt <= 0 {
		tmpInt = 16
	}
	PaletteColors = tmpInt
	tmpInt, _ = strconv.Atoi(os.Getenv("SLIDESHOW_BUFFERSIZE"))
	if tmpInt <= 0 {
		tmpInt = 4096
	}
	BufferSize = tmpInt
	if IsResolutionSet() {
		checkForConvert()
	}
}

// check if 'convert' is available
func checkForConvert() {
	cmd := exec.Command("convert")
	error := cmd.Run()
	if error == nil {
		return
	}
	Resolution = ""
	loggo.Warning("could not find imagemagick's 'convert' command, no scaling will be done", error.Error())
}

// check if a resolution has been specified
func IsResolutionSet() bool {
	return len(Resolution) > 0
}