slideshow/internal/config/config.go

package config

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

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

var ApiAddress string
var Interval time.Duration
var Resolution string
var PaletteFile string
var PaletteAlgorithm string
var PaletteColors int
var Script string
var ScriptArgs []string
var ScriptAsync bool
var ScriptStage string

// initialize the config
func Initialize() {
	loggo.SetLogLevelByName(os.Getenv("SLIDESHOW_LOGLEVEL"))
	ApiAddress = os.Getenv("SLIDESHOW_API")
	if len(ApiAddress) == 0 {
		loggo.Fatal("no adress of the slideshow-api server has been specified")
	}
	if !strings.HasPrefix(ApiAddress, "http://") && !strings.HasPrefix(ApiAddress, "https://") {
		ApiAddress = "http://" + ApiAddress
	}
	tmpInt, _ := strconv.Atoi(os.Getenv("SLIDESHOW_INTERVAL"))
	if tmpInt <= 0 {
		tmpInt = 60
	}
	Interval = 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 + "'")
		}
	}
	PaletteFile = os.Getenv("SLIDESHOW_PALETTE")
	PaletteAlgorithm = os.Getenv("SLIDESHOW_PALETTE_ALGORITHM")
	tmpInt, _ = strconv.Atoi(os.Getenv("SLIDESHOW_PALETTE_COLORS"))
	if tmpInt <= 0 {
		tmpInt = 16
	}
	PaletteColors = tmpInt
	Script = os.Getenv("SLIDESHOW_SCRIPT")
	ScriptArgs = strings.Split(os.Getenv("SLIDESHOW_SCRIPT_ARGS"), " ")
	ScriptAsync, _ = strconv.ParseBool(os.Getenv("SLIDESHOW_SCRIPT_ASYNC"))
	ScriptStage = strings.ToLower(os.Getenv("SLIDESHOW_SCRIPT_STAGE"))
	checkScript()
	checkFehCommand()
}

// check if a script has been specified and exists
func checkScript() {
	if len(Script) == 0 {
		return
	}
	stats, error := os.Stat(Script)
	if error != nil {
		loggo.Warning("encountered an error getting stats for the script '"+Script+"', script execution is unavailable", error.Error())
		Script = ""
		return
	}
	if stats.IsDir() {
		loggo.Warning("the script '"+Script+"' seems to be a directory, script execution is unavailable", error.Error())
		Script = ""
		return
	}
	if string(stats.Mode().Perm().String()[3]) != "x" {
		loggo.Warning("the script '"+Script+"' seems to be a directory, script execution is unavailable", error.Error())
		Script = ""
	}
	checkScriptStage()
}

// check if the specified script stage is valid
func checkScriptStage() {
	switch ScriptStage {
	case "pre_image":
		fallthrough
	case "post_image":
		fallthrough
	case "pre_palette":
		fallthrough
	case "post_palette":
		return
	default:
		ScriptStage = ""
	}
}

// check if 'feh' is available
func checkFehCommand() {
	cmd := exec.Command("which", "feh")
	error := cmd.Run()
	if error == nil {
		return
	}
	loggo.Fatal("could not find command 'feh'")
}

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

// check if a color palette should be generated
func IsPaletteSet() bool {
	return len(PaletteFile) > 0
}

// check if a script has been specified
func IsScriptSet() bool {
	return len(Script) > 0
}

// check if a script stage has been specified
func IsScriptStageSet() bool {
	return len(ScriptStage) > 0
}

// check if script stage 'pre_image' has been specified
func IsScriptStagePreImage() bool {
	return ScriptStage == "pre_image"
}

// check if script stage 'post_image' has been specified
func IsScriptStagePostImage() bool {
	return ScriptStage == "post_image"
}

// check if script stage 'pre_palette' has been specified
func IsScriptStagePrePalette() bool {
	return ScriptStage == "pre_palette"
}

// check if script stage 'post_palette' has been specified
func IsScriptStagePostPalette() bool {
	return ScriptStage == "post_palette"
}