Bugfixes (#13)

* several fixes:

- fix #9 + #10: switched to koanf module and dropped support for HCL
- fix #11: disabling colors on windows
- fix #12: fixed race condition in go routine call inside for loop,
  images had been downloaded multiple times
- remove hcl support and use toml format (same thing, better parser)
- update documentation and example config on TOML format of config file
- use Config as arg instead of singular args
- use x/errgroup instead of sync.Waitgroup inside image download loop

---------

Co-authored-by: Thomas von Dein <tom@vondein.org>

config.go

@@ -17,13 +17,22 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 package main
 
 import (
+	"errors"
+	"fmt"
 	"os"
+	"path/filepath"
+	"runtime"
 
-	"github.com/hashicorp/hcl/v2/hclsimple"
+	"github.com/knadh/koanf/parsers/toml"
+	"github.com/knadh/koanf/providers/confmap"
+	"github.com/knadh/koanf/providers/file"
+	"github.com/knadh/koanf/providers/posflag"
+	"github.com/knadh/koanf/v2"
+	flag "github.com/spf13/pflag"
 )
 
 const (
-	VERSION         string = "0.0.6"
+	VERSION         string = "0.1.0"
 	Baseuri         string = "https://www.kleinanzeigen.de"
 	Listuri         string = "/s-bestandsliste.html"
 	Defaultdir      string = "."
@@ -35,32 +44,135 @@ const (
 		"AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36"
 )
 
+const Usage string = `This is kleingebaeck, the kleinanzeigen.de backup tool.
+
+Usage: kleingebaeck [-dvVhmoclu] [<ad-listing-url>,...]
+
+Options:
+--user    -u <uid>      Backup ads from user with uid <uid>.
+--debug   -d            Enable debug output.
+--verbose -v            Enable verbose output.
+--outdir  -o <dir>      Set output dir (default: current directory)
+--limit   -l <num>      Limit the ads to download to <num>, default: load all.
+--config  -c <file>     Use config file <file> (default: ~/.kleingebaeck).
+--manual  -m            Show manual.
+--help    -h            Show usage.
+--version -V            Show program version.
+
+If one  or more ad listing url's  are specified, only  backup those,
+otherwise backup all ads of the given user.`
+
 type Config struct {
-	Verbose  *bool   `hcl:"verbose"`
-	User     *int    `hcl:"user"`
-	Outdir   *string `hcl:"outdir"`
-	Template *string `hcl:"template"`
+	Verbose          bool   `koanf:"verbose"` // loglevel=info
+	Debug            bool   `koanf:"debug"`   // loglevel=debug
+	Showversion      bool   `koanf:"version"` // -v
+	Showhelp         bool   `koanf:"help"`    // -h
+	Showmanual       bool   `koanf:"manual"`  // -m
+	User             int    `koanf:"user"`
+	Outdir           string `koanf:"outdir"`
+	Template         string `koanf:"template"`
+	Loglevel         string `koanf:"loglevel"`
+	Limit            int    `koanf:"limit"`
+	Adlinks          []string
+	StatsCountAds    int
+	StatsCountImages int
 }
 
-func ParseConfigfile(file string) (*Config, error) {
-	c := Config{}
-	if path, err := os.Stat(file); !os.IsNotExist(err) {
-		if !path.IsDir() {
-			configstring, err := os.ReadFile(file)
-			if err != nil {
-				return nil, err
-			}
+func (c *Config) IncrAds() {
+	c.StatsCountAds++
+}
 
-			err = hclsimple.Decode(
-				path.Name(), configstring,
-				nil, &c,
-			)
+func (c *Config) IncrImgs(num int) {
+	c.StatsCountImages += num
+}
 
-			if err != nil {
-				return nil, err
-			}
+// load commandline flags and config file
+func InitConfig() (*Config, error) {
+	var k = koanf.New(".")
+
+	// determine template based on os
+	template := DefaultTemplate
+	if runtime.GOOS == "windows" {
+		template = DefaultTemplateWin
+	}
+
+	// Load default values using the confmap provider.
+	k.Load(confmap.Provider(map[string]interface{}{
+		"template": template,
+		"outdir":   ".",
+		"loglevel": "notice",
+		"userid":   0,
+	}, "."), nil)
+
+	// setup custom usage
+	f := flag.NewFlagSet("config", flag.ContinueOnError)
+	f.Usage = func() {
+		fmt.Println(Usage)
+		os.Exit(0)
+	}
+
+	// parse commandline flags
+	f.StringP("config", "c", "", "config file")
+	f.StringP("outdir", "o", "", "directory where to store ads")
+	f.IntP("user", "u", 0, "user id")
+	f.IntP("limit", "l", 0, "limit ads to be downloaded (default 0, unlimited)")
+	f.BoolP("verbose", "v", false, "be verbose")
+	f.BoolP("debug", "d", false, "enable debug log")
+	f.BoolP("version", "V", false, "show program version")
+	f.BoolP("help", "h", false, "show usage")
+	f.BoolP("manual", "m", false, "show manual")
+
+	f.Parse(os.Args[1:])
+
+	// generate a  list of config files to try  to load, including the
+	// one provided via -c, if any
+	var configfiles []string
+	configfile, _ := f.GetString("config")
+	home, _ := os.UserHomeDir()
+	if configfile != "" {
+		configfiles = []string{configfile}
+	} else {
+		configfiles = []string{
+			"/etc/kleingebaeck.conf", "/usr/local/etc/kleingebaeck.conf", // unix variants
+			filepath.Join(home, ".config", "kleingebaeck", "config"),
+			filepath.Join(home, ".kleingebaeck"),
+			"kleingebaeck.conf",
 		}
 	}
 
-	return &c, nil
+	// Load the config file[s]
+	for _, cfgfile := range configfiles {
+		if path, err := os.Stat(cfgfile); !os.IsNotExist(err) {
+			if !path.IsDir() {
+				if err := k.Load(file.Provider(cfgfile), toml.Parser()); err != nil {
+					return nil, errors.New("error loading config file: " + err.Error())
+				}
+			}
+		}
+		// else: we ignore the file if it doesn't exists
+	}
+
+	// command line overrides config file
+	if err := k.Load(posflag.Provider(f, ".", k), nil); err != nil {
+		return nil, errors.New("error loading flags: " + err.Error())
+	}
+
+	// fetch values
+	conf := &Config{}
+	if err := k.Unmarshal("", &conf); err != nil {
+		return nil, errors.New("error unmarshalling: " + err.Error())
+	}
+
+	// adjust loglevel
+	switch conf.Loglevel {
+	case "verbose":
+		conf.Verbose = true
+	case "debug":
+		conf.Debug = true
+	}
+
+	// are there any args left on commandline? if so threat them as adlinks
+	conf.Adlinks = f.Args()
+
+	return conf, nil
 }