bell/config.go

package main

import (
	"bufio"
	"errors"
	"fmt"
	"log"
	"os"
	"strings"

	"git.sr.ht/~sircmpwn/getopt"
)

type Config struct {
	Host            string   //irc-server
	Pass            string   //pass
	User            string   //user
	Nick            string   //nick
	Match           []string //match
	AppToken        string   //app-token
	UserToken       string   //user-token
	ExcludeChannels []string //exclude-channels
	ExcludeUsers    []string //exclude-users
}

//Partially adapted from:
//https://stackoverflow.com/questions/40022861/parsing-values-from-property-file-in-golang/46860900
func LoadConfig() (*Config, error) {
	opts, optind, err := getopt.Getopts(os.Args, "h:u:p:m:n:a:t:")
	if err != nil {
		log.Fatalf("Unable to get options %s", err)
	}
	var config *Config
	if optind < len(os.Args) {
		filePath := os.Args[optind]
		config, err = loadConfigFromFile(filePath)
		if err != nil {
			return nil, fmt.Errorf("Unable to read config file: %w", err)
		}
	} else {
		config = &Config{User: "-bell"}
	}
	for _, opt := range opts {
		switch opt.Option {
		case 'h':
			config.Host = opt.Value
		case 'u':
			config.User = opt.Value
		case 'p':
			config.Pass = opt.Value
		case 'm':
			config.Match = splitClean(opt.Value)
		case 'n':
			config.Nick = opt.Value
		case 'a':
			config.AppToken = opt.Value
		case 't':
			config.UserToken = opt.Value
		case 'e':
			config.ExcludeChannels = splitClean(opt.Value)
		case 'x':
			config.ExcludeUsers = splitClean(opt.Value)
		}
	}
	if config.Host == "" {
		return nil, errors.New("Most specify host either in config file or with -h")
	}
	if config.Nick == "" {
		config.Nick = config.User
	}
	if len(config.Match) == 0 {
		config.Match = []string{config.Nick}
	}
	if config.AppToken == "" || config.UserToken == "" {
		return nil, errors.New("Must specify app-token and user-token for pushover")
	}
	return config, nil
}

func loadConfigFromFile(path string) (*Config, error) {
	if len(path) == 0 {
		return nil, errors.New("Cannot read empty path")
	}
	config := &Config{
		User: "-bell",
	}
	file, err := os.Open(path)
	if err != nil {
		return nil, fmt.Errorf("Unable to open config file: %w", err)
	}
	defer file.Close()
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := scanner.Text()
		//handle comments
		if line[0] == '#' {
			continue
		}
		// This is big and ugly
		if equal := strings.Index(line, "="); equal >= 0 {
			if key := strings.TrimSpace(line[:equal]); len(key) > 0 {
				value := ""
				if len(line) > equal {
					value = strings.TrimSpace(line[equal+1:])
				}
				//TODO (noah): parse into config
				switch key {
				case "irc-server":
					config.Host = value
				case "pass":
					config.Pass = value
				case "user":
					config.User = value
				case "nick":
					config.Nick = value
				case "match":
					config.Match = splitClean(value)
				case "app-token":
					config.AppToken = value
				case "user-token":
					config.UserToken = value
				case "exclude-channels":
					config.ExcludeChannels = splitClean(value)
				case "exclude-users":
					config.ExcludeUsers = splitClean(value)
				default:
					log.Printf("Unknown property in config file: %s=%s", key, value)
					break
				}
			}
		}
	}
	if err := scanner.Err(); err != nil {
		return nil, fmt.Errorf("Unable to scan through config file: %w", err)
	}
	return config, nil
}

func splitClean(s string) []string {
	split := strings.Split(strings.TrimSpace(s), ",")
	output := make([]string, 0, len(split))
	for _, v := range split {
		if v != "" && v != " " {
			output = append(output, strings.TrimSpace(v))
		}
	}
	return output
}