config.go

package main

import (
	"fmt"
	"os"

	"github.com/BurntSushi/toml"
	"github.com/nolanlum/tanya/irc"
	"github.com/nolanlum/tanya/token"
)

type slack struct {
	Token string
}

// Config holds configuration data for Tanya
type Config struct {
	Gateway []GatewayInstance
}

// SetDefaults overwrites config entries with their default values
func (c *Config) SetDefaults() {
	for i := range c.Gateway {
		c.Gateway[i].SetDefaults()
	}
}

// GatewayInstance holds configuration data for a single IRC<->Slack bridge instance
type GatewayInstance struct {
	Slack slack
	IRC   irc.Config
}

// SetDefaults overwrites config entries with their default values
func (g *GatewayInstance) SetDefaults() {
	g.IRC.SetDefaults()
}

// LoadConfig parses a config if it exists, or generates a new one
func LoadConfig(configPath string, disableConfigGen bool) (*Config, error) {
	tomlData, err := os.ReadFile(configPath)

	if !disableConfigGen && os.IsNotExist(err) {
		fmt.Println("config.toml does not exist, generating one...")
		return initializeConfig()
	} else if err != nil {
		return nil, err
	}

	return parseConfig(string(tomlData))
}

// initializeConfig interactively generates and writes a config
func initializeConfig() (*Config, error) {
	var conf Config
	conf.SetDefaults()
	slackToken, err := token.GetSlackToken()
	if err != nil {
		return nil, err
	}

	conf.Gateway = []GatewayInstance{{Slack: slack{Token: slackToken}}}

	fmt.Print("Writing config.toml...")
	f, err := os.Create("config.toml")
	if err != nil {
		return nil, err
	}
	defer f.Close()
	if err := toml.NewEncoder(f).Encode(conf); err != nil {
		return nil, err
	}
	fmt.Println("Done")
	return &conf, nil
}

// parseConfig reads a toml string and returns a parsed config
func parseConfig(tomlData string) (*Config, error) {
	var conf Config

	// Parse the config once to populate list fields
	if _, err := toml.Decode(tomlData, &conf); err != nil {
		return nil, err
	}

	// Re-parse the config to make sure defaults for each GatewayInstance are set
	conf.SetDefaults()
	if _, err := toml.Decode(tomlData, &conf); err != nil {
		return nil, err
	}

	return &conf, nil
}