RITlug/teleirc

package internal

import (
    "fmt"
    "os"
    "strings"

    "github.com/caarlos0/env/v6"
    "github.com/go-playground/validator"
    "github.com/joho/godotenv"
)

var validate *validator.Validate

const defaultPath = ".env"

// IRCSettings includes settings related to the IRC bot/message relaying
type IRCSettings struct {
    BindAddress         string   `env:"IRC_HOST_IP" envDefault:""`
    Server              string   `env:"IRC_SERVER,required"`
    ServerPass          string   `env:"IRC_SERVER_PASSWORD" envDefault:""`
    Port                int      `env:"IRC_PORT" envDefault:"6667" validate:"min=0,max=65535"`
    TLSAllowSelfSigned  bool     `env:"IRC_CERT_ALLOW_SELFSIGNED" envDefault:"true"`
    TLSAllowCertExpired bool     `env:"IRC_CERT_ALLOW_EXPIRED" envDefault:"true"`
    Channel             string   `env:"IRC_CHANNEL,required" validate:"notempty"`
    ChannelKey          string   `env:"IRC_CHANNEL_KEY" envDefault:""`
    BotIdent            string   `env:"IRC_BOT_IDENT,required" envDefault:"teleirc"`
    BotName             string   `env:"IRC_BOT_REALNAME" envDefault:"Powered by TeleIRC <github.com/RITlug/teleirc>"`
    BotNick             string   `env:"IRC_BOT_NAME,required" validate:"notempty"`
    SendStickerEmoji    bool     `env:"IRC_SEND_STICKER_EMOJI" envDefault:"true"`
    SendDocument        bool     `env:"IRC_SEND_DOCUMENT" envDefault:"true"`
    Prefix              string   `env:"IRC_PREFIX" envDefault:"<"`
    Suffix              string   `env:"IRC_SUFFIX" envDefault:">"`
    ShowJoinMessage     bool     `env:"IRC_SHOW_JOIN_MESSAGE" envDefault:"true"`
    ShowLeaveMessage    bool     `env:"IRC_SHOW_LEAVE_MESSAGE" envDefault:"true"`
    ShowZWSP            bool     `env:"IRC_SHOW_ZWSP" envDefault:"true"`
    ShowLocationMessage bool     `env:"IRC_SHOW_LOCATION_MESSAGE" envDefault:"false"`
    NickServUser        string   `env:"IRC_NICKSERV_USER" envDefault:""`
    NickServPassword    string   `env:"IRC_NICKSERV_PASS" envDefault:""`
    NickServService     string   `env:"IRC_NICKSERV_SERVICE" envDefault:""`
    EditedPrefix        string   `env:"IRC_EDITED_PREFIX" envDefault:"[EDIT] "`
    MaxMessageLength    int      `env:"IRC_MAX_MESSAGE_LENGTH" envDefault:"400"`
    IRCBlacklist        []string `env:"IRC_BLACKLIST" envDefault:"[]string{}"`
    UseSSL              bool     `env:"IRC_USE_SSL" envDefault:"false"`
    NoForwardPrefix     string   `env:"IRC_NO_FORWARD_PREFIX" envDefault:""`
    QuitMessage         string   `env:"IRC_QUIT_MESSAGE" envDefault:""`
}

// TelegramSettings includes settings related to the Telegram bot/message relaying
type TelegramSettings struct {
    Token                 string   `env:"TELEIRC_TOKEN,required"`
    ChatID                int64    `env:"TELEGRAM_CHAT_ID,required"`
    Prefix                string   `env:"TELEGRAM_MESSAGE_PREFIX" envDefault:"<"`
    Suffix                string   `env:"TELEGRAM_MESSAGE_SUFFIX" envDefault:">"`
    ReplyPrefix           string   `env:"TELEGRAM_MESSAGE_REPLY_PREFIX" envDefault:"["`
    ReplySuffix           string   `env:"TELEGRAM_MESSAGE_REPLY_SUFFIX" envDefault:"]"`
    ReplyLength           int      `env:"TELEGRAM_MESSAGE_REPLY_LENGTH" envDefault:"15"`
    ShowTopicMessage      bool     `env:"SHOW_TOPIC_MESSAGE" envDefault:"false"`
    ShowJoinMessage       bool     `env:"SHOW_JOIN_MESSAGE" envDefault:"false"`
    JoinMessageAllowList  []string `env:"JOIN_MESSAGE_ALLOW_LIST" envDefault:"[]string{}"`
    ShowActionMessage     bool     `env:"SHOW_ACTION_MESSAGE" envDefault:"true"`
    ShowLeaveMessage      bool     `env:"SHOW_LEAVE_MESSAGE" envDefault:"false"`
    LeaveMessageAllowList []string `env:"LEAVE_MESSAGE_ALLOW_LIST" envDefault:"[]string{}"`
    ShowKickMessage       bool     `env:"SHOW_KICK_MESSAGE" envDefault:"false"`
    ShowNickMessage       bool     `env:"SHOW_NICK_MESSAGE" envDefault:"false"`
    ShowDisconnectMessage bool     `env:"SHOW_DISCONNECT_MESSAGE" envDefault:"false"`
    MaxMessagePerMinute   int      `env:"MAX_MESSAGE_PER_MINUTE" envDefault:"20"`
}

// ImgurSettings includes settings related to Imgur uploading for Telegram photos
type ImgurSettings struct {
    ImgurClientID     string `env:"IMGUR_CLIENT_ID" envDefault:"7d6b00b87043f58"`
    ImgurClientSecret string `env:"IMGUR_CLIENT_SECRET" envDefault:""`
    ImgurRefreshToken string `env:"IMGUR_REFRESH_TOKEN" envDefault:""`
    ImgurAccessToken  string ``
    ImgurAlbumHash    string `env:"IMGUR_ALBUM_HASH" envDefault:""`
}

// Settings includes all user-configurable settings for TeleIRC
type Settings struct {
    IRC      IRCSettings
    Telegram TelegramSettings
    Imgur    ImgurSettings
}

func validateEmptyString(fl validator.FieldLevel) bool {
    return fl.Field().String() != ""
}

// ConfigErrors lets us wrap the validator errors in a type we can return
type ConfigErrors []validator.FieldError

func (ce ConfigErrors) Error() string {
    finalStr := ""
    for _, err := range ce {
        switch err.Tag() {
        case "notempty":
            finalStr += fmt.Sprintf("Field %s was an empty string. "+
                "Perhaps you had a # and need to surround the value with \"\"?\n", err.Namespace())
        case "min":
            finalStr += fmt.Sprintf("Field %s failed to validate: %s too small.\n",
                err.Namespace(), err.Param())
        case "max":
            finalStr += fmt.Sprintf("Field %s failed to validate: %s too large.\n",
                err.Namespace(), err.Param())
        default:
            finalStr += fmt.Sprintf("Field %s failed to validate: %s failed %s.\n",
                err.Namespace(), err.Param(), err.Tag())
        }
    }
    return finalStr
}

/*
For environment variables that are meant to be a list separated by whitespace,
we need to do that manually.   This function does just that.
*/
func splitEnvVar(list []string) []string {
    if list == nil {
        return list
    } else if len(list) == 0 {
        return list
    }

    return strings.Split(list[0], " ")
}

/*
LoadConfig loads in the .env file in the provided path (or ".env" by default)
If the user-provided config is valid, return a new Settings struct that contains these settings.
Otherwise, return the error that caused the failure.
*/
func LoadConfig(path string) (*Settings, error) {
    validate = validator.New()
    if err := validate.RegisterValidation("notempty", validateEmptyString); err != nil {
        return nil, err
    }
    // Attempt to load environment variables from path if path was provided
    if path != ".env" && path != "" {
        if err := godotenv.Load(path); err != nil {
            return nil, err
        }
    } else if _, err := os.Stat(defaultPath); !os.IsNotExist(err) {
        // Attempt to load from defaultPath if defaultPath exists
        if err := godotenv.Load(defaultPath); err != nil {
            return nil, err
        }
    }
    settings := &Settings{}
    if err := env.Parse(settings); err != nil {
        return nil, err
    }
    if err := validate.Struct(settings); err != nil {
        fieldErrs := ConfigErrors{}
        for _, errs := range err.(validator.ValidationErrors) {
            fieldErrs = append(fieldErrs, errs)
        }
        return nil, fieldErrs
    }

    settings.IRC.IRCBlacklist = splitEnvVar(settings.IRC.IRCBlacklist)
    settings.Telegram.JoinMessageAllowList = splitEnvVar(settings.Telegram.JoinMessageAllowList)
    settings.Telegram.LeaveMessageAllowList = splitEnvVar(settings.Telegram.LeaveMessageAllowList)

    return settings, nil
}