// Package discord provides utilities for interacting with the discord API
package discord

import (
	"strings"

	"git.haelnorr.com/h/golib/env"
	"github.com/pkg/errors"
)

type Config struct {
	ClientID     string `ezconf:"DISCORD_CLIENT_ID,required,description:Discord application client ID"`
	ClientSecret string `ezconf:"DISCORD_CLIENT_SECRET,required,description:Discord application client secret"`
	RedirectPath string `ezconf:"DISCORD_REDIRECT_PATH,required,description:Path for the OAuth redirect handler"`
	BotToken     string `ezconf:"DISCORD_BOT_TOKEN,required,description:Token for the discord bot"`
	GuildID      string `ezconf:"DISCORD_GUILD_ID,required,description:ID for the discord server the bot should connect to"`

	OAuthScopes string // Authorisation scopes for OAuth
}

func ConfigFromEnv() (any, error) {
	cfg := &Config{
		ClientID:     env.String("DISCORD_CLIENT_ID", ""),
		ClientSecret: env.String("DISCORD_CLIENT_SECRET", ""),
		OAuthScopes:  getOAuthScopes(),
		RedirectPath: env.String("DISCORD_REDIRECT_PATH", ""),
		BotToken:     env.String("DISCORD_BOT_TOKEN", ""),
		GuildID:      env.String("DISCORD_GUILD_ID", ""),
	}

	// Check required fields
	if cfg.ClientID == "" {
		return nil, errors.New("Envar not set: DISCORD_CLIENT_ID")
	}
	if cfg.ClientSecret == "" {
		return nil, errors.New("Envar not set: DISCORD_CLIENT_SECRET")
	}
	if cfg.RedirectPath == "" {
		return nil, errors.New("Envar not set: DISCORD_REDIRECT_PATH")
	}
	if cfg.BotToken == "" {
		return nil, errors.New("Envar not set: DISCORD_BOT_TOKEN")
	}
	if cfg.GuildID == "" {
		return nil, errors.New("Envar not set: DISCORD_GUILD_ID")
	}

	return cfg, nil
}

func getOAuthScopes() string {
	list := []string{
		"connections",
		"email",
		"guilds",
		"gdm.join",
		"guilds.members.read",
		"identify",
	}
	scopes := strings.Join(list, "+")
	return scopes
}