package config

import (
	"fmt"
	"os"

	"github.com/pelletier/go-toml/v2"
	"golang.org/x/oauth2"
)

type (
	GoogleConfig struct {
		ApiKey			string `toml:"api_key"`
		ClientID		string `toml:"client_id"`
		ClientSecret	string `toml:"client_secret"`
	}

	Config struct {
		Host		string `toml:"host" comment:"Address to host OAuth2 redirect flow"`
		RedirectUri	string `toml:"redirect_uri" comment:"URI to use in Google OAuth2 flow"`
		Google	GoogleConfig `toml:"google"`
		Token	*oauth2.Token `toml:"token" comment:"This section is filled in automatically on a successful authentication flow."`
	}
)

var defaultConfig = Config{
	Host: "localhost:8090",
	RedirectUri: "http://localhost:8090",
	Google: GoogleConfig{
		ApiKey: "<your API key here>",
		ClientID: "<your client ID here>",
		ClientSecret: "<your client secret here>",
	},
}

var CONFIG_FILENAME string = "config.toml"

func ReadConfig(filename string) (*Config, error) {
	cfgBytes, err := os.ReadFile(filename)
	if err != nil {
		if os.IsNotExist(err) {
			return nil, nil
		}
		return nil, fmt.Errorf("failed to open file: %v", err)
	}

	var config Config
	err = toml.Unmarshal(cfgBytes, &config)
	if err != nil { return &config, fmt.Errorf("failed to parse: %v", err) }

	return &config, nil
}

func WriteConfig(cfg *Config, filename string) error {
	file, err := os.OpenFile(filename, os.O_CREATE | os.O_RDWR, 0644)
	if err != nil { return err }

	err = toml.NewEncoder(file).Encode(cfg)
	return err
}

func GenerateConfig(filename string) error {
	return WriteConfig(&defaultConfig, filename)
}