package config

import (
	"io"
	"io/ioutil"
	"time"

	"github.com/caarlos0/env/v6"
	"github.com/pkg/errors"

	"gopkg.in/yaml.v2"
)

type Config struct {
	HTTP  HTTPConfig  `yaml:"http"`
	SMTP  SMTPConfig  `yaml:"smtp"`
	Data  DataConfig  `yaml:"data"`
	Relay RelayConfig `yaml:"relay"`
}

type HTTPConfig struct {
	Address     string `yaml:"address" env:"FAKESMTP_HTTP_ADDRESS"`
	TemplateDir string `yaml:"templateDir" env:"FAKESMTP_HTTP_TEMPLATEDIR"`
	PublicDir   string `yaml:"publicDir" env:"FAKESMTP_HTTP_PUBLICDIR"`
}

type SMTPConfig struct {
	Address           string        `yaml:"address" env:"FAKESMTP_SMTP_ADDRESS"`
	Username          string        `yaml:"username" env:"FAKESMTP_SMTP_USERNAME"`
	Password          string        `yaml:"password" env:"FAKESMTP_SMTP_PASSWORD"`
	Domain            string        `yaml:"domain" env:"FAKESMTP_SMTP_DOMAIN"`
	ReadTimeout       time.Duration `yaml:"readTimeout" env:"FAKESMTP_SMTP_READTIMEOUT"`
	WriteTimeout      time.Duration `yaml:"writeTimeout" env:"FAKESMTP_SMTP_WRITETIMEOUT"`
	MaxMessageBytes   int           `yaml:"maxMessageBytes" env:"FAKESMTP_SMTP_MAXMESSAGEBYTES"`
	MaxRecipients     int           `yaml:"maxRecipients" env:"FAKESMTP_SMTP_MAXRECIPIENTS"`
	AllowInsecureAuth bool          `yaml:"allowInsecureAuth" env:"FAKESMTP_SMTP_ALLOWINSECUREAUTH"`
	Debug             bool          `yaml:"debug" env:"FAKESMTP_SMTP_DEBUG"`
}

type RelayConfig struct {
	Enabled            bool   `yaml:"enabled" env:"FAKESMTP_RELAY_ENABLED"`
	Address            string `yaml:"address" env:"FAKESMTP_RELAY_ADDRESS"`
	Identity           string `yaml:"identity" env:"FAKESMTP_RELAY_IDENTITY"`
	Username           string `yaml:"username" env:"FAKESMTP_RELAY_USERNAME"`
	Password           string `yaml:"password" env:"FAKESMTP_RELAY_PASSWORD"`
	Anonymous          bool   `yaml:"anonymous" env:"FAKESMTP_RELAY_ANONYMOUS"`
	UseTLS             bool   `yaml:"useTLS" env:"FAKESMTP_RELAY_USE_TLS"`
	InsecureSkipVerify bool   `yaml:"insecureSkipVerify" env:"FAKESMTP_RELAY_INSECURE_SKIP_VERIFY"`
	FromOverride       string `yaml:"fromOverride" env:"FAKESMTP_RELAY_FROM_OVERRIDE"`
}

type DataConfig struct {
	Path string `yaml:"path" env:"FAKESMTP_DATA_PATH"`
}

// NewFromFile retrieves the configuration from the given file
func NewFromFile(filepath string) (*Config, error) {
	config := NewDefault()

	data, err := ioutil.ReadFile(filepath)
	if err != nil {
		return nil, errors.Wrapf(err, "could not read file '%s'", filepath)
	}

	if err := yaml.Unmarshal(data, config); err != nil {
		return nil, errors.Wrapf(err, "could not unmarshal configuration")
	}

	return config, nil
}

func WithEnvironment(conf *Config) error {
	if err := env.Parse(conf); err != nil {
		return err
	}

	return nil
}

func NewDumpDefault() *Config {
	config := NewDefault()
	return config
}

func NewDefault() *Config {
	return &Config{
		HTTP: HTTPConfig{
			Address:     ":8080",
			TemplateDir: "template",
			PublicDir:   "public",
		},
		SMTP: SMTPConfig{
			Address:           ":2525",
			Username:          "",
			Password:          "",
			Domain:            "localhost",
			ReadTimeout:       30 * time.Second,
			WriteTimeout:      30 * time.Second,
			MaxMessageBytes:   1024 * 1024,
			MaxRecipients:     50,
			AllowInsecureAuth: true,
			Debug:             true,
		},
		Data: DataConfig{
			Path: "fakesmtp.db",
		},
		Relay: RelayConfig{
			Enabled: false,
		},
	}
}

func Dump(config *Config, w io.Writer) error {
	data, err := yaml.Marshal(config)
	if err != nil {
		return errors.Wrap(err, "could not dump config")
	}

	if _, err := w.Write(data); err != nil {
		return err
	}

	return nil
}