package mail

import (
	"fmt"
	"net/smtp"
	"os"
	"time"
)

// Config holds SMTP server configuration
type Config struct {
	Host     string
	Port     string
	Username string
	Password string
	From     string
}

// Client handles email operations
type Client struct {
	Config Config
}

// Mailer is an alias for Client to maintain compatibility with backup package
type Mailer struct {
	Config Config
}

// NewClient creates a new mail client from environment variables
func NewClient() *Client {
	return &Client{
		Config: Config{
			Host:     os.Getenv("SMTP_HOST"),
			Port:     os.Getenv("SMTP_PORT"),
			Username: os.Getenv("SMTP_USERNAME"),
			Password: os.Getenv("SMTP_PASSWORD"),
			From:     os.Getenv("SMTP_FROM"),
		},
	}
}

// NewMailer creates a new mailer from environment variables
func NewMailer() *Mailer {
	client := NewClient()
	return &Mailer{
		Config: client.Config,
	}
}

// SendMail sends an email notification
func (c *Client) SendMail(to []string, subject, body string) error {
	addr := fmt.Sprintf("%s:%s", c.Config.Host, c.Config.Port)
	// Compose message
	message := []byte(fmt.Sprintf("From: %s\r\n"+
		"To: %s\r\n"+
		"Subject: %s\r\n"+
		"\r\n"+
		"%s\r\n", c.Config.From, to[0], subject, body))
	// Authenticate
	auth := smtp.PlainAuth("", c.Config.Username, c.Config.Password, c.Config.Host)
	// Send mail
	return smtp.SendMail(addr, auth, c.Config.From, to, message)
}

// SendMail sends an email notification (Mailer version)
func (m *Mailer) SendMail(to []string, subject, body string) error {
	addr := fmt.Sprintf("%s:%s", m.Config.Host, m.Config.Port)
	// Compose message
	message := []byte(fmt.Sprintf("From: %s\r\n"+
		"To: %s\r\n"+
		"Subject: %s\r\n"+
		"\r\n"+
		"%s\r\n", m.Config.From, to[0], subject, body))
	// Authenticate
	auth := smtp.PlainAuth("", m.Config.Username, m.Config.Password, m.Config.Host)
	// Send mail
	return smtp.SendMail(addr, auth, m.Config.From, to, message)
}

// SendSuccessNotification sends a backup success notification
func (m *Mailer) SendSuccessNotification(serviceName string, duration time.Duration) error {
	recipients := []string{os.Getenv("NOTIFICATION_EMAIL")}
	if recipients[0] == "" {
		recipients[0] = m.Config.From // Fallback to sender if no notification email set
	}

	subject := fmt.Sprintf("Backup Successful: %s", serviceName)
	body := fmt.Sprintf("The backup for service %s completed successfully in %v.", serviceName, duration)

	return m.SendMail(recipients, subject, body)
}

// SendErrorNotification sends a backup error notification
func (m *Mailer) SendErrorNotification(serviceName string, err error) error {
	recipients := []string{os.Getenv("NOTIFICATION_EMAIL")}
	if recipients[0] == "" {
		recipients[0] = m.Config.From // Fallback to sender if no notification email set
	}

	subject := fmt.Sprintf("Backup Failed: %s", serviceName)
	body := fmt.Sprintf("The backup for service %s failed with error: %v", serviceName, err)

	return m.SendMail(recipients, subject, body)
}