package service

import (
	"fmt"
	"os"
	"strings"

	"github.com/resend/resend-go/v2"
)

type EmailService struct {
	client    *resend.Client
	fromEmail string
}

func NewEmailService() *EmailService {
	apiKey := os.Getenv("RESEND_API_KEY")
	from := os.Getenv("RESEND_FROM_EMAIL")
	if from == "" {
		from = "noreply@multica.ai"
	}

	var client *resend.Client
	if apiKey != "" {
		client = resend.NewClient(apiKey)
	}

	return &EmailService{
		client:    client,
		fromEmail: from,
	}
}

func (s *EmailService) SendVerificationCode(to, code string) error {
	if s.client == nil {
		fmt.Printf("[DEV] Verification code for %s: %s\n", to, code)
		return nil
	}

	params := &resend.SendEmailRequest{
		From:    s.fromEmail,
		To:      []string{to},
		Subject: "Your Multica verification code",
		Html: fmt.Sprintf(
			`<div style="font-family: sans-serif; max-width: 400px; margin: 0 auto;">
				<h2>Your verification code</h2>
				<p style="font-size: 32px; font-weight: bold; letter-spacing: 8px; margin: 24px 0;">%s</p>
				<p>This code expires in 10 minutes.</p>
				<p style="color: #666; font-size: 14px;">If you didn't request this code, you can safely ignore this email.</p>
			</div>`, code),
	}

	_, err := s.client.Emails.Send(params)
	return err
}

// SendInvitationEmail notifies the invitee that they have been invited to a workspace.
// invitationID is included in the URL so the email deep-links to /invite/{id}.
func (s *EmailService) SendInvitationEmail(to, inviterName, workspaceName, invitationID string) error {
	appURL := strings.TrimSpace(os.Getenv("FRONTEND_ORIGIN"))
	if appURL == "" {
		appURL = "https://app.multica.ai"
	}
	inviteURL := fmt.Sprintf("%s/invite/%s", appURL, invitationID)

	if s.client == nil {
		fmt.Printf("[DEV] Invitation email to %s: %s invited you to %s — %s\n", to, inviterName, workspaceName, inviteURL)
		return nil
	}

	params := &resend.SendEmailRequest{
		From:    s.fromEmail,
		To:      []string{to},
		Subject: fmt.Sprintf("%s invited you to %s on Multica", inviterName, workspaceName),
		Html: fmt.Sprintf(
			`<div style="font-family: sans-serif; max-width: 480px; margin: 0 auto;">
				<h2>You're invited to join %s</h2>
				<p><strong>%s</strong> invited you to collaborate in the <strong>%s</strong> workspace on Multica.</p>
				<p style="margin: 24px 0;">
					<a href="%s" style="display: inline-block; padding: 12px 24px; background: #000; color: #fff; text-decoration: none; border-radius: 6px; font-weight: 500;">Accept invitation</a>
				</p>
				<p style="color: #666; font-size: 14px;">You'll need to log in to accept or decline the invitation.</p>
			</div>`, workspaceName, inviterName, workspaceName, inviteURL),
	}

	_, err := s.client.Emails.Send(params)
	return err
}