package ports

import (
	"context"
	"errors"
	"fmt"
	"strings"

	"galaxy/authsession/internal/domain/common"
)

// MailSender delivers the public login code or intentionally suppresses
// outward delivery while keeping the auth flow success-shaped.
type MailSender interface {
	// SendLoginCode attempts delivery for one generated login code. Explicit
	// delivery failure is reported through error, while sent vs suppressed is
	// returned in the result.
	SendLoginCode(ctx context.Context, input SendLoginCodeInput) (SendLoginCodeResult, error)
}

// SendLoginCodeInput describes one mail-delivery request generated by the auth
// flow.
type SendLoginCodeInput struct {
	// Email identifies the normalized target e-mail address.
	Email common.Email

	// Code stores the cleartext login code that should be delivered to Email.
	Code string
}

// Validate reports whether SendLoginCodeInput contains a complete delivery
// request.
func (i SendLoginCodeInput) Validate() error {
	if err := i.Email.Validate(); err != nil {
		return fmt.Errorf("send login code input email: %w", err)
	}
	switch {
	case strings.TrimSpace(i.Code) == "":
		return errors.New("send login code input code must not be empty")
	case strings.TrimSpace(i.Code) != i.Code:
		return errors.New("send login code input code must not contain surrounding whitespace")
	default:
		return nil
	}
}

// SendLoginCodeOutcome identifies the coarse mail-delivery outcome reported
// back to the auth flow.
type SendLoginCodeOutcome string

const (
	// SendLoginCodeOutcomeSent reports that delivery was attempted and accepted.
	SendLoginCodeOutcomeSent SendLoginCodeOutcome = "sent"

	// SendLoginCodeOutcomeSuppressed reports that outward behavior remains
	// success-shaped while actual delivery is intentionally skipped.
	SendLoginCodeOutcomeSuppressed SendLoginCodeOutcome = "suppressed"
)

// IsKnown reports whether SendLoginCodeOutcome is supported by the current
// mail-sender contract.
func (o SendLoginCodeOutcome) IsKnown() bool {
	switch o {
	case SendLoginCodeOutcomeSent, SendLoginCodeOutcomeSuppressed:
		return true
	default:
		return false
	}
}

// SendLoginCodeResult describes the stable outcome returned by MailSender for
// one delivery request.
type SendLoginCodeResult struct {
	// Outcome reports whether delivery was sent or intentionally suppressed.
	Outcome SendLoginCodeOutcome
}

// Validate reports whether SendLoginCodeResult satisfies the mail-sender
// contract invariants.
func (r SendLoginCodeResult) Validate() error {
	if !r.Outcome.IsKnown() {
		return fmt.Errorf("send login code result outcome %q is unsupported", r.Outcome)
	}

	return nil
}