package inviteui

import (
	"context"
	"errors"
	"fmt"

	"tug/internal/service/invite"
	"tug/internal/service/password"
	"tug/internal/transport/web"
)

type Redeemer struct {
	service *invite.Service
}

func New(service *invite.Service) Redeemer {
	if service == nil {
		panic("inviteui: the redeemer needs an invite service")
	}
	return Redeemer{service: service}
}

var inviteProblems = []struct {
	err     error
	problem web.InviteProblem
}{
	{invite.ErrUsernameGrammar, web.InviteUsernameGrammar},
	{invite.ErrUsernameTaken, web.InviteUsernameTaken},
	{invite.ErrDisplayNameInvalid, web.InviteDisplayNameInvalid},
	{password.ErrTooShort, web.InvitePasswordShort},
	{password.ErrTooLong, web.InvitePasswordLong},
	{invite.ErrPasswordMismatch, web.InvitePasswordMismatch},
}

func inviteError(err error) error {
	if errors.Is(err, invite.ErrInvalidToken) {
		return web.ErrInviteInvalid
	}
	if errors.Is(err, password.ErrBusy) {
		return fmt.Errorf("%w: %w", web.ErrInviteBusy, err)
	}
	for _, p := range inviteProblems {
		if errors.Is(err, p.err) {
			return p.problem
		}
	}
	return err
}

func (r Redeemer) Check(ctx context.Context, token string) error {
	if err := r.service.Check(ctx, token); err != nil {
		return inviteError(err)
	}
	return nil
}

func (r Redeemer) Redeem(ctx context.Context, token string, f web.InviteForm) (web.InviteRedeemed, error) {
	redeemed, err := r.service.RedeemAccount(ctx, token, invite.Form{
		Username:    f.Username,
		DisplayName: f.DisplayName,
		Password:    f.Password,
		Confirm:     f.Confirm,
	})
	if err != nil {
		return web.InviteRedeemed{}, inviteError(err)
	}
	return web.InviteRedeemed{Username: redeemed.Username, Code: redeemed.Code}, nil
}