package domain

import (
	"errors"
	"time"

	"github.com/google/uuid"
)

// CheckIn records that a guest walked in. One row per guest (the UNIQUE
// constraint prevents double check-in); arrival_count captures how many
// people were actually in the party — guest + plus-ones who showed.
// walk_in tags door-adds that weren't on the original guest list.
// Tier 2 Block H.
type CheckIn struct {
	ID           uuid.UUID  `json:"id"`
	GuestID      uuid.UUID  `json:"guest_id"`
	CheckedInAt  time.Time  `json:"checked_in_at"`
	CheckedInBy  *uuid.UUID `json:"checked_in_by,omitempty"`
	ArrivalCount int        `json:"arrival_count"`
	Notes        *string    `json:"notes,omitempty"`
	WalkIn       bool       `json:"walk_in"`
}

// CheckInSummary is the dashboard widget's data: total arrivals so far,
// and the original headcount goal (sum of attending + plus_ones).
type CheckInSummary struct {
	ArrivedHeadcount int `json:"arrived_headcount"`
	ExpectedHeadcount int `json:"expected_headcount"`
	GuestsCheckedIn  int `json:"guests_checked_in"`
}

var (
	ErrAlreadyCheckedIn = errors.New("guest is already checked in")
	ErrCheckInBadQR     = errors.New("invalid QR payload")
	ErrCheckInExpired   = errors.New("QR has expired")
	ErrCheckInMismatch  = errors.New("QR belongs to a different event")
)