package store

import (
	"context"
	"fmt"
	"time"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5/pgxpool"
)

// Item is the projection of an items row.
type Item struct {
	ID        uuid.UUID  `json:"id"`
	ListID    uuid.UUID  `json:"list_id"`
	Name      string     `json:"name"`
	Quantity  *string    `json:"quantity,omitempty"`
	Checked   bool       `json:"checked"`
	SortOrder *int       `json:"sort_order,omitempty"`
	CreatedAt time.Time  `json:"created_at"`
	UpdatedAt time.Time  `json:"updated_at"`
	DeletedAt *time.Time `json:"deleted_at,omitempty"`
	HLCTS     int64      `json:"hlc_ts"`
	ClientID  *uuid.UUID `json:"client_id,omitempty"`
	CheckedAt *time.Time `json:"checked_at,omitempty"`
}

// ItemStore provides read access to the items projection.
type ItemStore struct {
	pool *pgxpool.Pool
}

// NewItemStore creates an ItemStore backed by the given pool.
func NewItemStore(pool *pgxpool.Pool) *ItemStore { return &ItemStore{pool: pool} }

// GetItems returns all non-deleted items for listID, ordered by sort_order then creation time.
func (s *ItemStore) GetItems(ctx context.Context, listID uuid.UUID) ([]Item, error) {
	rows, err := s.pool.Query(ctx, `
		SELECT id, list_id, name, quantity, checked, sort_order,
		       created_at, updated_at, hlc_ts, client_id, checked_at
		FROM items
		WHERE list_id = $1 AND deleted_at IS NULL
		ORDER BY sort_order ASC NULLS LAST, created_at ASC`,
		listID,
	)
	if err != nil {
		return nil, fmt.Errorf("itemstore: get items: %w", err)
	}
	defer rows.Close()

	var items []Item
	for rows.Next() {
		var it Item
		if err := rows.Scan(
			&it.ID, &it.ListID, &it.Name, &it.Quantity, &it.Checked,
			&it.SortOrder, &it.CreatedAt, &it.UpdatedAt,
			&it.HLCTS, &it.ClientID, &it.CheckedAt,
		); err != nil {
			return nil, fmt.Errorf("itemstore: scan item row: %w", err)
		}
		items = append(items, it)
	}
	return items, rows.Err()
}