package repository

import (
	"context"
	"fmt"
	"time"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"
	"gogs.fxtmmsk.ru/foxtime/photoplaces/backend/internal/models"
)

type VisitorSessionRepo struct {
	pool *pgxpool.Pool
}

func NewVisitorSessionRepo(pool *pgxpool.Pool) *VisitorSessionRepo {
	return &VisitorSessionRepo{pool: pool}
}

func (r *VisitorSessionRepo) Create(ctx context.Context, vs *models.VisitorSession) error {
	err := r.pool.QueryRow(ctx,
		`INSERT INTO visitor_sessions (user_id, coordinates, last_active_at)
		 VALUES ($1, ST_SetSRID(ST_MakePoint($2, $3), 4326), $4)
		 RETURNING id, created_at`,
		vs.UserID, vs.Lng, vs.Lat, vs.LastActiveAt,
	).Scan(&vs.ID, &vs.CreatedAt)
	if err != nil {
		return fmt.Errorf("create visitor session: %w", err)
	}
	return nil
}

func (r *VisitorSessionRepo) GetByID(ctx context.Context, id string) (*models.VisitorSession, error) {
	row := r.pool.QueryRow(ctx,
		`SELECT id, user_id, ST_Y(coordinates::geometry) AS lat, ST_X(coordinates::geometry) AS lng,
		        last_active_at, created_at
		 FROM visitor_sessions WHERE id = $1`, id)
	return scanVisitorSession(row)
}

func (r *VisitorSessionRepo) UpdateLastActive(ctx context.Context, id string) error {
	_, err := r.pool.Exec(ctx,
		`UPDATE visitor_sessions SET last_active_at=$1 WHERE id=$2`,
		time.Now(), id)
	return err
}

func (r *VisitorSessionRepo) CountActive(ctx context.Context, since time.Duration) (int, error) {
	var count int
	err := r.pool.QueryRow(ctx,
		`SELECT COUNT(*) FROM visitor_sessions WHERE last_active_at > $1`,
		time.Now().Add(-since)).Scan(&count)
	if err != nil {
		return 0, fmt.Errorf("count active visitors: %w", err)
	}
	return count, nil
}

func scanVisitorSession(row interface{ Scan(dest ...any) error}) (*models.VisitorSession, error) {
	var vs models.VisitorSession
	err := row.Scan(&vs.ID, &vs.UserID, &vs.Lat, &vs.Lng, &vs.LastActiveAt, &vs.CreatedAt)
	if err != nil {
		if err == pgx.ErrNoRows {
			return nil, nil
		}
		return nil, err
	}
	return &vs, nil
}