package skykit

import (

	"database/sql"

	"fmt"

)

var (

	ErrIterStop = fmt.Errorf("stop iteration")

)

type Iter struct {

	Conn *sql.DB

	Text string

	Args []any

}

type reader func(ScanFunc) error

type ScanFunc func(...any) error

func (i *Iter) Exec() error {

	_, err := i.Conn.Exec(i.Text, i.Args...)

	return err

}

func (i *Iter) Scan(args ...any) error {

	row := i.Conn.QueryRow(i.Text, i.Args...)

	if err := row.Err(); err != nil {

		return err

	}

	return row.Scan(args...)

}

func (i *Iter) All(fn reader) error {

	rows, err := i.Conn.Query(i.Text, i.Args...)

	if err != nil {

		return err

	}

	defer rows.Close()

	for rows.Next() {

		if err := fn(rows.Scan); err != nil {

			return err

		}

	}

	return nil

}

func (i *Iter) Page(limit int, fn reader) (more bool, err error) {

	rows, err := i.Conn.Query(i.Text, i.Args...)

	if err != nil {

		return false, err

	}

	defer rows.Close()

	var count int

	for rows.Next() {

		if count++; count == limit+1 {

			return true, nil

		}

		if err := fn(rows.Scan); err != nil {

			return false, err

		}

	}

	return false, nil

}