package mdb

import (
	"context"

	"zombiezen.com/go/sqlite"
	"zombiezen.com/go/sqlite/sqlitex"
)

// load scans all results of sql and appends them to r.
func load[T any](ctx context.Context, db *sqlitex.Pool, r []T, sql string, row func(*sqlite.Stmt) T) ([]T, error) {
	conn, err := db.Take(ctx)
	defer db.Put(conn)
	if err != nil {
		return nil, err
	}
	stmt, err := conn.Prepare(sql)
	if err != nil {
		return nil, err
	}

	for {
		ok, err := stmt.Step()
		if err != nil {
			return r, err
		}
		if !ok {
			break
		}
		r = append(r, row(stmt))
	}
	return r, err
}