import { connector, toUpper, hasVal } from './util'

import { exprToSQL } from './expr'

function composePrefixValSuffix(stmt) {

if (!stmt) return []

return [toUpper(stmt.prefix), exprToSQL(stmt.value), toUpper(stmt.suffix)]

}

function fetchOffsetToSQL(stmt) {

const { fetch, offset } = stmt

const result = [...composePrefixValSuffix(offset), ...composePrefixValSuffix(fetch)]

return result.filter(hasVal).join(' ')

}

function limitOffsetToSQL(limit) {

const { seperator, value } = limit

return connector('LIMIT', value.map(exprToSQL).join(`${seperator === 'offset' ? ' ' : ''}${toUpper(seperator)} `))

}

function limitToSQL(limit) {

if (!limit) return ''

if (limit.fetch) return fetchOffsetToSQL(limit)

return limitOffsetToSQL(limit)

}

export {

limitToSQL,

}