import { columnDefinitionToSQL } from './column'

import { createDefinitionToSQL } from './create'

import { indexTypeAndOptionToSQL } from './index-definition'

import { tablesToSQL } from './tables'

import { exprToSQL } from './expr'

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

function alterToSQL(stmt) {

const { type, table, expr = [] } = stmt

const action = toUpper(type)

const tableName = tablesToSQL(table)

const exprList = expr.map(exprToSQL)

const result = [action, 'TABLE', tableName, exprList.join(', ')]

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

}

function alterExprToSQL(expr) {

const {

action, create_definitions: createDefinition, if_not_exists: ifNotExists,keyword, resource, symbol,

} = expr

let name = ''

let dataType = []

switch (resource) {

case 'column':

dataType = [columnDefinitionToSQL(expr)]

break

case 'index':

dataType = indexTypeAndOptionToSQL(expr)

name = expr[resource]

break

case 'table':

name = identifierToSql(expr[resource])

break

case 'algorithm':

case 'lock':

name = [symbol, toUpper(expr[resource])].filter(hasVal).join(' ')

break

case 'constraint':

name = identifierToSql(expr[resource])

dataType = [createDefinitionToSQL(createDefinition)]

break

default:

break

}

const alterArray = [toUpper(action), toUpper(keyword), toUpper(ifNotExists), name, dataType.filter(hasVal).join(' ')]

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

}

export {

alterToSQL,

alterExprToSQL,

}