'use strict'

const util = require('util')

/**

* Helper object to format and aggragate lines of code.

* Lines are aggregated in a `code` array, and need to be joined to obtain a proper code snippet.

*

* @class

*

* @param {string} indentation Desired indentation character for aggregated lines of code

* @param {string} join Desired character to join each line of code

*/

const CodeBuilder = function (indentation, join) {

this.code = []

this.indentation = indentation

this.lineJoin = join || '\n'

}

/**

* Add given indentation level to given string and format the string (variadic)

* @param {number} [indentationLevel=0] - Desired level of indentation for this line

* @param {string} line - Line of code. Can contain formatting placeholders

* @param {...anyobject} - Parameter to bind to `line`'s formatting placeholders

* @return {string}

*

* @example

* var builder = CodeBuilder('\t')

*

* builder.buildLine('console.log("hello world")')

* // returns: 'console.log("hello world")'

*

* builder.buildLine(2, 'console.log("hello world")')

* // returns: 'console.log("\t\thello world")'

*

* builder.buildLine(2, 'console.log("%s %s")', 'hello', 'world')

* // returns: 'console.log("\t\thello world")'

*/

CodeBuilder.prototype.buildLine = function (indentationLevel, line) {

let lineIndentation = ''

let slice = 2

if (Object.prototype.toString.call(indentationLevel) === '[object String]') {

slice = 1

line = indentationLevel

indentationLevel = 0

} else if (indentationLevel === null) {

return null

}

while (indentationLevel) {

lineIndentation += this.indentation

indentationLevel--

}

const format = Array.prototype.slice.call(arguments, slice, arguments.length)

format.unshift(lineIndentation + line)

return util.format.apply(this, format)

}

/**

* Invoke buildLine() and add the line at the top of current lines

* @param {number} [indentationLevel=0] Desired level of indentation for this line

* @param {string} line Line of code

* @return {this}

*/

CodeBuilder.prototype.unshift = function () {

this.code.unshift(this.buildLine.apply(this, arguments))

return this

}

/**

* Invoke buildLine() and add the line at the bottom of current lines

* @param {number} [indentationLevel=0] Desired level of indentation for this line

* @param {string} line Line of code

* @return {this}

*/

CodeBuilder.prototype.push = function () {

this.code.push(this.buildLine.apply(this, arguments))

return this

}

/**

* Add an empty line at the end of current lines

* @return {this}

*/

CodeBuilder.prototype.blank = function () {

this.code.push(null)

return this

}

/**

* Concatenate all current lines using the given lineJoin

* @return {string}

*/

CodeBuilder.prototype.join = function () {

return this.code.join(this.lineJoin)

}

module.exports = CodeBuilder