package ObjectIds
import NoWurst
import String
import ErrorHandling
import Wurstunit

string charMap = ".................................!.#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[.]^_`abcdefghijklmnopqrstuvwxyz{|}~................................................................................................................................."


/** Convert a integer id value into a 4-letter id code. */
public function idInteger2IdString(int value) returns string
	string result = ""
	int remainingValue = value
	int charValue

	for int byteno = 0 to 3
		charValue = ModuloInteger(remainingValue, 256)
		remainingValue = remainingValue div 256
		result = SubString(charMap, charValue, charValue + 1) + result

	return result

/** converts a 4-letter id code to an integer */
public function idString2IdInteger(string value) returns int
	var result = 0
	if value.length() != 4
		error("idInteger2IdString: value must be 4 chars long")
	else
		var factor = 1
		for i=0 to 3
			let pos = charMap.indexOf(value.charAt(3-i))
			result += factor*pos
			factor *= 256


	return result


@test function test_idString2IdInteger()
	idString2IdInteger("hfoo") .assertEquals('hfoo')
	idString2IdInteger("abcd") .assertEquals('abcd')
	idString2IdInteger("ABCD") .assertEquals('ABCD')


@test function test_idInteger2IdString()
	idInteger2IdString('hfoo') .assertEquals("hfoo")
	idInteger2IdString('abcd') .assertEquals("abcd")
	idInteger2IdString('ABCD') .assertEquals("ABCD")