<?php

class Complex
{
    private $realPart = 0;
    private $imaginaryPart = 0;
    private $suffix = null;

    public static function _parseComplex($complexNumber)
    {
        //    Test for real number, with no imaginary part
        if (is_numeric($complexNumber)) {
            return array($complexNumber, 0, null);
        }

        //    Fix silly human errors
        if (strpos($complexNumber, '+-') !== false) {
            $complexNumber = str_replace('+-', '-', $complexNumber);
        }
        if (strpos($complexNumber, '++') !== false) {
            $complexNumber = str_replace('++', '+', $complexNumber);
        }
        if (strpos($complexNumber, '--') !== false) {
            $complexNumber = str_replace('--', '-', $complexNumber);
        }

        //    Basic validation of string, to parse out real and imaginary parts, and any suffix
        $validComplex = preg_match('/^([\-\+]?(\d+\.?\d*|\d*\.?\d+)([Ee][\-\+]?[0-2]?\d{1,3})?)([\-\+]?(\d+\.?\d*|\d*\.?\d+)([Ee][\-\+]?[0-2]?\d{1,3})?)?(([\-\+]?)([ij]?))$/ui', $complexNumber, $complexParts);

        if (!$validComplex) {
            //    Neither real nor imaginary part, so test to see if we actually have a suffix
            $validComplex = preg_match('/^([\-\+]?)([ij])$/ui', $complexNumber, $complexParts);
            if (!$validComplex) {
                throw new Exception('COMPLEX: Invalid complex number');
            }
            //    We have a suffix, so set the real to 0, the imaginary to either 1 or -1 (as defined by the sign)
            $imaginary = 1;
            if ($complexParts[1] === '-') {
                $imaginary = 0 - $imaginary;
            }
            return array(0, $imaginary, $complexParts[2]);
        }

        //    If we don't have an imaginary part, identify whether it should be +1 or -1...
        if (($complexParts[4] === '') && ($complexParts[9] !== '')) {
            if ($complexParts[7] !== $complexParts[9]) {
                $complexParts[4] = 1;
                if ($complexParts[8] === '-') {
                    $complexParts[4] = -1;
                }
            //    ... or if we have only the real and no imaginary part (in which case our real should be the imaginary)
            } else {
                $complexParts[4] = $complexParts[1];
                $complexParts[1] = 0;
            }
        }

        //    Return real and imaginary parts and suffix as an array, and set a default suffix if user input lazily
        return array($complexParts[1], $complexParts[4], !empty($complexParts[9]) ? $complexParts[9] : 'i');
    }    //    function _parseComplex()


    public function __construct($realPart, $imaginaryPart = null, $suffix = 'i')
    {
        if ($imaginaryPart === null) {
            if (is_array($realPart)) {
                //    We have an array of (potentially) real and imaginary parts, and any suffix
                list ($realPart, $imaginaryPart, $suffix) = array_values($realPart) + array(0.0, 0.0, 'i');
            } elseif ((is_string($realPart)) || (is_numeric($realPart))) {
                //    We've been given a string to parse to extract the real and imaginary parts, and any suffix
                list ($realPart, $imaginaryPart, $suffix) = self::_parseComplex($realPart);
            }
        }

        //    Set parsed values in our properties
        $this->realPart = (float) $realPart;
        $this->imaginaryPart = (float) $imaginaryPart;
        $this->suffix = strtolower($suffix);
    }

    public function getReal()
    {
        return $this->realPart;
    }

    public function getImaginary()
    {
        return $this->imaginaryPart;
    }

    public function getSuffix()
    {
        return $this->suffix;
    }

    public function __toString()
    {
        $str = "";
        if ($this->imaginaryPart != 0.0) {
            if (abs($this->imaginaryPart) != 1.0) {
                $str .= $this->imaginaryPart . $this->suffix;
            } else {
                $str .= (($this->imaginaryPart < 0.0) ? '-' : ''). $this->suffix;
            }
        }
        if ($this->realPart != 0.0) {
            if (($str) && ($this->imaginaryPart > 0.0)) {
                $str = "+" . $str;
            }
            $str = $this->realPart . $str;
        }
        if (!$str) {
            $str = "0.0";
        }
        return $str;
    }
}
