<?php

namespace ChurchCRM;

// Utility functions used to process MICR data

class MICRFunctions
{
    public int $CHECKNO_FIRST = 1; // o<check>o t<route>t <account>o
    public int $ROUTE_FIRST1 = 2;   // t<route>t <account>o <check>
    public int $ROUTE_FIRST2 = 3;   // t<route>t o<account>o <check>
    public int $NOT_RECOGNIZED = 4;

    public function identifyFormat(string $micr): int
    {
        // t000000000t0000o0000000000000o ROUTE_FIRST2
        // t000000000t 0000000000o   0000 ROUTE_FIRST1
        // o000000o t000000000t 0000000000o CHECKNO_FIRST

        $firstChar = mb_substr($micr, 0, 1);
        if ($firstChar === 'o') {
            return $this->CHECKNO_FIRST;
        } elseif ($firstChar == 't') {
            $firstSmallO = strpos($micr, 'o');
            $secondSmallO = strrpos($micr, 'o');
            if ($firstSmallO === $secondSmallO) {
                // Only one 'o'
                $len = strlen($micr);
                if ($len - $firstSmallO > 12) {
                    return $this->NOT_RECOGNIZED;
                } else {
                    return $this->ROUTE_FIRST1;
                }
            } else {
                return $this->ROUTE_FIRST2;
            }
        }

        throw new \InvalidArgumentException('Unknown format provided');
    }

    public function findRoute(string $micr): string
    {
        $routeAndAccount = $this->findRouteAndAccount($micr);
        $breakChar = strpos($routeAndAccount, 't', 1);

        return mb_substr($micr, 1, $breakChar - 1);
    }

    public function findAccount(string $micr): string
    {
        $routeAndAccount = $this->findRouteAndAccount($micr);
        $breakChar = strpos($routeAndAccount, 't', 1);

        return mb_substr($routeAndAccount, $breakChar + 1, strlen($micr) - $breakChar);
    }

    public function findRouteAndAccount(string $micr): string
    {
        $formatID = $this->identifyFormat($micr);

        if ($formatID == $this->CHECKNO_FIRST) {
            $firstSmallT = strpos($micr, 't');

            return mb_substr($micr, $firstSmallT, strlen($micr) - $firstSmallT);
        } elseif ($formatID == $this->ROUTE_FIRST1) {
            $firstSmallO = strpos($micr, 'o');

            return mb_substr($micr, 0, $firstSmallO);
        } elseif ($formatID == $this->ROUTE_FIRST2) {
            // t000000000t0000o0000000000000o ROUTE_FIRST2
            // check number is in the middle, strip it out for family matching
            $routeNo = mb_substr($micr, 0, 10);
            $firstSmallO = strpos($micr, 'o');
            $accountNo = mb_substr($micr, $firstSmallO, strlen($micr) - $firstSmallO);

            return $routeNo . $accountNo;
        } else {
            return '';
        }
    }

    public function findCheckNo(string $micr): string
    {
        $formatID = $this->identifyFormat($micr);
        if ($formatID == $this->CHECKNO_FIRST) {
            $micrWithoutFirstO = mb_substr($micr, 1, strlen($micr) - 1);
            $secondSmallO = strpos($micrWithoutFirstO, 'o');

            return mb_substr($micrWithoutFirstO, 0, $secondSmallO);
        } elseif ($formatID == $this->ROUTE_FIRST1) {
            $firstSmallO = strpos($micr, 'o');

            return mb_substr($micr, $firstSmallO + 1, strlen($micr) - $firstSmallO - 1);
        } elseif ($formatID == $this->ROUTE_FIRST2) {
            $secondSmallt = strrpos($micr, 't');
            $firstSmallO = strpos($micr, 'o');

            return mb_substr($micr, $secondSmallt + 1, $firstSmallO - $secondSmallt - 1);
        } else {
            return '';
        }
    }
}
