chippyash/simple-accounts-3

<?php

declare(strict_types=1);

/**
 * Simple Double Entry Accounting V3

 * @author Ashley Kitson
 * @copyright Ashley Kitson, 2015, UK
 * @license BSD-3-Clause See LICENSE.md
 */

namespace SAccounts;

use MyCLabs\Enum\Enum;

/**
 * Defines account types as a 16 bit number
 *
 * @method static AccountType REAL()
 * @method static AccountType DR()
 * @method static AccountType CR()
 * @method static AccountType ASSET()
 * @method static AccountType BANK()
 * @method static AccountType CUSTOMER()
 * @method static AccountType EXPENSE()
 * @method static AccountType INCOME()
 * @method static AccountType LIABILITY()
 * @method static AccountType EQUITY()
 * @method static AccountType SUPPLIER()
 */
final class AccountType extends Enum
{
    /**
     * A dummy account - used internally, not for public consumption
     */
    public const DUMMY = 0b0000000000000000; //   0
    /**
     * Base of all accounts - used for root accounts: Balance = abs(cr - dr)
     */
    public const REAL = 0b0000000000000001; //   1

    /**
     * Debit account: Balance = dr - cr
     */
    public const DR = 0b0000000000000011; //   3

    /**
     * An account showing assets. Value coming in is DR, going out is CR.
     */
    public const ASSET = 0b0000000000001011; //  11
    /**
     * An account at a bank.  It is a special form of Asset Account
     */
    public const BANK = 0b0000000000011011; //  27
    /**
     * An asset account recording sales to a customer.
     */
    public const CUSTOMER = 0b0000000000101011; //  44
    /**
     * An account showing destination of expenses.  Expense is shown as DR, refund of expense as CR.
     */
    public const EXPENSE = 0b0000000001001011; //  77

    /**
     * Credit account: Balance = cr - dr
     */
    public const CR = 0b0000000000000101; //   5
    /**
     * An account recording liabilities (money owing to third parties.) Liability recorded as CR.
     */
    public const LIABILITY = 0b0000000010000101; // 133
    /**
     * An account showing sources of income.  Income is shown as CR, Refund as DR
     */
    public const INCOME = 0b0000000110000101; // 389
    /**
     * An account recording the capital or equity of an organisation.  Positive value is shown as CR, negative as DR.  Essentially a form of Liability as it is owed to the shareholders or owners.
     */
    public const EQUITY = 0b0000001010000101; // 645
    /**
     * A liability account recording details of purchases from Suppliers.
     */
    public const SUPPLIER = 0b0000010010000101; //1157

    /**
     * Debit and Credit column titles
     * @var array
     */
    private $titles = [
        self::DR => ['dr' => 'Debit', 'cr' => 'Credit'],
        self::CR => ['dr' => 'Debit', 'cr' => 'Credit'],
        self::ASSET => ['dr' => 'Increase', 'cr' => 'Decrease'],
        self::BANK => ['dr' => 'Increase', 'cr' => 'Decrease'],
        self::CUSTOMER => ['dr' => 'Increase', 'cr' => 'Decrease'],
        self::EXPENSE => ['dr' => 'Expense', 'cr' => 'Refund'],
        self::INCOME => ['dr' => 'Charge', 'cr' => 'Income'],
        self::LIABILITY => ['dr' => 'Decrease', 'cr' => 'Increase'],
        self::EQUITY => ['dr' => 'Decrease', 'cr' => 'Increase'],
        self::SUPPLIER => ['dr' => 'Decrease', 'cr' => 'Increase'],
    ];

    /**
     * Return the debit column title for this account type
     *
     * @return string
     * @throws AccountsException
     */
    public function drTitle(): string
    {
        if (!array_key_exists($this->value, $this->titles)) {
            throw new AccountsException('Invalid AccountType for drTitle: ' . $this->value);
        }

        return $this->titles[$this->value]['dr'];
    }

    /**
     * Return the credit column title for this account type
     *
     * @return string
     * @throws AccountsException
     */
    public function crTitle(): string
    {
        if (!array_key_exists($this->value, $this->titles)) {
            throw new AccountsException('Invalid AccountType for crTitle: ' . $this->value);
        }

        return $this->titles[$this->value]['cr'];
    }

    /**
     * Return balance of debit and credit amounts
     *
     * @param int $dr debit amount
     * @param int $cr credit amount
     *
     * @return int
     *
     * @throws AccountsException
     */
    public function balance(int $dr, int $cr): int
    {
        if (($this->value & self::DR) == self::DR) {
            //debit account type
            return $dr - $cr;
        }
        if (($this->value & self::CR) == self::CR) {
            //credit account type
            return $cr - $dr;
        }
        if (($this->value & self::REAL) == self::REAL) {
            //real balance - should always be zero as it is the root account
            return abs($cr - $dr);
        }

        throw new AccountsException('Cannot determine account type to set balance: ' . $this->value);
    }
}