<?php
/**********************************************************************
    Copyright (C) FrontAccounting, LLC.
	Released under the terms of the GNU General Public License, GPL, 
	as published by the Free Software Foundation, either version 3 
	of the License, or (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  
    See the License here <http://www.gnu.org/licenses/gpl-3.0.html>.
***********************************************************************/
function add_exchange_variation($trans_no, $date_, $acc_id, $account,
    $currency, $person_type_id=null, $person_id = "")
{
	if (is_company_currency($currency))
		return false;
	if ($date_ == null)
		$date_ = Today();
	$for_amount = 0;

	// We have to calculate all the currency accounts belonging to the GL account
	// upto $date_ and calculate with the exchange rates. And then compare with the GL account balance.
	$sql = "SELECT SUM(bt.amount) AS for_amount, ba.bank_curr_code 		
		FROM ".TB_PREF."bank_trans bt, ".TB_PREF."bank_accounts ba
		WHERE ba.id = bt.bank_act AND ba.account_code = ".db_escape($account)." AND bt.trans_date<='".date2sql($date_)."'
		GROUP BY ba.bank_curr_code";	
	$result = db_query($sql, "Transactions for bank account $acc_id could not be calculated");
	while ($row = db_fetch($result))
	{
		if ($row['for_amount'] == 0)
			continue;
		$rate = get_exchange_rate_from_home_currency($row['bank_curr_code'], $date_);
		$for_amount += round2($row['for_amount'] * $rate, user_price_dec());
	}	
	$amount = get_gl_trans_from_to("", $date_, $account);
	$diff = $amount - $for_amount;
	if (floatcmp($diff,0))
	{
		// generate journal entry // FIXME: use cart?
		global $Refs;

		begin_transaction();
		$trans_no = get_next_trans_no(ST_JOURNAL);
		$ref = $Refs->get_next(ST_JOURNAL);

		add_journal(ST_JOURNAL, $trans_no, $diff, $date_ , get_company_currency(), $ref, '', 1, $date_, $date_);
		$Refs->save(ST_JOURNAL, $trans_no, $ref);
		add_audit_trail(ST_JOURNAL, $trans_no, $date_);

		if ($person_type_id == null)
			$person_type_id = PT_MISC;
		add_gl_trans(ST_JOURNAL, $trans_no, $date_, $account, 0, 0, _("Exchange Variance"),
    		$diff, null, $person_type_id, $person_id);

    	add_gl_trans(ST_JOURNAL, $trans_no, $date_, get_company_pref('exchange_diff_act'), 0, 0, 
    		_("Exchange Variance"),	-$diff, null, $person_type_id, $person_id);
		commit_transaction();
		return true;
	}
	return false;
}

function add_cust_supp_revaluation($ledger_act, $ex_act, $date, $amount, $person_type_id, $person_id, $memo)
{
	global $Refs;
	if ($amount == 0)
		return;

	begin_transaction();
	$trans_no = get_next_trans_no(ST_JOURNAL);
	$ref = $Refs->get_next(ST_JOURNAL);

	add_journal(ST_JOURNAL, $trans_no, $amount, $date, get_company_currency(), $ref, '', 1, $date, $date);
	$Refs->save(ST_JOURNAL, $trans_no, $ref);
	add_audit_trail(ST_JOURNAL, $trans_no, $date);

	add_gl_trans(ST_JOURNAL, $trans_no, $date, $ledger_act, 0, 0, _("Exchange Variance"),
		$amount, null, $person_type_id, $person_id);
	add_gl_trans(ST_JOURNAL, $trans_no, $date, $ex_act, 0, 0, 
		_("Exchange Variance"),	-$amount, null, $person_type_id, $person_id);
	add_comments(ST_JOURNAL, $trans_no, $date, $memo);
	commit_transaction();
}

function get_cust_account_curr_balances($date)
{
	$to = date2sql($date);

    $sql = "SELECT SUM(IF(t.type IN(". implode(',', array(ST_CUSTCREDIT, ST_CUSTPAYMENT, ST_BANKDEPOSIT, ST_JOURNAL))."),
			-(t.ov_amount + t.ov_gst + t.ov_freight + t.ov_freight_tax + t.ov_discount), 
	    	(t.ov_amount + t.ov_gst + t.ov_freight + t.ov_freight_tax + t.ov_discount))) AS amount,
	    	dt.debtor_no, dt.name, dt.curr_code, b.receivables_account
		FROM ".TB_PREF."debtor_trans t 
			LEFT JOIN ".TB_PREF."debtors_master dt ON t.debtor_no = dt.debtor_no
			LEFT JOIN ".TB_PREF."cust_branch b ON t.debtor_no = b.debtor_no
			LEFT JOIN ".TB_PREF."voided as v ON v.type = t.type and v.id=t.trans_no
    	WHERE ISNULL(v.date_) AND t.type <> ".ST_CUSTDELIVERY." AND t.tran_date <= '$to' 
    		AND t.branch_code=b.branch_code AND dt.curr_code<>'".get_company_pref('curr_default')."' 
    		GROUP BY t.debtor_no, b.receivables_account";

    $result = db_query($sql,"Open balances in foreign currency for cannot be retrieved");
	return  $result;
}

function get_supp_account_curr_balances($date)
{
	$to = date2sql($date);

    $sql = "SELECT SUM(-(t.ov_amount + t.ov_gst + t.ov_discount)) AS amount,
	    	supp.supplier_id, supp.supp_name, supp.curr_code, supp.payable_account
		FROM ".TB_PREF."supp_trans t 
			LEFT JOIN ".TB_PREF."suppliers supp ON t.supplier_id = supp.supplier_id
			LEFT JOIN ".TB_PREF."voided as v ON v.type = t.type and v.id=t.trans_no
    	WHERE ISNULL(v.date_) AND t.tran_date <= '$to' 
    		AND supp.curr_code<>'".get_company_pref('curr_default')."' 
    		GROUP BY t.supplier_id";

    $result = db_query($sql,"Open balances in foreign currency for cannot be retrieved");
	return  $result;
}

function get_account_home_balance($person_id, $person_type, $rec_account, $to_date)
{
	$to = date2sql($to_date);

    $sql = "SELECT SUM(amount) FROM ".TB_PREF."gl_trans  
			WHERE person_id=".db_escape($person_id)." AND account='$rec_account' 
			AND person_type_id=$person_type AND tran_date <= '$to'";
	$result = db_query($sql, "The AR/AP balance for customer $person_id could not be calculated");
	$row = db_fetch_row($result);
	return $row[0];
}
//------------- New helper functions for revaluation of customer/supplier currencies 2011-05-08 Joe Hunt.

function add_exchange_variation_all($date=null, $ref="", $memo)
{
	global $Refs;
	begin_transaction();
	$exchanged = false;
	$trans_no = get_next_trans_no(ST_JOURNAL);
	$sql = "SELECT * FROM ".TB_PREF."bank_accounts";
	$result = db_query($sql, "could not retreive bank accounts");
	while ($myrow = db_fetch($result))
	{
		if (add_exchange_variation($trans_no, $date, $myrow['id'], $myrow['account_code'],
			$myrow['bank_curr_code']))
			$exchanged = true;
	}
	if ($exchanged)
	{
		add_comments(ST_JOURNAL, $trans_no, $date, $memo);
		if ($ref == "")
			$ref = $Refs->get_next(ST_JOURNAL, null, $date);
		$Refs->save(ST_JOURNAL, $trans_no, $ref);
		add_audit_trail(ST_JOURNAL, $trans_no, $date);
	}	

	//------------- BEGIN inserted for revaluation of customer/supplier currencies 2011-05-08 Joe Hunt.
	if ($date == null)
		$date = Today();
	$exchange_act = get_company_pref('exchange_diff_act');
	$je = 0;
	// debtors
	$res = get_cust_account_curr_balances($date);
	
	while($row = db_fetch($res)) 
	{
		$exrate = get_exchange_rate_from_home_currency($row['curr_code'], $date);
		$foreign = round2($row['amount']*$exrate, user_price_dec());
		$home = round2(get_account_home_balance($row['debtor_no'], PT_CUSTOMER, $row['receivables_account'], $date), user_price_dec());
		if ($foreign != $home) 
		{
			$amount = $foreign - $home;	
			add_cust_supp_revaluation($row['receivables_account'], $exchange_act, $date, $amount, PT_CUSTOMER, 
				$row['debtor_no'], $memo);
			$je++;	
		}
	}
	// creditors
	$res = get_supp_account_curr_balances($date);
	
	while($row = db_fetch($res)) 
	{
		$exrate = get_exchange_rate_from_home_currency($row['curr_code'], $date);
		$foreign = round2($row['amount']*$exrate, user_price_dec());
		$home = round2(get_account_home_balance($row['supplier_id'], PT_SUPPLIER, $row['payable_account'], $date), user_price_dec());
		if ($foreign != $home) 
		{
			$amount = $foreign - $home;	
			add_cust_supp_revaluation($row['payable_account'], $exchange_act, $date, $amount, PT_SUPPLIER, 
				$row['supplier_id'], $memo);
			$je++;	
		}
	}
	//------------- END

	commit_transaction();
	return array(($exchanged ? $trans_no : 0), $je);
}
//----------------------------------------------------------------------------------
//	Add bank tranfer to database.
//
//	$from_account - source bank account id
//	$to_account   -	target bank account id
//	

function add_bank_transfer($from_account, $to_account, $date_,
	$amount, $ref, $memo_, $charge=0, $target_amount=0)
{
	global $Refs, $SysPrefs;

	begin_transaction();
	$args = func_get_args(); if (count($args) < 8) $args[] = 0;
	$args = (object)array_combine(array('from_account', 'to_account', 'date_', 'amount',
		'ref', 'memo_', 'charge', 'target_amount'), $args);
	$args->trans_no = 0;
	hook_db_prewrite($args, ST_BANKTRANSFER);

	$trans_type = ST_BANKTRANSFER;

	$currency = get_bank_account_currency($from_account);

	$trans_no = get_next_trans_no($trans_type);
	
    $fromact = get_bank_account($from_account);
    $toact = get_bank_account($to_account);
    $person_id = _("From")." ".$fromact['bank_account_name']." "._("To")." ".$toact['bank_account_name'];

	$from_gl_account = get_bank_gl_account($from_account);
	$to_gl_account = get_bank_gl_account($to_account);
	
	$exchanged = false;
	$total = 0;
	// do the source account postings
    $total += add_gl_trans($trans_type, $trans_no, $date_, $from_gl_account, 0, 0, $person_id,
		-($amount + $charge), $currency);

    add_bank_trans($trans_type, $trans_no, $from_account, $ref,
		$date_, -($amount + $charge),
		PT_MISC, $person_id, $currency,
		"Cannot insert a source bank transaction");
	if ($SysPrefs->auto_currency_revaluation())
	{
		$trans_no1 = get_next_trans_no(ST_JOURNAL);
		if (add_exchange_variation($trans_no1, $date_, $from_account, $from_gl_account, 
			$currency, PT_MISC, $person_id))
			$exchanged = true;
	}
	if ($charge != 0)
	{
		/* Now Debit bank charge account with charges */
		$charge_act = get_bank_charge_account($from_account);
		$total += add_gl_trans($trans_type, $trans_no, $date_,
			$charge_act, 0, 0, $person_id, $charge, $currency);
	}

	// provide backward compatibility for extension modules (target amount can be not passed)
	$to_currency = $target_amount ? $toact['bank_curr_code'] : $currency;
	$to_amount = $target_amount ? $target_amount : $amount;

	// do the destination account postings
	$total += add_gl_trans($trans_type, $trans_no, $date_, $to_gl_account, 0, 0, $person_id,
		$to_amount, $to_currency);
		
	/*Post a balance post if $total != 0 */
	if ($currency == $to_currency)
		add_gl_balance($trans_type, $trans_no, $date_, -$total);
	else	// in this case those are exchange variances between bank and home rates
	   	add_gl_trans($trans_type, $trans_no, $date_, get_company_pref('exchange_diff_act'),
	   		0, 0, _("Exchange Variance"), -$total);
	
	add_bank_trans($trans_type, $trans_no, $to_account, $ref,
		$date_, $to_amount, PT_MISC, $person_id,
		$to_currency, "Cannot insert a destination bank transaction");

	if ($SysPrefs->auto_currency_revaluation())
	{
		$currency = get_bank_account_currency($to_account);
		if (add_exchange_variation($trans_no1, $date_, $to_account, $to_gl_account,	
			$currency, PT_MISC, $person_id))
			$exchanged = true;
	}
	if ($exchanged == true)
	{
		$ref1 = $Refs->get_next(ST_JOURNAL, null, $date_);
		$Refs->save(ST_JOURNAL, $trans_no1, $ref1);
		add_audit_trail(ST_JOURNAL, $trans_no1, $date_);
	}
	add_comments($trans_type, $trans_no, $date_, $memo_);

	$Refs->save($trans_type, $trans_no, $ref);
	add_audit_trail($trans_type, $trans_no, $date_);

	$args->trans_no = $trans_no;
	hook_db_postwrite($args, ST_BANKTRANSFER);
	commit_transaction();

	return $trans_no;
}

function check_bank_transfer($trans_no, $from_account, $to_account, $date_,
    $amount, $target_amount=0)
{
	$dbResult = get_bank_trans(ST_BANKTRANSFER, $trans_no);

	$old_from = db_fetch($dbResult);
	$old_to = db_fetch($dbResult);
	if ($old_to['amount'] < 0.0) {
		$tmp = $old_from;
		$old_from = $old_to;
		$old_to = $tmp;
	}
	// There are four accounts to consider:
	// 1) The original from account that is being voided. This results in funds being put back which is always fine.
	// 2) The original to account that is being voided. This results in funds being removed which may result in a
	//    negative balance in the account at some time and therefore needs to be checked.
	$problemTransaction = check_bank_account_history(-$old_to['amount'], $old_to['bank_act'], sql2date($old_from['trans_date']));
	if ($problemTransaction) {
		// If the destination account is the same as that being edited, it may be that this edit will resolve the
		// problem of voiding.
		if ($to_account == $old_to['bank_act'] && sql_date_comp($problemTransaction['trans_date'], date2sql($date_)) > 0) {
			$problemTransaction['amount'] += $amount;
			if ($problemTransaction['amount'] >= 0) {
				$problemTransaction = null;
			}
		}
		if ($problemTransaction != null) {
			$problemTransaction['account'] = $old_to['bank_act'];
			$problemTransaction['bank_account_name'] = $old_to['bank_account_name'];
			return $problemTransaction;
		}
	}

	// 3) The edited from account, that is having funds removed which may result in a
	//    negative balance in the account at some time and therefore needs to be checked.
	$balance_offset = 0;
	if ($from_account == $old_from['bank_act'] && sql_date_comp(date2sql($date_), $old_from['trans_date']) >= 0) {
		// If the edited from_account is the same as the original transaction, and the new date is later than the old date
		// then add the amount from the original from transaction when checking the history to simulate the void that would
		// take effect from that date.
		$balance_offset = -$old_from['amount'];
	}
	$problemTransaction = check_bank_account_history(-$amount, $from_account, $date_, null, $balance_offset);
	if ($problemTransaction != null) {
		$problemTransaction['account'] = $old_from['bank_act'];
		$problemTransaction['bank_account_name'] = $old_from['bank_account_name'];
		return $problemTransaction;
	}
	// 4) The edited to account, that is having funds added which is always ok.

	return $problemTransaction;
}

function update_bank_transfer(
	$trans_no, $from_account, $to_account, $date_,
	$amount, $ref, $memo_, $charge=0, $target_amount=0)
{
	begin_transaction();
	delete_comments(ST_BANKTRANSFER, $trans_no);
	void_transaction(ST_BANKTRANSFER, $trans_no, Today(), _("Document reentered."));
	void_gl_trans(ST_BANKTRANSFER, $trans_no, true);
	$new_trans_no = add_bank_transfer(
		$from_account, $to_account, $date_, $amount,
		$ref, $memo_, $charge, $target_amount
	);
	commit_transaction();
	return $new_trans_no;
}

//----------------------------------------------------------------------------------
//	Add bank payment or deposit to database.
//
//	$from_account - bank account id
//  $items - transaction cart (line amounts in bank account's currency); negative for deposit
//  $person_type_id - defines type of $person_id identifiers
//  $person_id	- supplier/customer/other id
//  $person_detail_id - customer branch id or not used
//  $settled_amount - settled amount in AR/AP (if applicable) in customer/supplier currency (always non-negative number)
//
// returns an array of (inserted trans type, trans no)
//
// FIXME -revise code for update case
//
function write_bank_transaction($trans_type, $trans_no, $from_account, $items, $date_,
	$person_type_id, $person_id, $person_detail_id,	$ref, $memo_, $use_transaction=true, $settled_amount=null)
{
	global $Refs, $SysPrefs;

	// we can only handle type 1 (payment)and type 2 (deposit)
	if ($trans_type != ST_BANKPAYMENT && $trans_type != ST_BANKDEPOSIT)
		display_db_error("Invalid type ($trans_type) sent to add_bank_transaction");

	$do_exchange_variance = false;
	$exchanged = false;
	if ($use_transaction)
		begin_transaction();

	$args = func_get_args(); if (count($args) < 11) $args[] = true;
	$args = (object)array_combine(array('trans_type', 'trans_no', 'from_account', 'items', 'date_',
		'person_type_id', 'person_id', 'person_detail_id', 'ref', 'memo_', 'use_transaction', 'settled_amount'),
		$args);
	hook_db_prewrite($args, $trans_type);

	$aid = 0;
	if ($trans_no) {
		$old_trans = $trans_no;
		$Refs->restore_last($trans_type, $trans_no);
		$aid = has_attachment($trans_type, $trans_no);
	} else
		$old_trans = false;

	$currency = get_bank_account_currency($from_account);
	$bank_gl_account = get_bank_gl_account($from_account);

	// the gl items are already inversed/negated for type 2 (deposit)
	$total_amount = $items->gl_items_total();

    if ($person_type_id == PT_CUSTOMER)
    {
    	// we need to add a customer transaction record
		// convert to customer currency
		if (!isset($settled_amount)) // leaved for backward/ext compatibility 
			$cust_amount = exchange_from_to(abs($total_amount), $currency, get_customer_currency($person_id), $date_);
		else
			$cust_amount = $settled_amount;

		if ($trans_type == ST_BANKPAYMENT)
			$cust_amount = -$cust_amount;

		$trans_no = write_customer_trans($trans_type, 0, $person_id, $person_detail_id, $date_,
        	$ref, $cust_amount);
		if ($old_trans)
			move_trans_attachments($trans_type, $old_trans, $trans_no);
    }
    elseif ($person_type_id == PT_SUPPLIER)
    {
    	// we need to add a supplier transaction record
		// convert to supp currency
		if (!isset($settled_amount)) // leaved for for backward/ext compatibility 
			$supp_amount = exchange_from_to(abs($total_amount), $currency, get_supplier_currency($person_id), $date_);
		else
			$supp_amount = $settled_amount;

		if ($trans_type == ST_BANKPAYMENT)
			$supp_amount = -$supp_amount;

		$trans_no = write_supp_trans($trans_type, 0, $person_id, $date_, '',
			$ref, "", $supp_amount, 0, 0);
		if ($old_trans)
			move_trans_attachments($trans_type, $old_trans, $trans_no);
    }
    else
    {
   		$trans_no = get_next_trans_no($trans_type);
    	$do_exchange_variance = $SysPrefs->auto_currency_revaluation();
    	if ($do_exchange_variance)
    		$trans_no1 = get_next_trans_no(ST_JOURNAL);
    }
	if ($aid != 0)
	{
		$row = get_attachment($aid);
		update_attachment($aid, $row['type_no'], $trans_no, $row['description'],
			$row['filename'], $row['unique_name'], $row['filesize'], $row['filetype']);
	}
	// do the source account postings

    add_bank_trans($trans_type, $trans_no, $from_account, $ref,
    	$date_, -$total_amount,
    	$person_type_id, $person_id,
    	$currency,
    	"Cannot insert a source bank transaction");
	$total = 0;
	foreach ($items->gl_items as $gl_item)
	{
		$is_bank_to = is_bank_account($gl_item->code_id);

		if ($trans_type == ST_BANKPAYMENT AND $is_bank_to)
		{
			// we don't allow payments to go to a bank account. use transfer for this !
			display_db_error("invalid payment entered. Cannot pay to another bank account", "");
		}

    	// do the destination account postings
    	$total += add_gl_trans($trans_type, $trans_no, $date_, $gl_item->code_id,
    		$gl_item->dimension_id, $gl_item->dimension2_id, $gl_item->reference,
    		$gl_item->amount, $currency, $person_type_id, $person_id);

    	if ($is_bank_to)
    	{
    		add_bank_trans($trans_type, $trans_no, $is_bank_to, $ref,
    			$date_, $gl_item->amount,
    			$person_type_id, $person_id, $currency,
    			"Cannot insert a destination bank transaction");
    		if ($do_exchange_variance)
    		{
    			add_exchange_variation($trans_no1, $date_, $is_bank_to, $gl_item->code_id, 
    				$currency, $person_type_id, $person_id);
    		}
    	}
		// store tax details if the gl account is a tax account

		$amount = $gl_item->amount;
		$ex_rate = get_exchange_rate_from_home_currency($currency, $date_);

		add_gl_tax_details($gl_item->code_id, $trans_type, $trans_no, -$amount,
			$ex_rate, $date_, $memo_);
	}

	// do the source account postings
    add_gl_trans($trans_type, $trans_no, $date_, $bank_gl_account, 0, 0, $memo_,
    	-$total, null, $person_type_id, $person_id);

    if ($do_exchange_variance)
    {
    	if ($exchanged || add_exchange_variation($trans_no1, $date_, $from_account, $bank_gl_account, 
    		$currency, $person_type_id, $person_id))
    	{
   			$ref1 = $Refs->get_next(ST_JOURNAL, null, $date_);
			$Refs->save(ST_JOURNAL, $trans_no1, $ref1);
			add_audit_trail(ST_JOURNAL, $trans_no1, $date_);
		}
	}

	add_comments($trans_type, $trans_no, $date_, $memo_);

	$Refs->save($trans_type, $trans_no, $ref);
	add_audit_trail($trans_type, $trans_no, $date_);

	// old transaction can be voided only after new transaction is entered,
	//  otherwise the operation could fail for cash accounts due to temporary negative balance
	if ($old_trans) 
	{
		$msg = void_transaction($trans_type, $old_trans, Today(), _("Document reentered."));
		if ($msg)
		{
			display_error($msg);
			return false;
		}
	}


	$args->trans_no = $trans_no;
	hook_db_postwrite($args, $trans_type);
	if ($use_transaction)
		commit_transaction();

	return array($trans_type, $trans_no);
}