<?php
/*
* 2007-2011 PrestaShop 
*
* NOTICE OF LICENSE
*
* This source file is subject to the Academic Free License (AFL 3.0)
* that is bundled with this package in the file LICENSE.txt.
* It is also available through the world-wide-web at this URL:
* http://opensource.org/licenses/afl-3.0.php
* If you did not receive a copy of the license and are unable to
* obtain it through the world-wide-web, please send an email
* to license@prestashop.com so we can send you a copy immediately.
*
* DISCLAIMER
*
* Do not edit or add to this file if you wish to upgrade PrestaShop to newer
* versions in the future. If you wish to customize PrestaShop for your
* needs please refer to http://www.prestashop.com for more information.
*
*  @author PrestaShop SA <contact@prestashop.com>
*  @copyright  2007-2011 PrestaShop SA
*  @version  Release: $Revision: 7541 $
*  @license    http://opensource.org/licenses/afl-3.0.php  Academic Free License (AFL 3.0)
*  International Registered Trademark & Property of PrestaShop SA
*/

if (!defined('_CAN_LOAD_FILES_'))
	exit;

class Followup extends Module
{
	function __construct()
	{
		$this->name = 'followup';
		$this->tab = 'advertising_marketing';
		$this->version = '1.0';
		$this->author = 'PrestaShop';
		$this->need_instance = 0;

		$this->confKeys = array(
		'PS_FOLLOW_UP_ENABLE_1', 'PS_FOLLOW_UP_ENABLE_2', 'PS_FOLLOW_UP_ENABLE_3', 'PS_FOLLOW_UP_ENABLE_4', 
		'PS_FOLLOW_UP_AMOUNT_1', 'PS_FOLLOW_UP_AMOUNT_2', 'PS_FOLLOW_UP_AMOUNT_3', 'PS_FOLLOW_UP_AMOUNT_4', 
		'PS_FOLLOW_UP_DAYS_1', 'PS_FOLLOW_UP_DAYS_2', 'PS_FOLLOW_UP_DAYS_3', 'PS_FOLLOW_UP_DAYS_4',
		'PS_FOLLOW_UP_THRESHOLD_3',
		'PS_FOLLOW_UP_DAYS_THRESHOLD_4',
		'PS_FOLLOW_UP_CLEAN_DB');

		parent::__construct();

		$this->displayName = $this->l('Customer follow-up');
		$this->description = $this->l('Follow-up with your customers with daily customized e-mails.');
		$this->confirmUninstall = $this->l('Are you sure you want to delete all settings and your logs?');
	}
	
	public function install()
	{
		$logEmailTable = Db::getInstance()->Execute('
		CREATE TABLE '._DB_PREFIX_.'log_email (
		`id_log_email` INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY ,
		`id_email_type` INT UNSIGNED NOT NULL ,
		`id_discount` INT UNSIGNED NOT NULL ,
		`id_customer` INT UNSIGNED NULL ,
		`id_cart` INT UNSIGNED NULL ,
		`date_add` DATETIME NOT NULL,
		 INDEX `date_add`(`date_add`),
		 INDEX `id_cart`(`id_cart`)
		) ENGINE='._MYSQL_ENGINE_);
		
		foreach ($this->confKeys AS $key)
			Configuration::updateValue($key, 0);
			
		Configuration::updateValue('PS_FOLLOWUP_SECURE_KEY', strtoupper(Tools::passwdGen(16)));
			
		return parent::install();
	}
	
	public function uninstall()
	{
		foreach ($this->confKeys AS $key)
			Configuration::deleteByName($key);
			
		Configuration::deleteByName('PS_FOLLOWUP_SECURE_KEY');
		
		Db::getInstance()->Execute('DROP TABLE '._DB_PREFIX_.'log_email');

		return parent::uninstall();
	}
	
	public function getContent()
	{	
		/* Save settings */
		if (Tools::isSubmit('submitFollowUp'))	
			foreach ($this->confKeys AS $c)
				Configuration::updateValue($c, (float)(Tools::getValue($c)));
		
		/* Init */
		$conf = Configuration::getMultiple($this->confKeys);
		foreach ($this->confKeys AS $k)
			if (!isset($conf[$k]))
				$conf[$k] = '';
		$currency = new Currency((int)(Configuration::get('PS_CURRENCY_DEFAULT')));

		$n1 = $this->cancelledCart(true);
		$n2 = $this->reOrder(true);
		$n3 = $this->bestCustomer(true);
		$n4 = $this->badCustomer(true);
		
		echo '
		<h2>'.$this->l('Customer follow-up').'</h2>
		<form action="'.$_SERVER['REQUEST_URI'].'" method="post">
			<fieldset style="width: 400px; float: left;">
				<legend><img src="'.$this->_path.'logo.gif" alt="" title="" />'.$this->l('Settings').'</legend>
				<p>'.$this->l('Four kinds of e-mail alerts available in order to stay in touch with your customers!').'<br /><br />
				'.$this->l('Define settings and place this URL in crontab or call it manually daily:').'<br />
				<b>'.Tools::getShopDomain(true, true).__PS_BASE_URI__.'modules/followup/cron.php?secure_key='.Configuration::get('PS_FOLLOWUP_SECURE_KEY').'</b></p>
				<hr size="1" />
				<p><b>1. '.$this->l('Cancelled carts').'</b><br /><br />'.$this->l('For each cancelled cart (with no order), generate a discount and send it to the customer.').'</p>
				<label>'.$this->l('Enable').'</label>
				<div class="margin-form" style="padding-top: 5px;"><input type="checkbox" name="PS_FOLLOW_UP_ENABLE_1" value="1" style="vertical-align: middle;" '.($conf['PS_FOLLOW_UP_ENABLE_1'] == 1 ? 'checked="checked"' : '').' /></div>
				<label>'.$this->l('Discount amount').'</label>
				<div class="margin-form"><input type="text" name="PS_FOLLOW_UP_AMOUNT_1" value="'.$conf['PS_FOLLOW_UP_AMOUNT_1'].'" size="6" onKeyUp="javascript:this.value = this.value.replace(/,/g, \'.\');" /> %</div>
				<label>'.$this->l('Discount validity').'</label>
				<div class="margin-form"><input type="text" name="PS_FOLLOW_UP_DAYS_1" value="'.$conf['PS_FOLLOW_UP_DAYS_1'].'" size="6" /> '.$this->l('day(s)').'</div>
				<p>'.$this->l('Next process will send:').' <b>'.(int)($n1).' '.($n1 > 1 ? $this->l('e-mails') : $this->l('e-mail')).'</b></p>
				<hr size="1" />
				<p><b>2. '.$this->l('Re-order').'</b><br /><br />'.$this->l('For each validated order, generate a discount and send it to the customer.').'</p>
				<label>'.$this->l('Enable').'</label>
				<div class="margin-form" style="padding-top: 5px;"><input type="checkbox" name="PS_FOLLOW_UP_ENABLE_2" value="1" style="vertical-align: middle;" '.($conf['PS_FOLLOW_UP_ENABLE_2'] == 1 ? 'checked="checked"' : '').' /></div>
				<label>'.$this->l('Discount amount').'</label>
				<div class="margin-form"><input type="text" name="PS_FOLLOW_UP_AMOUNT_2" value="'.$conf['PS_FOLLOW_UP_AMOUNT_2'].'" size="6" onKeyUp="javascript:this.value = this.value.replace(/,/g, \'.\');" /> %</div>
				<label>'.$this->l('Discount validity').'</label>
				<div class="margin-form"><input type="text" name="PS_FOLLOW_UP_DAYS_2" value="'.$conf['PS_FOLLOW_UP_DAYS_2'].'" size="6" /> '.$this->l('day(s)').'</div>
				<p>'.$this->l('Next process will send:').' <b>'.(int)($n2).' '.($n2 > 1 ? $this->l('e-mails') : $this->l('e-mail')).'</b></p>
				<hr size="1" />
				<p><b>3. '.$this->l('Best customers').'</b><br /><br />'.$this->l('For each customer raising a threshold, generate a discount and send it to the customer.').'</p>
				<label>'.$this->l('Enable').'</label>
				<div class="margin-form" style="padding-top: 5px;"><input type="checkbox" name="PS_FOLLOW_UP_ENABLE_3" value="1" style="vertical-align: middle;" '.($conf['PS_FOLLOW_UP_ENABLE_3'] == 1 ? 'checked="checked"' : '').' /></div>
				<label>'.$this->l('Discount amount').'</label>
				<div class="margin-form"><input type="text" name="PS_FOLLOW_UP_AMOUNT_3" value="'.$conf['PS_FOLLOW_UP_AMOUNT_3'].'" size="6" onKeyUp="javascript:this.value = this.value.replace(/,/g, \'.\');" /> %</div>
				<label>'.$this->l('Threshold').'</label>
				<div class="margin-form">'.($currency->format == 1 ? ' '.$currency->sign.' ' : '').'<input type="text" name="PS_FOLLOW_UP_THRESHOLD_3" value="'.$conf['PS_FOLLOW_UP_THRESHOLD_3'].'" size="6" onKeyUp="javascript:this.value = this.value.replace(/,/g, \'.\');" /> '.($currency->format == 2 ? ' '.$currency->sign : '').'</div>
				<label>'.$this->l('Discount validity').'</label>
				<div class="margin-form"><input type="text" name="PS_FOLLOW_UP_DAYS_3" value="'.$conf['PS_FOLLOW_UP_DAYS_3'].'" size="6" /> '.$this->l('day(s)').'</div>
				<p>'.$this->l('Next process will send:').' <b>'.(int)($n3).' '.($n3 > 1 ? $this->l('e-mails') : $this->l('e-mail')).'</b></p>
				<hr size="1" />
				<p><b>4. '.$this->l('Bad customers').'</b><br /><br />'.$this->l('For each customer who has already passed at least one order and with no orders since a given duration, generate a discount and send it to the customer.').'</p>
				<label>'.$this->l('Enable').'</label>
				<div class="margin-form" style="padding-top: 5px;"><input type="checkbox" name="PS_FOLLOW_UP_ENABLE_4" value="1" style="vertical-align: middle;" '.($conf['PS_FOLLOW_UP_ENABLE_4'] == 1 ? 'checked="checked"' : '').' /></div>
				<label>'.$this->l('Discount amount').'</label>
				<div class="margin-form"><input type="text" name="PS_FOLLOW_UP_AMOUNT_4" value="'.$conf['PS_FOLLOW_UP_AMOUNT_4'].'" size="6" onKeyUp="javascript:this.value = this.value.replace(/,/g, \'.\');" /> %</div>
				<label>'.$this->l('Since x days').'</label>
				<div class="margin-form"><input type="text" name="PS_FOLLOW_UP_DAYS_THRESHOLD_4" value="'.$conf['PS_FOLLOW_UP_DAYS_THRESHOLD_4'].'" size="6" /> '.$this->l('day(s)').'</div>
				<label>'.$this->l('Discount validity').'</label>
				<div class="margin-form"><input type="text" name="PS_FOLLOW_UP_DAYS_4" value="'.$conf['PS_FOLLOW_UP_DAYS_4'].'" size="6" /> '.$this->l('day(s)').'</div>
				<p>'.$this->l('Next process will send:').' <b>'.(int)($n4).' '.($n4 > 1 ? $this->l('e-mails') : $this->l('e-mail')).'</b></p>
				<hr size="1" />
				<input type="checkbox" style="vertical-align: middle;" name="PS_FOLLOW_UP_CLEAN_DB" value="1" '.($conf['PS_FOLLOW_UP_CLEAN_DB'] == 1 ? 'checked="checked"' : '').' /> '.$this->l('Delete outdated discounts during each launch to clean database.').'
				<hr size="1" />
				<center><input type="submit" name="submitFollowUp" value="'.$this->l('Save').'" class="button" /></center>
			</fieldset>
			
			<style type="text/css">
				table tr th {
					text-align: center;
					font-weight: bold;
				}
				
				table tr td, table tr th {
					padding: 3px;
				}
				
				table tr td {
					text-align: right;
				}
				
				table { width: 460px; border: 1px solid #666; }
			</style>
			<fieldset style="width: 460px; margin-left: 10px; float: left;">
				<legend><img src="'.$this->_path.'logo-2.gif" alt="" title="" />'.$this->l('Statistics').'</legend>
				'.$this->l('Detailed statistics for last 30 days:').'<br /><br />
				<p style="font-size: 10px; font-weight: bold;">
				'.$this->l('S = Number of sent e-mails').'<br />
				'.$this->l('U = Number of discounts used (valid orders only)').'<br />
				'.$this->l('% = Conversion rate').'
				</p><br />
				<table border="1" style="font-size: 11px;">
					<tr>
						<th rowspan="2" style="width: 75px;">'.$this->l('Date').'</th>
						<th colspan="3">'.$this->l('Cancelled carts').'</th>
						<th colspan="3">'.$this->l('Re-order').'</th>
						<th colspan="3">'.$this->l('Best cust.').'</th>
						<th colspan="3">'.$this->l('Bad cust.').'</th>
					</tr>';
					
			$stats = Db::getInstance(_PS_USE_SQL_SLAVE_)->ExecuteS('
			SELECT DATE_FORMAT(l.date_add, \'%Y-%m-%d\') date_stat, l.id_email_type, COUNT(l.id_log_email) nb, 
			(SELECT COUNT(l2.id_discount) 
			FROM '._DB_PREFIX_.'log_email l2
			LEFT JOIN '._DB_PREFIX_.'order_discount od ON (od.id_discount = l2.id_discount)
			LEFT JOIN '._DB_PREFIX_.'orders o ON (o.id_order = od.id_order)
			WHERE l2.id_email_type = l.id_email_type AND l2.date_add = l.date_add AND od.id_order IS NOT NULL AND o.valid = 1) nb_used
			FROM '._DB_PREFIX_.'log_email l
			WHERE l.date_add >= DATE_SUB(CURDATE(), INTERVAL 30 DAY)
			GROUP BY DATE_FORMAT(l.date_add, \'%Y-%m-%d\'), l.id_email_type');

			$statsArray = array();
			foreach ($stats AS $stat)
			{
				$statsArray[$stat['date_stat']][$stat['id_email_type']]['nb'] = (int)($stat['nb']);
				$statsArray[$stat['date_stat']][$stat['id_email_type']]['nb_used'] = (int)($stat['nb_used']);
			}
			
			echo '
			<tr>
				<td class="center">'.$this->l('S').'</td>
				<td class="center">'.$this->l('U').'</td>
				<td class="center">%</td>
				<td class="center">'.$this->l('S').'</td>
				<td class="center">'.$this->l('U').'</td>
				<td class="center">%</td>
				<td class="center">'.$this->l('S').'</td>
				<td class="center">'.$this->l('U').'</td>
				<td class="center">%</td>
				<td class="center">'.$this->l('S').'</td>
				<td class="center">'.$this->l('U').'</td>
				<td class="center">%</td>
			</tr>';
			
			if (!sizeof($statsArray))
				echo '<tr><td colspan="13" style="font-weight: bold; text-align: center;">'.$this->l('No statistics at this time.').'</td></tr>';
			foreach ($statsArray AS $date_stat => $array)
			{
				$rates = array();
				for ($i = 1; $i != 5; $i++)
					if (isset($statsArray[$date_stat][$i]['nb']) AND isset($statsArray[$date_stat][$i]['nb_used']) AND $statsArray[$date_stat][$i]['nb_used'] > 0)
						$rates[$i] = number_format(($statsArray[$date_stat][$i]['nb_used'] / $statsArray[$date_stat][$i]['nb'])*100, 2, '.', '');
				
				echo '
				<tr>
					<td>'.$date_stat.'</td>';
					
				for ($i = 1; $i != 5; $i++)
				{
					echo '
					<td>'.(isset($statsArray[$date_stat][$i]['nb']) ? (int)($statsArray[$date_stat][$i]['nb']) : 0).'</td>
					<td>'.(isset($statsArray[$date_stat][$i]['nb_used']) ? (int)($statsArray[$date_stat][$i]['nb_used']) : 0).'</td>
					<td>'.(isset($rates[$i]) ? '<b>'.$rates[$i].'</b>' : '0.00').'</td>';
				}

				echo '
				</tr>';
			}
			
			echo '
				</table>
			</fieldset>
			<div class="clear"></div>
		</form>';
	}
	
	/* Log each sent e-mail */
	private function logEmail($id_email_type, $id_discount, $id_customer = NULL, $id_cart = NULL)
	{
		$values = array('id_email_type' => (int)($id_email_type), 'id_discount' => (int)($id_discount), 'date_add' => date('Y-m-d H:i:s'));
		if (!empty($id_cart))
			$values['id_cart'] = (int)($id_cart);
		if (!empty($id_customer))
			$values['id_customer'] = (int)($id_customer);
		Db::getInstance()->autoExecute(_DB_PREFIX_.'log_email', $values, 'INSERT');
	}

	/* Each cart which wasn't transformed into an order */
	private function cancelledCart($count = false)
	{
		$emailLogs = $this->getLogsEmail(1);
		$sql = '
			SELECT c.id_cart, c.id_lang, cu.id_customer, cu.firstname, cu.lastname, cu.email
			FROM '._DB_PREFIX_.'cart c
			LEFT JOIN '._DB_PREFIX_.'orders o ON (o.id_cart = c.id_cart)
			LEFT JOIN '._DB_PREFIX_.'customer cu ON (cu.id_customer = c.id_customer)
			WHERE DATE_SUB(CURDATE(),INTERVAL 7 DAY) <= c.date_add AND cu.id_customer IS NOT NULL AND o.id_order IS NULL';

		if (!empty($emailLogs))
			$sql .= ' AND c.id_cart NOT IN ('.join(',', $emailLogs).')';

		$emails = Db::getInstance()->ExecuteS($sql);
		
		if ($count OR !sizeof($emails))
			return sizeof($emails);
		
		$conf = Configuration::getMultiple(array('PS_FOLLOW_UP_AMOUNT_1', 'PS_FOLLOW_UP_DAYS_1'));
		foreach ($emails AS $email)
		{
				$voucher = $this->createDiscount(1, (float)($conf['PS_FOLLOW_UP_AMOUNT_1']), (int)($email['id_customer']), strftime('%Y-%m-%d', strtotime('+'.(int)($conf['PS_FOLLOW_UP_DAYS_1']).' day')), $this->l('Discount for your cancelled cart'));				
				if ($voucher !== false)
				{
					$templateVars = array('{email}' => $email['email'], '{lastname}' => $email['lastname'], '{firstname}' => $email['firstname'], '{amount}' => $conf['PS_FOLLOW_UP_AMOUNT_1'], '{days}' => $conf['PS_FOLLOW_UP_DAYS_1'], '{voucher_num}' => $voucher->name);
					$result = Mail::Send((int)($email['id_lang']), 'followup_1', Mail::l('Your cart and your discount'), $templateVars, $email['email'], $email['firstname'].' '.$email['lastname'], NULL, NULL, NULL, NULL, dirname(__FILE__).'/mails/');
					$this->logEmail(1, (int)($voucher->id), (int)($email['id_customer']), (int)($email['id_cart']));
				}
		}
	}
	
	private function getLogsEmail($emailType)
	{
		static $idList = array(
			'1' => array(),
			'2' => array(),
			'3' => array(),
			'4' => array(),
		);
		static $executed = false;
		
		if (!$executed)
		{
			$query = '
			SELECT id_cart, id_customer, id_email_type FROM '._DB_PREFIX_.'log_email
			WHERE id_email_type <> 4 OR date_add >= DATE_SUB(date_add,INTERVAL '.(int)(Configuration::get('PS_FOLLOW_UP_DAYS_THRESHOLD_4')).' DAY)';
			$results = Db::getInstance()->ExecuteS($query);
			foreach ($results as $line)
			{
				switch ($line['id_email_type'])
				{
					case 1:
						$idList['1'][] = $line['id_cart'];
						break;
					case 2:
						$idList['2'][] = $line['id_cart'];
						break;
					case 3:
						$idList['3'][] = $line['id_customer'];
						break;
					case 4:
						$idList['4'][] = $line['id_customer'];
						break;
				}
			}
			$executed = true;
		}
		return $idList[$emailType];
	}
	
	/* For all validated orders, a discount if re-ordering before x days */
	private function reOrder($count = false)
	{
		$emailLogs =  $this->getLogsEmail(2);
		$sql = '
			SELECT o.id_order, c.id_cart, c.id_lang, cu.id_customer, cu.firstname, cu.lastname, cu.email
			FROM '._DB_PREFIX_.'orders o
			LEFT JOIN '._DB_PREFIX_.'customer cu ON (cu.id_customer = o.id_customer)
			LEFT JOIN '._DB_PREFIX_.'cart c ON (c.id_cart = o.id_cart)
			WHERE o.valid = 1 AND c.date_add >= DATE_SUB(CURDATE(),INTERVAL 7 DAY) AND o.id_cart';

		if (!empty($emailLogs))
			$sql .= ' NOT IN ('.join(',', $emailLogs).')';

		$emails = Db::getInstance()->ExecuteS($sql);

		if ($count OR !sizeof($emails))
			return sizeof($emails);
			
		$conf = Configuration::getMultiple(array('PS_FOLLOW_UP_AMOUNT_2', 'PS_FOLLOW_UP_DAYS_2'));
		foreach ($emails AS $email)
		{
				$voucher = $this->createDiscount(2, (float)($conf['PS_FOLLOW_UP_AMOUNT_2']), (int)($email['id_customer']), strftime('%Y-%m-%d', strtotime('+'.(int)($conf['PS_FOLLOW_UP_DAYS_2']).' day')), $this->l('Thank you for your order.'));				
				if ($voucher !== false)
				{
					$templateVars = array('{email}' => $email['email'], '{lastname}' => $email['lastname'], '{firstname}' => $email['firstname'], '{amount}' => $conf['PS_FOLLOW_UP_AMOUNT_2'], '{days}' => $conf['PS_FOLLOW_UP_DAYS_2'], '{voucher_num}' => $voucher->name);
					$result = Mail::Send((int)($email['id_lang']), 'followup_2', Mail::l('Thanks for your order'), $templateVars, $email['email'], $email['firstname'].' '.$email['lastname'], NULL, NULL, NULL, NULL, dirname(__FILE__).'/mails/');
					$this->logEmail(2, (int)($voucher->id), (int)($email['id_customer']), (int)($email['id_cart']));
				}
		}
	}
	
	/* For all customers with more than x euros in 90 days */
	private function bestCustomer($count = false)
	{
		$emailLogs =  $this->getLogsEmail(2);

		$sql = '
			SELECT SUM(o.total_paid) total, c.id_cart, c.id_lang, cu.id_customer, cu.firstname, cu.lastname, cu.email
			FROM '._DB_PREFIX_.'orders o
			LEFT JOIN '._DB_PREFIX_.'customer cu ON (cu.id_customer = o.id_customer)
			LEFT JOIN '._DB_PREFIX_.'cart c ON (c.id_cart = o.id_cart)
			WHERE o.valid = 1 AND DATE_SUB(CURDATE(),INTERVAL 90 DAY) <= o.date_add AND cu.id_customer';

		if (!empty($emailLogs))
			$sql .= ' NOT IN ('.join(',', $emailLogs).')';

		$sql .= '
			GROUP BY o.id_customer
			HAVING total >= '.(float)(Configuration::get('PS_FOLLOW_UP_THRESHOLD_3'));

		$emails = Db::getInstance()->ExecuteS($sql);
		
		if ($count OR !sizeof($emails))
			return sizeof($emails);
			
		$conf = Configuration::getMultiple(array('PS_FOLLOW_UP_AMOUNT_3', 'PS_FOLLOW_UP_DAYS_3'));
		foreach ($emails AS $email)
		{
				$voucher = $this->createDiscount(3, (float)($conf['PS_FOLLOW_UP_AMOUNT_3']), (int)($email['id_customer']), strftime('%Y-%m-%d', strtotime('+'.(int)($conf['PS_FOLLOW_UP_DAYS_3']).' day')), $this->l('You are one of our best customers!'));				
				if ($voucher !== false)
				{
					$templateVars = array('{email}' => $email['email'], '{lastname}' => $email['lastname'], '{firstname}' => $email['firstname'], '{amount}' => $conf['PS_FOLLOW_UP_AMOUNT_3'], '{days}' => $conf['PS_FOLLOW_UP_DAYS_3'], '{voucher_num}' => $voucher->name);
					$result = Mail::Send((int)($email['id_lang']), 'followup_3', Mail::l('You are one of our best customers'), $templateVars, $email['email'], $email['firstname'].' '.$email['lastname'], NULL, NULL, NULL, NULL, dirname(__FILE__).'/mails/');
					$this->logEmail(3, (int)($voucher->id), (int)($email['id_customer']), (int)($email['id_cart']));
				}
		}
	}
	
	/* For all customers with no orders since more than x days */

	/**
	 * badCustomer send mails to all customers with no orders since more than x days, 
	 * with at least one valid order in history
	 * 
	 * @param boolean $count if set to true, will return number of customer (default : false, will send mails, no return value)
	 * @return void
	 */
	private function badCustomer($count = false)
	{
		$emailLogs =  $this->getLogsEmail(4);
		$sql = '
			SELECT c.id_lang, c.id_cart, cu.id_customer, cu.firstname, cu.lastname, cu.email, (SELECT COUNT(o.id_order) FROM '._DB_PREFIX_.'orders o WHERE o.id_customer = cu.id_customer and o.valid = 1) nb_orders
			FROM '._DB_PREFIX_.'customer cu
			LEFT JOIN '._DB_PREFIX_.'orders o ON (o.id_customer = cu.id_customer)
			LEFT JOIN '._DB_PREFIX_.'cart c ON (c.id_cart = o.id_cart)
			WHERE cu.id_customer NOT IN
			(SELECT o.id_customer FROM '._DB_PREFIX_.'orders o WHERE DATE_SUB(CURDATE(),INTERVAL '.(int)(Configuration::get('PS_FOLLOW_UP_DAYS_THRESHOLD_4')).' DAY) <= o.date_add)';

		if (!empty($emailLogs))
			$sql .= 'AND cu.id_customer NOT IN ('.join(',', $emailLogs).')';

		$sql .= 'GROUP BY cu.id_customer HAVING nb_orders >= 1';

		$emails = Db::getInstance()->ExecuteS($sql);

		if ($count OR !sizeof($emails))
			return sizeof($emails);
			
		$conf = Configuration::getMultiple(array('PS_FOLLOW_UP_AMOUNT_4', 'PS_FOLLOW_UP_DAYS_4'));
		foreach ($emails AS $email)
		{
				$voucher = $this->createDiscount(4, (float)($conf['PS_FOLLOW_UP_AMOUNT_4']), (int)($email['id_customer']), strftime('%Y-%m-%d', strtotime('+'.(int)($conf['PS_FOLLOW_UP_DAYS_4']).' day')), $this->l('We miss you!'));				
				if ($voucher !== false)
				{
					$templateVars = array('{email}' => $email['email'], '{lastname}' => $email['lastname'], '{firstname}' => $email['firstname'], '{amount}' => $conf['PS_FOLLOW_UP_AMOUNT_4'], '{days}' => $conf['PS_FOLLOW_UP_DAYS_4'], '{days_threshold}' => (int)(Configuration::get('PS_FOLLOW_UP_DAYS_THRESHOLD_4')), '{voucher_num}' => $voucher->name);
					$result = Mail::Send((int)($email['id_lang']), 'followup_4', Mail::l('We miss you'), $templateVars, $email['email'], $email['firstname'].' '.$email['lastname'], NULL, NULL, NULL, NULL, dirname(__FILE__).'/mails/');
					$this->logEmail(4, (int)($voucher->id), (int)($email['id_customer']), (int)($email['id_cart']));
				}
		}
	}
	
	private function createDiscount($id_email_type, $amount, $id_customer, $dateValidity, $description)
	{
		$discount = new Discount();
		$discount->id_discount_type = 1;
		$discount->value = (float)($amount);
		$discount->id_customer = (int)($id_customer);
		$discount->date_to = $dateValidity;
		$discount->date_from = date('Y-m-d H:i:s');
		$discount->quantity = 1;
		$discount->quantity_per_user = 1;
		$discount->cumulable = 0;
		$discount->cumulable_reduction = 1;
		$discount->minimal = 0;
		
		$languages = Language::getLanguages(true);
		foreach ($languages AS $language)
			$discount->description[(int)($language['id_lang'])] = $description;
			
		$name = 'FLW-'.(int)($id_email_type).'-'.strtoupper(Tools::passwdGen(10));
		$discount->name = $name;
		$discount->active = 1;
		$result = $discount->add();
		
		if (!$result)
			return false;
		return $discount;
	}
	
	public function cronTask()
	{
		$conf = Configuration::getMultiple(array('PS_FOLLOW_UP_ENABLE_1', 'PS_FOLLOW_UP_ENABLE_2', 'PS_FOLLOW_UP_ENABLE_3', 'PS_FOLLOW_UP_ENABLE_4', 'PS_FOLLOW_UP_CLEAN_DB'));

		if ($conf['PS_FOLLOW_UP_ENABLE_1'])
			$this->cancelledCart();
		if ($conf['PS_FOLLOW_UP_ENABLE_2'])
			$this->reOrder();
		if ($conf['PS_FOLLOW_UP_ENABLE_3'])
			$this->bestCustomer();
		if ($conf['PS_FOLLOW_UP_ENABLE_4'])
			$this->badCustomer();
		
		/* Clean-up database by deleting all outdated discounts */
		if ($conf['PS_FOLLOW_UP_CLEAN_DB'] == 1)
		{
			$outdatedDiscounts = Db::getInstance()->ExecuteS('SELECT id_discount FROM '._DB_PREFIX_.'discount WHERE date_to < NOW()');
			foreach ($outdatedDiscounts AS $outdatedDiscount)
			{
				$discount = new Discount((int)($outdatedDiscount['id_discount']));
				if (Validate::isLoadedObject($discount))
					$discount->delete();
			}
		}
	}
}

