<?php
require_once 'function_db_operation.php';
function insert_login_log($user_name, $is_success)
{
	$ip_address = $_SERVER['REMOTE_ADDR'];
	$lb = new LoginBlock;
	$fail_count = $lb->get_fail_count();
	if ($is_success === false) {
		$fail_count++;
	}
	$max_fail_count = $lb->get_max_fail_count();
	$is_block = $fail_count >= $max_fail_count;
	save(NULL, 'login_log', array(
		'ip_address' => $ip_address,
		'user_name' => $user_name,
		'is_success' => $is_success === false ? '0' : '1',
		'is_block' => $is_block ? '1' : '0',
	));
}

function die_if_login_block()
{
	$lb = new LoginBlock;
	$lb->die_if_login_block();
}

class LoginBlock
{
	private $block_mins = 10;
	private $max_fail_count = 5;
	
	function get_max_fail_count()
	{
		return $this->max_fail_count;
	}
	
	function get_fail_count()
	{
		$block_mins = $this->block_mins;
		$max_fail_count = $this->max_fail_count;

		$ip_address = $_SERVER['REMOTE_ADDR'];
		$time = time() - ($block_mins * 60); // before $block_mins
		$after_datetime = date('Y-m-d H:i:s', $time);

		$variables = array(
			'ip_address', 'after_datetime',
		);
		foreach ($variables as $variable)
		{
			$html_variable = 'html_' . $variable;
			$$html_variable = htmlspecialchars($$variable, ENT_QUOTES);
			$mysql_variable = 'mysql_' . $variable;
			$$mysql_variable = "'" . mysql_real_escape_string($$html_variable) . "'";
		}

		$sql = "SELECT *
			FROM login_log
			WHERE ip_address = $mysql_ip_address AND create_on >= $mysql_after_datetime
			ORDER BY create_on DESC
			LIMIT $max_fail_count";
		$login_logs = get_records($sql);
		$fail_count = 0;
		foreach ($login_logs as $login_log) {
			if ($login_log['is_success'] == 1 || $login_log['is_block'] == 1) {
				break;
			} else {
				$fail_count++;
			}
		}
		return $fail_count;
	}

	function die_if_login_block()
	{
		$block_mins = $this->block_mins;
		$max_fail_count = $this->max_fail_count;

		$ip_address = $_SERVER['REMOTE_ADDR'];
		$time = time() - ($block_mins * 60); // before $block_mins
		$after_datetime = date('Y-m-d H:i:s', $time);

		$variables = array(
			'ip_address', 'after_datetime',
		);
		foreach ($variables as $variable)
		{
			$html_variable = 'html_' . $variable;
			$$html_variable = htmlspecialchars($$variable, ENT_QUOTES);
			$mysql_variable = 'mysql_' . $variable;
			$$mysql_variable = "'" . mysql_real_escape_string($$html_variable) . "'";
		}

		$sql = "SELECT
			CASE
				WHEN EXISTS(
					SELECT * FROM login_log
					WHERE ip_address = $mysql_ip_address AND create_on >= $mysql_after_datetime AND is_block = 1
				) THEN 1
				ELSE 0
			END AS is_block";
		$result = get_record($sql);
		$is_block = $result['is_block'] == 1;

		if ($is_block) {
			die("You login failure more than $max_fail_count times, please try again after $block_mins mins.");
		}
	}
}