<?php
//
// Sipmody.php
// Created by Brett Kokinadis (brett@attendme.io)
// Git openfax/sipmodify
// July 19, 2016
//
// This API talks to the OpenSips Core server's psqldb to activate and deactivate
// IVR/Fax Removal Service Numbers and Inbound Fax Numbers.
//
// Security & Access Notes:					This service uses the sip1.security table with group
//											type Outboundcoreserver.  You will need to add
//											IPs of the application servers that contact this
//											webservice.  Firewall updates take 5 minutes to sync.
//
// Published URL:	https://smod.openfax.com/api/
// Example call:	https://smod.openfax.com/api/?apikey=1&action=c&type=f&did=5554443333
//
// Passing Params:   api=apikey				!api key as sepecified in this file
//					action=c     			!request to create/provision number
//					or	action=d    		!request to delete/de-provision number
//					type=i       			!request pertains to an inbound ivr/fax removal number
//                  or	type=f   			!request pertains to an inbound fax DID
//					did=npanxxxxxxx			!though we do sterialize this number, we are
//											expected 10 digits. Ie. 5206651945
//
//
// Responses:		json encoded 			{"Result":"##","Description":"Value"}
//
//					Value  					Description
//                  ----------------------------------------------------------------------------------
//					-1  					Invalid API Key
//
// 					-2 						DID Invalid - Insufficient digits to sterilize.
//											Input: NPANXXXXX Sertialized Output: +1NPANXXXXXX'
//					-3 						Cannot add, DID already exists in table
//
//					-4						Requested function not yet supported in this API Version
//
//
//
//Static Settings
$dbcon = 'host=localhost port=5432 dbname=opensips user=XXXX password=XXXX!';
$apikey='XXXXX';


// Grabs information
$api = $_GET['api']; // API key
$action = $_GET['action']; // To c=create or d=delete entry
$type = $_GET ['type']; // f = inbound fax did, i = ivr fax removal
$phonenumber = $_GET['did']; // expecting NPANXXXXXX


$action = strtoupper($action); // makes action paramater case insenstitive
$type = strtoupper($type); // makes type paramater case insenstitive


//Validate API key
if ($api != $apikey) {
	$status = '-1';
	returnHandler($status);
} else {

//Sterilize DID for Opensip e.164 standard, this will work with North American numbers only
$did = preg_replace('~.*(\d{3})[^\d]{0,7}(\d{3})[^\d]{0,7}(\d{4}).*~', '+1$1$2$3', $phonenumber);

// Make sure we got 12 characters after sterilization, expecting NPANXXXXX input, ouput +1NPANXXXXXX

if (strlen($did) < 12) {
	$status = '-2';
	returnHandler($status);
}

//Determine CRUD action

	//Action to create entry
	if ($action == 'C') {

		if ($type == 'F') {
			//Create Fax DID Entry
			createEntry ($dbcon, $did, $type);
		} elseif ($type == 'I')  {
				//Create IVR DID
				createEntry ($dbcon, $did, $type);
		} else {
				//Invalud TYPE value (F)ax or (I)vr
				$status = '-6';
				returnHandler($status);
		}

	//Action Delete DID
	} elseif ($action == 'D') {

			if ($type == 'F') {
				//Delete Fax DID
				deleteEntry ($dbcon, $did,$type);
			} elseif ($type == 'I') {
					//Delete IVR DID
					deleteEntry ($dbcon, $did,$type);
			} else {
				//Not a valid DID format
				$status = '-6';
  				returnHandler($status);
  			}

	} else {
		//Not a valid Action
		$status = '-7';
  		returnHandler($status);
  	}
  }



function createEntry ($dbcon, $did,$type) {
	//connect to opensips psql db
	$conn = pg_connect($dbcon);

	//Complain about db connection error
	if (!$conn) {
  		$status = '0';
  		returnHandler($status);
	}

	//Search if entry already exists
	$result = pg_query($conn,"SELECT did FROM opensips_dids where did='".$did."'");
	echo $did;
	if (!$result) {
  		pg_close($conn);
  		$status = '0';
  		returnHandler($status);
  	}

	$row = pg_fetch_array($result);

	// Cannot add, DID already exists in table.
	if ($row[0] == $did) {
		pg_close($conn);
		$status = '-3';
  		returnHandler($status);
	}

	//Adds entry for Fax DID
	if ($type = 'F') {
		$addFax = pg_query($conn, "insert into opensips_dids (did, status, setid) values ('".$did."',0,20)");
		pg_close($conn);
		$status = '1';
  		returnHandler($status); //Added FaxDID successfully

	} elseif ($type = 'I') {
		$addIVR = pg_query($conn, "insert into opensips_dids (did, status, setid) values ('".$did."',0,30)");
		pg_close($conn);
		$status = '1';
  		returnHandler($status); //Added IVR successfully
	}

	else {
		// Future ivr settings, opensip rules not yet defined
		pg_close($conn);
		$status = '-4';
  		returnHandler($status); //Cannot add, feature unsupported at this time.
	}
}

function deleteEntry ($dbcon, $did,$type) {
	//connect to opensips psql db
	$conn = pg_connect($dbcon) or returnHandler('0');

	//Complain about db connection error
	if (!$conn) {
  		pg_close($conn);
  		$status = '0';
  		returnHandler($status);

  	}

	//Search if entry already exists
	$result = pg_query($conn,"SELECT did FROM opensips_dids where did='".$did."' and setid='".$settype.'"');

	if (!$result) {
  		pg_close($conn);
  		$status = '0';
  		returnHandler($status);
	}

	$row = pg_fetch_array($result);

	// Cannot delete, DID does not exists in table.



	if ($row[0] != $did) {
		pg_close($conn);
		$status = '-5';
  		returnHandler($status);
	}

	//Delete entry for Fax DID
	if ($type = 'F') {
		$delFax = pg_query($conn, "delete from opensips_dids where did = '".$did."'");
		pg_close($conn);
		$status = '1';
  		returnHandler($status);

	} elseif ($type = 'I') {
		$delIVR = pg_query($conn, "delete from opensips_dids where did = '".$did."'");
		pg_close($conn);
		$status = '1';
  		returnHandler($status);

	} else {

	// Future ivr settings, opensip rules not yet defined
		pg_close($conn);
		$status = '-4';
  		returnHandler($status);
  	}
}


function returnHandler ($status) {
	unset ($jsonResponse);
	//Define description responses for JSON

	if ($status == '-1' ) {
		$description ='Invalid API Key';
	}

	if ($status == '-2') {
		$description = 'DID Invalid - Insufficient digits to sterilize. Input: NPANXXXXX Sertialized Output: +1NPANXXXXXX';
	}

	if ($status == '-3') {
		$description = 'Cannot add, DID already exists in table';
	}

	if ($status == '-4') {
		$description = 'Requested function not yet supported in this api version';
	}

	if ($status == '-5') {
		$description = 'Cannot delete, DID does not exists in table';
	}

	if ($status == '-6') {
		$description = 'Invalid DID type, type value (F)ax or (I)vr.';
	}

	if ($status == '-7') {
		$description = 'Invalid Action type, type value (C)reate or (D)elete.';
	}

	if ($status == '0') {
		$description = 'An error occurred while working with the database';
	}
	if ($status == '1') {
		$description = 'Request processed successfully';
	}

	//Build & reply with json response
	$jsonResponse = array('Result' => $status, 'Description' => $description);
	echo json_encode($jsonResponse);
	die ();
}
?>