<?php

// Simple curl wrapper to return any data from a POST request or false if any failure.
function post_data( $url, $params ) {
	// Handle if someone gives us a key->value array
	if( is_array( $params ) ) {
		foreach( $params as $param => $value ) {
			$param_string .= "$param=$value&";
		}
		$param_string = rtrim( $param_string, "&" );
	} else {
		// or just use their string if they give it to us pre-joined.
		$param_string = $params;
	}

	$curl_handle = curl_init();
	curl_setopt($curl_handle, CURLOPT_URL, $url);
	curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($curl_handle,CURLOPT_POST,1);
	curl_setopt($curl_handle,CURLOPT_POSTFIELDS, $param_string );
	curl_setopt($curl_handle, CURLOPT_FAILONERROR, True ); // Enable fail on HTTP error codes >= 400
	$retval = curl_exec( $curl_handle );
	if( curl_errno( $curl_handle ) > 0 ) { // run the whole process
		if($debug) {
			echo( "Error accessing url: $url: " . curl_error( $curl_handle ) );
		}
		curl_close($curl_handle);
		return false;
	} else {
		curl_close($curl_handle);
		return $retval;
	}
}

// Simple curl wrapper to return any GET data or false if any failure.
// This is a suitable replacement for systems where fopen() isn't allowed
// to open remote files. (Which is sensible for security reasons.)
function get_data( $url ) {
	$curl_handle = curl_init();
	curl_setopt($curl_handle, CURLOPT_URL, $url);
	curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($curl_handle, CURLOPT_FAILONERROR, True ); // Enable failover on HTTP error codes >= 400
	$retval = curl_exec( $curl_handle );
	if( curl_errno( $curl_handle ) > 0 ) { // run the whole process
		if($debug) {
			echo( "Error accessing url: $url: " . curl_error( $curl_handle ) );
		}
		curl_close($curl_handle);
		return false;
	} else {
		curl_close($curl_handle);
		return $retval;
	}
}

/* This method takes an address in long form (a single string) and returns you either:
 * the latitude, longitude and accuracy (in an array form).  This is a thin wrapper
 * around Google's geo-coding API.
 * See: http://www.google.com/apis/maps/documentation/services.html#Geocoding for the
 * service information, and see:
 * http://www.google.com/apis/maps/documentation/reference.html#GGeoAddressAccuracy
 * for what the accuracy constants mean.
 *
 * Note that this method is primitive.  it doesn't do much in the way of error checking or
 * accuracy checking.  That should be done in a wrapper method for business critical applications.
 */
function get_lat_long_from_addr($address) {
	// make sure no wayward ampersands make it into the address field..
	$address = preg_replace("/&/", "and", $address);
	$url = sprintf("http://maps.google.com/maps/geo?q=%s&output=xml&key=%s", urlencode($address), $googlemap_api_key);
	if($debug) {
		echo("Accessing URL: $url<br>\n");
	}

	$data = get_data($url);

	if(!$data) {
		if($debug) {
			echo("Failed to retrieve lat/lon from Google.\n");
		}
		return False;
	} else {
		// We should have a fat XML blob now. On to pillage.
		$geocoded = array();

		if($debug) {
			echo("<p>Raw XML from google\n<tt>\n");
			echo($data . "</p></tt>\n");
		}

		$kml = new SimpleXMLElement(utf8_encode($data));	// utf data is not well supported here..
		foreach($kml->Response->Placemark as $row) {
			$address = $row->address;
			$accuracy = (string)$row->AddressDetails['Accuracy'];	// Lol type cast
			// I'm not sure what the 3rd parameter in the coordinates element is, so I don't store it. :?:
			// it should be noted that the XML returns the coordinates in reverse order as the CSV.
			list($long,$lat) = explode(',', $row->Point->coordinates);
			$geocoded[] = array( 'accuracy' => $accuracy, 'latitude' => $lat, 'longitude' => $long, 'addy' => $address );
			if($debug) {
				echo("<tt><p>\n");
				//var_dump($row);
				echo("Accuracy: $accuracy<br>\n");
				echo("Address: $address<br>\n");
				echo("Lat: $lat<br>\n");
				echo("Long: $long<br>\n");
				echo("</p>\n</tt>\n");
			}
		}

		if(count($geocoded) > 0) {
			return $geocoded;
		} else {
			return False;
		}
	}
}

?>