friendica-addons/geocoordinates/geocoordinates.php

<?php
/**
 * Name: Geocoordinates
 * Description: Use the OpenCage Geocoder http://geocoder.opencagedata.com to resolve nearest populated location for given latitude, longitude. Derived from "geonames"
 * Version: 0.1
 * Author: Michael Vogel <https://pirati.ca/profile/heluecht>
 */

function geocoordinates_install() {
	register_hook('post_local', 'addon/geocoordinates/geocoordinates.php', 'geocoordinates_post_hook');
	register_hook('post_remote', 'addon/geocoordinates/geocoordinates.php', 'geocoordinates_post_hook');
}


function geocoordinates_uninstall() {
	unregister_hook('post_local',    'addon/geocoordinates/geocoordinates.php', 'geocoordinates_post_hook');
	unregister_hook('post_remote',    'addon/geocoordinates/geocoordinates.php', 'geocoordinates_post_hook');
}

function geocoordinates_resolve_item(&$item) {
	if((!$item["coord"]) || ($item["location"]))
		return;

	$key = get_config("geocoordinates", "api_key");
	if ($key == "")
		return;

	$language = get_config("geocoordinates", "language");
	if ($language == "")
		$language = "de";

	$coords = explode(' ',$item["coord"]);

	if (count($coords) < 2)
		return;

	$coords[0] = round($coords[0], 5);
	$coords[1] = round($coords[1], 5);

	$result = Cache::get("geocoordinates:".$language.":".$coords[0]."-".$coords[1]);
	if (!is_null($result)) {
		$item["location"] = $result;
		return;
	}

	$s = fetch_url("https://api.opencagedata.com/geocode/v1/json?q=".$coords[0].",".$coords[1]."&key=".$key."&language=".$language);

	if (!$s) {
		logger("API could not be queried", LOGGER_DEBUG);
		return;
	}

	$data = json_decode($s);

	if ($data->status->code != "200") {
		logger("API returned error ".$data->status->code." ".$data->status->message, LOGGER_DEBUG);
		return;
	}

	if (($data->total_results == 0) || (count($data->results) == 0)) {
		logger("No results found for coordinates ".$item["coord"], LOGGER_DEBUG);
		return;
	}

	$item["location"] = $data->results[0]->formatted;

	logger("Got location for coordinates ".$coords[0]."-".$coords[1].": ".$item["location"], LOGGER_DEBUG);

	if ($item["location"] != "")
		Cache::set("geocoordinates:".$language.":".$coords[0]."-".$coords[1], $item["location"]);
}

function geocoordinates_post_hook($a, &$item) {
	geocoordinates_resolve_item($item);
}

function geocoordinates_plugin_admin(&$a,&$o) {

	$t = get_markup_template("admin.tpl", "addon/geocoordinates/");

	$o = replace_macros($t, array(
		'$submit' => t('Save Settings'),
		'$api_key' => array('api_key', t('API Key'),  get_config('geocoordinates', 'api_key' ), ''),
		'$language' => array('language', t('Language code (IETF format)'),  get_config('geocoordinates', 'language' ), ''),
	));
}

function geocoordinates_plugin_admin_post(&$a) {
	$api_key  = ((x($_POST,'api_key')) ? notags(trim($_POST['api_key']))   : '');
	set_config('geocoordinates','api_key',$api_key);

	$language  = ((x($_POST,'language')) ? notags(trim($_POST['language']))   : '');
	set_config('geocoordinates','language',$language);
	info(t('Settings updated.'). EOL);
}