Nominatim

use nominatim.qweruse nominatim_address, nominatim_search from nominatim      // Quillo 0.6: only these

ureq = "2"serde_json = { version = "1", features = ["preserve_order"] }

// Addresses on OpenStreetMap: a search, a structured address, the street at a position, a place by// its id, and the parts of an address in one shape. It keeps to the usage policy of the public// server, so every call waits its turn, at one a second, and an answer is kept for a day.////   NOMINATIM_USER_AGENT="myshop/1.0 (ops@example.com)" quillo run nominatim.qwe//   then open http://localhost:8080/search?q=Dam+Amsterdam, /reverse, /parts, /status and /refused//// NOMINATIM_API_URL points at your own server, and NOMINATIM_MIN_INTERVAL_MS sets its gap.use "nominatim.qwer"route GET /search ? { q: str } {    let r = nominatim_search(q, { limit: 3 })    if is_err(r) { reply 502 r.error }    r}route GET /structured = {    place: first(nominatim_structured({ street: "1 Dam", city: "Amsterdam", country: "Nederland" }, { limit: 1 })?).display_name,    none: nominatim_search("nowhere at all", {})?,    other_country: nominatim_search("Dam", { countrycodes: "fr" })?,    bounded: len(nominatim_search("Dam", { viewbox: "4.8,52.4,5.0,52.3", bounded: true, language: "nl" })?),}route GET /reverse = {    here: nominatim_reverse(52.3731, 4.8932, { zoom: 18 })?,    at_sea: nominatim_reverse(0.0, 0.0, {})?,    by_id: nominatim_lookup(["W95014", "N1"], {})? | map((p) => p.osm_id),}route GET /parts = {    city: first(nominatim_search("Dam", { extratags: true })?).address,    village: first(nominatim_search("Kleindorp", {})?).address,    tags: first(nominatim_search("Dam", { extratags: true })?).extratags,    by_hand: nominatim_address({ town: "Oss", road: "Molenstraat", country_code: "nl" }),}route GET /status = nominatim_status()?route GET /refused = {    empty: nominatim_search("  ", {}).error,    position: nominatim_reverse(99.0, 0.0, {}).error,    id: nominatim_lookup(["X1"], {}).error,    option: nominatim_search("Dam", { colour: "red" }).error,    part: nominatim_structured({ planet: "Earth" }, {}).error,    too_many: nominatim_search("Dam", { limit: 500 }).error,}

//! Nominatim, OpenStreetMap's geocoder: places by name or structured address, reverse lookups and OSM ids, address parts tidied, and the public server's usage policy kept by a User-Agent, one request a second, and a cache.//! version: 1.0.0//!//! [dependencies]//! ureq = "2"//! serde_json = { version = "1", features = ["preserve_order"] }use serde_json::{json, Map, Value};use std::collections::HashMap;use std::sync::{Mutex, OnceLock};use std::thread::sleep;use std::time::{Duration, Instant};const PUBLIC: &str = "https://nominatim.openstreetmap.org";const TTL: Duration = Duration::from_secs(24 * 3600);fn base() -> String {    std::env::var("NOMINATIM_API_URL").ok().filter(|v| !v.is_empty()).unwrap_or(PUBLIC.to_string()).trim_end_matches('/').to_string()}fn user_agent() -> Result<String, String> {    match std::env::var("NOMINATIM_USER_AGENT").ok().filter(|v| !v.trim().is_empty()) {        Some(u) => Ok(u),        None => Err("set NOMINATIM_USER_AGENT to something naming your application and how to reach you, like `myshop/1.0 (ops@example.com)`: the usage policy requires it, and the public server refuses stock ones".into()),    }}fn enc(s: &str) -> String {    s.bytes().map(|b| if b.is_ascii_alphanumeric() || b"-_.~,".contains(&b) { (b as char).to_string() } else { format!("%{:02X}", b) }).collect()}// The policy asks for one request a second across the whole application, so every thread queues// here. Your own Nominatim can set NOMINATIM_MIN_INTERVAL_MS lower.static LAST: Mutex<Option<Instant>> = Mutex::new(None);fn wait_turn() {    let gap = std::env::var("NOMINATIM_MIN_INTERVAL_MS").ok().and_then(|v| v.parse::<u64>().ok()).unwrap_or(1000);    let mut last = LAST.lock().unwrap_or_else(|e| e.into_inner());    if let Some(t) = *last {        let spent = t.elapsed();        if spent < Duration::from_millis(gap) {            sleep(Duration::from_millis(gap) - spent);        }    }    *last = Some(Instant::now());}fn cache() -> &'static Mutex<HashMap<String, (Instant, Value)>> {    static C: OnceLock<Mutex<HashMap<String, (Instant, Value)>>> = OnceLock::new();    C.get_or_init(|| Mutex::new(HashMap::new()))}fn call(path: &str, params: Vec<(String, String)>) -> Result<Value, String> {    let ua = user_agent()?;    let q: Vec<String> = params.iter().map(|(k, v)| format!("{}={}", k, enc(v))).collect();    let url = format!("{}{}?{}", base(), path, q.join("&"));    // The policy asks that results be kept; the same question a day later costs the server nothing.    if let Some((t, v)) = cache().lock().unwrap_or_else(|e| e.into_inner()).get(&url) {        if t.elapsed() < TTL {            return Ok(v.clone());        }    }    let agent = ureq::AgentBuilder::new().timeout(Duration::from_secs(20)).user_agent(&ua).build();    for attempt in 0..2 {        wait_turn();        match agent.get(&url).call() {            Ok(r) => {                let t = r.into_string().map_err(|e| e.to_string())?;                let v: Value = serde_json::from_str(&t).map_err(|_| format!("Nominatim's answer is not JSON: {:?}", t.chars().take(200).collect::<String>()))?;                let mut c = cache().lock().unwrap_or_else(|e| e.into_inner());                if c.len() >= 4096 {                    c.clear();                }                c.insert(url, (Instant::now(), v.clone()));                return Ok(v);            }            Err(ureq::Error::Status(429, _)) if attempt == 0 => sleep(Duration::from_secs(2)),            Err(ureq::Error::Status(403, _)) => return Err("Nominatim answered 403: the User-Agent was refused, or this address is blocked for too many requests".into()),            Err(ureq::Error::Status(429, _)) => return Err("Nominatim answered 429: slow down, the public server takes one request a second".into()),            Err(ureq::Error::Status(code, r)) => {                let t = r.into_string().unwrap_or_default();                let msg = serde_json::from_str::<Value>(&t).ok().and_then(|v| v.pointer("/error/message").and_then(|m| m.as_str()).map(String::from)).unwrap_or(t.chars().take(200).collect());                return Err(format!("Nominatim answered {}: {}", code, msg));            }            Err(e) => return Err(format!("cannot reach Nominatim: {}", e)),        }    }    Err("Nominatim kept answering 429".into())}const CITY: [&str; 6] = ["city", "town", "village", "hamlet", "municipality", "suburb"];/// Address parts as one shape, whatever the place: { house_number, road, neighbourhood, city, county, state, postcode, country, country_code }. Nominatim says city, town, village or hamlet by size, so `city` takes the first it finds.pub fn nominatim_address(place: serde_json::Value) -> Value {    let a = place.get("address").cloned().unwrap_or(place);    let text = |k: &str| a.get(k).cloned().unwrap_or(Value::Null);    let city = CITY.iter().find_map(|k| a.get(*k)).cloned().unwrap_or(Value::Null);    let near = ["neighbourhood", "quarter", "suburb"].iter().find_map(|k| a.get(*k)).cloned().unwrap_or(Value::Null);    let house = a.get("house_number").or(a.get("house_name")).cloned().unwrap_or(Value::Null);    let road = ["road", "pedestrian", "footway", "path", "cycleway"].iter().find_map(|k| a.get(*k)).cloned().unwrap_or(Value::Null);    json!({ "house_number": house, "road": road, "neighbourhood": near, "city": city, "county": text("county"), "state": text("state"), "postcode": text("postcode"), "country": text("country"), "country_code": text("country_code") })}fn num(v: Option<&Value>) -> Value {    match v {        Some(Value::String(s)) => s.parse::<f64>().map(|x| json!(x)).unwrap_or(Value::Null),        Some(x) => x.clone(),        None => Value::Null,    }}// Lat, lon and the box come as strings; here they are numbers, the box as west, south, east, north.fn tidy(p: &Value) -> Value {    let box_: Option<Vec<f64>> = p.get("boundingbox").and_then(|b| b.as_array()).map(|b| b.iter().filter_map(|x| x.as_str().and_then(|s| s.parse().ok())).collect());    let mut o = Map::new();    o.insert("name".into(), p.get("name").cloned().unwrap_or(Value::Null));    o.insert("display_name".into(), p.get("display_name").cloned().unwrap_or(Value::Null));    o.insert("lat".into(), num(p.get("lat")));    o.insert("lon".into(), num(p.get("lon")));    o.insert("bbox".into(), box_.filter(|b| b.len() == 4).map(|b| json!([b[2], b[0], b[3], b[1]])).unwrap_or(Value::Null));    o.insert("category".into(), p.get("category").cloned().unwrap_or(Value::Null));    o.insert("type".into(), p.get("type").cloned().unwrap_or(Value::Null));    o.insert("importance".into(), p.get("importance").cloned().unwrap_or(Value::Null));    let id = match (p.get("osm_type").and_then(|t| t.as_str()), p.get("osm_id")) {        (Some(t), Some(i)) => json!(format!("{}{}", t.chars().next().unwrap_or('?').to_ascii_uppercase(), i)),        _ => Value::Null,    };    o.insert("osm_id".into(), id);    o.insert("address".into(), if p.get("address").is_some() { nominatim_address(p.clone()) } else { Value::Null });    if let Some(x) = p.get("extratags") {        o.insert("extratags".into(), x.clone());    }    o.insert("licence".into(), p.get("licence").cloned().unwrap_or(Value::Null));    Value::Object(o)}fn shared(options: &Value, p: &mut Vec<(String, String)>) -> Result<(), String> {    p.push(("format".into(), "jsonv2".into()));    p.push(("addressdetails".into(), "1".into()));    for (k, v) in options.as_object().ok_or("options must be a map")? {        let text = v.as_str().map(String::from).unwrap_or(v.to_string());        match k.as_str() {            "language" => p.push(("accept-language".into(), text)),            "limit" | "countrycodes" | "viewbox" | "layer" | "zoom" | "featureType" | "email" | "polygon_threshold" => p.push((k.clone(), text)),            "bounded" | "extratags" | "namedetails" | "dedupe" => p.push((k.clone(), if v == &json!(true) { "1".to_string() } else if v == &json!(false) { "0".to_string() } else { text })),            o => return Err(format!("no option `{}`; there are language, limit, countrycodes, viewbox, bounded, zoom, layer, featureType, extratags, namedetails, email", o)),        }    }    Ok(())}/// Places by free text, best first: [{ name, display_name, lat, lon, bbox, category, type, importance, osm_id, address, licence }]. `options`: { limit, countrycodes, viewbox, bounded, language, extratags, email }. No match is an empty list. Show the `licence`: OpenStreetMap's attribution is required.pub fn nominatim_search(query: &str, options: serde_json::Value) -> Result<Value, String> {    if query.trim().is_empty() {        return Err("nothing to search for".into());    }    let mut p = vec![("q".to_string(), query.trim().to_string())];    shared(&options, &mut p)?;    let v = call("/search", p)?;    Ok(json!(v.as_array().map(|a| a.iter().map(tidy).collect::<Vec<_>>()).unwrap_or_default()))}/// Places by a structured address, which finds better than one line: { street, city, county, state, country, postalcode, amenity }, with `street` holding the number and name.pub fn nominatim_structured(address: serde_json::Value, options: serde_json::Value) -> Result<Value, String> {    let a = address.as_object().ok_or("give the address as a map")?;    let mut p = vec![];    for (k, v) in a {        if !["street", "city", "county", "state", "country", "postalcode", "amenity"].contains(&k.as_str()) {            return Err(format!("no address part `{}`; there are street, city, county, state, country, postalcode, amenity", k));        }        p.push((k.clone(), v.as_str().map(String::from).unwrap_or(v.to_string())));    }    if p.is_empty() {        return Err("an empty address".into());    }    shared(&options, &mut p)?;    let v = call("/search", p)?;    Ok(json!(v.as_array().map(|a| a.iter().map(tidy).collect::<Vec<_>>()).unwrap_or_default()))}/// The place at a position, or null where there is nothing, as at sea. `options`: { zoom (3 country to 18 building), language, layer }. Not an error, as Nominatim's own `Unable to geocode` is an ordinary answer.pub fn nominatim_reverse(lat: f64, lon: f64, options: serde_json::Value) -> Result<Value, String> {    if !(-90.0..=90.0).contains(&lat) || !(-180.0..=180.0).contains(&lon) {        return Err(format!("({}, {}) is not a position", lat, lon));    }    let mut p = vec![("lat".to_string(), lat.to_string()), ("lon".to_string(), lon.to_string())];    shared(&options, &mut p)?;    let v = call("/reverse", p)?;    if v.get("error").is_some() {        return Ok(Value::Null);    }    Ok(tidy(&v))}/// Places by OpenStreetMap id, up to 50: `["W95014", "N240109189", "R146656"]`. An id with no place is left out of the answer.pub fn nominatim_lookup(ids: Vec<String>, options: serde_json::Value) -> Result<Value, String> {    if ids.is_empty() || ids.len() > 50 {        return Err(format!("lookup takes 1 to 50 ids, not {}", ids.len()));    }    for i in &ids {        let ok = i.len() > 1 && matches!(i.as_bytes()[0], b'N' | b'W' | b'R') && i[1..].bytes().all(|b| b.is_ascii_digit());        if !ok {            return Err(format!("`{}` is no OSM id: N, W or R and a number", i));        }    }    let mut p = vec![("osm_ids".to_string(), ids.join(","))];    shared(&options, &mut p)?;    let v = call("/lookup", p)?;    Ok(json!(v.as_array().map(|a| a.iter().map(tidy).collect::<Vec<_>>()).unwrap_or_default()))}/// The server's health: { ok, message, data_updated, software_version }. For a self-hosted Nominatim; it is not cached by a client that wants the truth, so call it sparingly.pub fn nominatim_status() -> Result<Value, String> {    let v = call("/status", vec![("format".to_string(), "json".to_string())])?;    Ok(json!({ "ok": v.get("status") == Some(&json!(0)), "message": v.get("message"), "data_updated": v.get("data_updated"), "software_version": v.get("software_version") }))}