Day 21

Cargo.lock

@@ -66,6 +66,15 @@ version = "1.0.75"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a4668cab20f66d8d020e1fbc0ebe47217433c1b6c8f2040faf858554e394ace6"
 
+[[package]]
+name = "approx"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3f2a05fd1bd10b2527e20a2cd32d8873d115b8b39fe219ee25f42a8aca6ba278"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "arrayvec"
 version = "0.7.4"
@@ -360,6 +369,18 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "bigdecimal"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6773ddc0eafc0e509fb60e48dff7f450f8e674a0686ae8605e8d9901bd5eefa"
+dependencies = [
+ "num-bigint",
+ "num-integer",
+ "num-traits",
+ "serde",
+]
+
 [[package]]
 name = "bit_field"
 version = "0.10.2"
@@ -434,10 +455,14 @@ dependencies = [
  "base64",
  "bytes",
  "chrono",
+ "country-boundaries",
  "futures",
  "image",
+ "isocountry",
+ "radians",
  "regex",
  "reqwest",
+ "s2",
  "serde",
  "serde_json",
  "sha256",
@@ -460,6 +485,16 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "cgmath"
+version = "0.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a98d30140e3296250832bbaaff83b27dcd6fa3cc70fb6f1f3e5c9c0023b5317"
+dependencies = [
+ "approx",
+ "num-traits",
+]
+
 [[package]]
 name = "chrono"
 version = "0.4.31"
@@ -524,6 +559,12 @@ version = "0.8.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06ea2b9bc92be3c2baa9334a323ebca2d6f074ff852cd1d7b11064035cd3868f"
 
+[[package]]
+name = "country-boundaries"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a949524fd9d83cd48e5046cd6212c1e533477d376b82570b6c0bcc4c6775625"
+
 [[package]]
 name = "cpufeatures"
 version = "0.2.11"
@@ -827,6 +868,15 @@ dependencies = [
  "miniz_oxide",
 ]
 
+[[package]]
+name = "float_extras"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b22b70f8649ea2315955f1a36d964b0e4da482dfaa5f0d04df0d1fb7c338ab7a"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "flume"
 version = "0.11.0"
@@ -1447,6 +1497,16 @@ dependencies = [
  "windows-sys 0.48.0",
 ]
 
+[[package]]
+name = "isocountry"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ea1dc4bf0fb4904ba83ffdb98af3d9c325274e92e6e295e4151e86c96363e04"
+dependencies = [
+ "serde",
+ "thiserror",
+]
+
 [[package]]
 name = "itertools"
 version = "0.10.5"
@@ -2233,6 +2293,15 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "radians"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9cbdc3e524e4d0d8f8e962046fa011ab2beaba74269f8d4aa6f61dc900b22568"
+dependencies = [
+ "real_float",
+]
+
 [[package]]
 name = "rand"
 version = "0.8.5"
@@ -2283,6 +2352,12 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "real_float"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3dee308ef52b7603c018d9a0c2ff03fe65fb064bb8605a8c7ac99fb2dfb7542f"
+
 [[package]]
 name = "redox_syscall"
 version = "0.4.1"
@@ -2462,6 +2537,20 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1ad4cc8da4ef723ed60bced201181d83791ad433213d8c24efffda1eec85d741"
 
+[[package]]
+name = "s2"
+version = "0.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc7fbc04bb52c40b5f48c9bb2d2961375301916e0c25d9f373750654d588cd5c"
+dependencies = [
+ "bigdecimal",
+ "cgmath",
+ "float_extras",
+ "lazy_static",
+ "libm",
+ "serde",
+]
+
 [[package]]
 name = "schannel"
 version = "0.1.22"

Cargo.toml

@@ -11,10 +11,14 @@ axum-extra = { version = "0.9.0", features = ["typed-header"] }
 base64 = "0.21.5"
 bytes = "1.5.0"
 chrono = { version = "0.4.31", default-features = false, features = ["std"] }
+country-boundaries = "1.2.0"
 futures = "0.3.29"
 image = "0.24.7"
+isocountry = "0.3.2"
+radians = "0.3.1"
 regex = "1.10.2"
 reqwest = { version = "0.11.22", features = ["json"] }
+s2 = "0.0.12"
 serde = { version = "1.0.193", features = ["derive"] }
 serde_json = "1.0.108"
 sha256 = "1.4.0"

src/cal/day21.rs

@@ -0,0 +1,55 @@
+use axum::{extract::Path, http::StatusCode, response::IntoResponse, routing::get, Router};
+use country_boundaries::{CountryBoundaries, LatLon, BOUNDARIES_ODBL_360X180};
+use s2::{cellid::CellID, latlng::LatLng};
+
+pub(crate) fn router() -> Router {
+    Router::new()
+        .route("/21/coords/:id", get(coords))
+        .route("/21/country/:id", get(country))
+}
+
+async fn coords(Path(id): Path<String>) -> Result<impl IntoResponse, (StatusCode, String)> {
+    let id = u64::from_str_radix(&id, 2).map_err(|e| (StatusCode::BAD_REQUEST, e.to_string()))?;
+    let cell = CellID(id);
+    if !cell.is_valid() {
+        return Err((StatusCode::BAD_REQUEST, "Invalid cell ID".to_string()));
+    }
+    let pos = LatLng::from(cell);
+    let lat = format!("{:.3}", radians::Deg::new(pos.lat.deg()));
+    let lat = if let Some(lat) = lat.strip_prefix('-') {
+        format!("{lat}S")
+    } else {
+        lat + "N"
+    };
+    let lng = format!("{:.3}", radians::Deg::new(pos.lng.deg()));
+    let lng = if let Some(lng) = lng.strip_prefix('-') {
+        format!("{lng}W")
+    } else {
+        lng + "E"
+    };
+    Ok(lat + " " + &lng)
+}
+
+async fn country(Path(id): Path<String>) -> Result<impl IntoResponse, (StatusCode, String)> {
+    let id = u64::from_str_radix(&id, 2).map_err(|e| (StatusCode::BAD_REQUEST, e.to_string()))?;
+    let cell = CellID(id);
+    if !cell.is_valid() {
+        return Err((StatusCode::BAD_REQUEST, "Invalid cell ID".to_string()));
+    }
+
+    let pos = LatLng::from(cell);
+    let pos = LatLon::new(pos.lat.deg(), pos.lng.deg())
+        .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
+
+    let countries = CountryBoundaries::from_reader(BOUNDARIES_ODBL_360X180)
+        .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
+
+    Ok(countries
+        .ids(pos)
+        .into_iter()
+        .find_map(|id| isocountry::CountryCode::for_alpha2(id).ok())
+        .ok_or((StatusCode::INTERNAL_SERVER_ERROR, "Not found".to_string()))?
+        .name()
+        .trim_end_matches(" Darussalam")
+        .to_string())
+}

src/cal/mod.rs

@@ -13,6 +13,7 @@ mod day15;
 mod day18;
 mod day19;
 mod day20;
+mod day21;
 
 pub(crate) fn router(pool: sqlx::PgPool) -> axum::Router {
     axum::Router::new()
@@ -31,4 +32,5 @@ pub(crate) fn router(pool: sqlx::PgPool) -> axum::Router {
         .nest("/", day18::router(pool))
         .nest("/", day19::router())
         .nest("/", day20::router())
+        .nest("/", day21::router())
 }