From 0b2c9f1465cd2b801874da3851112b7dbcefdc20 Mon Sep 17 00:00:00 2001
From: Aadi Desai <21363892+supleed2@users.noreply.github.com>
Date: Tue, 12 Dec 2023 18:06:21 +0000
Subject: [PATCH] Day 12

---
 Cargo.lock       | 14 +++++++
 Cargo.toml       |  3 ++
 src/cal/day12.rs | 95 ++++++++++++++++++++++++++++++++++++++++++++++++
 src/cal/mod.rs   |  2 +
 4 files changed, 114 insertions(+)
 create mode 100644 src/cal/day12.rs

diff --git a/Cargo.lock b/Cargo.lock
index 08fad26..02b43f3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -316,6 +316,7 @@ dependencies = [
  "axum 0.7.2",
  "axum-extra",
  "base64",
+ "chrono",
  "image",
  "reqwest",
  "serde",
@@ -325,6 +326,8 @@ dependencies = [
  "tokio",
  "tower-http 0.5.0",
  "tracing",
+ "ulid",
+ "uuid",
 ]
 
 [[package]]
@@ -2851,6 +2854,17 @@ version = "1.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"
 
+[[package]]
+name = "ulid"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7e37c4b6cbcc59a8dcd09a6429fbc7890286bcbb79215cea7b38a3c4c0921d93"
+dependencies = [
+ "rand",
+ "serde",
+ "uuid",
+]
+
 [[package]]
 name = "unicase"
 version = "2.7.0"
diff --git a/Cargo.toml b/Cargo.toml
index feeee17..9268bbb 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,6 +7,7 @@ edition = "2021"
 axum = { version = "0.7.2", features = ["macros", "multipart"] }
 axum-extra = { version = "0.9.0", features = ["typed-header"] }
 base64 = "0.21.5"
+chrono = { version = "0.4.31", default-features = false, features = ["std"] }
 image = "0.24.7"
 reqwest = { version = "0.11.22", features = ["json"] }
 serde = { version = "1.0.193", features = ["derive"] }
@@ -16,3 +17,5 @@ shuttle-runtime = "0.35.0"
 tokio = "1.34.0"
 tower-http = { version = "0.5.0", features = ["fs"] }
 tracing = "0.1.40"
+ulid = { version = "1.1.0", features = ["uuid", "serde"] }
+uuid = "1.6.1"
diff --git a/src/cal/day12.rs b/src/cal/day12.rs
new file mode 100644
index 0000000..f5054a6
--- /dev/null
+++ b/src/cal/day12.rs
@@ -0,0 +1,95 @@
+use axum::{
+    extract::{Path, State},
+    http::StatusCode,
+    response::IntoResponse,
+    routing::{get, post},
+    Json, Router,
+};
+use chrono::{DateTime, Datelike, Utc};
+use std::{
+    collections::HashMap,
+    sync::{Arc, Mutex},
+    time::SystemTime,
+};
+
+struct Day12State {
+    times: HashMap<String, SystemTime>,
+}
+
+pub(crate) fn router() -> Router {
+    Router::new()
+        .route("/12/save/:string", post(save))
+        .route("/12/load/:string", get(load))
+        .route("/12/ulids", post(ulids))
+        .route("/12/ulids/:weekday", post(ulids_weekday))
+        .with_state(Arc::new(Mutex::new(Day12State {
+            times: HashMap::new(),
+        })))
+}
+
+async fn save(State(state): State<Arc<Mutex<Day12State>>>, Path(string): Path<String>) {
+    state
+        .lock()
+        .expect("Should not error unless another thread panics")
+        .times
+        .insert(string, SystemTime::now());
+}
+
+async fn load(
+    State(state): State<Arc<Mutex<Day12State>>>,
+    Path(string): Path<String>,
+) -> Result<impl IntoResponse, (StatusCode, String)> {
+    Ok(state
+        .lock()
+        .expect("Should not error unless another thread panics")
+        .times
+        .get(&string)
+        .ok_or((
+            StatusCode::NOT_FOUND,
+            "String not saved previously".to_string(),
+        ))?
+        .elapsed()
+        .expect("Time should not go backwards")
+        .as_secs()
+        .to_string())
+}
+
+async fn ulids(Json(ulids): Json<Vec<ulid::Ulid>>) -> Json<Vec<uuid::Uuid>> {
+    Json(ulids.into_iter().map(Into::into).rev().collect())
+}
+
+#[derive(serde::Serialize)]
+struct UlidsWeekday {
+    #[serde(rename = "christmas eve")]
+    christmas_eve: usize,
+    weekday: usize,
+    #[serde(rename = "in the future")]
+    in_the_future: usize,
+    #[serde(rename = "LSB is 1")]
+    lsb_is_1: usize,
+}
+
+#[axum::debug_handler]
+async fn ulids_weekday(
+    Path(weekday): Path<u32>,
+    Json(ulids): Json<Vec<ulid::Ulid>>,
+) -> Json<UlidsWeekday> {
+    let lsb_is_1 = ulids.iter().filter(|u| u.random() & 1 == 1).count();
+    let ulids: Vec<DateTime<Utc>> = ulids.into_iter().map(|u| u.datetime().into()).collect();
+    let christmas_eve = ulids
+        .iter()
+        .filter(|u| u.month() == 12 && u.day() == 24)
+        .count();
+    let weekday = ulids
+        .iter()
+        .filter(|u| u.weekday().num_days_from_monday() == weekday)
+        .count();
+    let now = Utc::now();
+    let in_the_future = ulids.iter().filter(|&u| u > &now).count();
+    Json(UlidsWeekday {
+        christmas_eve,
+        weekday,
+        in_the_future,
+        lsb_is_1,
+    })
+}
diff --git a/src/cal/mod.rs b/src/cal/mod.rs
index 097ecac..ada9dec 100644
--- a/src/cal/mod.rs
+++ b/src/cal/mod.rs
@@ -5,6 +5,7 @@ mod day06;
 mod day07;
 mod day08;
 mod day11;
+mod day12;
 
 pub(crate) fn router() -> axum::Router {
     axum::Router::new()
@@ -15,4 +16,5 @@ pub(crate) fn router() -> axum::Router {
         .nest("/", day07::router())
         .nest("/", day08::router())
         .nest("/", day11::router())
+        .nest("/", day12::router())
 }