feat: download cli command

.cargo/config

@@ -1,3 +1,5 @@
 [alias]
 prepare = "run --bin prepare --"
+download = "run --bin download --"
+
 solve = "run --bin"

.env.example

@@ -0,0 +1,2 @@
+TOKEN=secret
+YEAR=2022

Cargo.toml

@@ -8,4 +8,8 @@ default-run = "aoc"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+# framework
+dotenv = "0.15.0"
 pico-args = "0.5.0"
+reqwest = { version = "0.11.13", features = ["blocking"] }
+# for solving

README.md

@@ -16,6 +16,21 @@ cargo prepare <day>
 # 🎄 Type `cargo solve 01` to run your solution.
 ```
 
+### Download input
+prepare `.env` file
+```
+cp .env.example .env
+```
+set `YEAR` to whichever year you are solving for and `TOKEN` to AoC session Cookie.
+
+```sh
+# example: `cargo download 1`
+cargo download <day>
+
+# output:
+# Downloaded input file "src/inputs/01.txt"
+```
+
 ### Solve
 ```sh
 # example: `cargo solve 01`

src/bin/download.rs

@@ -0,0 +1,62 @@
+use dotenv::dotenv;
+use reqwest::blocking::Client;
+use reqwest::header;
+use std::{env, fs::OpenOptions, io::Write, process};
+
+fn main() {
+    let day: u8 = match aoc::parse_args() {
+        Ok(day) => day,
+        Err(_) => {
+            eprintln!("Need to specify a day (as integer). example: `cargo download 7`");
+            process::exit(1);
+        }
+    };
+    dotenv().ok();
+
+    let day_padded = format!("{:02}", day);
+    let token = env::var("TOKEN").expect("$TOKEN is not set");
+    let year = env::var("YEAR")
+        .expect("$YEAR is not set")
+        .parse::<u32>()
+        .expect("$YEAR must be a number");
+
+    let mut headers = header::HeaderMap::new();
+    let mut session_header = header::HeaderValue::from_str(format!("session={}", token).as_str())
+        .expect("Error building cookie header");
+    session_header.set_sensitive(true);
+    headers.insert(header::COOKIE, session_header);
+
+    let client = Client::builder().default_headers(headers).build().unwrap();
+    let res = client
+        .get(format!(
+            "https://adventofcode.com/{}/day/{}/input",
+            year, day
+        ))
+        .send()
+        .unwrap()
+        .text()
+        .unwrap();
+
+    let input_path = format!("src/inputs/{}.txt", day_padded);
+    let mut file = match OpenOptions::new()
+        .write(true)
+        .create(true)
+        .open(&input_path)
+    {
+        Ok(file) => file,
+        Err(e) => {
+            eprintln!("Failed to create module file: {}", e);
+            process::exit(1);
+        }
+    };
+
+    match file.write_all(res.as_bytes()) {
+        Ok(_) => {
+            println!("Downloaded input file \"{}\"", &input_path);
+        }
+        Err(e) => {
+            eprintln!("Failed to write module contents: {}", e);
+            process::exit(1);
+        }
+    }
+}

src/bin/prepare.rs

@@ -35,11 +35,6 @@ mod tests {
 }
 "###;
 
-fn parse_args() -> Result<u8, pico_args::Error> {
-    let mut args = pico_args::Arguments::from_env();
-    args.free_from_str()
-}
-
 fn safe_create_file(path: &str) -> Result<File, std::io::Error> {
     OpenOptions::new().write(true).create_new(true).open(path)
 }
@@ -49,7 +44,7 @@ fn create_file(path: &str) -> Result<File, std::io::Error> {
 }
 
 fn main() {
-    let day = match parse_args() {
+    let day = match aoc::parse_args() {
         Ok(day) => day,
         Err(_) => {
             eprintln!("Need to specify a day (as integer). example: `cargo prepare 7`");

src/helpers.rs

@@ -0,0 +1 @@
+

src/lib.rs

@@ -54,6 +54,11 @@ fn parse_time(val: &str, postfix: &str) -> f64 {
     val.split(postfix).next().unwrap().parse().unwrap()
 }
 
+pub fn parse_args() -> Result<u8, pico_args::Error> {
+    let mut args = pico_args::Arguments::from_env();
+    args.free_from_str()
+}
+
 pub fn parse_exec_time(output: &str) -> f64 {
     output.lines().fold(0_f64, |acc, l| {
         if !l.contains("elapsed:") {