Add command to extract examples

Fixes fspoettel#81

Author: thesamet

src/template/aoc_cli.rs

@@ -84,7 +84,7 @@ fn get_input_path(day: Day) -> String {
     format!("data/inputs/{day}.txt")
 }
 
-fn get_puzzle_path(day: Day) -> String {
+pub fn get_puzzle_path(day: Day) -> String {
     format!("data/puzzles/{day}.md")
 }
 

src/template/commands/extract.rs

@@ -0,0 +1,62 @@
+use itertools::Itertools;
+
+use crate::template::{aoc_cli, Day, ANSI_BOLD, ANSI_RESET};
+use std::process;
+
+fn example_file_path(day: Day) -> String {
+    format!("data/examples/{day}.txt")
+}
+
+fn example_file_path_part(day: Day, part: u8) -> String {
+    format!("data/examples/{day}-{part}.txt")
+}
+
+fn extract_examples(text: &str) -> Vec<&str> {
+    text.split("```\n").skip(1).step_by(2).collect_vec()
+}
+
+pub fn handle(day: Day) {
+    println!("Extracting day {}...", day);
+    let text = std::fs::read_to_string(aoc_cli::get_puzzle_path(day)).unwrap_or_else(|err| {
+        eprintln!("Error reading file: {}", err);
+        process::exit(1);
+    });
+    let examples = extract_examples(&text);
+    let mut selected = Vec::new();
+    if examples.len() == 1 {
+        selected = examples.clone();
+    } else {
+        for (i, block) in examples.iter().enumerate() {
+            println!("Extracted block {}", i + 1);
+            println!("--------------------");
+            println!("{ANSI_BOLD}{}{ANSI_RESET}", block.trim());
+            println!("--------------------");
+            println!("Write this block to a file? [y/N/q]");
+            let mut input = String::new();
+            std::io::stdin().read_line(&mut input).unwrap();
+            if input.trim().to_lowercase() == "y" {
+                selected.push(block);
+            } else if input.trim().to_lowercase() == "q" {
+                println!("Aborted.");
+                process::exit(0);
+            }
+        }
+    }
+    if selected.len() == 1 {
+        let path = example_file_path(day);
+        std::fs::write(&path, selected[0]).unwrap_or_else(|err| {
+            eprintln!("Error writing file: {}", err);
+            process::exit(1);
+        });
+        println!("🎄 Successfully wrote example to \"{}\".", &path);
+    } else {
+        for (i, out) in selected.iter().enumerate() {
+            let path = example_file_path_part(day, (i + 1) as u8);
+            std::fs::write(&path, out).unwrap_or_else(|err| {
+                eprintln!("Error writing file: {}", err);
+                process::exit(1);
+            });
+            println!("🎄 Successfully wrote example to \"{}\".", &path);
+        }
+    }
+}

src/template/commands/mod.rs

@@ -1,5 +1,6 @@
 pub mod all;
 pub mod download;
+pub mod extract;
 pub mod read;
 pub mod scaffold;
 pub mod solve;