ft: arg parsing

src/main.rs

@@ -1,11 +1,15 @@
+mod cli;
+
+use clap::Parser;
 use std::{
     collections::{HashMap, HashSet},
-    env,
     num::ParseIntError,
 };
 
 use dotenv::dotenv;
-use image::{DynamicImage, GenericImageView, ImageReader, Rgb};
+use image::{DynamicImage, GenericImageView, Rgb};
+
+use crate::cli::Cli;
 
 // TODO (medium priority): replace hashset with another hashmap<u8, Vec<(u32, u32)>>;
 // that way we can track pixel locations for colours.
@@ -45,7 +49,7 @@ fn extract_colours_set(img: DynamicImage) -> HashSet<Rgb<u8>> {
     out.into_iter().map(|c| Rgb([c[0], c[1], c[2]])).collect()
 }
 
-fn closest_colour(colour: Colour, all: &ColourSet) -> Option<Colour> {
+fn closest_colour(colour: &Colour, all: &ColourSet) -> Option<Colour> {
     // use redmean to calculate the distance between colours
     // inevitably O(len(all))
     let mut closest: Option<Colour> = None;
@@ -71,31 +75,23 @@ fn closest_colour(colour: Colour, all: &ColourSet) -> Option<Colour> {
     return closest;
 }
 
-fn map_image_list(img_file: &str, args: &Vec<String>) -> HashMap<Colour, Colour> {
-    let img = ImageReader::open(img_file).unwrap().decode().unwrap(); // FIXME: unwraps
-
-    let all_cols = extract_colours(img);
+fn map_image_list(all_cols: &ColourSet, cols: Vec<Colour>) -> HashMap<Colour, Colour> {
     let mut output_cols: HashMap<Colour, Colour> = HashMap::new();
 
-    args.iter().skip(2).for_each(|c_str| {
-        let c = decode_hex(c_str).unwrap(); // FIXME: unwraps
-        if let Some(col) = closest_colour(c, &all_cols) {
+    for c in cols {
+        if let Some(col) = closest_colour(&c, &all_cols) {
             output_cols.insert(c, col);
         }
-    });
+    }
     output_cols
 }
 
-fn map_image_image(img_file_1: &str, img_file_2: &str) -> HashMap<Colour, Colour> {
-    let img_1 = ImageReader::open(img_file_1).unwrap().decode().unwrap();
-    let img_2 = ImageReader::open(img_file_2).unwrap().decode().unwrap();
-
-    let img_1_cols = extract_colours_set(img_1);
-    let img_2_cols = extract_colours(img_2);
+fn map_image_image(img_1_cols: &ColourSet, img_2: DynamicImage) -> HashMap<Colour, Colour> {
+    let img_2_cols = extract_colours_set(img_2);
 
     let mut output_cols: HashMap<Colour, Colour> = HashMap::new();
-    img_1_cols.iter().for_each(|c| {
-        if let Some(col) = closest_colour(*c, &img_2_cols) {
+    img_2_cols.iter().for_each(|c| {
+        if let Some(col) = closest_colour(c, &img_1_cols) {
             output_cols.insert(*c, col);
         }
     });
@@ -103,22 +99,29 @@ fn map_image_image(img_file_1: &str, img_file_2: &str) -> HashMap<Colour, Colour
     output_cols
 }
 
+fn encode_hex(c: &Colour) -> String {
+    format!("#{:02x}{:02x}{:02x}", c[0], c[1], c[2])
+}
+
+fn pretty_print(h: HashMap<Colour, Colour>) {
+    h.iter()
+        .for_each(|(k, v)| println!("{}: {}", encode_hex(k), encode_hex(v)))
+}
+
 fn main() {
     dotenv().ok();
     pretty_env_logger::init();
+    let cli = Cli::parse();
 
-    // TODO (high priority): proper arg parsing
-    let args: Vec<String> = env::args().collect();
-    if args.len() > 2 {
-        // list of colours and image
-        // let out_cols = map_image_list(&args[1], &args);
-        let out_cols = map_image_image(&args[1], &args[2]);
+    let set = extract_colours(cli.image);
 
-        out_cols.iter().for_each(|(k, v)| {
-            println!(
-                "({}, {}, {}): ({}, {}, {})",
-                k[0], k[1], k[2], v[0], v[1], v[2]
-            )
-        })
+    if let Some(cs) = cli.colours {
+        let colours = map_image_list(&set, cs);
+        pretty_print(colours);
+    }
+
+    if let Some(i) = cli.second_image {
+        let colours = map_image_image(&set, i);
+        pretty_print(colours);
     }
 }