clean: removed unused function + small fixme

Cargo.lock

@@ -35,6 +35,56 @@ dependencies = [
  "equator",
 ]
 
+[[package]]
+name = "anstream"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "824a212faf96e9acacdbd09febd34438f8f711fb84e09a8916013cd7815ca28d"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "940b3a0ca603d1eade50a4846a2afffd5ef57a9feac2c0e2ec2e14f9ead76000"
+
+[[package]]
+name = "anstyle-parse"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "52ce7f38b242319f7cabaa6813055467063ecdc9d355bbb4ce0c68908cd8130e"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
+dependencies = [
+ "anstyle",
+ "once_cell_polyfill",
+ "windows-sys",
+]
+
 [[package]]
 name = "anyhow"
 version = "1.0.102"
@@ -196,12 +246,58 @@ dependencies = [
  "rand_core 0.10.1",
 ]
 
+[[package]]
+name = "clap"
+version = "4.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ddb117e43bbf7dacf0a4190fef4d345b9bad68dfc649cb349e7d17d28428e51"
+dependencies = [
+ "clap_builder",
+ "clap_derive",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "714a53001bf66416adb0e2ef5ac857140e7dc3a0c48fb28b2f10762fc4b5069f"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2ce8604710f6733aa641a2b3731eaa1e8b3d9973d5e3565da11800813f997a9"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "clap_lex"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
+
 [[package]]
 name = "color_quant"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3d7b894f5411737b7867f4827955924d7c254fc9f4d91a6aad6b097804b1018b"
 
+[[package]]
+name = "colorchoice"
+version = "1.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d07550c9036bf2ae0c684c4297d503f838287c83c53686d05370d0e139ae570"
+
 [[package]]
 name = "cpufeatures"
 version = "0.3.0"
@@ -387,6 +483,12 @@ dependencies = [
  "zerocopy",
 ]
 
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
 [[package]]
 name = "hermit-abi"
 version = "0.5.2"
@@ -437,6 +539,7 @@ dependencies = [
 name = "imagepicker"
 version = "0.1.0"
 dependencies = [
+ "clap",
  "dotenv",
  "image",
  "log",
@@ -472,6 +575,12 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
+
 [[package]]
 name = "itertools"
 version = "0.14.0"
@@ -650,6 +759,12 @@ version = "1.21.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9f7c3e4beb33f85d45ae3e3a1792185706c8e16d043238c593331cc7cd313b50"
 
+[[package]]
+name = "once_cell_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
+
 [[package]]
 name = "paste"
 version = "1.0.15"
@@ -954,6 +1069,12 @@ version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ce2be8dc25455e1f91df71bfa12ad37d7af1092ae736f3a6cd0e37bc7810596"
 
+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
 [[package]]
 name = "syn"
 version = "2.0.118"
@@ -1014,6 +1135,12 @@ version = "1.0.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
 
+[[package]]
+name = "utf8parse"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
+
 [[package]]
 name = "v_frame"
 version = "0.3.9"

Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+clap = { version = "4.6.*", features = ["derive"] }
 dotenv = "0.15.0"
 image = {version = "0.25.10", features = ["png"]}
 log = "0.4.29"

src/main.rs

@@ -1,10 +1,7 @@
 mod cli;
 
 use clap::Parser;
-use std::{
+use std::collections::{HashMap, HashSet};
-    collections::{HashMap, HashSet},
-    num::ParseIntError,
-};
 
 use dotenv::dotenv;
 use image::{DynamicImage, GenericImageView, Rgb};
@@ -16,19 +13,6 @@ use crate::cli::Cli;
 type ColourSet = HashMap<u8, HashMap<u8, HashSet<u8>>>;
 type Colour = Rgb<u8>;
 
-pub fn decode_hex(s: &str) -> Result<Colour, Box<dyn std::error::Error>> {
-    let u8s: Vec<u8> = (0..s.len())
-        .step_by(2)
-        .map(|i| u8::from_str_radix(&s[i..i + 2], 16))
-        .collect::<Result<Vec<u8>, ParseIntError>>()?;
-
-    let rgb: [u8; 3] = u8s
-        .try_into()
-        .map_err(|_| <&str as Into<String>>::into("Hex string must decode to exactly 3 bytes"))?;
-
-    Ok(Rgb(rgb))
-}
-
 fn extract_colours(img: DynamicImage) -> ColourSet {
     let mut out: ColourSet = HashMap::new();
     for (_x, _y, p) in img.pixels() {
@@ -51,17 +35,17 @@ fn extract_colours_set(img: DynamicImage) -> HashSet<Rgb<u8>> {
 
 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;
     let mut dist: f32 = f32::MAX;
+
+    let (colour_r, colour_g, colour_b) = (colour[0] as f32, colour[1] as f32, colour[2] as f32);
     for (r, gbs) in all.iter() {
-        let r_bar = 0.5 * (*r as f32 + colour[0] as f32); //FIXME (low priority): i dont like the
+        let r_bar = 0.5 * (*r as f32 + colour_r);
-        //clunky as f32s everywhere
+        let r_squared = (*r as f32 - colour_r) * (*r as f32 - colour_r);
-        let r_squared = (*r as f32 - colour[0] as f32) * (*r as f32 - colour[0] as f32);
         for (g, bs) in gbs.iter() {
-            let g_squared = (*g as f32 - colour[1] as f32) * (*g as f32 - colour[1] as f32);
+            let g_squared = (*g as f32 - colour_g) * (*g as f32 - colour_g);
             for b in bs {
-                let b_squared = (*b as f32 - colour[2] as f32) * (*b as f32 - colour[2] as f32);
+                let b_squared = (*b as f32 - colour_b) * (*b as f32 - colour_b);
                 let delta = (2.0 + r_bar / 256.0) * r_squared
                     + 4.0 * g_squared
                     + (2.0 + (255.0 - r_bar) / 256.0) * b_squared;