1#![deny(warnings)]
2
3use std::cmp::Ordering::Equal;
4use std::str::FromStr;
5
6use clap::Arg;
7use palette::{FromColor, Hsv, Srgb};
8
9const VERSION: &str = env!("CARGO_PKG_VERSION");
10
11#[derive(Debug)]
12struct OutputValue {
13    value: f32,
14    rgb: Srgb<u8>,
15    is_original: bool,
16}
17
18fn main() {
19    let matches = clap::Command::new("brightness_adjust")
20        .version(VERSION)
21        .author("Alex Chan <alex@alexwlchan.net>")
22        .about("Show some darker/lighter variants of a given colour")
23        .arg(
24            Arg::new("COLOUR")
25                .help("colour to start with as a hex string, e.g. #d01c11")
26                .required(true)
27                .index(1),
28        )
29        .get_matches();
30
31    // This .unwrap() is safe because "path" is a required param
32    let base_colour = matches
33        .get_one::<String>("COLOUR")
34        .expect("`COLOUR` is required");
35
36    let rgb = match Srgb::from_str(base_colour) {
37        Ok(c) => c.into_format::<u8>(),
38        Err(e) => {
39            eprintln!("Unable to parse COLOUR {:?} as hex: {}", base_colour, e);
40            std::process::exit(1);
41        }
42    };
43
44    let hsv: Hsv = Hsv::from_color(rgb.into_format::<f32>());
45
46    let mut outputs = vec![OutputValue {
47        value: hsv.value,
48        rgb: rgb,
49        is_original: true,
50    }];
51
52    for value in (0..=100).step_by(5) {
53        let modified_hsv = Hsv::new(hsv.hue, hsv.saturation, value as f32 / 100.0);
54        outputs.push(OutputValue {
55            value: modified_hsv.value,
56            rgb: Srgb::from_color(modified_hsv).into_format::<u8>(),
57            is_original: false,
58        });
59    }
60
61    // https://www.reddit.com/r/rust/comments/29kia3/comment/cilrzik/
62    outputs.sort_by(|a, b| a.value.partial_cmp(&b.value).unwrap_or(Equal));
63
64    for op in outputs {
65        let rgb = op.rgb;
66        print!(
67            "{:3}% = \x1B[38;2;{};{};{}m▇ #{:02x}{:02x}{:02x}\x1B[0m",
68            (op.value * 100.0).round(),
69            rgb.red,
70            rgb.green,
71            rgb.blue,
72            rgb.red,
73            rgb.green,
74            rgb.blue
75        );
76        if op.is_original {
77            println!(" (original colour)");
78        } else {
79            println!("");
80        }
81    }
82}