From 95f7c147f12108e231066193afa02a98d3054cad Mon Sep 17 00:00:00 2001
From: mat <27899617+mat-1@users.noreply.github.com>
Date: Tue, 16 Jul 2024 03:07:23 -0500
Subject: [PATCH] Add color picker answer (#13)

* Add color picker answer

* set autocomplete=off for the inputs

* add symbols to the regexes

* tweak hsv and hsl regex

* don't show wikipedia when searching 'color picker'
---
 src/engines/answer.rs                 |   1 +
 src/engines/answer/colorpicker.rs     | 383 ++++++++++++++++++++++++++
 src/engines/answer/wikipedia.rs       |  52 ++--
 src/engines/mod.rs                    |   2 +
 src/web/assets/scripts/colorpicker.js | 349 +++++++++++++++++++++++
 src/web/assets/style.css              |  76 +++++
 src/web/mod.rs                        |   1 +
 7 files changed, 847 insertions(+), 17 deletions(-)
 create mode 100644 src/engines/answer/colorpicker.rs
 create mode 100644 src/web/assets/scripts/colorpicker.js

diff --git a/src/engines/answer.rs b/src/engines/answer.rs
index dff5b48..1e239ee 100644
--- a/src/engines/answer.rs
+++ b/src/engines/answer.rs
@@ -1,3 +1,4 @@
+pub mod colorpicker;
 pub mod dictionary;
 pub mod fend;
 pub mod ip;
diff --git a/src/engines/answer/colorpicker.rs b/src/engines/answer/colorpicker.rs
new file mode 100644
index 0000000..7ac0ca4
--- /dev/null
+++ b/src/engines/answer/colorpicker.rs
@@ -0,0 +1,383 @@
+use maud::html;
+
+use crate::engines::{EngineResponse, SearchQuery};
+
+use super::regex;
+
+pub fn request(query: &SearchQuery) -> EngineResponse {
+    let matched_colors = MatchedColorModel::new(&query.query);
+
+    let rgb;
+    let cmyk;
+    let hsv;
+    let hsl;
+
+    if let Some(rgb_) = matched_colors.rgb {
+        rgb = rgb_;
+        cmyk = rgb_to_cmyk(rgb);
+        hsv = rgb_to_hsv(rgb);
+        hsl = rgb_to_hsl(rgb);
+    } else if let Some(cmyk_) = matched_colors.cmyk {
+        cmyk = cmyk_;
+        rgb = cmyk_to_rgb(cmyk);
+        hsv = rgb_to_hsv(rgb);
+        hsl = rgb_to_hsl(rgb);
+    } else if let Some(hsv_) = matched_colors.hsv {
+        hsv = hsv_;
+        rgb = hsv_to_rgb(hsv);
+        cmyk = rgb_to_cmyk(rgb);
+        hsl = hsv_to_hsl(hsv);
+    } else if let Some(hsl_) = matched_colors.hsl {
+        hsl = hsl_;
+        rgb = hsv_to_rgb(hsl_to_hsv(hsl));
+        cmyk = rgb_to_cmyk(rgb);
+        hsv = rgb_to_hsv(rgb);
+    } else {
+        return EngineResponse::new();
+    }
+
+    let (r, g, b) = rgb;
+    let (c, m, y, k) = cmyk;
+    let (hsv_h, hsv_s, hsv_v) = hsv;
+    let (hsl_h, hsl_s, hsl_l) = hsl;
+
+    let hex_str = format!(
+        "#{:02x}{:02x}{:02x}",
+        (r * 255.) as u8,
+        (g * 255.) as u8,
+        (b * 255.) as u8
+    );
+    let rgb_str = format!(
+        "{}, {}, {}",
+        (r * 255.) as u8,
+        (g * 255.) as u8,
+        (b * 255.) as u8
+    );
+    let cmyk_str = format!(
+        "{:.0}%, {:.0}%, {:.0}%, {:.0}%",
+        c * 100.,
+        m * 100.,
+        y * 100.,
+        k * 100.
+    );
+    let hsv_str = format!(
+        "{:.0}°, {:.0}%, {:.0}%",
+        hsv_h * 360.,
+        hsv_s * 100.,
+        hsv_v * 100.
+    );
+    let hsl_str = format!(
+        "{:.0}°, {:.0}%, {:.0}%",
+        hsl_h * 360.,
+        hsl_s * 100.,
+        hsl_l * 100.
+    );
+
+    let hue_picker_x = hsv_h * 100.;
+    let picker_x = hsv_s * 100.;
+    let picker_y = (1. - hsv_v) * 100.;
+
+    let hue_css_color = format!("hsl({}, 100%, 50%)", hsv_h * 360.);
+
+    // yes the design of this is absolutely nabbed from google's
+    EngineResponse::answer_html(html! {
+        div.answer-colorpicker {
+            div.answer-colorpicker-preview-container {
+                div.answer-colorpicker-preview style=(format!("background-color: {hex_str}")) {}
+                div.answer-colorpicker-canvas-container {
+                    div.answer-colorpicker-picker-container {
+                        div.answer-colorpicker-picker style=(format!("background-color: {hex_str}; left: {picker_x}%; top: {picker_y}%;")) {}
+                    }
+                    svg.answer-colorpicker-canvas {
+                        defs {
+                            linearGradient id="saturation" x1="0%" x2="100%" y1="0%" y2="0%" {
+                                stop offset="0%" stop-color="#fff" {}
+                                stop.answer-colorpicker-canvas-hue-svg offset="100%" stop-color=(hex_str) {}
+                            }
+                            linearGradient id="value" x1="0%" x2="0%" y1="0%" y2="100%" {
+                                stop offset="0%" stop-color="#fff" {}
+                                stop offset="100%" stop-color="#000" {}
+                            }
+                        }
+                        // the .1 fixes a bug that's present at least on firefox that makes the
+                        // rightmost column of pixels look wrong
+                        rect width="100.1%" height="100%" fill="url(#saturation)" {}
+                        rect width="100.1%" height="100%" fill="url(#value)" style="mix-blend-mode: multiply" {}
+                    }
+                }
+            }
+            div.answer-colorpicker-slider-container {
+                div.answer-colorpicker-huepicker style=(format!("background-color: {hue_css_color}; left: {hue_picker_x}%")) {}
+                svg.answer-colorpicker-slider {
+                    defs {
+                        linearGradient id="hue" x1="0%" x2="100%" y1="0%" y2="0%" {
+                            stop offset="0%" stop-color="#ff0000" {}
+                            stop offset="16.666%" stop-color="#ffff00" {}
+                            stop offset="33.333%" stop-color="#00ff00" {}
+                            stop offset="50%" stop-color="#00ffff" {}
+                            stop offset="66.666%" stop-color="#0000ff" {}
+                            stop offset="83.333%" stop-color="#ff00ff" {}
+                            stop offset="100%" stop-color="#ff0000" {}
+                        }
+                    }
+                    rect width="100%" height="50%" y="25%" fill="url(#hue)" {}
+                }
+            }
+            div.answer-colorpicker-hex-input-container {
+                label for="answer-colorpicker-hex-input" { "HEX" }
+                div.answer-colorpicker-input-container {
+                    input #answer-colorpicker-hex-input type="text" autocomplete="off" value=(hex_str) {}
+                }
+            }
+            div.answer-colorpicker-other-inputs {
+                div {
+                    label for="answer-colorpicker-rgb-input" { "RGB" }
+                    div.answer-colorpicker-input-container {
+                        input #answer-colorpicker-rgb-input type="text" autocomplete="off" value=(rgb_str) {}
+                    }
+                }
+                div {
+                    label for="answer-colorpicker-cmyk-input" { "CMYK" }
+                    div.answer-colorpicker-input-container {
+                        input #answer-colorpicker-cmyk-input type="text" autocomplete="off" value=(cmyk_str) {}
+                    }
+                }
+                div {
+                    label for="answer-colorpicker-hsv-input" { "HSV" }
+                    div.answer-colorpicker-input-container {
+                        input #answer-colorpicker-hsv-input type="text" autocomplete="off" value=(hsv_str) {}
+                    }
+                }
+                div {
+                    label for="answer-colorpicker-hsl-input" { "HSL" }
+                    div.answer-colorpicker-input-container {
+                        input #answer-colorpicker-hsl-input type="text" autocomplete="off" value=(hsl_str) {}
+                    }
+                }
+            }
+        }
+        script src="/scripts/colorpicker.js" {}
+    })
+}
+
+pub struct MatchedColorModel {
+    pub rgb: Option<(f64, f64, f64)>,
+    pub cmyk: Option<(f64, f64, f64, f64)>,
+    pub hsv: Option<(f64, f64, f64)>,
+    pub hsl: Option<(f64, f64, f64)>,
+}
+impl MatchedColorModel {
+    pub fn new(query: &str) -> Self {
+        let mut rgb = None;
+        let mut cmyk = None;
+        let mut hsv = None;
+        let mut hsl = None;
+
+        if regex!("^color ?picker$").is_match(&query.to_lowercase()) {
+            // default to red
+            rgb = Some((1., 0., 0.));
+        } else if let Some(caps) = regex!("^#?([0-9a-f]{6})$").captures(query) {
+            let hex_str = caps.get(1).unwrap().as_str();
+            let hex_num = u32::from_str_radix(hex_str, 16).unwrap();
+            let r = ((hex_num >> 16) & 0xff) as f64 / 255.;
+            let g = ((hex_num >> 8) & 0xff) as f64 / 255.;
+            let b = (hex_num & 0xff) as f64 / 255.;
+
+            let r = r.clamp(0., 1.);
+            let g = g.clamp(0., 1.);
+            let b = b.clamp(0., 1.);
+
+            rgb = Some((r, g, b));
+        } else if let Some(caps) =
+            regex!("^rgb\\((\\d{1,3}), ?(\\d{1,3}), ?(\\d{1,3})\\)$").captures(query)
+        {
+            let r = caps
+                .get(1)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 255.;
+            let g = caps
+                .get(2)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 255.;
+            let b = caps
+                .get(3)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 255.;
+
+            let r = r.clamp(0., 1.);
+            let g = g.clamp(0., 1.);
+            let b = b.clamp(0., 1.);
+
+            rgb = Some((r, g, b));
+        } else if let Some(caps) =
+            regex!("^cmyk\\((\\d{1,3})%, ?(\\d{1,3})%, ?(\\d{1,3})%, ?(\\d{1,3})%\\)$")
+                .captures(query)
+        {
+            let c = caps
+                .get(1)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 100.;
+            let m = caps
+                .get(2)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 100.;
+            let y = caps
+                .get(3)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 100.;
+            let k = caps
+                .get(4)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 100.;
+
+            let c = c.clamp(0., 1.);
+            let m = m.clamp(0., 1.);
+            let y = y.clamp(0., 1.);
+            let k = k.clamp(0., 1.);
+
+            cmyk = Some((c, m, y, k));
+        } else if let Some(caps) =
+            regex!("^hsv\\((\\d{1,3})(?:°|deg|), ?(\\d{1,3})%, ?(\\d{1,3})%\\)$").captures(query)
+        {
+            let h = caps
+                .get(1)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 360.;
+            let s = caps
+                .get(2)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 100.;
+            let v = caps
+                .get(3)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 100.;
+
+            let h = h.clamp(0., 1.);
+            let s = s.clamp(0., 1.);
+            let v = v.clamp(0., 1.);
+
+            hsv = Some((h, s, v));
+        } else if let Some(caps) =
+            regex!("^hsl\\((\\d{1,3})(?:°|deg|), ?(\\d{1,3})%, ?(\\d{1,3})%\\)$").captures(query)
+        {
+            let h = caps
+                .get(1)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 360.;
+            let s = caps
+                .get(2)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 100.;
+            let l = caps
+                .get(3)
+                .and_then(|m| m.as_str().parse::<f64>().ok())
+                .unwrap_or_default()
+                / 100.;
+
+            let h = h.clamp(0., 1.);
+            let s = s.clamp(0., 1.);
+            let l = l.clamp(0., 1.);
+
+            hsl = Some((h, s, l));
+        }
+
+        Self {
+            rgb,
+            cmyk,
+            hsv,
+            hsl,
+        }
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.rgb.is_none() && self.cmyk.is_none() && self.hsv.is_none() && self.hsl.is_none()
+    }
+}
+
+// this is the code from colorpicker.js ported to rust
+// see that file for credits
+fn hsv_to_hsl((h, s, v): (f64, f64, f64)) -> (f64, f64, f64) {
+    let l = v - (v * s) / 2.;
+    let m = f64::min(l, 1. - l);
+    (h, if m != 0. { (v - l) / m } else { 0. }, l)
+}
+fn hsl_to_hsv((h, s, l): (f64, f64, f64)) -> (f64, f64, f64) {
+    let v = s * f64::min(l, 1. - l) + l;
+    (h, if v != 0. { 2. - (2. * l) / v } else { 0. }, v)
+}
+fn hsv_to_rgb((h, s, v): (f64, f64, f64)) -> (f64, f64, f64) {
+    let f = |n: f64| {
+        let k = (n + h * 6.) % 6.;
+        v - v * s * f64::max(f64::min(k, 4. - k), 0.)
+    };
+    (f(5.), f(3.), f(1.))
+}
+fn rgb_to_hsv((r, g, b): (f64, f64, f64)) -> (f64, f64, f64) {
+    let v = f64::max(r, f64::max(g, b));
+    let c = v - f64::min(r, f64::min(g, b));
+    let h = if c != 0. {
+        if v == r {
+            (g - b) / c
+        } else if v == g {
+            2. + (b - r) / c
+        } else {
+            4. + (r - g) / c
+        }
+    } else {
+        0.
+    };
+    (
+        if h < 0. { h + 6. } else { h } / 6.,
+        if v != 0. { c / v } else { 0. },
+        v,
+    )
+}
+fn rgb_to_hsl((r, g, b): (f64, f64, f64)) -> (f64, f64, f64) {
+    let v = f64::max(r, f64::max(g, b));
+    let c = v - f64::min(r, f64::min(g, b));
+    let f = 1. - f64::abs(v + v - c - 1.);
+    let h = if c != 0. {
+        if v == r {
+            (g - b) / c
+        } else if v == g {
+            2. + (b - r) / c
+        } else {
+            4. + (r - g) / c
+        }
+    } else {
+        0.
+    };
+    (
+        if h < 0. { h + 6. } else { h } / 6.,
+        if f != 0. { c / f } else { 0. },
+        (v + v - c) / 2.,
+    )
+}
+fn rgb_to_cmyk((r, g, b): (f64, f64, f64)) -> (f64, f64, f64, f64) {
+    let k = 1. - f64::max(r, f64::max(g, b));
+    if k == 1. {
+        return (0., 0., 0., 1.);
+    }
+    let c = (1. - r - k) / (1. - k);
+    let m = (1. - g - k) / (1. - k);
+    let y = (1. - b - k) / (1. - k);
+    (c, m, y, k)
+}
+fn cmyk_to_rgb((c, m, y, k): (f64, f64, f64, f64)) -> (f64, f64, f64) {
+    let r = (1. - c) * (1. - k);
+    let g = (1. - m) * (1. - k);
+    let b = (1. - y) * (1. - k);
+    (r, g, b)
+}
diff --git a/src/engines/answer/wikipedia.rs b/src/engines/answer/wikipedia.rs
index ed6ff7b..2c10de7 100644
--- a/src/engines/answer/wikipedia.rs
+++ b/src/engines/answer/wikipedia.rs
@@ -4,25 +4,43 @@ use maud::html;
 use serde::Deserialize;
 use url::Url;
 
-use crate::engines::{EngineResponse, CLIENT};
+use crate::engines::{EngineResponse, RequestResponse, CLIENT};
 
-pub fn request(query: &str) -> reqwest::RequestBuilder {
-    CLIENT.get(
-        Url::parse_with_params(
-            "https://en.wikipedia.org/w/api.php",
-            &[
-                ("format", "json"),
-                ("action", "query"),
-                ("prop", "extracts|pageimages"),
-                ("exintro", ""),
-                ("explaintext", ""),
-                ("redirects", "1"),
-                ("exsentences", "2"),
-                ("titles", query),
-            ],
+use super::colorpicker;
+
+pub fn request(mut query: &str) -> RequestResponse {
+    if !colorpicker::MatchedColorModel::new(query).is_empty() {
+        // "color picker" is a wikipedia article but we only want to show the
+        // actual color picker answer
+        return RequestResponse::None;
+    }
+
+    // adding "wikipedia" to the start or end of your query is common when you
+    // want to get a wikipedia article
+    if let Some(stripped_query) = query.strip_suffix(" wikipedia") {
+        query = stripped_query
+    } else if let Some(stripped_query) = query.strip_prefix("wikipedia ") {
+        query = stripped_query
+    }
+
+    CLIENT
+        .get(
+            Url::parse_with_params(
+                "https://en.wikipedia.org/w/api.php",
+                &[
+                    ("format", "json"),
+                    ("action", "query"),
+                    ("prop", "extracts|pageimages"),
+                    ("exintro", ""),
+                    ("explaintext", ""),
+                    ("redirects", "1"),
+                    ("exsentences", "2"),
+                    ("titles", query),
+                ],
+            )
+            .unwrap(),
         )
-        .unwrap(),
-    )
+        .into()
 }
 
 #[derive(Debug, Deserialize)]
diff --git a/src/engines/mod.rs b/src/engines/mod.rs
index e23593e..ad9dc64 100644
--- a/src/engines/mod.rs
+++ b/src/engines/mod.rs
@@ -42,6 +42,7 @@ engines! {
     Fend = "fend",
     Ip = "ip",
     Notepad = "notepad",
+    ColorPicker = "colorpicker",
     Numbat = "numbat",
     Thesaurus = "thesaurus",
     Timezone = "timezone",
@@ -70,6 +71,7 @@ engine_requests! {
     Fend => answer::fend::request, None,
     Ip => answer::ip::request, None,
     Notepad => answer::notepad::request, None,
+    ColorPicker => answer::colorpicker::request, None,
     Numbat => answer::numbat::request, None,
     Thesaurus => answer::thesaurus::request, parse_response,
     Timezone => answer::timezone::request, None,
diff --git a/src/web/assets/scripts/colorpicker.js b/src/web/assets/scripts/colorpicker.js
new file mode 100644
index 0000000..7edde30
--- /dev/null
+++ b/src/web/assets/scripts/colorpicker.js
@@ -0,0 +1,349 @@
+// some guy on stackoverflow wrote a bunch of codegolfed color space conversion functions so i
+// stole them for this (except the cmyk functions, those were stolen from other places)
+
+// https://stackoverflow.com/a/54116681
+function hsvToHsl(h, s, v) {
+  const l = v - (v * s) / 2;
+  const m = Math.min(l, 1 - l);
+  return [h, m ? (v - l) / m : 0, l];
+}
+function hslToHsv(h, s, l) {
+  let v = s * Math.min(l, 1 - l) + l;
+  return [h, v ? 2 - (2 * l) / v : 0, v];
+}
+
+// https://stackoverflow.com/a/54024653
+function hsvToRgb(h, s, v) {
+  let f = (n, k = (n + h / 60) % 6) =>
+    v - v * s * Math.max(Math.min(k, 4 - k, 1), 0);
+  return [f(5), f(3), f(1)];
+}
+// https://stackoverflow.com/a/54070620
+function rgbToHsv(r, g, b) {
+  let v = Math.max(r, g, b),
+    c = v - Math.min(r, g, b);
+  let h =
+    c && (v == r ? (g - b) / c : v == g ? 2 + (b - r) / c : 4 + (r - g) / c);
+  return [60 * (h < 0 ? h + 6 : h), v && c / v, v];
+}
+// https://stackoverflow.com/a/54071699
+function rgbToHsl(r, g, b) {
+  let v = Math.max(r, g, b),
+    c = v - Math.min(r, g, b),
+    f = 1 - Math.abs(v + v - c - 1);
+  let h =
+    c && (v == r ? (g - b) / c : v == g ? 2 + (b - r) / c : 4 + (r - g) / c);
+  return [60 * (h < 0 ? h + 6 : h), f ? c / f : 0, (v + v - c) / 2];
+}
+
+// https://www.codeproject.com/Articles/4488/XCmyk-CMYK-to-RGB-Calculator-with-source-code
+function rgbToCmyk(r, g, b) {
+  const k = 1 - Math.max(r, g, b);
+  if (k === 1) return [0, 0, 0, 1];
+  const c = (1 - r - k) / (1 - k);
+  const m = (1 - g - k) / (1 - k);
+  const y = (1 - b - k) / (1 - k);
+  return [c, m, y, k];
+}
+// https://stackoverflow.com/a/37643472
+function cmykToRgb(c, m, y, k) {
+  const r = (1 - c) * (1 - k);
+  const g = (1 - m) * (1 - k);
+  const b = (1 - y) * (1 - k);
+  return [r, g, b];
+}
+
+// used for making it so an input isn't modified if we just typed in it
+let activeInput = null;
+document.addEventListener("keydown", () => {
+  activeInput = document.activeElement;
+});
+document.addEventListener("focusout", () => {
+  activeInput = null;
+
+  // in case they set an input to an invalid value
+  updateColorPreview();
+});
+
+const colorPickerEl = document.getElementsByClassName("answer-colorpicker")[0];
+
+const canvasEl = colorPickerEl.getElementsByClassName(
+  "answer-colorpicker-canvas"
+)[0];
+const canvasHueSvgEl = canvasEl.getElementsByClassName(
+  "answer-colorpicker-canvas-hue-svg"
+)[0];
+const pickerEl = colorPickerEl.getElementsByClassName(
+  "answer-colorpicker-picker"
+)[0];
+const previewEl = colorPickerEl.getElementsByClassName(
+  "answer-colorpicker-preview"
+)[0];
+const sliderEl = colorPickerEl.getElementsByClassName(
+  "answer-colorpicker-slider"
+)[0];
+const huepickerEl = colorPickerEl.getElementsByClassName(
+  "answer-colorpicker-huepicker"
+)[0];
+
+const hexInputEl = document.getElementById("answer-colorpicker-hex-input");
+const rgbInputEl = document.getElementById("answer-colorpicker-rgb-input");
+const cmykInputEl = document.getElementById("answer-colorpicker-cmyk-input");
+const hsvInputEl = document.getElementById("answer-colorpicker-hsv-input");
+const hslInputEl = document.getElementById("answer-colorpicker-hsl-input");
+
+let hsv = parseHsv(hsvInputEl.value);
+let hsl = parseHsl(hslInputEl.value);
+let rgb = parseRgb(rgbInputEl.value);
+let cmyk = parseCmyk(cmykInputEl.value);
+
+function clamp(n, min, max) {
+  return Math.max(min, Math.min(max, n));
+}
+
+function setHsv(h, s, v) {
+  h = clamp(h, 0, 360);
+  s = clamp(s, 0, 1);
+  v = clamp(v, 0, 1);
+
+  hsv = [h, s, v];
+  hsl = hsvToHsl(...hsv);
+  rgb = hsvToRgb(...hsv);
+  cmyk = rgbToCmyk(...rgb);
+  updateColorPreview();
+}
+function setHsl(h, s, l) {
+  h = clamp(h, 0, 360);
+  s = clamp(s, 0, 1);
+  l = clamp(l, 0, 1);
+
+  hsl = [h, s, l];
+  hsv = hslToHsv(...hsl);
+  rgb = hsvToRgb(...hsv);
+  cmyk = rgbToCmyk(...rgb);
+  updateColorPreview();
+}
+function setRgb(r, g, b) {
+  r = clamp(r, 0, 1);
+  g = clamp(g, 0, 1);
+  b = clamp(b, 0, 1);
+
+  rgb = [r, g, b];
+  hsl = rgbToHsl(...rgb);
+  hsv = hslToHsv(...hsl);
+  cmyk = rgbToCmyk(...rgb);
+  updateColorPreview();
+}
+function setCmyk(c, m, y, k) {
+  c = clamp(c, 0, 1);
+  m = clamp(m, 0, 1);
+  y = clamp(y, 0, 1);
+  k = clamp(k, 0, 1);
+
+  cmyk = [c, m, y, k];
+  rgb = cmykToRgb(...cmyk);
+  hsl = rgbToHsl(...rgb);
+  hsv = rgbToHsv(...rgb);
+  updateColorPreview();
+}
+
+let mouseInCanvas = false;
+function canvasMouseDown(clientX, clientY) {
+  activeInput = null;
+  updatePicker(clientX, clientY);
+  mouseInCanvas = true;
+}
+function canvasMouseMove(clientX, clientY) {
+  activeInput;
+  if (mouseInCanvas) updatePicker(clientX, clientY);
+}
+function canvasMouseUp() {
+  mouseInCanvas = false;
+}
+canvasEl.addEventListener("mousedown", (e) => {
+  canvasMouseDown(e.clientX, e.clientY);
+});
+canvasEl.addEventListener("touchstart", (e) => {
+  canvasMouseDown(e.touches[0].clientX, e.touches[0].clientY);
+});
+document.addEventListener("mouseup", () => {
+  canvasMouseUp();
+});
+document.addEventListener("touchend", () => {
+  canvasMouseUp();
+});
+document.addEventListener("mousemove", (e) => {
+  canvasMouseMove(e.clientX, e.clientY);
+});
+document.addEventListener("touchmove", (e) => {
+  canvasMouseMove(e.touches[0].clientX, e.touches[0].clientY);
+});
+
+let mouseInSlider = false;
+function sliderMouseDown(clientX) {
+  updateHuePicker(clientX);
+  mouseInSlider = true;
+}
+function sliderMouseMove(clientX) {
+  if (mouseInSlider) updateHuePicker(clientX);
+}
+function sliderMouseUp() {
+  mouseInSlider = false;
+}
+sliderEl.addEventListener("mousedown", (e) => {
+  sliderMouseDown(e.clientX);
+});
+sliderEl.addEventListener("touchstart", (e) => {
+  sliderMouseDown(e.touches[0].clientX);
+});
+huepickerEl.addEventListener("mousedown", (e) => {
+  sliderMouseDown(e.clientX);
+});
+huepickerEl.addEventListener("touchstart", (e) => {
+  sliderMouseDown(e.touches[0].clientX);
+});
+document.addEventListener("mouseup", () => {
+  sliderMouseUp();
+});
+document.addEventListener("touchend", () => {
+  sliderMouseUp();
+});
+document.addEventListener("mousemove", (e) => {
+  sliderMouseMove(e.clientX);
+});
+document.addEventListener("touchmove", (e) => {
+  sliderMouseMove(e.touches[0].clientX);
+});
+
+function updatePicker(clientX, clientY) {
+  const rect = canvasEl.getBoundingClientRect();
+  let x = clientX - rect.left;
+  let y = clientY - rect.top;
+  if (x < 0) x = 0;
+  if (y < 0) y = 0;
+  if (x > rect.width) x = rect.width;
+  if (y > rect.height) y = rect.height;
+
+  pickerEl.style.left = `${(x / rect.width) * 100}%`;
+  pickerEl.style.top = `${(y / rect.height) * 100}%`;
+
+  const hue = hsv[0];
+  setHsv(hue, x / rect.width, 1 - y / rect.height);
+}
+
+function updateHuePicker(clientX) {
+  const rect = sliderEl.getBoundingClientRect();
+  let x = clientX - rect.left;
+  if (x < 0) x = 0;
+  if (x > rect.width) x = rect.width;
+
+  huepickerEl.style.left = `${(x / rect.width) * 100}%`;
+
+  const hue = (x / rect.width) * 360;
+  setHsv(hue, hsv[1], hsv[2]);
+}
+
+function updateColorPreview() {
+  const [r, g, b] = rgb;
+  const [hue, saturation, value] = hsv;
+
+  const color = `rgb(${r * 255}, ${g * 255}, ${b * 255})`;
+  pickerEl.style.backgroundColor = color;
+  previewEl.style.backgroundColor = color;
+
+  const hueColor = `hsl(${hue}, 100%, 50%)`;
+  huepickerEl.style.backgroundColor = hueColor;
+  canvasHueSvgEl.style.setProperty("stop-color", hueColor);
+
+  pickerEl.style.left = `${saturation * 100}%`;
+  pickerEl.style.top = `${(1 - value) * 100}%`;
+
+  if (activeInput !== hexInputEl) {
+    hexInputEl.value =
+      "#" +
+      rgb
+        .map((c) =>
+          Math.round(c * 255)
+            .toString(16)
+            .padStart(2, "0")
+        )
+        .join("");
+  }
+  if (activeInput !== rgbInputEl) {
+    rgbInputEl.value = rgb.map((c) => Math.round(c * 255)).join(", ");
+  }
+  if (activeInput !== cmykInputEl) {
+    const cmykPercent = cmyk.map((c) => Math.round(c * 100));
+    cmykInputEl.value = `${cmykPercent[0]}%, ${cmykPercent[1]}%, ${cmykPercent[2]}%, ${cmykPercent[3]}%`;
+  }
+  if (activeInput !== hsvInputEl) {
+    const hAngle = Math.round(hsv[0]);
+    hsvInputEl.value = `${hAngle}°, ${Math.round(hsv[1] * 100)}%, ${Math.round(
+      hsv[2] * 100
+    )}%`;
+  }
+  if (activeInput !== hslInputEl) {
+    hslInputEl.value = `${Math.round(hsl[0])}°, ${Math.round(
+      hsl[1] * 100
+    )}%, ${Math.round(hsl[2] * 100)}%`;
+  }
+}
+
+function parseHex(value) {
+  value = hexInputEl.value.replace("#", "");
+  if (value.length === 6) {
+    const r = parseInt(value.slice(0, 2), 16) / 255;
+    const g = parseInt(value.slice(2, 4), 16) / 255;
+    const b = parseInt(value.slice(4, 6), 16) / 255;
+    return [r, g, b];
+  } else if (value.length === 3) {
+    const r = parseInt(value[0] + value[0], 16) / 255;
+    const g = parseInt(value[1] + value[1], 16) / 255;
+    const b = parseInt(value[2] + value[2], 16) / 255;
+    return [r, g, b];
+  }
+}
+function setFromHexInput() {
+  setRgb(...parseHex(hexInputEl.value));
+}
+hexInputEl.addEventListener("input", setFromHexInput);
+
+function parseRgb(value) {
+  return value.split(",").map((c) => parseInt(c) / 255);
+}
+function setFromRgbInput() {
+  setRgb(...parseRgb(rgbInputEl.value));
+}
+rgbInputEl.addEventListener("input", setFromRgbInput);
+
+function parseCmyk(value) {
+  return value.split(",").map((c) => parseInt(c) / 100);
+}
+function setFromCmykInput() {
+  setCmyk(...parseCmyk(cmykInputEl.value));
+}
+cmykInputEl.addEventListener("input", setFromCmykInput);
+
+function parseHsv(value) {
+  value = hsvInputEl.value.split(",").map((c) => parseInt(c));
+  value[1] /= 100;
+  value[2] /= 100;
+  return value;
+}
+function setFromHsvInput() {
+  setHsv(...parseHsv(hsvInputEl.value));
+}
+hsvInputEl.addEventListener("input", setFromHsvInput);
+
+function parseHsl(value) {
+  value = hslInputEl.value.split(",").map((c) => parseInt(c));
+  value[1] /= 100;
+  value[2] /= 100;
+  return value;
+}
+function setFromHslInput() {
+  setHsl(...parseHsl(hslInputEl.value));
+}
+hslInputEl.addEventListener("input", setFromHslInput);
+
+updateColorPreview();
diff --git a/src/web/assets/style.css b/src/web/assets/style.css
index 3308037..c785788 100644
--- a/src/web/assets/style.css
+++ b/src/web/assets/style.css
@@ -368,6 +368,82 @@ h3.answer-thesaurus-category-title {
   resize: none;
 }
 
+.answer-colorpicker-preview-container {
+  display: flex;
+  height: 228px;
+}
+.answer-colorpicker-preview {
+  width: 204px;
+  max-width: 33%;
+}
+.answer-colorpicker-picker-container {
+  position: absolute;
+  pointer-events: none;
+  width: 100%;
+  height: 100%;
+}
+.answer-colorpicker-picker,
+.answer-colorpicker-huepicker {
+  position: absolute;
+  width: 1rem;
+  height: 1rem;
+  transform: translate(-0.5rem, -0.5rem);
+  border-radius: 50%;
+  border: 2px solid #fff;
+
+  touch-action: none;
+}
+.answer-colorpicker-canvas-container {
+  flex: 1;
+  position: relative;
+}
+.answer-colorpicker-canvas {
+  height: 100%;
+  width: 100%;
+
+  touch-action: none;
+}
+.answer-colorpicker-slider-container {
+  margin: 1rem;
+  position: relative;
+  height: 1rem;
+
+  touch-action: none;
+}
+.answer-colorpicker-slider {
+  height: 100%;
+  width: 100%;
+}
+.answer-colorpicker-huepicker {
+  transform: translate(-0.5rem, -50%);
+  top: 50%;
+}
+.answer-colorpicker label {
+  display: block;
+  width: fit-content;
+}
+.answer-colorpicker-hex-input-container {
+  text-align: center;
+  margin-bottom: 0.5rem;
+}
+.answer-colorpicker-hex-input-container label {
+  margin: 0 auto;
+}
+#answer-colorpicker-hex-input {
+  width: 100%;
+  text-align: center;
+}
+.answer-colorpicker-other-inputs {
+  display: flex;
+  gap: 0.5rem;
+}
+.answer-colorpicker-input-container {
+  display: flex;
+}
+.answer-colorpicker-other-inputs input {
+  width: 100%;
+}
+
 /* infobox */
 .infobox {
   margin-bottom: 1rem;
diff --git a/src/web/mod.rs b/src/web/mod.rs
index a20b404..f0e606e 100644
--- a/src/web/mod.rs
+++ b/src/web/mod.rs
@@ -73,6 +73,7 @@ pub async fn run(config: Config) {
         "style.css",
         "script.js",
         "robots.txt",
+        "scripts/colorpicker.js",
         "themes/catppuccin-mocha.css",
         "themes/catppuccin-latte.css",
         "themes/nord-bluish.css",