//! The headless-browser side of `impeccable font-match`, wired over //! `crates/browser`'s CDP client. This is the one piece the open //! `impeccable-comp-verbs` crate cannot do on its own; it is injected as a //! `FontRenderer` so the browser (and its `core` dependency) stays out of that //! crate. Ported from `font-match.mjs` `renderCandidates` / `renderProofSheet`, //! which drove Playwright/Puppeteer; here the same steps run over CDP against a //! discovered Chrome (the browser the URL engine already uses). use std::collections::HashMap; use std::time::Duration; use base64::Engine as _; use impeccable_browser::cdp::{default_chrome_args, Browser, EvalOutcome, Page, Viewport}; use impeccable_browser::discovery; use impeccable_comp::font_fingerprint::{fingerprint, FpOpts}; use impeccable_comp::png_io; use impeccable_comp::raster::Image; use impeccable_comp_verbs::font_match::{FontRenderer, RankCandidate, RenderedCandidate}; const NAV_TIMEOUT: Duration = Duration::from_secs(30); /// A renderer that discovers and drives an installed Chrome over CDP. pub struct CdpFontRenderer { env: HashMap, } impl CdpFontRenderer { pub fn from_process_env() -> Self { CdpFontRenderer { env: std::env::vars().collect() } } fn launch(&self) -> Option { let exe = discovery::find_browser(&self.env).ok()?; // JS launchArgs: `process.env.CI ? ['--no-sandbox','--disable-setuid-sandbox'] : []`. let mut user_args: Vec = Vec::new(); if self.env.get("CI").map(|v| !v.is_empty()).unwrap_or(false) { user_args.push("--no-sandbox".into()); user_args.push("--disable-setuid-sandbox".into()); } let dangerous = self.env.get("PUPPETEER_DANGEROUS_NO_SANDBOX").map(String::as_str) == Some("true"); let _ = default_chrome_args(&user_args, dangerous); // parity: same flag set the URL engine uses Browser::launch(&exe, &user_args, dangerous).ok() } } fn b64(bytes: &[u8]) -> String { base64::engine::general_purpose::STANDARD.encode(bytes) } fn data_url(html: &str) -> String { format!("data:text/html;base64,{}", b64(html.as_bytes())) } /// encodeURIComponent(fam).replace(/%20/g,'+') for the Google Fonts css2 URL. fn encode_family(fam: &str) -> String { let mut out = String::new(); for ch in fam.chars() { if ch == ' ' { out.push('+'); } else if ch.is_ascii_alphanumeric() || matches!(ch, '-' | '_' | '.' | '!' | '~' | '*' | '\'' | '(' | ')') { out.push(ch); } else { let mut buf = [0u8; 4]; for byte in ch.encode_utf8(&mut buf).bytes() { out.push_str(&format!("%{byte:02X}")); } } } out } fn wfmt(w: f64) -> String { (w as i64).to_string() } fn js_string(s: &str) -> String { serde_json::to_string(s).unwrap_or_else(|_| "\"\"".to_string()) } fn links_html(candidates: &[RankCandidate]) -> String { candidates .iter() .map(|c| { format!( "", encode_family(&c.family), wfmt(c.weight) ) }) .collect() } fn eval_bool(page: &mut Page<'_>, expr: &str) -> bool { match page.evaluate(expr) { Ok(EvalOutcome::Value(v)) => v.as_bool().unwrap_or(false), _ => false, } } fn eval_value(page: &mut Page<'_>, expr: &str) -> Option { match page.evaluate(expr) { Ok(EvalOutcome::Value(v)) => Some(v), _ => None, } } impl FontRenderer for CdpFontRenderer { fn render_candidates( &mut self, candidates: &[RankCandidate], text: &str, target_cap_px: f64, transform: &str, ) -> Option> { let mut browser = self.launch()?; let links = links_html(candidates); let html = format!( "{links}" ); let size0 = 12f64.max((target_cap_px * 1.4).round()); let mut results: Vec = Vec::new(); let outcome = (|| -> Option<()> { let mut page = browser.new_page().ok()?; page.set_viewport(Viewport { width: 1600, height: 400 }).ok()?; page.goto(&data_url(&html), "load", NAV_TIMEOUT).ok()?; std::thread::sleep(Duration::from_millis(800)); for c in candidates { let mut size = size0; let mut fp = None; let mut ok = true; for pass in 0..2 { let div = format!( "

{}

", c.family, wfmt(c.weight), size as i64, text ); let set = format!("(() => {{ document.body.innerHTML = {}; }})()", js_string(&div)); let _ = page.evaluate(&set); // Loaded means a real face of this family covers the weight. let check = format!( "(async () => {{ const f = {{ family: {}, weight: {} }}; const faces = await document.fonts.load(f.weight + \" 32px '\" + f.family + \"'\"); await document.fonts.ready; const covers = (face) => {{ const w = String(face.weight || '400').split(/\\s+/).map(Number); const lo = w[0], hi = w[1] ?? w[0]; return f.weight >= lo - 50 && f.weight <= hi + 50; }}; return faces.some((face) => face.family.replace(/[\"']/g, '') === f.family && face.status === 'loaded' && covers(face)); }})()", js_string(&c.family), wfmt(c.weight) ); let loaded = eval_bool(&mut page, &check); std::thread::sleep(Duration::from_millis(100)); if !loaded { ok = false; } let box_v = eval_value(&mut page, "(() => { const r = document.querySelector('div.s').getBoundingClientRect(); return { w: Math.ceil(r.width) + 8, h: Math.ceil(r.height) + 8 }; })()"); let (bw, bh) = box_v .as_ref() .map(|v| (v.get("w").and_then(|x| x.as_f64()).unwrap_or(0.0), v.get("h").and_then(|x| x.as_f64()).unwrap_or(0.0))) .unwrap_or((0.0, 0.0)); let clip_w = 1600f64.min(bw); let clip_h = 400f64.min(bh); let shot = page.screenshot_clip(0.0, 0.0, clip_w, clip_h).ok()?; let png = base64::engine::general_purpose::STANDARD.decode(shot.as_bytes()).ok()?; fp = png_io::decode_png(&png).ok().and_then(|d| fingerprint(&d.image, &FpOpts::default())); if fp.is_none() || pass == 1 { break; } let cap = fp.as_ref().unwrap().cap_height_px; size = 8f64.max((size * (target_cap_px / cap)).round()); } results.push(RenderedCandidate { family: c.family.clone(), weight: c.weight, loaded: ok, font_size_px: size as i64, fp, }); } page.close(); Some(()) })(); browser.close(); outcome.map(|_| results) } fn render_proof_sheet( &mut self, comp_crop: &Image, top: &[RenderedCandidate], text: &str, _cap_px: f64, transform: &str, ) -> Option> { let comp_png = png_io::encode_png(comp_crop, &[]).ok()?; let comp_b64 = b64(&comp_png); let links: String = top .iter() .map(|c| { format!( "", encode_family(&c.family), wfmt(c.weight) ) }) .collect(); let rows: String = top .iter() .map(|c| { format!( "

{} {} · {}px

{}

", &c.family, wfmt(c.weight), c.font_size_px, c.family, wfmt(c.weight), c.font_size_px, transform, text ) }) .collect(); let html = format!( "{links}

COMP

{rows}" ); let mut browser = self.launch()?; let vw = 1600u32.min(600u32.max(comp_crop.width as u32 + 24)); let outcome = (|| -> Option> { let mut page = browser.new_page().ok()?; page.set_viewport(Viewport { width: vw, height: 200 }).ok()?; page.goto(&data_url(&html), "load", NAV_TIMEOUT).ok()?; let _ = page.evaluate("(async () => { await document.fonts.ready; })()"); std::thread::sleep(Duration::from_millis(600)); let size = eval_value(&mut page, "(() => ({ w: Math.ceil(document.documentElement.scrollWidth), h: Math.ceil(document.documentElement.scrollHeight) }))()"); let (w, h) = size .as_ref() .map(|v| (v.get("w").and_then(|x| x.as_f64()).unwrap_or(vw as f64), v.get("h").and_then(|x| x.as_f64()).unwrap_or(200.0))) .unwrap_or((vw as f64, 200.0)); let shot = page.screenshot_clip(0.0, 0.0, w, h).ok()?; let png = base64::engine::general_purpose::STANDARD.decode(shot.as_bytes()).ok()?; page.close(); Some(png) })(); browser.close(); outcome } }