From 56dbad1ef9f59eb9be045f130e1cfb0dc0fb1e3e Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Sun, 22 Jan 2023 18:12:46 +0100
Subject: [PATCH] [Dev] Teact: Add debug overlay

---
 src/hooks/useFlag.ts     |   4 +-
 src/lib/teact/teact.ts   |  10 ++--
 src/util/debugOverlay.ts | 109 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 118 insertions(+), 5 deletions(-)
 create mode 100644 src/util/debugOverlay.ts

diff --git a/src/hooks/useFlag.ts b/src/hooks/useFlag.ts
index 7acd11b6c..3d8150cd6 100644
--- a/src/hooks/useFlag.ts
+++ b/src/hooks/useFlag.ts
@@ -1,7 +1,7 @@
 import { useCallback, useState } from '../lib/teact/teact';
 
-const useFlag = (initial = false): [boolean, NoneToVoidFunction, NoneToVoidFunction] => {
-  const [value, setValue] = useState(initial);
+const useFlag = (initial = false, debugKey?: string): [boolean, NoneToVoidFunction, NoneToVoidFunction] => {
+  const [value, setValue] = useState(initial, debugKey);
 
   const setTrue = useCallback(() => {
     setValue(true);
diff --git a/src/lib/teact/teact.ts b/src/lib/teact/teact.ts
index 47f7883a8..ff7cc24b8 100644
--- a/src/lib/teact/teact.ts
+++ b/src/lib/teact/teact.ts
@@ -6,13 +6,12 @@ import {
 import { orderBy } from '../../util/iteratees';
 import { getUnequalProps } from '../../util/arePropsShallowEqual';
 import { handleError } from '../../util/handleError';
+import { incrementOverlayCounter } from '../../util/debugOverlay';
 
 export type Props = AnyLiteral;
 export type FC<P extends Props = any> = (props: P) => any;
 // eslint-disable-next-line @typescript-eslint/naming-convention
-export type FC_withDebug = FC & {
-  DEBUG_contentComponentName?: string;
-};
+export type FC_withDebug = FC & { DEBUG_contentComponentName?: string };
 
 export enum VirtualElementTypesEnum {
   Empty,
@@ -339,6 +338,11 @@ export function renderComponent(componentInstance: ComponentInstance) {
       }
       DEBUG_components[componentName].renderTimes.push(duration);
       DEBUG_components[componentName].renderCount++;
+
+      if (DEBUG_MORE) {
+        incrementOverlayCounter(`${componentName} renders`);
+        incrementOverlayCounter(`${componentName} duration`, duration);
+      }
     }
   } catch (err: any) {
     handleError(err);
diff --git a/src/util/debugOverlay.ts b/src/util/debugOverlay.ts
new file mode 100644
index 000000000..e30378c0e
--- /dev/null
+++ b/src/util/debugOverlay.ts
@@ -0,0 +1,109 @@
+import { throttle } from './schedulers';
+
+const KEYS_TO_IGNORE = new Set([
+  'TeactMemoWrapper renders',
+  'TeactNContainer renders',
+  'Button renders',
+]);
+const MIN_RENDERS_TO_SHOW = 5;
+const MIN_DURATION_TO_SHOW = 2;
+const BG_GREEN = ' style="background: lightgreen"';
+
+let counters: Record<string, {
+  value: number;
+  lastUpdateAt: number;
+}> = {};
+
+const renderCountersThrottled = throttle(renderCounters, 500, false);
+
+let loggerEl: HTMLDivElement;
+
+export function debugToOverlay(text: string) {
+  if (!loggerEl) {
+    setupOverlay();
+  }
+
+  const date = new Date();
+  const dateFormatted = `${date.toLocaleTimeString()}.${date.getMilliseconds()}`;
+  const wasAtBottom = loggerEl.scrollTop + 10 >= loggerEl.scrollHeight - loggerEl.offsetHeight;
+
+  loggerEl.innerHTML += `${dateFormatted}: ${text}<br/>`;
+
+  if (wasAtBottom) {
+    loggerEl.scrollTop = loggerEl.scrollHeight;
+  }
+}
+
+export function incrementOverlayCounter(key: string, value = 1) {
+  const now = Date.now();
+  if (!counters[key]) {
+    counters[key] = { value, lastUpdateAt: now };
+  } else {
+    counters[key].value += value;
+    counters[key].lastUpdateAt = now;
+  }
+
+  renderCountersThrottled();
+}
+
+export function renderCounters() {
+  if (!loggerEl) {
+    setupOverlay();
+  }
+
+  const halfSecondAgo = Date.now() - 500;
+  const [maxRenders, maxDuration] = Object.entries(counters).reduce((acc, [key, { value }]) => {
+    if (KEYS_TO_IGNORE.has(key)) {
+      return acc;
+    }
+
+    if (key.includes('renders') && value > acc[0]) {
+      acc[0] = value;
+    }
+
+    if (key.includes('duration') && value > acc[1]) {
+      acc[1] = value;
+    }
+
+    return acc;
+  }, [0, 0]);
+
+  loggerEl.innerHTML = Object
+    .entries(counters)
+    .filter(([key, { value }]) => (
+      (!KEYS_TO_IGNORE.has(key)) && (
+        (key.includes('renders') && value > MIN_RENDERS_TO_SHOW)
+        || (key.includes('duration') && value > MIN_DURATION_TO_SHOW)
+      )
+    ))
+    .sort((a, b) => (
+      b[1].lastUpdateAt - a[1].lastUpdateAt
+    ))
+    .map(([key, { value, lastUpdateAt }]) => ([
+      `<div style="background: #ff0000${factorToHex(value / (key.includes('renders') ? maxRenders : maxDuration))}">`,
+      `  <span${lastUpdateAt > halfSecondAgo ? BG_GREEN : ''}>${key}: ${Math.round(value)}</span>`,
+      '</div>',
+    ].join('\n')))
+    .join('\n');
+}
+
+function setupOverlay() {
+  loggerEl = document.createElement('div');
+  loggerEl.style.cssText = 'position: absolute; left: 0; bottom: 25px; z-index: 9998; width: 260px; height: 200px;'
+    + ' border: 1px solid #555; background: rgba(255, 255, 255, 0.9); overflow: auto; font-size: 10px;';
+  document.body.appendChild(loggerEl);
+
+  const clearEl = document.createElement('a');
+  clearEl.style.cssText = 'position: absolute; left: 222px; bottom: 198px; z-index: 9999; font-size: 20px; '
+    + 'cursor: pointer;';
+  clearEl.innerText = '🔄';
+  clearEl.addEventListener('click', () => {
+    counters = {};
+    renderCountersThrottled();
+  });
+  document.body.appendChild(clearEl);
+}
+
+function factorToHex(factor: number) {
+  return Math.round(255 * factor).toString(16).padStart(2, '0');
+}