Add developer support for using next.js to serve generated static files (#814)

To improve the developer experience for front-end development, we're migrating to Next.js. In order to do this migration page-by-page, we're using static site generation via Next.js. This also helps us avoid making cross site requests from front-end to back-end for the time being, while giving a ramp to separating out server and client if needed for scale down the road.

Dev instructions for using the next.js setup are in the added README.

This adds scaffolding for including the built files in the python package as well as the docker images. Docker setup has been tested locally. In order to verify the build is working as expected, we can navigate to the {khoj_host}:42110/experimental and verify that the experiment page comes up.

This setup works with serving static files included in the src/interface/web folder from the Django app. The key bit for understanding the setup is in the yarn export command in package.json.

src/interface/web/app/globals.css

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+@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+Arabic:wght@100..900&family=Noto+Sans:ital,wght@0,100..900;1,100..900&display=swap');
+
+:root {
+  --max-width: 1100px;
+  --border-radius: 12px;
+  --font-mono: ui-monospace, Menlo, Monaco, "Cascadia Mono", "Segoe UI Mono",
+    "Roboto Mono", "Oxygen Mono", "Ubuntu Monospace", "Source Code Pro",
+    "Fira Mono", "Droid Sans Mono", "Courier New", monospace;
+
+  --foreground-rgb: 0, 0, 0;
+  --background-start-rgb: 214, 219, 220;
+  --background-end-rgb: 255, 255, 255;
+
+  --primary-glow: conic-gradient(
+    from 180deg at 50% 50%,
+    #16abff33 0deg,
+    #0885ff33 55deg,
+    #54d6ff33 120deg,
+    #0071ff33 160deg,
+    transparent 360deg
+  );
+  --secondary-glow: radial-gradient(
+    rgba(255, 255, 255, 1),
+    rgba(255, 255, 255, 0)
+  );
+
+  --tile-start-rgb: 239, 245, 249;
+  --tile-end-rgb: 228, 232, 233;
+  --tile-border: conic-gradient(
+    #00000080,
+    #00000040,
+    #00000030,
+    #00000020,
+    #00000010,
+    #00000010,
+    #00000080
+  );
+
+  --callout-rgb: 238, 240, 241;
+  --callout-border-rgb: 172, 175, 176;
+  --card-rgb: 180, 185, 188;
+  --card-border-rgb: 131, 134, 135;
+
+  --primary: #f9f5de;
+  --primary-hover: #fee285;
+  --primary-focus: rgba(255, 179, 0, 0.125);
+  --primary-inverse: rgba(0, 0, 0, 0.75);
+  --background-color: #f5f4f3;
+  --frosted-background-color: rgba(245, 244, 243, 0.75);
+  --main-text-color: #475569;
+  --summer-sun: #fcc50b;
+  --water: #44b9da;
+  --leaf: #7b990a;
+  --flower: #ffaeae;
+  --font-family: "Noto Sans", "Noto Sans Arabic", sans-serif !important;
+  --calm-blue: #E4D9D9;
+  --calmer-blue: #e4cdcd;
+  --calm-green: #d0f5d6;
+  --intense-green: #1C2841;
+}
+
+@media (prefers-color-scheme: dark) {
+  :root {
+    --foreground-rgb: 255, 255, 255;
+    --background-start-rgb: 0, 0, 0;
+    --background-end-rgb: 0, 0, 0;
+
+    --primary-glow: radial-gradient(rgba(1, 65, 255, 0.4), rgba(1, 65, 255, 0));
+    --secondary-glow: linear-gradient(
+      to bottom right,
+      rgba(1, 65, 255, 0),
+      rgba(1, 65, 255, 0),
+      rgba(1, 65, 255, 0.3)
+    );
+
+    --tile-start-rgb: 2, 13, 46;
+    --tile-end-rgb: 2, 5, 19;
+    --tile-border: conic-gradient(
+      #ffffff80,
+      #ffffff40,
+      #ffffff30,
+      #ffffff20,
+      #ffffff10,
+      #ffffff10,
+      #ffffff80
+    );
+
+    --callout-rgb: 20, 20, 20;
+    --callout-border-rgb: 108, 108, 108;
+    --card-rgb: 100, 100, 100;
+    --card-border-rgb: 200, 200, 200;
+
+    --primary: #f9f5de;
+    --primary-hover: #fee285;
+    --primary-focus: rgba(255, 179, 0, 0.125);
+    --primary-inverse: rgba(0, 0, 0, 0.75);
+    --background-color: #f5f4f3;
+    --frosted-background-color: rgba(245, 244, 243, 0.75);
+    --main-text-color: #475569;
+    --summer-sun: #fcc50b;
+    --water: #44b9da;
+    --leaf: #7b990a;
+    --flower: #ffaeae;
+    --font-family: "Noto Sans", "Noto Sans Arabic", sans-serif !important;
+  }
+}
+
+* {
+  box-sizing: border-box;
+}
+
+html,
+body {
+  max-width: 100vw;
+  overflow-x: hidden;
+  font-family: var(--font-family);
+}
+
+input,
+div,
+button,
+p,
+textarea {
+  font-family: var(--font-family);
+}
+
+body {
+  color: var(--main-text-color);
+  background-color: var(--background-color);
+}
+
+a {
+  color: inherit;
+  text-decoration: none;
+}
+
+p {
+  margin: 0;
+}
+
+pre code.hljs {
+  white-space: preserve;
+}
+
+body {
+  margin: 0;
+}
+
+button:hover {
+  cursor: pointer;
+}
+
+/* Uncomment when ready for dark-mode */
+/* @media (prefers-color-scheme: dark) {
+  html {
+    color-scheme: dark;
+  }
+} */

src/interface/web/app/layout.tsx

@@ -0,0 +1,22 @@
+import type { Metadata } from "next";
+import { Noto_Sans } from "next/font/google";
+import "./globals.css";
+
+const inter = Noto_Sans({ subsets: ["latin"] });
+
+export const metadata: Metadata = {
+  title: "Khoj AI",
+  description: "An AI copilot for your second brain",
+};
+
+export default function RootLayout({
+  children,
+}: Readonly<{
+  children: React.ReactNode;
+}>) {
+  return (
+    <html lang="en">
+      <body className={inter.className}>{children}</body>
+    </html>
+  );
+}

src/interface/web/app/page.module.css

@@ -0,0 +1,230 @@
+.main {
+  display: flex;
+  flex-direction: column;
+  justify-content: space-between;
+  align-items: center;
+  padding: 6rem;
+  min-height: 100vh;
+}
+
+.description {
+  display: inherit;
+  justify-content: inherit;
+  align-items: inherit;
+  font-size: 0.85rem;
+  max-width: var(--max-width);
+  width: 100%;
+  z-index: 2;
+  font-family: var(--font-mono);
+}
+
+.description a {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  gap: 0.5rem;
+}
+
+.description p {
+  position: relative;
+  margin: 0;
+  padding: 1rem;
+  background-color: rgba(var(--callout-rgb), 0.5);
+  border: 1px solid rgba(var(--callout-border-rgb), 0.3);
+  border-radius: var(--border-radius);
+}
+
+.code {
+  font-weight: 700;
+  font-family: var(--font-mono);
+}
+
+.grid {
+  display: grid;
+  grid-template-columns: repeat(4, minmax(25%, auto));
+  max-width: 100%;
+  width: var(--max-width);
+}
+
+.card {
+  padding: 1rem 1.2rem;
+  border-radius: var(--border-radius);
+  background: rgba(var(--card-rgb), 0);
+  border: 1px solid rgba(var(--card-border-rgb), 0);
+  transition: background 200ms, border 200ms;
+}
+
+.card span {
+  display: inline-block;
+  transition: transform 200ms;
+}
+
+.card h2 {
+  font-weight: 600;
+  margin-bottom: 0.7rem;
+}
+
+.card p {
+  margin: 0;
+  opacity: 0.6;
+  font-size: 0.9rem;
+  line-height: 1.5;
+  max-width: 30ch;
+  text-wrap: balance;
+}
+
+.center {
+  display: flex;
+  justify-content: center;
+  align-items: center;
+  position: relative;
+  padding: 4rem 0;
+}
+
+.center::before {
+  background: var(--secondary-glow);
+  border-radius: 50%;
+  width: 480px;
+  height: 360px;
+  margin-left: -400px;
+}
+
+.center::after {
+  background: var(--primary-glow);
+  width: 240px;
+  height: 180px;
+  z-index: -1;
+}
+
+.center::before,
+.center::after {
+  content: "";
+  left: 50%;
+  position: absolute;
+  filter: blur(45px);
+  transform: translateZ(0);
+}
+
+.logo {
+  position: relative;
+}
+/* Enable hover only on non-touch devices */
+@media (hover: hover) and (pointer: fine) {
+  .card:hover {
+    background: rgba(var(--card-rgb), 0.1);
+    border: 1px solid rgba(var(--card-border-rgb), 0.15);
+  }
+
+  .card:hover span {
+    transform: translateX(4px);
+  }
+}
+
+@media (prefers-reduced-motion) {
+  .card:hover span {
+    transform: none;
+  }
+}
+
+/* Mobile */
+@media (max-width: 700px) {
+  .content {
+    padding: 4rem;
+  }
+
+  .grid {
+    grid-template-columns: 1fr;
+    margin-bottom: 120px;
+    max-width: 320px;
+    text-align: center;
+  }
+
+  .card {
+    padding: 1rem 2.5rem;
+  }
+
+  .card h2 {
+    margin-bottom: 0.5rem;
+  }
+
+  .center {
+    padding: 8rem 0 6rem;
+  }
+
+  .center::before {
+    transform: none;
+    height: 300px;
+  }
+
+  .description {
+    font-size: 0.8rem;
+  }
+
+  .description a {
+    padding: 1rem;
+  }
+
+  .description p,
+  .description div {
+    display: flex;
+    justify-content: center;
+    position: fixed;
+    width: 100%;
+  }
+
+  .description p {
+    align-items: center;
+    inset: 0 0 auto;
+    padding: 2rem 1rem 1.4rem;
+    border-radius: 0;
+    border: none;
+    border-bottom: 1px solid rgba(var(--callout-border-rgb), 0.25);
+    background: linear-gradient(
+      to bottom,
+      rgba(var(--background-start-rgb), 1),
+      rgba(var(--callout-rgb), 0.5)
+    );
+    background-clip: padding-box;
+    backdrop-filter: blur(24px);
+  }
+
+  .description div {
+    align-items: flex-end;
+    pointer-events: none;
+    inset: auto 0 0;
+    padding: 2rem;
+    height: 200px;
+    background: linear-gradient(
+      to bottom,
+      transparent 0%,
+      rgb(var(--background-end-rgb)) 40%
+    );
+    z-index: 1;
+  }
+}
+
+/* Tablet and Smaller Desktop */
+@media (min-width: 701px) and (max-width: 1120px) {
+  .grid {
+    grid-template-columns: repeat(2, 50%);
+  }
+}
+
+@media (prefers-color-scheme: dark) {
+  .vercelLogo {
+    filter: invert(1);
+  }
+
+  .logo {
+    filter: invert(1) drop-shadow(0 0 0.3rem #ffffff70);
+  }
+}
+
+@keyframes rotate {
+  from {
+    transform: rotate(360deg);
+  }
+  to {
+    transform: rotate(0deg);
+  }
+}

src/interface/web/app/page.tsx

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+import styles from "./page.module.css";
+
+export default function Home() {
+  return (
+    <main className={styles.main}>
+      Hi, Khoj here.
+    </main>
+  );
+}