Background Run

"use client"

import * as React from "react"
import { BackgroundRun, BackgroundRunStatus } from "@/components/ui/background-run"

const FIT_CSS = "html,body{overflow:hidden}[data-fit-small] [data-fit-hide]{display:none!important}"

/**
 * 21st shows a demo in a small frame: about 674 by 421 on a component page, 358 by 224 on a
 * phone and 245 by 139 on a profile card. A demo taller than its frame gets scrollbars, which
 * render white on dark pages. FitFrame fills the frame exactly instead.
 *
 * - "scale": the content shrinks until it fits, centered. For visuals such as orbs.
 * - "crop": the content stays at full size from the top and fades out at the bottom. For text
 *   that streams in, where a changing scale would make the page breathe.
 *
 * `minWidth` lays out a wide demo (a table, a two column panel) at that width and scales it down
 * to the frame, instead of letting it collapse to a narrow layout. The frame centers it, so it
 * shrinks evenly on both sides.
 *
 * Anything marked `data-fit-hide` (state buttons, the chatcn.dev line) drops out in frames
 * shorter than `hideBelow`, so a profile card shows the visual alone.
 */
function FitFrame({
  children,
  mode = "scale",
  hideBelow = 360,
  minWidth,
}: {
  children: React.ReactNode
  mode?: "scale" | "crop"
  hideBelow?: number
  minWidth?: string
}) {
  const content = React.useRef<HTMLDivElement>(null)
  const [cropped, setCropped] = React.useState(false)

  React.useLayoutEffect(() => {
    const el = content.current
    if (!el) return
    const measure = () => {
      const vw = window.innerWidth
      const vh = window.innerHeight
      el.toggleAttribute("data-fit-small", vh < hideBelow)
      // Layout sizes ignore the transform, so measuring never feeds back.
      const w = Math.max(el.offsetWidth, el.scrollWidth)
      const h = Math.max(el.offsetHeight, el.scrollHeight)
      const scale = mode === "scale" ? Math.min(1, vw / w, vh / h) : 1
      el.style.transform = scale < 1 ? `scale(${scale})` : ""
      setCropped(mode === "crop" && h > vh + 1)
    }
    measure()
    const observer = new ResizeObserver(measure)
    observer.observe(el)
    // Content that changes inside a fixed width box (a headline that cycles words) never resizes
    // the box itself, so changes below it measure again on the next frame.
    let frame = 0
    const mutations = new MutationObserver(() => {
      cancelAnimationFrame(frame)
      frame = requestAnimationFrame(measure)
    })
    mutations.observe(el, { subtree: true, childList: true, characterData: true })
    window.addEventListener("resize", measure)
    return () => {
      observer.disconnect()
      mutations.disconnect()
      cancelAnimationFrame(frame)
      window.removeEventListener("resize", measure)
    }
  }, [mode, hideBelow])

  const fade = "linear-gradient(to bottom, #000 calc(100% - 40px), transparent)"
  return (
    <div
      className="flex w-full justify-center overflow-hidden"
      style={{
        height: "100dvh",
        alignItems: mode === "crop" ? "flex-start" : "center",
        maskImage: cropped ? fade : undefined,
        WebkitMaskImage: cropped ? fade : undefined,
      }}
    >
      <style>{FIT_CSS}</style>
      <div
        ref={content}
        className="w-full shrink-0"
        style={{ transformOrigin: mode === "crop" ? "top center" : "center", minWidth }}
      >
        {children}
      </div>
    </div>
  )
}

type Phase =
  | { status: "queued" }
  | { status: "running"; step: number }
  | { status: "needs-input"; step: number }
  | { status: "done" }

// The demo's times count back from the moment it renders. Read through `performance`, which
// Next.js allows while it prerenders a page; `Date.now()` during render fails the build there.
const demoNow = () => performance.timeOrigin + performance.now()

const APPROVAL_AT = 3

const STEPS = [
  "Reading tests/e2e/checkout.spec.ts",
  "Running pnpm test:e2e --grep checkout",
  "Comparing 3 failing traces",
  "Waiting for approval",
  "Running pnpm db:migrate --env preview",
  "Editing tests/e2e/checkout.spec.ts",
  "Running pnpm test:e2e --grep checkout --repeat-each 20",
]

const RESEARCH = [
  "Searching for vector database pricing 2026",
  "Reading turbopuffer.com/docs/pricing",
  "Reading pinecone.io/pricing",
  "Comparing storage cost per GB",
  "Reading pgvector benchmarks on a 10M row table",
]

function BackgroundRunDemo() {
  const [phase, setPhase] = React.useState<Phase>({ status: "queued" })
  const [startedAt, setStartedAt] = React.useState<number>()
  const [research, setResearch] = React.useState(0)
  const [researchStart] = React.useState(() => demoNow() - 134_000)

  React.useEffect(() => {
    let wait = 1200
    let next: () => void = () => {}
    if (phase.status === "queued") {
      next = () => {
        setStartedAt(Date.now())
        setPhase({ status: "running", step: 0 })
      }
    } else if (phase.status === "running") {
      wait = 1300
      next = () =>
        setPhase(
          phase.step + 1 === APPROVAL_AT
            ? { status: "needs-input", step: APPROVAL_AT }
            : phase.step + 1 >= STEPS.length
              ? { status: "done" }
              : { status: "running", step: phase.step + 1 },
        )
    } else if (phase.status === "needs-input") {
      wait = 3600
      next = () => setPhase({ status: "running", step: phase.step + 1 })
    } else {
      wait = 4500
      next = () => {
        setStartedAt(undefined)
        setPhase({ status: "queued" })
      }
    }
    const id = window.setTimeout(next, wait)
    return () => window.clearTimeout(id)
  }, [phase])

  React.useEffect(() => {
    const id = window.setInterval(() => setResearch((r) => (r + 1) % RESEARCH.length), 2200)
    return () => window.clearInterval(id)
  }, [])

  const status: BackgroundRunStatus = phase.status
  const done = phase.status === "done" ? STEPS.length : phase.status === "queued" ? 0 : phase.step

  return (
    <div className="flex w-full max-w-md flex-col gap-3">
      <BackgroundRun
        title="Fix flaky checkout test"
        context="tallyline/web · fix/checkout-flake"
        status={status}
        step={phase.status === "running" ? STEPS[phase.step] : undefined}
        request="Approve pnpm db:migrate --env preview"
        summary="2 files changed. The checkout test passed 20 of 20 runs."
        queuePosition={1}
        steps={{ done, total: STEPS.length }}
        startedAt={startedAt}
        unread={phase.status === "needs-input" || phase.status === "done"}
        onOpen={() => {}}
        onCancel={() => {}}
        onRespond={() =>
          phase.status === "needs-input" && setPhase({ status: "running", step: phase.step + 1 })
        }
      />
      <BackgroundRun
        title="Research vector databases"
        context="Deep research"
        status="running"
        step={RESEARCH[research]}
        startedAt={researchStart}
        onOpen={() => {}}
        onCancel={() => {}}
      />
    </div>
  )
}

/** The line under each 21st demo that points back to the kit. */
function MoreOn({ slug, children }: { slug: string; children: React.ReactNode }) {
  return (
    <p data-fit-hide className="text-[0.75rem]/[1rem] text-(color:--chatcn-fg-faint) text-center text-balance">
      {children}{" "}
      <a
        href={`https://chatcn.dev/docs/components/${slug}`}
        target="_blank"
        rel="noopener"
        className="text-(color:--chatcn-fg-subtle) hover:text-(color:--chatcn-fg) underline underline-offset-2"
      >
        chatcn.dev
      </a>
    </p>
  )
}

/** The kit's own example, framed for the 21st preview. */
export default function BackgroundRunPreview() {
  return (
    <FitFrame minWidth="36rem">
      <div className="flex w-full flex-col items-center justify-center gap-4 p-6">
        <div className="flex w-full max-w-xl justify-center">
          <BackgroundRunDemo />
        </div>
        <MoreOn slug="background-run">Agent runs that keep going in the background, with progress. On</MoreOn>
      </div>
    </FitFrame>
  )
}