JSON Viewer

"use client"

import * as React from "react"
import { JsonViewer } from "@/components/ui/json-viewer"

/** Searches the tour types in, each opening the path to its matches. Empty shows the outline. */
const QUERIES = ["timed out", "503", "us-east-2", ""]

/** How long a choice holds a tour before it carries on. */
const RESUME_MS = 1800

/** True until `RESUME_MS` after the last `hold()`, for tours with their own state. */
function useHold() {
  const [held, setHeld] = React.useState(false)
  const timer = React.useRef(0)
  React.useEffect(() => () => window.clearTimeout(timer.current), [])
  const hold = React.useCallback(() => {
    setHeld(true)
    window.clearTimeout(timer.current)
    timer.current = window.setTimeout(() => setHeld(false), RESUME_MS)
  }, [])
  return [held, hold] as const
}

const reducedMotion = () => window.matchMedia("(prefers-reduced-motion: reduce)").matches

const REST_MS = 1500

const TYPE_MS = 70

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>
  )
}

/** A `search_logs` tool result, the kind of payload an agent hands back. */
const RESULT = {
  query: "service:checkout level:error",
  took_ms: 184,
  hits: [
    {
      timestamp: "2026-10-21T09:14:03.218Z",
      service: "checkout",
      level: "error",
      message: "Payment intent timed out after 30000 ms",
      context: { region: "eu-west-1", attempt: 3, retryable: true },
    },
    {
      timestamp: "2026-10-21T09:14:07.902Z",
      service: "checkout",
      level: "error",
      message: "Upstream returned 503 from payments-gateway",
      context: { region: "eu-west-1", attempt: 1, upstream: "payments-gateway" },
    },
    {
      timestamp: "2026-10-21T09:15:41.006Z",
      service: "checkout",
      level: "warn",
      message: "Card declined: insufficient funds",
      context: { region: "us-east-2", attempt: 1, retryable: false },
    },
  ],
  total: 3,
  truncated: false,
}

/** 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>
  )
}

/**
 * A log search result from an agent's tool call, explored the way a person would: a search for
 * "timed out", then "503", then a region types in, and each one opens the tree to its matches and
 * highlights them. Loops. Type your own search and the tour waits for you.
 */
export default function JsonViewerPreview() {
  const [step, setStep] = React.useState({ query: 0, typed: QUERIES[0]!.length - 3 })
  const [held, hold] = useHold()
  const [touched, setTouched] = React.useState(false)

  React.useEffect(() => {
    if (reducedMotion() || held || touched) return
    const full = QUERIES[step.query]!
    const done = step.typed >= full.length
    const id = window.setTimeout(
      () =>
        setStep((s) =>
          done
            ? { query: (s.query + 1) % QUERIES.length, typed: 0 }
            : { query: s.query, typed: s.typed + 1 },
        ),
      done ? REST_MS : TYPE_MS,
    )
    return () => window.clearTimeout(id)
  }, [step, held, touched])

  // Back on tour after a visitor's own search, the next search starts fresh.
  React.useEffect(() => {
    if (held || !touched) return
    setTouched(false)
    setStep((s) => ({ query: (s.query + 1) % QUERIES.length, typed: 0 }))
  }, [held, touched])

  const query = QUERIES[step.query]!.slice(0, step.typed)

  return (
    <FitFrame minWidth="38rem">
      <div className="flex w-full flex-col items-center justify-center gap-4 p-6">
        <div
          className="h-[21.5rem] w-full max-w-xl"
          onInput={() => {
            setTouched(true)
            hold()
          }}
          onPointerDown={() => {
            setTouched(true)
            hold()
          }}
        >
          <JsonViewer
            key={touched ? "mine" : `${step.query}:${query}`}
            data={RESULT}
            defaultExpandDepth={query ? 0 : 1}
            defaultQuery={query}
            maxHeight={286}
            label="search_logs result"
          />
        </div>
        <MoreOn slug="json-viewer">Search, fold, copy paths and values from any JSON. On</MoreOn>
      </div>
    </FitFrame>
  )
}