Stepper with status list

"use client"

import { useId, useRef, useState } from "react"
import { Frame, FramePanel } from "@/components/reui/frame"
import {
  Stepper,
  StepperContent,
  StepperIndicator,
  StepperItem,
  StepperNav,
  StepperPanel,
  StepperTitle,
  StepperTrigger,
} from "@/components/reui/stepper"

import { Button } from "@/components/ui/button"
import { Separator } from "@/components/ui/separator"
import { IconPlaceholder } from "@/app/(create)/components/icon-placeholder"

const steps = [
  { title: "Resolution", detail: "Weighing a rollback against a hotfix." },
  { title: "Scoping", detail: "Confirming only 6 pods in eu-west-1 are hit." },
  { title: "Execution", detail: "Rolling api-gateway back to v2.14.1." },
  { title: "Verification", detail: "Watching error rate and p95 latency." },
  { title: "Approval", detail: "Waiting on the incident lead to sign off." },
  { title: "Summary", detail: "Writing up the root cause and follow-ups." },
]

// The design draws the 10px check with a 1.2px line: 2.88 on a 24-unit grid.
// *:stroke-[2.88] repeats it on the paths, so the weight holds where a
// wrapper drops the prop.
const completed = (
  <span className="border-success bg-success/10 text-success flex size-3.5 items-center justify-center rounded-full border">
    <IconPlaceholder
      lucide="CheckIcon"
      tabler="IconCheck"
      hugeicons="Tick02Icon"
      phosphor="CheckIcon"
      remixicon="RiCheckLine"
      strokeWidth={2.88}
      className="size-2.5 *:stroke-[2.88]"
      aria-hidden="true"
    />
  </span>
)

const pending = (
  <IconPlaceholder
    lucide="CircleDashedIcon"
    tabler="IconCircleDashed"
    hugeicons="CircleDashedIcon"
    phosphor="CircleDashedIcon"
    remixicon="RiCheckboxBlankCircleLine"
    className="text-ring/60 size-3.5"
    aria-hidden="true"
  />
)

// The drawn ring: r=6 at a 1.2px stroke, a 3:1 dashed track and a 140deg
// arc from -118deg. The track is evened out to ten dashes, so no long seam
// dash shows as the arc spins past. The arc starts through its dash offset
// because the spin's CSS transform would replace a rotate() attribute.
const loading = (
  <svg
    viewBox="0 0 14 14"
    fill="none"
    strokeWidth={1.2}
    className="size-3.5"
    aria-hidden="true"
  >
    <circle
      cx="7"
      cy="7"
      r="6"
      pathLength={40}
      strokeDasharray="3 1"
      transform="rotate(-54 7 7)"
      className="stroke-ring/80"
    />
    <circle
      cx="7"
      cy="7"
      r="6"
      pathLength={360}
      strokeDasharray="140 220"
      strokeDashoffset={118}
      className="origin-center stroke-blue-500 motion-safe:animate-spin"
    />
  </svg>
)

const indicators = { completed, inactive: pending, loading }

export function Pattern() {
  // The primitive derives tab ids from the step number alone and points
  // aria-controls at a panel nothing renders, so both are scoped here.
  const id = useId()
  const panelId = `${id}-panel`
  const [current, setCurrent] = useState(3)
  const prevRef = useRef<HTMLButtonElement>(null)
  const nextRef = useRef<HTMLButtonElement>(null)
  // One past the last step marks every step complete. No tab is selected
  // then, so the last one keeps the tablist's tab stop.
  const allDone = current > steps.length

  function goTo(step: number) {
    setCurrent(step)
    // The pressed button disables itself at either end, so focus moves to
    // its partner.
    if (step === 1) nextRef.current?.focus()
    if (step > steps.length) prevRef.current?.focus()
  }

  return (
    <Stepper
      value={current}
      onValueChange={setCurrent}
      orientation="vertical"
      indicators={indicators}
      className="@container mx-auto max-w-lg"
      aria-label="Incident response"
    >
      {/* The list keeps its 180px design width. Under 28rem the content
          beside it would get less than 236px, so it stacks below. */}
      <div className="flex flex-col gap-6 @md:flex-row @md:items-start">
        {/* The frame paints nothing: it only lends each row its per-style
            radius, border color and padding. 3px under the ghost panel radius
            lands on the drawn 8px, and 6px of block padding around the 20px
            text-sm line keeps the drawn 34px row. */}
        <Frame
          variant="ghost"
          spacing="xs"
          className="w-45 shrink-0 bg-transparent p-0 [--frame-panel-py-base:--spacing(1.5)]"
        >
          <StepperNav className="gap-1.5">
            {steps.map((item, index) => {
              const step = index + 1
              const status =
                step < current
                  ? "completed"
                  : step === current
                    ? "in progress"
                    : "upcoming"

              // The primitive shows loading on the active step only, so every
              // step carries the flag and the spinner follows the selection.
              return (
                <StepperItem key={item.title} step={step} loading>
                  {/* Every row keeps a transparent border, so selecting one
                      never shifts the list: gap-1.5 absorbs it vertically to
                      hold the drawn 40px pitch, and 1px less padding keeps
                      the icons 8px in. The theme has no blue token, so the
                      active step takes blue-500. leading-5 is text-sm's own
                      line height, since truncate clips descenders at
                      leading-none. */}
                  <StepperTrigger
                    tabIndex={allDone && step === steps.length ? 0 : undefined}
                    id={`${id}-tab-${step}`}
                    aria-controls={panelId}
                    render={<FramePanel />}
                    className="hover:bg-muted/50 data-[state=active]:bg-muted/50 w-full gap-2 rounded-[calc(var(--frame-panel-radius)-3px)] border-transparent bg-transparent px-[calc(var(--frame-panel-px)-1px)] shadow-none data-[state=active]:border-(--frame-panel-border-color)"
                  >
                    <StepperIndicator className="size-3.5 overflow-visible bg-transparent data-[state=active]:bg-transparent data-[state=completed]:bg-transparent" />
                    <StepperTitle className="data-[state=inactive]:text-muted-foreground min-w-0 flex-1 truncate leading-5 data-[state=active]:text-blue-500">
                      {item.title}
                    </StepperTitle>
                    <span className="sr-only">, {status}</span>
                    {step === current && (
                      <span
                        aria-hidden="true"
                        className="pointer-events-none absolute start-0 top-1/2 h-5 w-0.5 -translate-y-1/2 rounded-e-full bg-blue-500"
                      />
                    )}
                  </StepperTrigger>
                </StepperItem>
              )
            })}
          </StepperNav>
        </Frame>

        {/* Stacked, px-2 lines the text up with the row icons 8px in. */}
        {/* Decorative, so hidden from assistive tech: a line across while the
            columns stack, a line between them once they sit side by side. */}
        <Separator aria-hidden="true" className="@md:hidden" />
        <Separator
          aria-hidden="true"
          orientation="vertical"
          className="hidden @md:block"
        />
        <div className="flex min-w-0 flex-1 flex-col gap-3 px-2 text-start @md:px-0">
          <StepperPanel>
            {steps.map((item, index) => (
              <StepperContent key={item.title} value={index + 1}>
                <div id={panelId}>
                  <p className="text-muted-foreground text-xs">
                    Step {index + 1} of {steps.length}
                  </p>
                  <p className="text-sm font-medium">{item.title}</p>
                  <p className="text-muted-foreground text-sm text-pretty">
                    {item.detail}
                  </p>
                </div>
              </StepperContent>
            ))}
            <StepperContent value={steps.length + 1}>
              <div id={panelId}>
                <p className="text-muted-foreground text-xs">
                  All {steps.length} steps done
                </p>
                <p className="text-sm font-medium">Response complete</p>
                <p className="text-muted-foreground text-sm text-pretty">
                  The incident is approved, summarized and closed.
                </p>
              </div>
            </StepperContent>
          </StepperPanel>
          <div className="flex justify-start gap-2">
            <Button
              ref={prevRef}
              variant="outline"
              size="sm"
              disabled={current === 1}
              onClick={() => goTo(current - 1)}
            >
              Previous
            </Button>
            <Button
              ref={nextRef}
              variant="outline"
              size="sm"
              disabled={allDone}
              onClick={() => goTo(current + 1)}
            >
              Next
            </Button>
          </div>
        </div>
      </div>
    </Stepper>
  )
}