Stepper with horizontal step cards

"use client"

import { useRef, useState } from "react"
import { Frame, FramePanel } from "@/components/reui/frame"
import { IconTile } from "@/components/reui/icon-tile"
import {
  Stepper,
  StepperContent,
  StepperDescription,
  StepperIndicator,
  StepperItem,
  StepperNav,
  StepperPanel,
  StepperTitle,
  StepperTrigger,
} from "@/components/reui/stepper"
import { cn } from "cn"

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

const steps = [
  {
    title: "Resolution",
    detail: "Choose a fix: roll back, scale out or patch forward.",
    icon: (
      <IconPlaceholder
        lucide="ListChecksIcon"
        tabler="IconListCheck"
        hugeicons="CheckListIcon"
        phosphor="ListChecksIcon"
        remixicon="RiListCheck"
      />
    ),
  },
  {
    title: "Execute",
    detail: "Roll api-gateway back to v2.14.1 across 6 pods.",
    icon: (
      <IconPlaceholder
        lucide="WorkflowIcon"
        tabler="IconSitemap"
        hugeicons="WorkflowCircle01Icon"
        phosphor="TreeStructureIcon"
        remixicon="RiFlowChart"
      />
    ),
  },
  {
    title: "Verify",
    detail: "Watch error rate and p95 latency for 10 minutes.",
    icon: (
      <IconPlaceholder
        lucide="ClipboardCheckIcon"
        tabler="IconClipboardCheck"
        hugeicons="TaskDone02Icon"
        phosphor="ClipboardTextIcon"
        remixicon="RiClipboardLine"
      />
    ),
  },
  {
    title: "Summary",
    detail: "Record the timeline, root cause and follow-ups.",
    icon: (
      <IconPlaceholder
        lucide="ScrollTextIcon"
        tabler="IconScript"
        hugeicons="ScrollIcon"
        phosphor="ScrollIcon"
        remixicon="RiFileListLine"
      />
    ),
  },
]

const completed = (
  <IconPlaceholder
    lucide="CheckIcon"
    tabler="IconCheck"
    hugeicons="Tick02Icon"
    phosphor="CheckIcon"
    remixicon="RiCheckLine"
    className="size-2.5"
    aria-hidden="true"
  />
)

export function Pattern() {
  const [current, setCurrent] = useState(2)
  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}
      indicators={{ completed }}
      className="@container flex max-w-150 flex-col gap-6 pt-2"
      aria-label="Incident resolution"
    >
      {/* The frame paints nothing: it only lends each card its per-style
          radius, padding, border and surface. The default variant, not ghost,
          so vega and nova cards round at the drawn 10px rather than 11px. */}
      <Frame spacing="xs" className="border-0 bg-transparent p-0">
        {/* Two columns below 36rem, where four would cut the titles short. */}
        <StepperNav className="grid grid-cols-2 gap-2 @xl:grid-cols-4">
          {steps.map((item, index) => {
            const step = index + 1
            const done = step < current

            return (
              <StepperItem key={item.title} step={step} className="isolate">
                {/* The card is the tab itself, so all of it takes the click
                    and the focus ring. The radius undoes the trigger's pill.
                    The done tint is a 5% layer over the card's own surface,
                    as drawn: an sRGB color-mix would carry the success
                    color's out-of-gamut red into the result. */}
                <StepperTrigger
                  tabIndex={allDone && step === steps.length ? 0 : undefined}
                  render={<FramePanel />}
                  className="hover:border-ring/60 data-[state=active]:border-ring/50 data-[state=active]:bg-input/20 data-[state=completed]:border-success data-[state=completed]:from-success/5 data-[state=completed]:to-success/5 min-w-0 gap-2 overflow-visible rounded-(--frame-panel-radius) px-2.5 shadow-none data-[state=completed]:bg-linear-to-b"
                >
                  {/* outline's dark:bg-input/32 would outrank a state class in
                      dark mode, so a done step swaps to the solid variant. Its
                      white edge is drawn outside the fill, hence a ring. */}
                  <IconTile
                    variant={done ? "solid" : "outline"}
                    size="xs"
                    className={cn(
                      "shadow-xs [--icon-tile-size:--spacing(7)]",
                      done
                        ? "bg-success text-white ring-1 ring-white/15"
                        : "border-ring/30"
                    )}
                    aria-hidden="true"
                  >
                    {item.icon}
                  </IconTile>

                  {/* leading-5 is text-sm's own line height: truncate clips at
                      the line box, so the title's default leading-none would
                      cut the descenders of Verify and Summary. */}
                  <div className="flex min-w-0 flex-col">
                    <StepperTitle className="data-[state=completed]:text-success-foreground dark:data-[state=completed]:text-success truncate leading-5">
                      {item.title}
                    </StepperTitle>
                    <StepperDescription className="truncate text-xs">
                      Step {step}
                    </StepperDescription>
                    {done && <span className="sr-only">, completed</span>}
                  </div>

                  {/* A child of the card so the check takes the click too:
                      half of it lies past the corner arc, where a rounded box
                      takes no pointer hits, hence overflow-visible (min-w-0
                      keeps the titles truncating). Centered 0.4r in from the
                      edge and 1px above the arc (0.2r down there): 3px out
                      and 6px up at the drawn 10px, less the 1px border the
                      offsets start inside; max() floors the square styles at
                      0. The stepper's pt-2 keeps the first row's check off
                      any clipping parent, and the item's isolate keeps a
                      focused card's z-10 off the host page. */}
                  <StepperIndicator className="data-[state=completed]:bg-success absolute end-[calc(max(0px,var(--frame-panel-radius))*0.4-8px)] top-[calc(max(0px,var(--frame-panel-radius))*0.2-9px)] size-3.5 shadow-sm ring-1 ring-white/8 not-data-[state=completed]:hidden data-[state=completed]:text-white" />
                </StepperTrigger>
              </StepperItem>
            )
          })}
        </StepperNav>
      </Frame>

      <StepperPanel className="text-center">
        {steps.map((item, index) => (
          <StepperContent key={item.title} value={index + 1}>
            <p className="text-sm font-medium">{item.title}</p>
            <p className="text-muted-foreground text-sm">{item.detail}</p>
          </StepperContent>
        ))}
        <StepperContent value={steps.length + 1}>
          <p className="text-sm font-medium">Incident resolved</p>
          <p className="text-muted-foreground text-sm">
            Every step is recorded and the incident closed.
          </p>
        </StepperContent>
        <div className="mt-3 flex justify-center 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>
      </StepperPanel>
    </Stepper>
  )
}