Timeline accordion

"use client"

import * as React from "react"
import { ChevronDown } from "lucide-react"
import { AnimatePresence, motion, useReducedMotion } from "motion/react"

import { cn } from "@/lib/utils"

/* Timeline accordion family: 5 vertical-line accordions. A vertical connector
   runs down the left edge with a node dot on every row; the variants change the
   style of the line and the node. Every export is a complete accordion: internal
   single-open state, a button header with aria-expanded, framer height auto
   animation. Colour comes ONLY from tokens. Alpha via color-mix. Under
   reduced-motion opening and closing are instant. Size = padding + text scale.
   Renders without props too. */

export type StyledSize = "sm" | "md" | "lg" | "xl"

export interface StyledAccordionItem {
  value: string
  title: React.ReactNode
  content: React.ReactNode
}

interface StyledAccordionProps {
  className?: string
  size?: StyledSize
  items?: StyledAccordionItem[]
  defaultOpen?: string
}

const headerPad: Record<StyledSize, string> = {
  sm: "py-2.5 text-sm",
  md: "py-3 text-sm",
  lg: "py-4 text-base",
  xl: "py-5 text-lg",
}

const bodyPad: Record<StyledSize, string> = {
  sm: "pb-2.5 text-sm",
  md: "pb-3 text-sm",
  lg: "pb-4 text-base",
  xl: "pb-5 text-base",
}

const iconSize: Record<StyledSize, string> = {
  sm: "size-4",
  md: "size-4",
  lg: "size-5",
  xl: "size-5",
}

const defaultItems: StyledAccordionItem[] = [
  {
    value: "item-1",
    title: "What is included?",
    content:
      "Every plan ships the full component library, semantic tokens, and lifetime updates for the tier you own.",
  },
  {
    value: "item-2",
    title: "How does installation work?",
    content:
      "Add any component with a single CLI command. Files land in your project and stay fully editable.",
  },
  {
    value: "item-3",
    title: "Can I use it in production?",
    content:
      "Yes. The system is framework agnostic, self contained, and safe to ship to any number of projects.",
  },
]

function useSingleOpen(defaultOpen?: string) {
  const [open, setOpen] = React.useState<string | null>(defaultOpen ?? null)
  const toggle = React.useCallback(
    (value: string) => setOpen((cur) => (cur === value ? null : value)),
    []
  )
  return { open, toggle }
}

const headerBase =
  "flex w-full items-center justify-between gap-3 pr-1 text-left font-medium outline-none transition-colors focus-visible:ring-[3px] focus-visible:ring-ring/50"

function Panel({
  isOpen,
  size,
  children,
}: {
  isOpen: boolean
  size: StyledSize
  children: React.ReactNode
}) {
  const reduce = useReducedMotion()
  return (
    <AnimatePresence initial={false}>
      {isOpen && (
        <motion.div
          key="panel"
          initial={reduce ? false : { height: 0, opacity: 0 }}
          animate={{ height: "auto", opacity: 1 }}
          exit={{ height: 0, opacity: 0 }}
          transition={
            reduce ? { duration: 0 } : { duration: 0.25, ease: [0.4, 0, 0.2, 1] }
          }
          className="overflow-hidden"
        >
          <div className={cn(bodyPad[size], "pr-1 text-muted-foreground")}>
            {children}
          </div>
        </motion.div>
      )}
    </AnimatePresence>
  )
}

function Chevron({ isOpen, size }: { isOpen: boolean; size: StyledSize }) {
  const reduce = useReducedMotion()
  return (
    <motion.span
      aria-hidden
      className="shrink-0 text-muted-foreground"
      animate={{ rotate: isOpen ? 180 : 0 }}
      transition={reduce ? { duration: 0 } : { duration: 0.2 }}
    >
      <ChevronDown className={iconSize[size]} />
    </motion.span>
  )
}

/* Shared timeline shell: a vertical connector on the left edge plus a node dot
   on every row. lineClass carries the line style, nodeClass the node style. */
function TimelineShell({
  props,
  lineClass,
  nodeClass,
}: {
  props: StyledAccordionProps
  lineClass: string
  nodeClass: string
}) {
  const { className, size = "md", items = defaultItems, defaultOpen } = props
  const { open, toggle } = useSingleOpen(defaultOpen)
  return (
    <div
      data-slot="styled-accordion"
      className={cn("flex flex-col", className)}
    >
      {items.map((item, i) => {
        const isOpen = open === item.value
        const isLast = i === items.length - 1
        return (
          <div key={item.value} className="relative pl-7">
            {/* vertical connector line */}
            {!isLast && (
              <span
                aria-hidden
                className={cn(
                  "absolute left-[5px] top-5 bottom-0 w-px",
                  lineClass
                )}
              />
            )}
            {/* node noktasi */}
            <span
              aria-hidden
              className={cn(
                "absolute left-0 top-4 size-[11px] rounded-full transition-colors",
                nodeClass,
                isOpen && "bg-primary"
              )}
            />
            <button
              type="button"
              aria-expanded={isOpen}
              onClick={() => toggle(item.value)}
              className={cn(headerBase, headerPad[size])}
            >
              <span className="min-w-0">{item.title}</span>
              <Chevron isOpen={isOpen} size={size} />
            </button>
            <Panel isOpen={isOpen} size={size}>
              {item.content}
            </Panel>
          </div>
        )
      })}
    </div>
  )
}

/* Line: a plain thin token line plus a hollow node ring. */
export function LineAccordion(props: StyledAccordionProps) {
  return (
    <TimelineShell
      props={props}
      lineClass="bg-border"
      nodeClass="border-2 border-border bg-background"
    />
  )
}

/* Dashed: a dashed vertical line plus a hollow node ring. */
export function DashedAccordion(props: StyledAccordionProps) {
  return (
    <TimelineShell
      props={props}
      lineClass="w-0 border-l border-dashed border-border bg-transparent"
      nodeClass="border-2 border-border bg-background"
    />
  )
}

/* Node: a pronounced ring node plus a token line. */
export function NodeAccordion(props: StyledAccordionProps) {
  return (
    <TimelineShell
      props={props}
      lineClass="bg-border"
      nodeClass="border-2 border-primary bg-background"
    />
  )
}

/* Filled: a solid primary node plus a token line. */
export function FilledAccordion(props: StyledAccordionProps) {
  return (
    <TimelineShell
      props={props}
      lineClass="bg-border"
      nodeClass="bg-primary"
    />
  )
}

/* Gradient: a line fading from top to bottom plus a solid node. */
export function GradientAccordion(props: StyledAccordionProps) {
  return (
    <TimelineShell
      props={props}
      lineClass="bg-gradient-to-b from-primary to-[color-mix(in_oklab,var(--color-primary)_10%,transparent)]"
      nodeClass="bg-primary"
    />
  )
}