/**
 * Material 3: the surfaces.
 *
 * Tonal rather than outlined — a widget is told from the ground by being a
 * step further toward the primary, which is what lets a palette recolour the
 * whole look. Nothing here holds state: the behaviour is in `ui/core`.
 */
import { Link } from "@tanstack/react-router"
import { Lock } from "lucide-react"
import { motion } from "motion/react"

import {
  Tooltip,
  TooltipContent,
  TooltipTrigger,
} from "@/components/ui/tooltip"
import { cn } from "@/lib/utils"
import { ICONS } from "../../icons"
import type {
  BackdropProps,
  FrameProps,
  NoticeProps,
  RailProps,
} from "../core/contract"
import { TESTID } from "../core/contract"
import { LOOK } from "../core/motion"

/** Material's ground is the surface colour itself; only an image is drawn. */
export function Backdrop({ image }: BackdropProps) {
  if (!image) return null
  return (
    <div
      aria-hidden
      data-testid="canvas-ground"
      className="pointer-events-none absolute inset-0 bg-cover bg-center"
      style={{ backgroundImage: `url(${JSON.stringify(image)})` }}
    />
  )
}

function Issue({ issue }: { issue: string }) {
  return (
    <Tooltip>
      <TooltipTrigger asChild>
        <span
          role="img"
          className="block size-2 shrink-0 rounded-full bg-destructive"
          aria-label={issue}
          data-testid={TESTID.issue}
        />
      </TooltipTrigger>
      <TooltipContent className="max-w-xs break-words">{issue}</TooltipContent>
    </Tooltip>
  )
}

export function Frame({
  title,
  issue,
  grip,
  scroll,
  selected,
  onClick,
  children,
}: FrameProps) {
  return (
    // A card is not a control: the click only picks it in edit mode, and every
    // interactive element inside keeps its own role and keyboard handling.
    // biome-ignore lint/a11y/useKeyWithClickEvents: see above.
    // biome-ignore lint/a11y/noStaticElementInteractions: see above.
    <div
      data-testid={TESTID.frame}
      data-selected={selected ? "" : undefined}
      className="dui-frame m3-frame"
      onClick={onClick}
    >
      {title ? (
        <div
          className={cn(
            "dui-frame-head m3-frame-title",
            grip &&
              `${TESTID.grip} -m-1 cursor-grab p-1 active:cursor-grabbing`,
          )}
        >
          <span className="dui-frame-title">{title}</span>
          {issue ? <Issue issue={issue} /> : null}
        </div>
      ) : null}
      <div className={cn("dui-frame-body", scroll && "dui-frame-scroll")}>
        {children}
      </div>
      {/* No header to sit in, so the fault takes the corner instead — a widget
          drawn without its title still says when it is mis-wired. */}
      {!title && issue ? (
        <div className="dui-frame-corner">
          <Issue issue={issue} />
        </div>
      ) : null}
      {/* And the editor still needs something to drag it by. */}
      {!title && grip ? (
        <span
          aria-hidden
          className={cn(
            TESTID.grip,
            "absolute left-1/2 top-1 z-[2] h-1 w-8 -translate-x-1/2 cursor-grab rounded-full bg-current opacity-20 active:cursor-grabbing",
          )}
        />
      ) : null}
    </div>
  )
}

/** Two letters off the title, so a rail of four reads as four different things. */
function initials(label: string): string {
  const words = label.split(/[\s_-]+/).filter(Boolean)
  if (words.length === 0) return "?"
  if (words.length === 1) return words[0].slice(0, 2).toUpperCase()
  return (words[0][0] + words[1][0]).toUpperCase()
}

export function Rail({ entries }: RailProps) {
  return (
    <nav
      aria-label="Dashboards on this panel"
      data-testid={TESTID.rail}
      className={cn(
        "m3-rail pointer-events-auto absolute left-3 top-1/2 z-10 flex max-h-[calc(100%-1.5rem)] w-12 -translate-y-1/2 flex-col items-center gap-1 p-1",
        // As tall as what it carries, centred in the column it reserves: a
        // rail of two stretched to the height of the panel is mostly empty
        // pill. More dashboards than the panel is tall still scroll, but no
        // bar is ever drawn — a wall panel is swiped, and there is no room.
        "overflow-y-auto [scrollbar-width:none] [&::-webkit-scrollbar]:hidden",
      )}
    >
      {entries.map((entry) => {
        const Glyph = ICONS[entry.icon ?? ""]
        return (
          <Tooltip key={entry.name}>
            <TooltipTrigger asChild>
              <Link
                {...entry.link}
                aria-label={entry.label}
                aria-current={entry.active ? "page" : undefined}
                data-testid={`panel-rail-${entry.name}`}
                className={cn(
                  "m3-pressable relative flex size-10 shrink-0 items-center justify-center rounded-full text-xs font-medium",
                  entry.active
                    ? "text-card-foreground"
                    : "text-muted-foreground",
                )}
              >
                <span className="m3-state" aria-hidden />
                {entry.active ? (
                  <motion.span
                    aria-hidden
                    layoutId="m3-rail-active"
                    transition={LOOK.material.spring}
                    className="absolute inset-0 rounded-full"
                    style={{ background: "var(--m3-sc)" }}
                  />
                ) : null}
                <span className="relative z-[1]">
                  {Glyph ? <Glyph className="size-5" /> : initials(entry.label)}
                </span>
              </Link>
            </TooltipTrigger>
            <TooltipContent side="right">{entry.label}</TooltipContent>
          </Tooltip>
        )
      })}
    </nav>
  )
}

export function Notice({ children }: NoticeProps) {
  return (
    <div
      // Announced rather than merely drawn: `locked` may be driven by a flow,
      // so the state can change under someone already looking at the page.
      aria-live="polite"
      data-testid={TESTID.locked}
      className="m3-notice pointer-events-none absolute bottom-0 right-0 flex items-center gap-1.5 px-3 py-1.5 text-sm"
    >
      <Lock className="size-4" aria-hidden />
      {children}
    </div>
  )
}