// Dev-only design kit (#254), React port of the deleted kit.ts + kit.css.
// Specimen page for the Tailwind token mapping (tailwind.config.ts ->
// src/styles.css) so the visual system can be reviewed as a whole. Loads on
// `?kit` (see index.tsx) and never ships to a production bundle.

import { useState, type ReactNode } from "react";

import { ActivityRail, STATE_WORDS } from "../sidebar/ActivityRail.js";
import { SessionCard, type SessionCardProps } from "../sidebar/SessionCard.js";
import { PaneTitle } from "../layout/PaneTitle.js";
import { PALETTES, useTheme, type Palette } from "../../contexts/ThemeContext.js";
import type { Session } from "../../types.js";

/** The accent each palette lands on, read from styles.css — shown so all six
 * are comparable at a glance without switching the live one one at a time. */
const PALETTE_ACCENT: Record<Palette, string> = {
  graphite: "oklch(0.92 0.005 256)",
  "ice-cyan": "oklch(0.85 0.115 205)",
  periwinkle: "oklch(0.75 0.125 275)",
  "amber-phosphor": "oklch(0.85 0.16 85)",
  ember: "oklch(0.78 0.16 40)",
  orchid: "oklch(0.78 0.13 320)",
};

const COLOR_TOKENS = [
  "--bg",
  "--bg-grid",
  "--surface",
  "--surface-2",
  "--surface-3",
  "--border",
  "--border-strong",
  "--ink",
  "--muted",
  "--faint",
  "--accent",
  "--accent-strong",
  "--accent-ink",
  "--accent-tint",
  "--accent-fill",
  "--live",
  "--danger",
  "--danger-tint",
  "--warn",
  "--term-bg",
] as const;

// Tailwind's content scanner needs each utility to appear as a literal,
// contiguous string in source — a template-built `w-${token}` is invisible
// to it, so every scale below pairs the token label with its whole class name.
const SPACING_TOKENS = [
  { token: "sp-1", widthClass: "w-sp-1" },
  { token: "sp-2", widthClass: "w-sp-2" },
  { token: "sp-3", widthClass: "w-sp-3" },
  { token: "sp-4", widthClass: "w-sp-4" },
  { token: "sp-5", widthClass: "w-sp-5" },
  { token: "sp-6", widthClass: "w-sp-6" },
  { token: "sp-8", widthClass: "w-sp-8" },
] as const;
const RADIUS_TOKENS = [
  { token: "r-1", radiusClass: "rounded-r-1" },
  { token: "r-2", radiusClass: "rounded-r-2" },
  { token: "r-3", radiusClass: "rounded-r-3" },
  { token: "r-pill", radiusClass: "rounded-r-pill" },
] as const;
const FONT_SIZE_TOKENS = [
  { token: "fs-11", sizeClass: "text-fs-11" },
  { token: "fs-12", sizeClass: "text-fs-12" },
  { token: "fs-13", sizeClass: "text-fs-13" },
  { token: "fs-14", sizeClass: "text-fs-14" },
  { token: "fs-15", sizeClass: "text-fs-15" },
  { token: "fs-17", sizeClass: "text-fs-17" },
  { token: "fs-20", sizeClass: "text-fs-20" },
] as const;
const Z_INDEX_TOKENS = [
  { name: "z-sticky", value: 10 },
  { name: "z-backdrop", value: 40 },
  { name: "z-modal", value: 50 },
  { name: "z-toast", value: 60 },
] as const;

function Section({
  title,
  note,
  children,
}: {
  title: string;
  note?: string;
  children: ReactNode;
}) {
  return (
    <section className="border-t border-border py-sp-6 first:border-t-0 first:pt-0">
      <h2 className="text-fs-17 font-semibold text-ink">{title}</h2>
      {note && <p className="mt-sp-1 max-w-[70ch] text-fs-12 text-muted">{note}</p>}
      <div className="mt-sp-4 flex flex-wrap gap-sp-4">{children}</div>
    </section>
  );
}

function Specimen({ label, children }: { label: string; children: React.ReactNode }) {
  return (
    <div className="flex flex-col items-start gap-sp-2">
      <div className="flex min-h-[48px] items-center rounded-r-2 border border-border bg-surface p-sp-3">
        {children}
      </div>
      <span className="font-mono text-fs-11 text-faint">{label}</span>
    </div>
  );
}

function fakeSession(overrides: Partial<Session>): Session {
  return {
    id: "00000000-0000-0000-0000-000000000000",
    cwd: "/home/dev/maestro",
    command: "claude",
    env: {},
    metadata: {},
    status: "Running",
    created_at: new Date().toISOString(),
    activity_since: new Date(Date.now() - 4 * 60_000).toISOString(),
    ...overrides,
  };
}

const NOOP_CARD_HANDLERS: Omit<SessionCardProps, "session" | "depth" | "now" | "highlighted" | "active" | "open" | "previewing" | "renaming"> = {
  onSelect: () => {},
  onOpenMenu: () => {},
  onSpawnSimilar: () => {},
  onKill: () => {},
  onRenameCommit: () => {},
  onRenameCancel: () => {},
};

const CARD_SPECIMENS: Array<{ label: string; props: Omit<SessionCardProps, keyof typeof NOOP_CARD_HANDLERS> }> = [
  {
    label: "idle",
    props: {
      session: fakeSession({ command: "bash" }),
      depth: 0,
      now: Date.now(),
      highlighted: false,
      active: false,
      open: false,
      previewing: false,
      renaming: false,
    },
  },
  {
    label: "active, focused",
    props: {
      session: fakeSession({ activity: "Active", command: "vite dev" }),
      depth: 0,
      now: Date.now(),
      highlighted: false,
      active: true,
      open: true,
      previewing: false,
      renaming: false,
    },
  },
  {
    label: "awaiting-input",
    props: {
      session: fakeSession({ activity: "AwaitingInput", activity_since: new Date(Date.now() - 12_000).toISOString() }),
      depth: 0,
      now: Date.now(),
      highlighted: false,
      active: false,
      open: false,
      previewing: false,
      renaming: false,
    },
  },
  {
    label: "error",
    props: {
      session: fakeSession({ activity: "Error", activity_detail: "tests failing", activity_since: new Date(Date.now() - 7_200_000).toISOString() }),
      depth: 0,
      now: Date.now(),
      highlighted: false,
      active: false,
      open: false,
      previewing: false,
      renaming: false,
    },
  },
  {
    label: "previewing",
    props: {
      session: fakeSession({ command: "opencode" }),
      depth: 0,
      now: Date.now(),
      highlighted: false,
      active: false,
      open: false,
      previewing: true,
      renaming: false,
    },
  },
  {
    label: "exited",
    props: {
      session: fakeSession({ status: "Dead", command: "btop" }),
      depth: 0,
      now: Date.now(),
      highlighted: false,
      active: false,
      open: false,
      previewing: false,
      renaming: false,
    },
  },
];

const ACTIVITY_STATES = Object.keys(STATE_WORDS) as Array<keyof typeof STATE_WORDS>;

export function DesignKit() {
  const { theme, palette, toggleTheme, setPalette } = useTheme();
  // "open" is deliberately display:none in the real app (.mv-pane's rule,
  // styles.css) — a streaming pane already shows it's connected — so start on
  // a state the kit page can actually show.
  const [attachState, setAttachState] = useState<"connecting" | "open" | "closed">("connecting");

  return (
    // #root is a fixed-height, overflow-hidden flex column (main.css) built for
    // the app shell's own internal scrolling — this page needs its own scroll
    // container to match, or everything past the first viewport is clipped.
    <div className="h-full overflow-y-auto bg-bg text-ink">
      <header className="flex items-center justify-between border-b border-border px-sp-4 py-sp-3">
        <h1 className="text-fs-20 font-semibold">
          maestro<span className="text-accent">_</span> · design kit
        </h1>
        <div className="flex items-center gap-sp-2">
          <button type="button" className="btn btn-ghost" onClick={toggleTheme}>
            {theme === "dark" ? "☀ light" : "☾ dark"}
          </button>
        </div>
      </header>

      <main className="mx-auto max-w-5xl px-sp-4 py-sp-4">
        <Section
          title="Colour palettes"
          note="6 palettes, picked via data-palette on <html> through ThemeContext. Switching one recolours every token below live."
        >
          {PALETTES.map((p) => (
            <button
              key={p}
              type="button"
              onClick={() => setPalette(p)}
              className={`flex flex-col items-center gap-sp-1 rounded-r-2 border p-sp-2 ${
                p === palette ? "border-accent" : "border-border"
              }`}
            >
              <span
                className="h-sp-6 w-sp-8 rounded-r-1"
                style={{ background: PALETTE_ACCENT[p] }}
              />
              <span className="font-mono text-fs-11 text-muted">{p}</span>
            </button>
          ))}
        </Section>

        <Section title="Colour tokens" note="Current palette + theme, applied through var(--token).">
          {COLOR_TOKENS.map((t) => (
            <div key={t} className="flex flex-col items-start gap-sp-1">
              <div
                className="h-sp-8 w-sp-8 rounded-r-2 border border-border"
                style={{ background: `var(${t})` }}
              />
              <span className="font-mono text-fs-11 text-faint">{t}</span>
            </div>
          ))}
        </Section>

        <Section title="Typography" note="fontSize -> var(--fs-N), from tailwind.config.ts.">
          {FONT_SIZE_TOKENS.map(({ token, sizeClass }) => (
            <Specimen key={token} label={token}>
              <span className={`font-mono ${sizeClass}`}>Sessions</span>
            </Specimen>
          ))}
        </Section>

        <Section title="Spacing scale" note="spacing -> var(--sp-N).">
          {SPACING_TOKENS.map(({ token, widthClass }) => (
            <div key={token} className="flex flex-col items-start gap-sp-1">
              <div className={`h-sp-3 bg-accent ${widthClass}`} />
              <span className="font-mono text-fs-11 text-faint">{token}</span>
            </div>
          ))}
        </Section>

        <Section title="Border radii" note="borderRadius -> var(--r-N).">
          {RADIUS_TOKENS.map(({ token, radiusClass }) => (
            <div key={token} className="flex flex-col items-start gap-sp-1">
              <div className={`h-sp-6 w-sp-8 border-2 border-accent ${radiusClass}`} />
              <span className="font-mono text-fs-11 text-faint">{token}</span>
            </div>
          ))}
        </Section>

        <Section title="Z-index scale" note="zIndex -> var(--z-*).">
          {Z_INDEX_TOKENS.map((z) => (
            <div key={z.name} className="flex items-baseline gap-sp-2 font-mono text-fs-12">
              <span className="text-muted">{z.name}</span>
              <span className="text-ink">{z.value}</span>
            </div>
          ))}
        </Section>

        <Section title="Buttons" note="Terminal-native bracket chrome — .btn / .btn-primary / .btn-ghost / .btn-icon / .btn-danger.">
          <Specimen label="btn">
            <button type="button" className="btn">Cancel</button>
          </Specimen>
          <Specimen label="btn-primary">
            <button type="button" className="btn btn-primary">+ Spawn</button>
          </Specimen>
          <Specimen label="btn-ghost">
            <button type="button" className="btn btn-ghost">Dismiss</button>
          </Specimen>
          <Specimen label="btn-icon">
            <button type="button" className="btn btn-icon">✕</button>
          </Specimen>
          <Specimen label="btn-danger">
            <button type="button" className="btn btn-danger">Kill</button>
          </Specimen>
          <Specimen label="btn:disabled">
            <button type="button" className="btn btn-primary" disabled>+ Spawn</button>
          </Specimen>
        </Section>

        <Section title="Activity rail" note="ActivityRail.tsx — one state per session card, colour-coded and never colour-only (title/aria-label carry the word).">
          {ACTIVITY_STATES.map((slug) => (
            <Specimen key={slug} label={`${slug} · ${STATE_WORDS[slug]}`}>
              <div className="relative h-[32px] w-[24px] overflow-hidden rounded-r-1 bg-surface-2">
                <ActivityRail activity={slug} />
              </div>
            </Specimen>
          ))}
        </Section>

        <Section title="Session cards" note="SessionCard.tsx, docs/SIDEBAR.md states.">
          <div className="w-full max-w-sm divide-y divide-border rounded-r-2 border border-border bg-surface-2">
            {CARD_SPECIMENS.map(({ label, props }) => (
              <div key={label} className="relative">
                <SessionCard {...props} {...NOOP_CARD_HANDLERS} />
              </div>
            ))}
          </div>
        </Section>

        <Section title="Terminal chrome" note="attach-header + attach-body, as worn by TerminalPane/StructuredPane.">
          <div className="w-full max-w-lg overflow-hidden rounded-r-2 border border-border">
            <div className="attach-header">
              <PaneTitle
                sessionId="11111111-2222-3333-4444-555555555555"
                session={fakeSession({ command: "claude" })}
              />
              <span className="flex-1" />
              <button
                type="button"
                className="attach-state"
                data-state={attachState}
                onClick={() =>
                  setAttachState((s) => (s === "open" ? "connecting" : s === "connecting" ? "closed" : "open"))
                }
                title="Click to cycle"
              >
                {attachState}
              </button>
              <button type="button" className="btn btn-icon disconnect" title="Disconnect">
                ⏻
              </button>
            </div>
            <div className="attach-body h-[120px] items-start">
              <span className="font-mono text-fs-13 text-muted">$ pnpm test</span>
            </div>
          </div>
        </Section>
      </main>
    </div>
  );
}