#!/usr/bin/env node
/**
 * UISpec P2 — dashboard palette contrast gate.
 *
 * P2-12 was "the provider swatches are hardcoded hex and 5/11 fall under 3:1 on
 * one theme or the other". The fix moved them to theme-aware tokens; this gate
 * is what keeps them honest, and it also re-checks the token pairs the account
 * UI leans on (labels, badges, dots, brand blocks). The DashboardColor pass
 * adds the status/accent -text twins on --surface/-soft and the
 * --border-control boundary on every surface rung.
 *
 * Floors (WCAG 2.2):
 *   4.5:1 — text (--text, --text-muted, --text-dim; badge labels; brand button text)
 *   3.0:1 — graphical objects (swatches, status dots, meter fills) (1.4.11)
 *   1.08  — surface ladder steps (UIPlan G4: a card must separate from its page)
 *
 * --text-faint is deliberately NOT checked: it is the disabled/decorative token
 * and never carries body copy (see the comment on its definition).
 *
 * Exit 0 = every pair clears its floor in BOTH themes.
 * Exported as lintDashboardContrast() for the test suite.
 */

import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';
import {
  readStyleBlock, customProperties, resolveVar, parseColor, composite, contrastRatio,
} from './dashboard-css.mjs';

const ROOT = path.join(path.dirname(fileURLToPath(import.meta.url)), '..');

export const PROVIDERS = [
  'anthropic', 'openai', 'google', 'deepseek', 'xai', 'alibaba',
  'moonshot', 'zhipu', 'minimax', 'windsurf', 'other',
];

/** Hue tokens that render as dots / bars / borders — graphical floor. */
export const GRAPHICAL = ['--accent', '--success', '--warn', '--error', '--info'];

/** Soft washes that sit behind a --text label inside .badge / chips, and the
 *  hue each wash puts in the 6px dot. */
export const SOFT = {
  '--surface-3': '--text-dim',
  '--success-soft': '--success',
  '--error-soft': '--error',
  '--warn-soft': '--warn',
  '--info-soft': '--info',
  '--accent-soft': '--accent',
};

/** AA label twins: the -text hue must clear 4.5 on --surface AND on the
 *  matching -soft wash it is painted over (chips, tiers, status rows). */
export const TEXT_ON_SOFT = {
  '--accent-text': '--accent-soft',
  '--success-text': '--success-soft',
  '--warn-text': '--warn-soft',
  '--error-text': '--error-soft',
  '--info-text': '--info-soft',
};

/** Interactive control boundaries — 3:1 on every rung of the surface ladder. */
export const UI_BORDERS = ['--border-control'];

/** Accent interaction states used as rings/borders — graphical 3:1 floor. */
export const ACCENT_STATES = ['--accent-hover', '--accent-active', '--accent-focus'];

/** Status fills and their explicit hover fills; each carries its own on-* label
 *  (P1-C3 removed brightness() filters so hover is a measured pair, not a
 *  post-processed one). */
export const STATUS_FILLS = {
  '--success': '--success-hover',
  '--warn': '--warn-hover',
  '--error': '--error-hover',
  '--info': '--info-hover',
};

export const ON_FILL = {
  '--on-success': '--success',
  '--on-warn': '--warn',
  '--on-error': '--error',
  '--on-info': '--info',
};

/** Runtime-scoped custom properties the GlowGrid writes from JS; they are not
 *  declared in the stylesheet by design. Everything else must resolve. */
export const RUNTIME_VARS = ['--gg-delay', '--gg-dur', '--gg-hit-tint'];

export const TEXT_FLOOR = 4.5;
export const GRAPHICAL_FLOOR = 3;
export const LADDER_FLOOR = 1.08;

function readDashboardHtml() {
  return fs.readFileSync(path.join(ROOT, 'src/dashboard/index.html'), 'utf8');
}

function themeMaps(html) {
  const css = readStyleBlock(html);
  const light = customProperties(css, ':root');
  const dark = { ...light, ...customProperties(css, '[data-theme="dark"]') };
  return { light, dark };
}

function color(vars, name) {
  const raw = resolveVar(vars[name], vars);
  const parsed = parseColor(raw);
  if (!parsed) throw new Error(`${name} is not a colour: ${raw}`);
  return parsed;
}

function onSurface(vars, name) {
  const surface = color(vars, '--surface');
  const fg = color(vars, name);
  return fg.a < 1 ? composite(fg, surface) : fg;
}

/** Resolve a foreground over a possibly-translucent background that itself
 *  sits on `base`. Used for label-on-soft and border-on-surface pairs. */
function onBackground(vars, fgName, bgName, baseName = '--surface') {
  const base = color(vars, baseName);
  let bg = color(vars, bgName);
  if (bg.a < 1) bg = composite(bg, base);
  const fg = color(vars, fgName);
  return fg.a < 1 ? composite(fg, bg) : fg;
}

/** Every `var(--x)` reference must resolve to a declared custom property (or an
 *  allowlisted runtime-scoped one). This catches the class of bug where
 *  `var(--muted)` silently inherits instead of using the muted ramp. */
export function undefinedCustomProperties(html = readDashboardHtml()) {
  const declared = new Set();
  for (const m of html.matchAll(/(--[A-Za-z0-9_-]+)\s*:/g)) declared.add(m[1]);
  const missing = new Set();
  for (const m of html.matchAll(/var\(\s*(--[A-Za-z0-9_-]+)/g)) {
    const name = m[1];
    if (!declared.has(name) && !RUNTIME_VARS.includes(name)) missing.add(name);
  }
  return [...missing].sort();
}

export function lintDashboardContrast(html = readDashboardHtml()) {
  const problems = [];
  const { light, dark } = themeMaps(html);

  for (const token of undefinedCustomProperties(html)) {
    problems.push(`undefined custom property referenced: ${token}`);
  }

  for (const [theme, vars] of Object.entries({ light, dark })) {
    const surface = color(vars, '--surface');

    // 1. Provider swatches: 3:1 against the surface they sit on.
    for (const provider of PROVIDERS) {
      const token = `--prov-${provider}`;
      if (!(token in vars)) { problems.push(`${theme}: ${token} is not defined`); continue; }
      const ratio = contrastRatio(onSurface(vars, token), surface);
      if (ratio < GRAPHICAL_FLOOR) problems.push(`${theme}: ${token} is ${ratio}:1 on --surface (needs ${GRAPHICAL_FLOOR})`);
    }

    // 2. Text tokens.
    for (const token of ['--text', '--text-muted', '--text-dim']) {
      const ratio = contrastRatio(onSurface(vars, token), surface);
      if (ratio < TEXT_FLOOR) problems.push(`${theme}: ${token} is ${ratio}:1 on --surface (needs ${TEXT_FLOOR})`);
    }

    // 2b. Text tokens on the raised surfaces. The DevIn panel paints 10px
    // --text-dim labels on --surface-2 (.dm-stat-label, .dm-req-num) and the
    // surface ladder's top step carries chips, so these are text backgrounds
    // too — not only borders between cards.
    for (const token of ['--text', '--text-muted', '--text-dim']) {
      for (const raised of ['--surface-2', '--surface-3']) {
        const ratio = contrastRatio(color(vars, token), color(vars, raised));
        if (ratio < TEXT_FLOOR) problems.push(`${theme}: ${token} is ${ratio}:1 on ${raised} (needs ${TEXT_FLOOR})`);
      }
    }

    // 2c. AA status/accent labels on --surface and on their own soft wash.
    for (const [token, soft] of Object.entries(TEXT_ON_SOFT)) {
      for (const bg of ['--surface', '--surface-2', '--surface-3', soft]) {
        const ratio = contrastRatio(onBackground(vars, token, bg), onSurface(vars, bg));
        if (ratio < TEXT_FLOOR) problems.push(`${theme}: ${token} is ${ratio}:1 on ${bg} (needs ${TEXT_FLOOR})`);
      }
    }

    // 3. Graphical tokens (status dots, meter fills, focus rings).
    for (const token of GRAPHICAL) {
      const ratio = contrastRatio(onSurface(vars, token), surface);
      if (ratio < GRAPHICAL_FLOOR) problems.push(`${theme}: ${token} is ${ratio}:1 on --surface (needs ${GRAPHICAL_FLOOR})`);
    }

    // 3b. Accent interaction states are rings/borders too — same 3:1 floor.
    for (const token of ACCENT_STATES) {
      const ratio = contrastRatio(onSurface(vars, token), surface);
      if (ratio < GRAPHICAL_FLOOR) problems.push(`${theme}: ${token} is ${ratio}:1 on --surface (needs ${GRAPHICAL_FLOOR})`);
    }

    // 3c. Control borders must stay visible on every surface rung.
    for (const token of UI_BORDERS) {
      for (const bg of ['--surface', '--surface-2', '--surface-3']) {
        const ratio = contrastRatio(onBackground(vars, token, bg), color(vars, bg));
        if (ratio < GRAPHICAL_FLOOR) problems.push(`${theme}: ${token} is ${ratio}:1 on ${bg} (needs ${GRAPHICAL_FLOOR})`);
      }
    }

    // 4. Filled blocks: the label colour on the fill and its explicit hover
    // fill. P1-C3 replaced brightness() filters with these measured pairs.
    const onAccent = color(vars, '--on-accent');
    const fillPairs = [['--on-accent', '--accent'], ['--on-accent', '--accent-hover']];
    for (const [label, fill] of Object.entries(ON_FILL)) {
      fillPairs.push([label, ON_FILL[label]], [label, STATUS_FILLS[ON_FILL[label]]]);
    }
    for (const [label, fill] of fillPairs) {
      const ratio = contrastRatio(color(vars, label), color(vars, fill));
      if (ratio < TEXT_FLOOR) problems.push(`${theme}: ${label} is ${ratio}:1 on ${fill} (needs ${TEXT_FLOOR})`);
    }

    for (const brand of ['google', 'github']) {
      const fg = color(vars, `--brand-${brand}-fg`);
      for (const bg of [`--brand-${brand}-bg`, `--brand-${brand}-bg-hover`]) {
        const ratio = contrastRatio(fg, color(vars, bg));
        if (ratio < TEXT_FLOOR) problems.push(`${theme}: --brand-${brand}-fg is ${ratio}:1 on ${bg} (needs ${TEXT_FLOOR})`);
      }
    }

    // 5. Badge: --text label on the soft wash, hue dot on the same wash.
    const label = color(vars, '--text');
    for (const [soft, dot] of Object.entries(SOFT)) {
      const wash = onSurface(vars, soft);
      const labelRatio = contrastRatio(label, wash);
      if (labelRatio < TEXT_FLOOR) problems.push(`${theme}: --text is ${labelRatio}:1 on ${soft} (needs ${TEXT_FLOOR})`);
      const dotRatio = contrastRatio(color(vars, dot), wash);
      if (dotRatio < GRAPHICAL_FLOOR) problems.push(`${theme}: ${dot} is ${dotRatio}:1 on ${soft} (needs ${GRAPHICAL_FLOOR})`);
    }

    // 6. Surface ladder: each step must separate from the one below it.
    const ladder = ['--paper', '--surface', '--surface-2', '--surface-3'];
    for (let i = 1; i < ladder.length; i++) {
      const ratio = contrastRatio(color(vars, ladder[i]), color(vars, ladder[i - 1]));
      if (ratio < LADDER_FLOOR) problems.push(`${theme}: ${ladder[i]} is ${ratio}:1 against ${ladder[i - 1]} (needs ${LADDER_FLOOR})`);
    }
  }

  return { ok: problems.length === 0, problems };
}

const invokedDirectly = process.argv[1] && path.resolve(process.argv[1]) === path.resolve(fileURLToPath(import.meta.url));
if (invokedDirectly) {
  const { ok, problems } = lintDashboardContrast();
  if (ok) {
    console.log('✓ dashboard palette: every token pair clears its WCAG floor in both themes');
    process.exit(0);
  }
  console.error(`✗ dashboard palette: ${problems.length} contrast failure(s)`);
  for (const p of problems) console.error(`  - ${p}`);
  process.exit(1);
}