import js from '@eslint/js';
import tseslint from 'typescript-eslint';
import reactHooks from 'eslint-plugin-react-hooks';
import jsxA11y from 'eslint-plugin-jsx-a11y';
import sonarjs from 'eslint-plugin-sonarjs';
import globals from 'globals';

// Named `.mjs` because this package is CommonJS — `eslint.config.js` would be
// parsed as CJS and the imports above would fail.
//
// Policy: every preset is downgraded to advisory, and the rules that actually
// fail the build are listed once at the bottom. That way the CI gate is
// readable in one place rather than inferred from four presets' defaults.
// The reasoning behind the split, and the measurements it rests on, are in
// docs/superpowers/specs/2026-08-19-eslint-design.md.

/**
 * Rewrites a preset's enabled rules to `warn`, preserving each rule's options.
 * Rules the preset explicitly turned off stay off — a preset that disables a
 * rule means it, and flipping those to `warn` turns the whole of SonarJS's
 * opt-in catalogue (file headers, naming conventions) into daily noise.
 */
const advisory = (config) => ({
  ...config,
  rules: Object.fromEntries(
    Object.entries(config.rules ?? {}).map(([rule, level]) => {
      const severity = Array.isArray(level) ? level[0] : level;
      if (severity === 'off' || severity === 0) return [rule, level];
      return [rule, Array.isArray(level) ? ['warn', ...level.slice(1)] : 'warn'];
    })
  ),
});

export default tseslint.config(
  { ignores: ['dist/**', 'playwright-report/**', 'test-results/**', 'eslint.config.mjs'] },

  ...[
    js.configs.recommended,
    ...tseslint.configs.recommended,
    sonarjs.configs.recommended,
    // v7 of this plugin ships the React Compiler rule set alongside the two
    // classic rules. This is React 18 with no compiler in the build, so those
    // extra rules advise against a stricter model than the code was written
    // for — worth seeing (`purity` catches a real `Date.now()` in render), not
    // worth failing a build over.
    reactHooks.configs.flat['recommended-latest'],
    { rules: jsxA11y.flatConfigs.recommended.rules },
  ].map(advisory),

  { plugins: { 'jsx-a11y': jsxA11y } },

  {
    // `tests/` and the Playwright specs are deliberately out of scope for now:
    // tsconfig.json only includes `src`, so type-aware linting has no program
    // for them, and widening it is a separate change with its own count.
    files: ['src/**/*.{ts,tsx}'],
    languageOptions: {
      globals: globals.browser,
      parserOptions: {
        projectService: true,
        tsconfigRootDir: import.meta.dirname,
      },
    },
    rules: {
      // Hooks called conditionally break React outright.
      'react-hooks/rules-of-hooks': 'error',
      // The stale-closure rule. PR #11 fixed a cart badge that did not update
      // after account creation, which is precisely what this catches.
      'react-hooks/exhaustive-deps': 'error',
      // An unawaited promise fails silently — the same class of defect as the
      // unwrapped async routes in #59, and what the project's Playwright notes
      // already warn about for missing `await`.
      '@typescript-eslint/no-floating-promises': 'error',
      // `attributes: false` because `onClick={async () => ...}` is idiomatic
      // React and safe when the handler catches its own errors. Left at the
      // default this rule flags every antd button in the admin screens — 25 of
      // its 28 hits here — and a rule that is 89% noise gets switched off.
      '@typescript-eslint/no-misused-promises': [
        'error',
        { checksVoidReturn: { attributes: false } },
      ],
      // A storefront image with no alt text is unusable in a screen reader, and
      // the fix is one attribute.
      'jsx-a11y/alt-text': 'error',
    },
  }
);