import js from '@eslint/js';
import globals from 'globals';
import reactHooks from 'eslint-plugin-react-hooks';
import reactRefresh from 'eslint-plugin-react-refresh';
import tseslint from 'typescript-eslint';
import prettier from 'eslint-config-prettier';

// ESLint 9 flat config. Order matters: `prettier` must come last so it can
// switch off any stylistic rules that would fight the formatter — ESLint owns
// code-correctness, Prettier owns formatting.
export default tseslint.config(
  { ignores: ['dist', 'node_modules', 'coverage'] },
  {
    files: ['**/*.{ts,tsx}'],
    extends: [js.configs.recommended, ...tseslint.configs.recommended],
    languageOptions: {
      ecmaVersion: 2022,
      globals: globals.browser,
    },
    plugins: {
      'react-hooks': reactHooks,
      'react-refresh': reactRefresh,
    },
    rules: {
      ...reactHooks.configs.recommended.rules,
      'react-refresh/only-export-components': ['warn', { allowConstantExport: true }],
    },
  },
  {
    // Test + setup files also touch Node globals (process, etc.) and use
    // jsdom; allow both global sets.
    files: ['**/*.test.{ts,tsx}', 'src/test/**/*.ts'],
    languageOptions: {
      globals: { ...globals.browser, ...globals.node },
    },
  },
  {
    // Context files intentionally export a Provider component *and* its hook
    // from the same module — the standard React Context pattern. The
    // react-refresh rule flags this; the trade-off (marginally less optimal
    // HMR) isn't worth splitting every context into two files.
    files: ['src/hooks/**/*.tsx'],
    rules: {
      'react-refresh/only-export-components': 'off',
    },
  },
  {
    // Config files run in Node.
    files: ['*.config.{js,ts}'],
    languageOptions: {
      globals: globals.node,
    },
  },
  prettier,
);