import eslint from '@eslint/js';
import tseslint from 'typescript-eslint';
import importPlugin from 'eslint-plugin-import-x';

export default [
  {
    ignores: [
      'node_modules/**',
      'dist/**',
      'tmp/**',
      'logs/**',
      'scripts/**',
      // Generated/seed data run via tsx, not part of the typechecked sources.
      'src/db/migrations/**',
      'src/db/seeders/**',
    ],
  },
  eslint.configs.recommended,
  {
    // CommonJS scripts/config (.cjs) kept outside the ESM TypeScript sources.
    files: ['**/*.{js,cjs}'],
    plugins: {
      'import-x': importPlugin,
    },
    languageOptions: {
      ecmaVersion: 'latest',
      sourceType: 'commonjs',
      globals: {
        Buffer: 'readonly',
        __dirname: 'readonly',
        console: 'readonly',
        module: 'readonly',
        process: 'readonly',
        require: 'readonly',
        setInterval: 'readonly',
        setTimeout: 'readonly',
        URL: 'readonly',
      },
    },
    settings: {
      'import-x/resolver': {
        node: { extensions: ['.js', '.ts', '.json'] },
      },
    },
    rules: {
      'import-x/no-unresolved': 'error',
    },
  },
  // TypeScript: type-aware resolution is handled by tsc, not import-x.
  ...tseslint.configs.recommended.map((config) => ({
    ...config,
    files: ['**/*.ts'],
  })),
  {
    files: ['**/*.ts'],
    rules: {
      '@typescript-eslint/no-unused-vars': [
        'error',
        {
          argsIgnorePattern: '^_',
          varsIgnorePattern: '^_',
          caughtErrorsIgnorePattern: '^_',
        },
      ],
    },
  },
  // Layer import boundaries — hard invariants (see
  // backend/docs/backend-architecture-refactor-plan.md). Debt that is still
  // being paid down (API->DAL, BLL->HTTP) is ratcheted by the boundary test in
  // src/shared/architecture/import-boundaries.test.ts, not here.
  {
    files: ['src/db/models/**/*.ts'],
    rules: {
      'no-restricted-imports': [
        'error',
        {
          patterns: [
            {
              group: ['@/services/*', '@/api/*', '@/routes/*', '@/middlewares/*'],
              message: 'DAL models must not import the BLL or API layers.',
            },
            { group: ['express'], message: 'DAL models must not depend on Express.' },
          ],
        },
      ],
    },
  },
  {
    files: ['src/db/api/**/*.ts'],
    rules: {
      'no-restricted-imports': [
        'error',
        {
          patterns: [
            {
              group: ['@/api/*', '@/routes/*', '@/middlewares/*'],
              message: 'The DAL must not import the API layer.',
            },
          ],
        },
      ],
    },
  },
  {
    files: ['src/shared/**/*.ts'],
    rules: {
      'no-restricted-imports': [
        'error',
        {
          patterns: [
            {
              group: [
                '@/api/*',
                '@/routes/*',
                '@/middlewares/*',
                '@/services/*',
                '@/db/*',
              ],
              message:
                'Cross-cutting code (shared/*) must not import any layer.',
            },
          ],
        },
      ],
    },
  },
  {
    // Routes and controllers go through the BLL; they must not reach the DAL.
    files: ['src/routes/**/*.ts', 'src/api/controllers/**/*.ts'],
    rules: {
      'no-restricted-imports': [
        'error',
        {
          patterns: [
            {
              group: ['@/db/api/*', '@/db/models/*'],
              message:
                'The API layer must call a service (BLL), not the DAL directly.',
            },
          ],
        },
      ],
    },
  },
];