Legacy API

import type { FlatConfig } from '@typescript-eslint/utils/ts-eslint';

/**
 * @deprecated Use `defineConfigWithVueTs` + `vueTsConfigs` instead
 * Creates ESLint configuration with legacy options format
 * @param options - Configuration options with extends and script language support
 * @returns ESLint flat configuration array
 */
export default function createConfig(options?: ConfigOptions): FlatConfig.ConfigArray;

type ConfigOptions = ProjectOptions & {
  /** Array of config names to extend from typescript-eslint. Defaults to `['recommended']` */
  extends?: ExtendableConfigName[];
  /** 
   * @deprecated Use ProjectOptions.scriptLangs instead
   * Record of script languages with boolean flags
   */
  supportedScriptLangs?: Record<ScriptLang, boolean>;
};

interface ProjectOptions {
  tsSyntaxInTemplates?: boolean;
  scriptLangs?: ScriptLang[];
  allowComponentTypeUnsafety?: boolean;
  rootDir?: string;
}

type ScriptLang = "ts" | "tsx" | "js" | "jsx";
type ExtendableConfigName = 
  | "all" | "base" | "disableTypeChecked" | "eslintRecommended"
  | "recommended" | "recommendedTypeChecked" | "recommendedTypeCheckedOnly"
  | "strict" | "strictTypeChecked" | "strictTypeCheckedOnly"
  | "stylistic" | "stylisticTypeChecked" | "stylisticTypeCheckedOnly";

// Legacy import style
import createConfig from "@vue/eslint-config-typescript";

// Basic configuration
export default createConfig();

// Configuration with extends
export default createConfig({
  extends: ["recommended", "stylistic"],
});

// Configuration with script language support
export default createConfig({
  extends: ["strictTypeChecked"],
  supportedScriptLangs: {
    ts: true,
    tsx: false,
    js: false,
    jsx: false,
  },
  rootDir: process.cwd(),
});

// OLD (deprecated)
import createConfig from "@vue/eslint-config-typescript";

export default createConfig({
  extends: ["recommended", "stylistic"],
  supportedScriptLangs: { ts: true, js: false, tsx: false, jsx: false },
});

// NEW (recommended)
import { 
  defineConfigWithVueTs, 
  vueTsConfigs, 
  configureVueProject 
} from "@vue/eslint-config-typescript";

configureVueProject({
  scriptLangs: ["ts"],
});

export default defineConfigWithVueTs(
  vueTsConfigs.recommended,
  vueTsConfigs.stylistic,
);

/**
 * @deprecated `defineConfig` is renamed to `defineConfigWithVueTs` in 14.3.0
 * Alias for defineConfigWithVueTs function
 */
export const defineConfig: typeof defineConfigWithVueTs;

// OLD (deprecated)
import { defineConfig, vueTsConfigs } from "@vue/eslint-config-typescript";

export default defineConfig(vueTsConfigs.recommended);

// NEW (recommended)
import { defineConfigWithVueTs, vueTsConfigs } from "@vue/eslint-config-typescript";

export default defineConfigWithVueTs(vueTsConfigs.recommended);

// Invalid config name detection
createConfig({ extends: ["recommended-type-checked"] });
// Error: The config name "recommended-type-checked" is not supported in "extends". 
// Please use "recommendedTypeChecked" instead.

// Unknown config detection  
createConfig({ extends: ["unknown-config"] });
// Error: Unknown config name in "extends": unknown-config.

// Default configuration when no options provided
const defaultOptions = {
  extends: ["recommended"],
  supportedScriptLangs: { 
    ts: true, 
    tsx: false, 
    js: false, 
    jsx: false 
  },
  rootDir: process.cwd(),
};

// Before
import createConfig from "@vue/eslint-config-typescript";
import { defineConfig } from "@vue/eslint-config-typescript";

// After  
import {
  defineConfigWithVueTs,
  vueTsConfigs,
  configureVueProject,
} from "@vue/eslint-config-typescript";

// Before - createConfig
export default createConfig({
  extends: ["strict"],
  supportedScriptLangs: { ts: true, js: true, tsx: false, jsx: false },
});

// After - modern API
configureVueProject({
  scriptLangs: ["ts", "js"],
});

export default defineConfigWithVueTs(vueTsConfigs.strict);

// Before - mixed legacy/modern patterns
export default createConfig({
  extends: ["recommendedTypeChecked"],
  // Custom rules were difficult to add
});

// After - full flexibility
configureVueProject({
  scriptLangs: ["ts"],
  tsSyntaxInTemplates: true,
});

export default defineConfigWithVueTs(
  vueTsConfigs.recommendedTypeChecked,
  {
    name: "custom-overrides",
    files: ["**/*.vue"],
    rules: {
      // Easy to add custom rules
      "vue/multi-word-component-names": "off",
    },
  },
);