/**
 * Shared Vite configuration factory for React projects
 * Following DRY principle - single source of truth for React build configs
 */
import { defineConfig, mergeConfig, type UserConfig } from 'vite';
import react from '@vitejs/plugin-react';
import * as path from 'path';

/**
 * Standard alias patterns used across all React apps
 * Apps can extend but should not duplicate
 */
const standardAliases = {
  '@': 'src',
  '@components': 'src/components',
  '@features': 'src/features',
  '@hooks': 'src/hooks',
  '@providers': 'src/providers',
  '@routes': 'src/routes',
  '@lib': 'src/lib',
  '@config': 'src/config',
  '@store': 'src/store',
  '@services': 'src/services',
  '@types': 'src/types',
  '@styles': 'src/styles',
  '@utils': 'src/utils',
  '@assets': 'src/assets',
  '@pages': 'src/pages',
  '@layouts': 'src/layouts',
  '@api': 'src/api',
};

/**
 * Base Vite configuration for all React applications
 * Provides sensible defaults that can be overridden
 */
const baseConfig = defineConfig({
  plugins: [react()] as any, // Type assertion to handle Vite version mismatches

  resolve: {
    alias: Object.entries(standardAliases).reduce((acc, [key, value]) => {
      acc[key] = path.resolve(value);
      return acc;
    }, {} as Record<string, string>),
  },

  server: {
    host: true,
    cors: true,
    strictPort: false,
  },

  build: {
    outDir: 'dist',
    sourcemap: true,
    rollupOptions: {
      output: {
        manualChunks: {
          'react-vendor': ['react', 'react-dom'],
          'router': ['react-router-dom'],
        },
      },
    },
  },

  optimizeDeps: {
    include: ['react', 'react-dom', 'react-router-dom'],
  },
});

/**
 * Create a Vite configuration with project-specific overrides
 * @param overrides - Project-specific configuration to merge
 * @returns Merged Vite configuration
 */
export function createViteConfig(overrides: UserConfig = {}): UserConfig {
  // If overrides has resolve.alias, merge it properly with base aliases
  if (overrides.resolve?.alias) {
    const customAliases = overrides.resolve.alias;
    const mergedAliases = { ...(baseConfig.resolve!.alias as Record<string, string>) };

    // Handle both object and array formats for aliases
    if (Array.isArray(customAliases)) {
      customAliases.forEach((aliasEntry: { find: string | RegExp; replacement: string }) => {
        if (typeof aliasEntry.find === 'string') {
          mergedAliases[aliasEntry.find] = aliasEntry.replacement;
        }
      });
    } else {
      Object.assign(mergedAliases, customAliases);
    }

    overrides.resolve.alias = mergedAliases;
  }

  return mergeConfig(baseConfig, overrides) as UserConfig;
}

/**
 * Export the base config as default for backward compatibility
 */
export default baseConfig;

/**
 * Export individual parts for advanced use cases
 */
export { standardAliases, baseConfig };