import { defineConfig, loadEnv } from 'vite';
import react from '@vitejs/plugin-react';
import path from 'node:path';

const projectRoot = import.meta.dirname;
const outDir = path.resolve(projectRoot, 'dist');

function normalizeBasePath(value) {
  const trimmed = String(value || '/').trim();
  const withLeadingSlash = trimmed.startsWith('/') ? trimmed : `/${trimmed}`;
  return withLeadingSlash.endsWith('/') ? withLeadingSlash : `${withLeadingSlash}/`;
}

function rewritePageRequest(request, basePath) {
  if (request.method !== 'GET' || !request.url) return;

  const [pathname, query = ''] = request.url.split('?');
  const suffix = query ? `?${query}` : '';
  const panelPath = `${basePath}panel`.replace(/\/+/g, '/');
  const apiPath = `${panelPath}/api`;

  if (pathname === basePath || pathname === basePath.slice(0, -1)) {
    request.url = `/login.html${suffix}`;
    return;
  }

  if (
    pathname !== apiPath &&
    !pathname.startsWith(`${apiPath}/`) &&
    (pathname === panelPath || pathname.startsWith(`${panelPath}/`))
  ) {
    request.url = `/index.html${suffix}`;
  }
}

function adminPagesPlugin(basePath) {
  const configure = (server) => {
    server.middlewares.use((request, _response, next) => {
      rewritePageRequest(request, basePath);
      next();
    });
  };

  return {
    name: 'admin-ui-pages',
    apply: 'serve',
    transformIndexHtml(html) {
      const escaped = basePath.replace(/\\/g, '\\\\').replace(/"/g, '\\"');
      const tag = `<script>window.ADMIN_UI_BASE_PATH="${escaped}";</script>`;
      return html.replace('</head>', `${tag}</head>`);
    },
    configureServer: configure,
    configurePreviewServer: configure,
  };
}

function createProxy(backendTarget) {
  if (!backendTarget) return undefined;
  return {
    '^/(?:[^/]+/)?(?:login|logout|getTwoFactorEnable|csrf-token|panel/api)(?:/|$)': {
      target: backendTarget,
      changeOrigin: true,
    },
  };
}

export default defineConfig(({ mode }) => {
  const env = loadEnv(mode, projectRoot, '');
  const basePath = normalizeBasePath(env.VITE_ADMIN_BASE_PATH);
  const backendTarget = env.VITE_BACKEND_TARGET?.trim();

  return {
    plugins: [react(), adminPagesPlugin(basePath)],
    resolve: {
      alias: {
        '@': path.resolve(projectRoot, 'src'),
      },
    },
    experimental: {
      renderBuiltUrl(filename, { hostType }) {
        if (hostType === 'js') {
          return {
            runtime: `((window.ADMIN_UI_BASE_PATH||'/')+${JSON.stringify(filename)})`,
          };
        }
        return undefined;
      },
    },
    build: {
      outDir,
      emptyOutDir: true,
      sourcemap: env.VITE_SOURCEMAP === 'true',
      target: 'es2020',
      chunkSizeWarningLimit: 1500,
      rollupOptions: {
        input: {
          index: path.resolve(projectRoot, 'index.html'),
          login: path.resolve(projectRoot, 'login.html'),
        },
        output: {
          manualChunks(id) {
            if (!id.includes('node_modules')) return undefined;
            if (id.includes('/node_modules/antd/')) return 'vendor-antd';
            if (id.includes('/@ant-design/icons/') || id.includes('/@ant-design/icons-svg/')) {
              return 'vendor-icons';
            }
            if (
              id.includes('/node_modules/@rc-component/') ||
              id.includes('/node_modules/rc-') ||
              id.includes('/@ant-design/cssinjs') ||
              id.includes('/@ant-design/colors') ||
              id.includes('/@ant-design/fast-color') ||
              id.includes('/@ant-design/react-slick') ||
              id.includes('/@ctrl/tinycolor')
            ) {
              return 'vendor-antd';
            }
            if (
              id.includes('/node_modules/react-i18next/') ||
              id.includes('/node_modules/i18next/')
            ) {
              return 'vendor-i18next';
            }
            if (
              id.includes('/node_modules/react/') ||
              id.includes('/node_modules/react-dom/') ||
              id.includes('/node_modules/scheduler/')
            ) {
              return 'vendor-react';
            }
            if (id.includes('/node_modules/@tanstack/')) return 'vendor-tanstack';
            if (id.includes('/node_modules/react-hook-form/')) return 'vendor-react-hook-form';
            if (id.includes('/node_modules/react-router')) return 'vendor-router';
            if (id.includes('/node_modules/dayjs/')) return 'vendor-dayjs';
            return 'vendor';
          },
        },
      },
    },
    server: {
      host: '0.0.0.0',
      port: 19999,
      strictPort: true,
      proxy: createProxy(backendTarget),
    },
    preview: {
      host: '0.0.0.0',
      port: 19999,
      strictPort: true,
    },
  };
});