import { existsSync } from "node:fs";
import { createRequire } from "node:module";
import { dirname, join } from "node:path";
import { fileURLToPath, URL } from "node:url";
import { defineConfig, type Plugin } from "vite";
import react from "@vitejs/plugin-react";

const require = createRequire(import.meta.url);
const webuiRoot = dirname(fileURLToPath(import.meta.url));
const installedModulesVirtualId = "virtual:govoplan-installed-modules";
const resolvedInstalledModulesVirtualId = `\0${installedModulesVirtualId}`;

const defaultWebModulePackages = [
  "@govoplan/access-webui",
  "@govoplan/admin-webui",
  "@govoplan/addresses-webui",
  "@govoplan/audit-webui",
  "@govoplan/calendar-webui",
  "@govoplan/campaign-webui",
  "@govoplan/dashboard-webui",
  "@govoplan/docs-webui",
  "@govoplan/files-webui",
  "@govoplan/idm-webui",
  "@govoplan/mail-webui",
  "@govoplan/notifications-webui",
  "@govoplan/organizations-webui",
  "@govoplan/ops-webui",
  "@govoplan/policy-webui",
  "@govoplan/scheduling-webui"
];

function configuredWebModulePackages(): string[] {
  const configured = process.env.GOVOPLAN_WEBUI_MODULE_PACKAGES;
  if (configured === undefined) return defaultWebModulePackages;
  return configured.split(",").map((specifier) => specifier.trim()).filter(Boolean);
}

function packageDirectory(specifier: string): string {
  const parts = specifier.startsWith("@") ? specifier.split("/") : [specifier];
  return join(webuiRoot, "node_modules", ...parts);
}

function packageInstalled(specifier: string): boolean {
  if (existsSync(join(packageDirectory(specifier), "package.json"))) return true;
  try {
    require.resolve(specifier);
    return true;
  } catch {
    return false;
  }
}

function availableWebModuleSpecifiers(): string[] {
  return configuredWebModulePackages().filter(packageInstalled);
}

function govoplanInstalledModulesPlugin(): Plugin {
  return {
    name: "govoplan-installed-modules",
    resolveId(id: string) {
      if (id === installedModulesVirtualId) return resolvedInstalledModulesVirtualId;
      return null;
    },
    load(id: string) {
      if (id !== resolvedInstalledModulesVirtualId) return null;
      const imports = availableWebModuleSpecifiers();
      return [
        ...imports.map((specifier, index) => `import module${index} from ${JSON.stringify(specifier)};`),
        `export const installedWebModules = [${imports.map((_specifier, index) => `module${index}`).join(", ")}];`,
        "export default installedWebModules;"
      ].join("\n");
    }
  };
}

export default defineConfig({
  plugins: [govoplanInstalledModulesPlugin(), react()],
  optimizeDeps: {
    exclude: availableWebModuleSpecifiers()
  },
  build: {
    // Full-product builds include the host shell plus all installed module wiring.
    // Dedicated route/vendor splitting belongs in a separate performance pass.
    chunkSizeWarningLimit: 1200
  },
  resolve: {
    preserveSymlinks: true,
    dedupe: ["react", "react-dom", "react-router-dom"],
    alias: [
      { find: "@govoplan/core-webui/app", replacement: fileURLToPath(new URL("./src/app.ts", import.meta.url)) },
      { find: "@govoplan/core-webui", replacement: fileURLToPath(new URL("./src/index.ts", import.meta.url)) }
    ]
  },
  server: {
    fs: {
      allow: [
        fileURLToPath(new URL('.', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-access/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-admin/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-addresses/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-audit/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-calendar/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-dashboard/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-docs/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-files/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-idm/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-mail/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-notifications/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-organizations/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-campaign/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-ops/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-policy/webui', import.meta.url)),
        fileURLToPath(new URL('../../govoplan-scheduling/webui', import.meta.url))
      ]
    },
    proxy: {
      "/api": {
        target: process.env.VITE_API_PROXY_TARGET || "http://127.0.0.1:8000",
        changeOrigin: true
      },
      "/health": {
        target: process.env.VITE_API_PROXY_TARGET || "http://127.0.0.1:8000",
        changeOrigin: true
      }
    }
  }
});