import { sveltekit } from '@sveltejs/kit/vite';
import { defineConfig, loadEnv } from 'vite';
import { mockApiPlugin } from './mocks/vitePlugin';

/**
 * Three dev modes are supported:
 *
 *   1. VITE_USE_MOCK_API=true
 *        → serve fake data from ./mocks. No backend needed.
 *
 *   2. VITE_API_BASE_URL starts with '/'
 *        → client makes same-origin requests; the dev server proxies
 *          VITE_API_BASE_URL to VITE_API_PROXY_TARGET (default
 *          http://localhost:8000). This matches production where the web
 *          server routes /api to Django.
 *
 *   3. VITE_API_BASE_URL is an absolute URL
 *        → client talks to it directly. CORS must be enabled on that host.
 *          No proxy is registered.
 */
export default defineConfig(({ mode }) => {
	const env = loadEnv(mode, process.cwd(), '');
	const useMock = env.VITE_USE_MOCK_API === 'true';
	const base = env.VITE_API_BASE_URL ?? '/api';
	const proxyTarget = env.VITE_API_PROXY_TARGET ?? 'http://localhost:8000';
	const shouldProxy = !useMock && base.startsWith('/');

	return {
		plugins: [sveltekit(), ...(useMock ? [mockApiPlugin()] : [])],
		server: {
			proxy: shouldProxy
				? {
						[base]: {
							target: proxyTarget,
							changeOrigin: true,
						},
					}
				: undefined,
		},
	};
});