/** All application Axios imports belong here. New calls and axios.create()
 *  clients inherit the instance's browser identity, proxy and timeout. */
import axios, { type AxiosInstance } from 'axios';
import { applyBrokerHttpDefaults, applyBrokerProxy } from './outbound-proxy';
import { getRequestUserAgent } from './request-user-agent';

const g = globalThis as typeof globalThis & { __configuredHttpClients?: WeakSet<AxiosInstance> };
const configured = g.__configuredHttpClients ??= new WeakSet<AxiosInstance>();

function configure<T extends AxiosInstance>(client: T): T {
    if (configured.has(client)) return client;
    applyBrokerHttpDefaults(client.defaults);
    // Builds import route modules but must not choose an instance's identity.
    if (process.env.NEXT_PHASE !== 'phase-production-build') {
        client.defaults.headers.common['User-Agent'] = getRequestUserAgent();
        try {
            applyBrokerProxy(client.defaults);
        } catch (err) {
            console.error(`[proxy] could not apply proxy_url at load: ${err instanceof Error ? err.message : String(err)}`);
        }
    }
    client.interceptors.request.use((config) => {
        // Force replacement even for differently cased headers or `false`.
        // This also replaces a stale per-call UA without losing auth headers.
        config.headers.set('User-Agent', getRequestUserAgent(), true);
        return config;
    }, undefined, { synchronous: true });

    // Axios copies defaults into child clients, but not interceptors.
    const create = client.create.bind(client);
    client.create = (options) => configure(create(options));
    configured.add(client);
    return client;
}

export default configure(axios);