package org.apache.sling.crankstart.launcher;

import java.io.IOException;

import org.apache.http.HttpException;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpRequestInterceptor;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.AuthState;
import org.apache.http.auth.Credentials;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.impl.auth.BasicScheme;
import org.apache.http.protocol.ExecutionContext;
import org.apache.http.protocol.HttpContext;

/** It's not like httpclient 4.1 makes this simple... */
class PreemptiveAuthInterceptor implements HttpRequestInterceptor {

    public void process(HttpRequest request, HttpContext context) throws HttpException, IOException {

        AuthState authState = (AuthState) context.getAttribute(ClientContext.TARGET_AUTH_STATE);
        CredentialsProvider credsProvider = (CredentialsProvider) context.getAttribute(ClientContext.CREDS_PROVIDER);
        HttpHost targetHost = (HttpHost) context.getAttribute(ExecutionContext.HTTP_TARGET_HOST);

        // If not auth scheme has been initialized yet
        if (authState.getAuthScheme() == null) {
            AuthScope authScope = new AuthScope(targetHost.getHostName(), targetHost.getPort());

            // Obtain credentials matching the target host
            Credentials creds = credsProvider.getCredentials(authScope);

            // If found, generate BasicScheme preemptively
            if (creds != null) {
                authState.setAuthScheme(new BasicScheme());
                authState.setCredentials(creds);
            }
        }
    }
}