package com.pushtechnology.diffusion.examples;

import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.pushtechnology.diffusion.client.Diffusion;
import com.pushtechnology.diffusion.client.features.control.clients.SystemAuthenticationControl;
import com.pushtechnology.diffusion.client.features.control.clients.SystemAuthenticationControl.ScriptBuilder;
import com.pushtechnology.diffusion.client.session.Session;

/**
 * An example of using a control client to alter the system authentication
 * configuration.
 * <P>
 * This uses the {@link SystemAuthenticationControl} feature only.
 *
 * @author Push Technology Limited
 * @since 5.2
 */
public class ControlClientChangingSystemAuthentication {

    private static final Logger LOG =
        LoggerFactory.getLogger(
            ControlClientChangingSystemAuthentication.class);

    private final SystemAuthenticationControl systemAuthenticationControl;
    private final ScriptBuilder emptyScript;

    /**
     * Constructor.
     */
    public ControlClientChangingSystemAuthentication() {

        final Session session = Diffusion.sessions()
            // Authenticate with a user that has the VIEW_SECURITY and
            // MODIFY_SECURITY permissions.
            .principal("admin").password("password")
            // Use a secure channel because we're transferring sensitive
            // information.
            .open("wss://diffusion.example.com:80");

        systemAuthenticationControl =
            session.feature(SystemAuthenticationControl.class);
        emptyScript = systemAuthenticationControl.scriptBuilder();
    }

    /**
     * For all system users, update the assigned roles to replace the
     * "SUPERUSER" role and with "ADMINISTRATOR".
     *
     * @return a CompletableFuture that completes when the operation succeeds or
     *         fails.
     *
     *         <p>
     *         If the operation was successful, the CompletableFuture will
     *         complete successfully.
     *
     *         <p>
     *         Otherwise, the CompletableFuture will complete exceptionally with
     *         an {@link ExecutionException}. See
     *         {@link SystemAuthenticationControl#getSystemAuthentication()} and
     *         {@link SystemAuthenticationControl#updateStore(String)} for
     *         common failure reasons.
     */
    public CompletableFuture<Void> changeSuperUsersToAdministrators() {

        return systemAuthenticationControl
            .getSystemAuthentication()
            .thenCompose(configuration -> {

                final String script = configuration

                    // For each principal ...
                    .getPrincipals().stream()

                    // ... that has the SUPERUSER assigned role ...
                    .filter(p -> p.getAssignedRoles().contains("SUPERUSER"))

                    // ... create a script that updates the assigned roles to
                    // replace SUPERUSER with ADMINISTRATOR ...
                    .map(p -> {
                        final Set<String> newRoles =
                            new HashSet<>(p.getAssignedRoles());
                        newRoles.remove("SUPERUSER");
                        newRoles.add("ADMINISTRATOR");
                        return emptyScript.assignRoles(p.getName(), newRoles);
                    })

                    // ... create a single combined script.
                    .reduce(emptyScript, (sb1, sb2) -> sb1.append(sb2))
                    .script();

                LOG.info("Sending the following script to the server:\n{}",
                    script);

                return systemAuthenticationControl.updateStore(script)
                    // Convert CompletableFuture<?> to
                    // CompletableFuture<Void>.
                    .thenAccept(ignored -> { });
            });
    }

    /**
     * Close the session.
     */
    public void close() {
        systemAuthenticationControl.getSession().close();
    }
}
                    

/*
 * This examples demonstrates how to interact with the system
 * authentication store.
 */

#include <stdio.h>

#include <apr.h>
#include <apr_thread_mutex.h>
#include <apr_thread_cond.h>

#include "diffusion.h"
#include "args.h"
#include "service/svc-system-auth-control.h"

apr_pool_t *pool = NULL;
apr_thread_mutex_t *mutex = NULL;
apr_thread_cond_t *cond = NULL;

ARG_OPTS_T arg_opts[] = {
        ARG_OPTS_HELP,
        {'u', "url", "Diffusion server URL", ARG_OPTIONAL, ARG_HAS_VALUE, "ws://localhost:8080"},
        {'p', "principal", "Principal (username) for the connection", ARG_OPTIONAL, ARG_HAS_VALUE, NULL},
        {'c', "credentials", "Credentials (password) for the connection", ARG_OPTIONAL, ARG_HAS_VALUE, NULL},
        END_OF_ARG_OPTS
};

/*
 * This callback is invoked when the system authentication store is
 * received, and prints the contents of the store.
 */
int
on_get_system_authentication_store(SESSION_T *session,
                                   const SYSTEM_AUTHENTICATION_STORE_T store,
                                   void *context)
{
        puts("on_get_system_authentication_store()");

        printf("Got %ld principals\n", store.system_principals->size);

        char **names = get_principal_names(store);
        for(char **name = names; *name != NULL; name++) {
                printf("Principal: %s\n", *name);

                char **roles = get_roles_for_principal(store, *name);
                for(char **role = roles; *role != NULL; role++) {
                    printf("  |- Role: %s\n", *role);
                }
                free(roles);
        }
        free(names);

        switch(store.anonymous_connection_action) {
        case ANONYMOUS_CONNECTION_ACTION_ALLOW:
                puts("Allow anonymous connections");
                break;
        case ANONYMOUS_CONNECTION_ACTION_DENY:
                puts("Deny anonymous connections");
                break;
        case ANONYMOUS_CONNECTION_ACTION_ABSTAIN:
                puts("Abstain from making anonymous connection decision");
                break;
        }

        puts("Anonymous connection roles:");
        char **roles = get_anonymous_roles(store);
        for(char **role = roles; *role != NULL; role++) {
                printf("  |- Role: %s\n", *role);
        }
        free(roles);

        apr_thread_mutex_lock(mutex);
        apr_thread_cond_broadcast(cond);
        apr_thread_mutex_unlock(mutex);

        return HANDLER_SUCCESS;
}

int
main(int argc, char **argv)
{
        /*
         * Standard command-line parsing.
         */
        const HASH_T *options = parse_cmdline(argc, argv, arg_opts);
        if(options == NULL || hash_get(options, "help") != NULL) {
                show_usage(argc, argv, arg_opts);
                return EXIT_FAILURE;
        }

        const char *url = hash_get(options, "url");
        const char *principal = hash_get(options, "principal");
        CREDENTIALS_T *credentials = NULL;
        const char *password = hash_get(options, "credentials");
        if(password != NULL) {
                credentials = credentials_create_password(password);
        }

        /*
         * Setup for condition variable
         */
        apr_initialize();
        apr_pool_create(&pool, NULL);
        apr_thread_mutex_create(&mutex, APR_THREAD_MUTEX_UNNESTED, pool);
        apr_thread_cond_create(&cond, pool);

        /*
         * Create a session with Diffusion.
         */
        SESSION_T *session;
        DIFFUSION_ERROR_T error = { 0 };
        session = session_create(url, principal, credentials, NULL, NULL, &error);
        if(session == NULL) {
                fprintf(stderr, "TEST: Failed to create session\n");
                fprintf(stderr, "ERR : %s\n", error.message);
                return EXIT_FAILURE;
        }

        /*
         * Request the system authentication store.
         */
        const GET_SYSTEM_AUTHENTICATION_STORE_PARAMS_T params = {
                .on_get = on_get_system_authentication_store
        };

        apr_thread_mutex_lock(mutex);

        get_system_authentication_store(session, params);

        apr_thread_cond_wait(cond, mutex);
        apr_thread_mutex_unlock(mutex);

        /*
         * Close the session and tidy up.
         */
        session_close(session, NULL);
        session_free(session);

        apr_thread_mutex_destroy(mutex);
        apr_thread_cond_destroy(cond);
        apr_pool_destroy(pool);
        apr_terminate();

        return EXIT_SUCCESS;
}