/*
 * Copyright (c) 2008, 2009, 2010 Nicira Networks.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <config.h>

#include <errno.h>
#include <getopt.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include "command-line.h"
#include "daemon.h"
#include "dirs.h"
#include "dynamic-string.h"
#include "timeval.h"
#include "unixctl.h"
#include "util.h"

static void usage(void);
static const char *parse_command_line(int argc, char *argv[]);
static struct unixctl_client *connect_to_target(const char *target);

int
main(int argc, char *argv[])
{
    struct unixctl_client *client;
    const char *target;
    struct ds request;
    int code, error;
    char *reply;
    int i;

    set_program_name(argv[0]);

    /* Parse command line and connect to target. */
    target = parse_command_line(argc, argv);
    client = connect_to_target(target);

    /* Compose request. */
    ds_init(&request);
    for (i = optind; i < argc; i++) {
        if (i != optind) {
            ds_put_char(&request, ' ');
        }
        ds_put_cstr(&request, argv[i]);
    }

    /* Transact request and process reply. */
    error = unixctl_client_transact(client, ds_cstr(&request), &code, &reply);
    if (error) {
        ovs_fatal(error, "%s: transaction error", target);
    }
    if (code / 100 != 2) {
        fputs(reply, stderr);
        ovs_error(0, "%s: server returned reply code %03d", target, code);
        exit(2);
    }
    fputs(reply, stdout);

    unixctl_client_destroy(client);
    free(reply);
    ds_destroy(&request);

    return 0;
}

static void
usage(void)
{
    printf("%s, for querying and controlling Open vSwitch daemon\n"
           "usage: %s [TARGET] COMMAND [ARG...]\n"
           "Targets:\n"
           "  -t, --target=TARGET  pidfile or socket to contact\n"
           "Common commands:"
           "  help               List commands supported by the target\n"
           "  vlog/list          List current logging levels\n"
           "  vlog/set MODULE[:FACILITY[:LEVEL]]\n"
           "        Set MODULE and FACILITY log level to LEVEL\n"
           "        MODULE may be any valid module name or 'ANY'\n"
           "        FACILITY may be 'syslog', 'console', 'file', or 'ANY' (default)\n"
           "        LEVEL may be 'emer', 'err', 'warn', 'info', or 'dbg' (default)\n"
           "  vlog/reopen        Make the program reopen its log file\n"
           "Other options:\n"
           "  -h, --help         Print this helpful information\n"
           "  -V, --version      Display version information\n",
           program_name, program_name);
    exit(EXIT_SUCCESS);
}

static const char *
parse_command_line(int argc, char *argv[])
{
    static const struct option long_options[] = {
        {"target", required_argument, NULL, 't'},
        {"execute", no_argument, NULL, 'e'},
        {"help", no_argument, NULL, 'h'},
        {"version", no_argument, NULL, 'V'},
        {0, 0, 0, 0},
    };
    const char *target;
    int e_options;

    target = NULL;
    e_options = 0;
    for (;;) {
        int option;

        option = getopt_long(argc, argv, "+t:hVe", long_options, NULL);
        if (option == -1) {
            break;
        }
        switch (option) {
        case 't':
            if (target) {
                ovs_fatal(0, "-t or --target may be specified only once");
            }
            target = optarg;
            break;

        case 'e':
            /* We ignore -e for compatibility.  Older versions specified the
             * command as the argument to -e.  Since the current version takes
             * the command as non-option arguments and we say that -e has no
             * arguments, this just works in the common case. */
            if (e_options++) {
                ovs_fatal(0, "-e or --execute may be speciifed only once");
            }
            break;

        case 'h':
            usage();
            break;

        case 'V':
            OVS_PRINT_VERSION(0, 0);
            exit(EXIT_SUCCESS);

        case '?':
            exit(EXIT_FAILURE);

        default:
            NOT_REACHED();
        }
    }

    if (optind >= argc) {
        ovs_fatal(0, "at least one non-option argument is required "
                  "(use --help for help)");
    }

    return target ? target : "ovs-vswitchd";
}

static struct unixctl_client *
connect_to_target(const char *target)
{
    struct unixctl_client *client;
    char *socket_name;
    int error;

    if (target[0] != '/') {
        char *pidfile_name;
        pid_t pid;

        pidfile_name = xasprintf("%s/%s.pid", ovs_rundir(), target);
        pid = read_pidfile(pidfile_name);
        if (pid < 0) {
            ovs_fatal(-pid, "cannot read pidfile \"%s\"", pidfile_name);
        }
        free(pidfile_name);
        socket_name = xasprintf("%s/%s.%ld.ctl",
                                ovs_rundir(), target, (long int) pid);
    } else {
        socket_name = xstrdup(target);
    }

    error = unixctl_client_create(socket_name, &client);
    if (error) {
        ovs_fatal(error, "cannot connect to \"%s\"", socket_name);
    }
    free(socket_name);

    return client;
}