/*
    Task Spooler - a task queue system for the unix user
    Copyright (C) 2007  Lluís Batlle i Rossell

    Please find the license in the provided COPYING file.
*/
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>

#include <stdio.h>

#include "main.h"

extern char *optarg;
extern int optind, opterr, optopt;

/* Globals */
struct Command_line command_line;
int server_socket;

/* Globals for the environment of getopt */
static char getopt_env[] = "POSIXLY_CORRECT=YES";
static char *old_getopt_env;

static char version[] = "Task Spooler v0.4.1 - a task queue system for the unix user.\n"
"Copyright (C) 2007  Lluis Batlle i Rossell";


static void default_command_line()
{
    command_line.request = c_LIST;
    command_line.need_server = 0;
    command_line.store_output = 1;
    command_line.should_go_background = 1;
    command_line.should_keep_finished = 1;
    command_line.gzip = 0;
    command_line.send_output_by_mail = 0;
}

void get_command(int index, int argc, char **argv)
{
    command_line.command.array = &(argv[index]);
    command_line.command.num = argc - index;
}

static int get_two_jobs(const char *str, int *j1, int *j2)
{
    char tmp[50];
    char *tmp2;

    if(strlen(str) >= 50)
        return 0;
    strcpy(tmp, str);

    tmp2 = strchr(tmp , '-');
    if (tmp2 == NULL)
        return 0;

    /* We change the '-' to '\0', so we have a delimiter,
     * and we can access the two strings for the ids */
    *tmp2 = '\0';
    /* Skip the '\0', and point tmp2 to the second id */
    ++tmp2;

    *j1 = atoi(tmp);
    *j2 = atoi(tmp2);
    return 1;
}

void parse_opts(int argc, char **argv)
{
    int c;
    int res;

    /* Parse options */
    while(1) {
        c = getopt(argc, argv, ":VhKgClnfmr:t:c:o:p:w:u:s:U:");

        if (c == -1)
            break;

        switch(c)
        {
            case 'K':
                command_line.request = c_KILL_SERVER;
                command_line.should_go_background = 0;
                break;
            case 'l':
                command_line.request = c_LIST;
                break;
            case 'h':
                command_line.request = c_SHOW_HELP;
                break;
            case 'V':
                command_line.request = c_SHOW_VERSION;
                break;
            case 'C':
                command_line.request = c_CLEAR_FINISHED;
                break;
            case 'c':
                command_line.request = c_CAT;
                command_line.jobid = atoi(optarg);
                break;
            case 'o':
                command_line.request = c_SHOW_OUTPUT_FILE;
                command_line.jobid = atoi(optarg);
                break;
            case 'n':
                command_line.store_output = 0;
                break;
            case 'g':
                command_line.gzip = 1;
                break;
            case 'f':
                command_line.should_go_background = 0;
                break;
            case 'm':
                command_line.send_output_by_mail = 1;
                break;
            case 't':
                command_line.request = c_TAIL;
                command_line.jobid = atoi(optarg);
                break;
            case 'p':
                command_line.request = c_SHOW_PID;
                command_line.jobid = atoi(optarg);
                break;
            case 'r':
                command_line.request = c_REMOVEJOB;
                command_line.jobid = atoi(optarg);
                break;
            case 'w':
                command_line.request = c_WAITJOB;
                command_line.jobid = atoi(optarg);
                break;
            case 'u':
                command_line.request = c_URGENT;
                command_line.jobid = atoi(optarg);
                break;
            case 's':
                command_line.request = c_GET_STATE;
                command_line.jobid = atoi(optarg);
                break;
            case 'U':
                command_line.request = c_SWAP_JOBS;
                res = get_two_jobs(optarg, &command_line.jobid,
                        &command_line.jobid2);
                if (!res)
                {
                    fprintf(stderr, "Wrong <id-id> for -U.\n");
                    exit(-1);
                }
                if (command_line.jobid == command_line.jobid2)
                {
                    fprintf(stderr, "Wrong <id-id> for -U. "
                            "Use different ids.\n");
                    exit(-1);
                }
                break;
            case ':':
                switch(optopt)
                {
                    case 't':
                        command_line.request = c_TAIL;
                        command_line.jobid = -1; /* This means the 'last' job */
                        break;
                    case 'c':
                        command_line.request = c_CAT;
                        command_line.jobid = -1; /* This means the 'last' job */
                        break;
                    case 'o':
                        command_line.request = c_SHOW_OUTPUT_FILE;
                        command_line.jobid = -1; /* This means the 'last' job */
                        break;
                    case 'p':
                        command_line.request = c_SHOW_PID;
                        command_line.jobid = -1; /* This means the 'last' job */
                        break;
                    case 'r':
                        command_line.request = c_REMOVEJOB;
                        command_line.jobid = -1; /* This means the 'last'
                                                    added job */
                        break;
                    case 'w':
                        command_line.request = c_WAITJOB;
                        command_line.jobid = -1; /* This means the 'last'
                                                    added job */
                        break;
                    case 'u':
                        command_line.request = c_URGENT;
                        command_line.jobid = -1; /* This means the 'last'
                                                    added job */
                        break;
                    case 's':
                        command_line.request = c_GET_STATE;
                        command_line.jobid = -1; /* This means the 'last'
                                                    added job */
                        break;
                    default:
                        fprintf(stderr, "Option %c missing argument: %s\n",
                                optopt, optarg);
                        exit(-1);
                }
                break;
            case '?':
                fprintf(stderr, "Wrong option %c.\n", optopt);
                exit(-1);
        }
    }

    command_line.command.num = 0;

    /* if the request is still the default option... 
     * (the default values should be centralized) */
    if (optind < argc && command_line.request == c_LIST)
    {
        command_line.request = c_QUEUE;
        get_command(optind, argc, argv);
    }

    if (command_line.request != c_SHOW_HELP &&
            command_line.request != c_SHOW_VERSION)
        command_line.need_server = 1;

    if ( ! command_line.store_output && ! command_line.should_go_background )
        command_line.should_keep_finished = 0;

    if ( command_line.send_output_by_mail && ((! command_line.store_output) ||
                command_line.gzip) )
    {
        fprintf(stderr,
                "For e-mail, you should store the output (not through gzip)\n");
        exit(-1);
    }
}

static void fill_first_3_handles()
{
    int tmp_pipe1[2];
    int tmp_pipe2[2];
    /* This will fill handles 0 and 1 */
    pipe(tmp_pipe1);
    /* This will fill handles 2 and 3 */
    pipe(tmp_pipe2);

    close(tmp_pipe2[1]);
}

static void go_background()
{
    int pid;
    pid = fork();

    switch(pid)
    {
        case -1:
            error("fork failed");
            break;
        case 0:
            close(0);
            close(1);
            close(2);
            /* This is a weird thing. But we will later want to
             * allocate special files to the 0, 1 or 2 fds. It's
             * almost impossible, if other important things got
             * allocated here. */
            fill_first_3_handles();
            setsid();
            break;
        default:
            exit(0);
    }
}

static void print_help(const char *cmd)
{
    printf("usage: %s [action] [-ngfm] [cmd...]\n", cmd);
    printf("Env vars:\n");
    printf("  TS_SOCKET  the path to the unix socket used by the ts command\n");
    printf("  TS_MAILTO  where to mail the result (on -m). Local user by default\n");
    printf("  TS_MAXFINISHED  maximum finished jobs in the queue\n");
    printf("  TS_ONFINISH  binary called on job end (passing jobid, error, outfile, command)\n");
    printf("Actions:\n");
    printf("  -K       kill the task spooler server\n");
    printf("  -C       clear the list of finished jobs\n");
    printf("  -l       show the job list (default action)\n");
    printf("  -t [id]  tail -f the output of the job. Last run if not specified.\n");
    printf("  -c [id]  cat the output of the job. Last run if not specified.\n");
    printf("  -p [id]  show the pid of the job. Last run if not specified.\n");
    printf("  -o [id]  show the output file. Of last job run, if not specified.\n");
    printf("  -s [id]  show the job state. Of the last added, if not specified.\n");
    printf("  -r [id]  remove a job. The last added, if not specified.\n");
    printf("  -w [id]  wait for a job. The last added, if not specified.\n");
    printf("  -u [id]  put that job first. The last added, if not specified.\n");
    printf("  -U <id-id>  swap two jobs in the queue.\n");
    printf("  -h       show this help\n");
    printf("  -V       show the program version\n");
    printf("Options adding jobs:\n");
    printf("  -n       don't store the output of the command.\n");
    printf("  -g       gzip the stored output (if not -n).\n");
    printf("  -f       don't fork into background.\n");
    printf("  -m       send the output by e-mail (uses sendmail).\n");
}

static void print_version()
{
    puts(version);
}

static void set_getopt_env()
{
    old_getopt_env = getenv("POSIXLY_CORRECT");
    putenv(getopt_env);
}

static void unset_getopt_env()
{
    if (old_getopt_env == NULL)
    {
        /* Wipe the string from the environment */
        putenv("POSIXLY_CORRECT");
    }
    else
        sprintf(getopt_env, "POSIXLY_CORRECT=%s", old_getopt_env);
}

int main(int argc, char **argv)
{
    int errorlevel = 0;

    process_type = CLIENT;

    set_getopt_env();
    /* This is needed in a gnu system, so getopt works well */
    default_command_line();
    parse_opts(argc, argv);
    unset_getopt_env();

    /* This will be inherited by the server, if it's run */
    ignore_sigpipe();

    if (command_line.need_server)
        ensure_server_up();

    switch(command_line.request)
    {
    case c_SHOW_VERSION:
        print_version(argv[0]);
        break;
    case c_SHOW_HELP:
        print_help(argv[0]);
        break;
    case c_QUEUE:
        if (command_line.command.num <= 0)
            error("Tried to queue a void command. parameters: %i",
                    command_line.command.num);
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_new_job();
        command_line.jobid = c_wait_newjob_ok();
        if (command_line.store_output)
        {
            printf("%i\n", command_line.jobid);
            fflush(stdout);
        }
        if (command_line.should_go_background)
        {
            go_background();
            c_wait_server_commands();
        } else
        {
            errorlevel = c_wait_server_commands();
        }
        break;
    case c_LIST:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_list_jobs();
        c_wait_server_lines();
        break;
    case c_KILL_SERVER:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_shutdown_server();
        break;
    case c_CLEAR_FINISHED:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_clear_finished();
        break;
    case c_TAIL:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_tail();
        /* This will not return! */
        break;
    case c_CAT:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_cat();
        /* This will not return! */
        break;
    case c_SHOW_OUTPUT_FILE:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_show_output_file();
        break;
    case c_SHOW_PID:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_show_pid();
        break;
    case c_REMOVEJOB:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_remove_job();
        break;
    case c_WAITJOB:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        errorlevel = c_wait_job();
        break;
    case c_URGENT:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_move_urgent();
        break;
    case c_SWAP_JOBS:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        c_swap_jobs();
        break;
    case c_GET_STATE:
        if (!command_line.need_server)
            error("The command %i needs the server", command_line.request);
        /* This will also print the state into stdout */
        c_get_state();
        break;
    }

    if (command_line.need_server)
    {
        close(server_socket);
    }

    return errorlevel;
}