/*
 * secde -- experimental lightweight Wayland/X11 server
 * Copyright (C) 2019  Samuel Lidén Borell
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

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

#include "epoll.h"
#include "settings.h"
#include "version.h"

/* X11 */
#define MAXNUMLEN 10
static struct {
    char prefix[16]; /* no null terminator */
    char number[MAXNUMLEN+1];
} x11_sockfile = { "/tmp/.X11-unix/X", "" };
static const char digits[] = "0123456789";

static int show_usage = 0;
static int show_help = 0;
static int show_version = 0;
static int dispnum_set = 0;
static int dont_start = 0;

static struct Settings settings;


static int parse_nonflag(const char *progname, const char *arg)
{
    if (arg[0] == ':') {
        /* X11 display number */
        arg++;
        size_t len = strlen(arg);
        if (len > MAXNUMLEN || strspn(arg, digits) != len) {
            fprintf(stderr, "%s: invalid display number: %s\n",
                    progname, arg);
            return 2;
        }
        if (dispnum_set) {
            fprintf(stderr, "%s: multiple display numbers specified\n",
                    progname);
            return 2;
        }
        memcpy(&x11_sockfile.number, arg, len+1);
        dispnum_set = 1;
        return 0;
    } else {
        fprintf(stderr, "%s: invalid argument: %s\n",
                progname, arg);
        return 2;
    }
}


static int parse_args(int argc, char **argv)
{
    char **argp = argv;
    int no_more_flags = 0;
    int ret = 0;
  next_arg: while (--argc) {
        const char *arg = *++argp;
        if (no_more_flags || arg[0] != '-' || arg[1] == '\0') {
            /* Not a flag */
            int r = parse_nonflag(argv[0], arg);
            if (r > ret) { ret = r; }
            continue;
        }
        /* Flag */
        if (arg[1] == '-') {
            /* -- */
            if (arg[2] == '\0') {
                no_more_flags = 1;
                continue;
            }
            /* Long flag */
            arg += 2;
            if (!strcmp(arg, "help")) {
                show_usage = 1;
                show_help = 1;
                dont_start = 1;
            } else if (!strcmp(arg, "version")) {
                show_version = 1;
                dont_start = 1;
            } else {
                fprintf(stderr, "%s: unrecognized option '%s'\n",
                        argv[0],*argp);
                ret = 2;
            }
            continue;
        }
        while (*arg) {
            switch (arg[1]) {
                case 'h':
                    show_usage = 1;
                    show_help = 1;
                    dont_start = 1;
                    break;
                default:
                    fprintf(stderr, "%s: invalid option '%c' in argument '%s'\n",
                            argv[0], *arg, *argp);
                    ret = 2;
                    goto next_arg;
            }
            arg++;
        }
    }
    if (ret) {
        dont_start = 1;
        return ret;
    }
    if (!dispnum_set) {
        strcpy(x11_sockfile.number, "0");
    }
    settings.x11sockfile = x11_sockfile.prefix;
    return 0;
}


static void print_usage(const char *progname) {
    printf("usage: %s [OPTIONS ...] [:DISPLAY]\n", progname);
}


static void print_help() {
    printf(
"\n"
"Starts the secde display server and desktop environment.\n"
"\n"
"An X11 display number may be specified, this controls the name of\n"
"the socket that applications connect to. If not specified it will\n"
"use :0 for the display number.\n"
"\n"
"List of options:\n"
"    --help         Shows this help\n"
"    --version      Shows version\n"
"\n");
}


static void print_version() {
    printf("secde " VERSION_STRING "\n");
}

int main(int argc, char **argv)
{
    int ret = parse_args(argc, argv);
    if (show_usage) {
        print_usage(argv[0]);
    }
    if (show_help) {
        print_help();
    }
    if (show_version) {
        print_version();
    }
    if (dont_start) return ret;

    return mainloop_epoll(&settings);

}