/*
 * Copyright (c) 2011 The Chromium OS Authors.
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <stdlib.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <linux/types.h>

#include <asm/getopt.h>
#include <asm/sections.h>
#include <asm/state.h>
#include <os.h>

/* Operating System Interface */

ssize_t os_read(int fd, void *buf, size_t count)
{
        return read(fd, buf, count);
}

ssize_t os_write(int fd, const void *buf, size_t count)
{
        return write(fd, buf, count);
}

off_t os_lseek(int fd, off_t offset, int whence)
{
        if (whence == OS_SEEK_SET)
                whence = SEEK_SET;
        else if (whence == OS_SEEK_CUR)
                whence = SEEK_CUR;
        else if (whence == OS_SEEK_END)
                whence = SEEK_END;
        else
                os_exit(1);
        return lseek(fd, offset, whence);
}

int os_open(const char *pathname, int os_flags)
{
        int flags;

        switch (os_flags & OS_O_MASK) {
        case OS_O_RDONLY:
        default:
                flags = O_RDONLY;
                break;

        case OS_O_WRONLY:
                flags = O_WRONLY;
                break;

        case OS_O_RDWR:
                flags = O_RDWR;
                break;
        }

        if (os_flags & OS_O_CREAT)
                flags |= O_CREAT;

        return open(pathname, flags, 0777);
}

int os_close(int fd)
{
        return close(fd);
}

void os_exit(int exit_code)
{
        exit(exit_code);
}

/* Restore tty state when we exit */
static struct termios orig_term;

static void os_fd_restore(void)
{
        tcsetattr(0, TCSANOW, &orig_term);
}

/* Put tty into raw mode so <tab> and <ctrl+c> work */
void os_tty_raw(int fd)
{
        static int setup = 0;
        struct termios term;

        if (setup)
                return;
        setup = 1;

        /* If not a tty, don't complain */
        if (tcgetattr(fd, &orig_term))
                return;

        term = orig_term;
        term.c_iflag = IGNBRK | IGNPAR;
        term.c_oflag = OPOST | ONLCR;
        term.c_cflag = CS8 | CREAD | CLOCAL;
        term.c_lflag = 0;
        if (tcsetattr(fd, TCSANOW, &term))
                return;

        atexit(os_fd_restore);
}

void *os_malloc(size_t length)
{
        return mmap(NULL, length, PROT_READ | PROT_WRITE,
                        MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
}

void os_usleep(unsigned long usec)
{
        usleep(usec);
}

u64 os_get_nsec(void)
{
#if defined(CLOCK_MONOTONIC) && defined(_POSIX_MONOTONIC_CLOCK)
        struct timespec tp;
        if (EINVAL == clock_gettime(CLOCK_MONOTONIC, &tp)) {
                struct timeval tv;

                gettimeofday(&tv, NULL);
                tp.tv_sec = tv.tv_sec;
                tp.tv_nsec = tv.tv_usec * 1000;
        }
        return tp.tv_sec * 1000000000ULL + tp.tv_nsec;
#else
        struct timeval tv;
        gettimeofday(&tv, NULL);
        return tv.tv_sec * 1000000000ULL + tv.tv_usec * 1000;
#endif
}

static char *short_opts;
static struct option *long_opts;

int os_parse_args(struct sandbox_state *state, int argc, char *argv[])
{
        struct sb_cmdline_option **sb_opt = __u_boot_sandbox_option_start;
        size_t num_options = __u_boot_sandbox_option_count();
        size_t i;

        int hidden_short_opt;
        size_t si;

        int c;

        if (short_opts || long_opts)
                return 1;

        state->argc = argc;
        state->argv = argv;

        /* dynamically construct the arguments to the system getopt_long */
        short_opts = os_malloc(sizeof(*short_opts) * num_options * 2 + 1);
        long_opts = os_malloc(sizeof(*long_opts) * num_options);
        if (!short_opts || !long_opts)
                return 1;

        /*
         * getopt_long requires "val" to be unique (since that is what the
         * func returns), so generate unique values automatically for flags
         * that don't have a short option.  pick 0x100 as that is above the
         * single byte range (where ASCII/ISO-XXXX-X charsets live).
         */
        hidden_short_opt = 0x100;
        si = 0;
        for (i = 0; i < num_options; ++i) {
                long_opts[i].name = sb_opt[i]->flag;
                long_opts[i].has_arg = sb_opt[i]->has_arg ?
                        required_argument : no_argument;
                long_opts[i].flag = NULL;

                if (sb_opt[i]->flag_short) {
                        short_opts[si++] = long_opts[i].val = sb_opt[i]->flag_short;
                        if (long_opts[i].has_arg == required_argument)
                                short_opts[si++] = ':';
                } else
                        long_opts[i].val = sb_opt[i]->flag_short = hidden_short_opt++;
        }
        short_opts[si] = '\0';

        /* we need to handle output ourselves since u-boot provides printf */
        opterr = 0;

        /*
         * walk all of the options the user gave us on the command line,
         * figure out what u-boot option structure they belong to (via
         * the unique short val key), and call the appropriate callback.
         */
        while ((c = getopt_long(argc, argv, short_opts, long_opts, NULL)) != -1) {
                for (i = 0; i < num_options; ++i) {
                        if (sb_opt[i]->flag_short == c) {
                                if (sb_opt[i]->callback(state, optarg)) {
                                        state->parse_err = sb_opt[i]->flag;
                                        return 0;
                                }
                                break;
                        }
                }
                if (i == num_options) {
                        /*
                         * store the faulting flag for later display.  we have to
                         * store the flag itself as the getopt parsing itself is
                         * tricky: need to handle the following flags (assume all
                         * of the below are unknown):
                         *   -a        optopt='a' optind=<next>
                         *   -abbbb    optopt='a' optind=<this>
                         *   -aaaaa    optopt='a' optind=<this>
                         *   --a       optopt=0   optind=<this>
                         * as you can see, it is impossible to determine the exact
                         * faulting flag without doing the parsing ourselves, so
                         * we just report the specific flag that failed.
                         */
                        if (optopt) {
                                static char parse_err[3] = { '-', 0, '\0', };
                                parse_err[1] = optopt;
                                state->parse_err = parse_err;
                        } else
                                state->parse_err = argv[optind - 1];
                        break;
                }
        }

        return 0;
}