/**
 * rofi
 *
 * MIT/X11 License
 * Copyright 2013-2014 Qball  Cow <qball@gmpclient.org>
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <X11/X.h>

#include <unistd.h>
#include <signal.h>
#include <sys/types.h>
#include <dirent.h>
#include <strings.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include "rofi.h"
#include "ssh-dialog.h"
#ifdef TIMING
#include <time.h>
#endif

#define SSH_CACHE_FILE    "rofi.sshcache"

static inline int execshssh ( const char *host )
{
    return execlp ( config.terminal_emulator, config.terminal_emulator, "-e", "ssh", host, NULL );
}
// execute sub-process
static pid_t exec_ssh ( const char *cmd )
{
    if ( !cmd || !cmd[0] )
    {
        return -1;
    }

    signal ( SIGCHLD, catch_exit );
    pid_t pid = fork ();

    if ( !pid )
    {
        setsid ();
        execshssh ( cmd );
        exit ( EXIT_FAILURE );
    }

    int          curr   = -1;
    unsigned int index  = 0;
    char         **retv = NULL;

    /**
     * This happens in non-critical time (After launching app)
     * It is allowed to be a bit slower.
     */
    char *path = allocate ( strlen ( cache_dir ) + strlen ( SSH_CACHE_FILE ) + 3 );
    sprintf ( path, "%s/%s", cache_dir, SSH_CACHE_FILE );
    FILE *fd = fopen ( path, "r" );

    if ( fd != NULL )
    {
        char buffer[1024];
        while ( fgets ( buffer, 1024, fd ) != NULL )
        {
            retv                          = reallocate ( retv, ( index + 2 ) * sizeof ( char* ) );
            buffer[strlen ( buffer ) - 1] = '\0';
            retv[index]                   = strdup ( buffer );
            retv[index + 1]               = NULL;

            if ( strcasecmp ( retv[index], cmd ) == 0 )
            {
                curr = index;
            }

            index++;
        }

        fclose ( fd );
    }

    /**
     * Write out the last 25 results again.
     */
    fd = fopen ( path, "w" );

    if ( fd )
    {
        // Last one goes on top!
        fputs ( cmd, fd );
        fputc ( '\n', fd );

        for ( int i = 0; i < ( int ) index && i < 20; i++ )
        {
            if ( i != curr )
            {
                fputs ( retv[i], fd );
                fputc ( '\n', fd );
            }
        }

        fclose ( fd );
    }

    for ( int i = 0; retv != NULL && retv[i] != NULL; i++ )
    {
        free ( retv[i] );
    }

    free ( retv );

    free ( path );

    return pid;
}
static void delete_ssh ( const char *cmd )
{
    if ( !cmd || !cmd[0] )
    {
        return;
    }

    int          curr   = -1;
    unsigned int index  = 0;
    char         **retv = NULL;

    /**
     * This happens in non-critical time (After launching app)
     * It is allowed to be a bit slower.
     */
    char *path = allocate ( strlen ( cache_dir ) + strlen ( SSH_CACHE_FILE ) + 3 );
    sprintf ( path, "%s/%s", cache_dir, SSH_CACHE_FILE );
    FILE *fd = fopen ( path, "r" );

    if ( fd != NULL )
    {
        char buffer[1024];
        while ( fgets ( buffer, 1024, fd ) != NULL )
        {
            retv                          = reallocate ( retv, ( index + 2 ) * sizeof ( char* ) );
            buffer[strlen ( buffer ) - 1] = '\0';
            retv[index]                   = strdup ( buffer );
            retv[index + 1]               = NULL;

            if ( strcasecmp ( retv[index], cmd ) == 0 )
            {
                curr = index;
            }

            index++;
        }

        fclose ( fd );
    }

    /**
     * Write out the last 25 results again.
     */
    fd = fopen ( path, "w" );

    if ( fd )
    {
        for ( int i = 0; i < ( int ) index && i < 20; i++ )
        {
            if ( i != curr )
            {
                fputs ( retv[i], fd );
                fputc ( '\n', fd );
            }
        }

        fclose ( fd );
    }

    for ( int i = 0; retv != NULL && retv[i] != NULL; i++ )
    {
        free ( retv[i] );
    }

    free ( retv );

    free ( path );
}
static int sort_func ( const void *a, const void *b )
{
    const char *astr = *( const char * const * ) a;
    const char *bstr = *( const char * const * ) b;
    return strcasecmp ( astr, bstr );
}
static char ** get_ssh ( )
{
    unsigned int    num_favorites = 0;
    unsigned int    index         = 0;
    char            *path;
    char            **retv = NULL;
#ifdef TIMING
    struct timespec start, stop;
    clock_gettime ( CLOCK_REALTIME, &start );
#endif

    if ( getenv ( "HOME" ) == NULL )
    {
        return NULL;
    }

    path = allocate ( strlen ( cache_dir ) + strlen ( "/"SSH_CACHE_FILE ) + 2 );
    sprintf ( path, "%s/%s", cache_dir, SSH_CACHE_FILE );
    FILE *fd = fopen ( path, "r" );
    char buffer[1024];

    if ( fd != NULL )
    {
        while ( fgets ( buffer, 1024, fd ) != NULL )
        {
            retv                          = reallocate ( retv, ( index + 2 ) * sizeof ( char* ) );
            buffer[strlen ( buffer ) - 1] = '\0';
            retv[index]                   = strdup ( buffer );
            retv[index + 1]               = NULL;
            index++;
            num_favorites++;
        }

        fclose ( fd );
    }

    free ( path );
    const char *hd = getenv ( "HOME" );
    path = allocate ( strlen ( hd ) + strlen ( ".ssh/config" ) + 3 );
    sprintf ( path, "%s/%s", hd, ".ssh/config" );
    fd = fopen ( path, "r" );

    if ( fd != NULL )
    {
        while ( fgets ( buffer, 1024, fd ) != NULL )
        {
            if ( strncasecmp ( buffer, "Host", 4 ) == 0 )
            {
                int start = 0, stop = 0;
                buffer[strlen ( buffer ) - 1] = '\0';

                for ( start = 4; isspace ( buffer[start] ); start++ )
                {
                    ;
                }

                for ( stop = start; isalnum ( buffer[stop] ) ||
                      buffer[stop] == '_' ||
                      buffer[stop] == '.'; stop++ )
                {
                    ;
                }

                int found = 0;

                if ( start == stop )
                {
                    continue;
                }

                // This is a nice little penalty, but doable? time will tell.
                // given num_favorites is max 25.
                for ( unsigned int j = 0; found == 0 && j < num_favorites; j++ )
                {
                    if ( strncasecmp ( &buffer[start], retv[j], stop - start ) == 0 )
                    {
                        found = 1;
                    }
                }

                if ( found == 1 )
                {
                    continue;
                }

                retv            = reallocate ( retv, ( index + 2 ) * sizeof ( char* ) );
                retv[index]     = strndup ( &buffer[start], stop - start );
                retv[index + 1] = NULL;
                index++;
            }
        }

        fclose ( fd );
    }

    // TODO: check this is still fast enough. (takes 1ms on laptop.)
    if ( index > num_favorites )
    {
        qsort ( &retv[num_favorites], index - num_favorites, sizeof ( char* ), sort_func );
    }
    free ( path );
#ifdef TIMING
    clock_gettime ( CLOCK_REALTIME, &stop );

    if ( stop.tv_sec != start.tv_sec )
    {
        stop.tv_nsec += ( stop.tv_sec - start.tv_sec ) * 1e9;
    }

    long diff = stop.tv_nsec - start.tv_nsec;
    printf ( "Time elapsed: %ld us\n", diff / 1000 );
#endif
    return retv;
}

SwitcherMode ssh_switcher_dialog ( char **input )
{
    SwitcherMode retv = MODE_EXIT;
    // act as a launcher
    char         **cmd_list = get_ssh ( );

    if ( cmd_list == NULL )
    {
        cmd_list    = allocate ( 2 * sizeof ( char * ) );
        cmd_list[0] = strdup ( "No ssh hosts found" );
        cmd_list[1] = NULL;
    }

    int shift         = 0;
    int selected_line = 0;
    int mretv         = menu ( cmd_list, input, "ssh", NULL, &shift, token_match, NULL, &selected_line );

    if ( mretv == MENU_NEXT )
    {
        retv = NEXT_DIALOG;
    }
    else if ( mretv == MENU_OK && cmd_list[selected_line] != NULL )
    {
        exec_ssh ( cmd_list[selected_line] );
    }
    else if ( mretv == MENU_CUSTOM_INPUT && *input != NULL && *input[0] != '\0' )
    {
        exec_ssh ( *input );
    }
    else if ( mretv == MENU_ENTRY_DELETE && cmd_list[selected_line] )
    {
        delete_ssh ( cmd_list[selected_line] );
        // Stay
        retv = SSH_DIALOG;
    }

    for ( int i = 0; cmd_list[i] != NULL; i++ )
    {
        free ( cmd_list[i] );
    }

    if ( cmd_list != NULL )
    {
        free ( cmd_list );
    }

    return retv;
}