/*
 *  RT-Thread module shell implementation.
 *
 * COPYRIGHT (C) 2013, Shanghai Real-Thread Technology Co., Ltd
 *
 *  This file is part of RT-Thread (http://www.rt-thread.org)
 *  Maintainer: bernard.xiong <bernard.xiong at gmail.com>
 *
 *  All rights reserved.
 *
 *  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.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2013-03-30     Bernard      the first verion for finsh
 * 2014-01-03     Bernard      msh can execute module.
 */

#include "msh.h"
#include <finsh.h>
#include <shell.h>

#ifdef RT_USING_DFS
#include <dfs_posix.h>
#endif

#define RT_FINSH_ARG_MAX    10
typedef int (*cmd_function_t)(int argc, char** argv);

#ifdef FINSH_USING_MSH
#ifdef FINSH_USING_MSH_ONLY
rt_bool_t msh_is_used(void)
{
    return RT_TRUE;
}
#else
#ifdef FINSH_USING_MSH_DEFAULT
static rt_bool_t __msh_state = RT_TRUE;
#else
static rt_bool_t __msh_state = RT_FALSE;
#endif
rt_bool_t msh_is_used(void)
{
    return __msh_state;
}

static int msh_exit(int argc, char** argv)
{
    /* return to finsh shell mode */
    __msh_state = RT_FALSE;

    return 0;
}
FINSH_FUNCTION_EXPORT_ALIAS(msh_exit, __cmd_exit, return to RT-Thread shell mode.);

static int msh_enter(void)
{
    /* enter module shell mode */
    __msh_state = RT_TRUE;
    return 0;
}
FINSH_FUNCTION_EXPORT_ALIAS(msh_enter, msh, use module shell);
#endif

int msh_help(int argc, char** argv)
{
    rt_kprintf("RT-Thread shell commands:\n");
    {
        struct finsh_syscall *index;

        for (index = _syscall_table_begin;
            index < _syscall_table_end;
            FINSH_NEXT_SYSCALL(index))
        {
            if (strncmp(index->name, "__cmd_", 6) != 0) continue;
#if defined(FINSH_USING_DESCRIPTION) && defined(FINSH_USING_SYMTAB)
            rt_kprintf("%-16s - %s\n", &index->name[6], index->desc);
#else
            rt_kprintf("%s ", &index->name[6]);
#endif
        }
    }
    rt_kprintf("\n");

    return 0;
}
FINSH_FUNCTION_EXPORT_ALIAS(msh_help, __cmd_help, RT-Thread shell help.);

static int msh_split(char* cmd, rt_size_t length, char* argv[RT_FINSH_ARG_MAX])
{
    char *ptr;
    rt_size_t position;
    rt_size_t argc;

    ptr = cmd;
    position = 0; argc = 0;

    while (position < length)
    {
        /* strip bank and tab */
        while ((*ptr == ' ' || *ptr == '\t') && position < length)
        {
            *ptr = '\0';
            ptr ++; position ++;
        }
        if (position >= length) break;

        /* handle string */
        if (*ptr == '"')
        {
            ptr ++; position ++;
            argv[argc] = ptr; argc ++;

            /* skip this string */
            while (*ptr != '"' && position < length)
            {
                if (*ptr == '\\')
                {
                    if (*(ptr + 1) == '"')
                    {
                        ptr ++; position ++;
                    }
                }
                ptr ++; position ++;
            }
            if (position >= length) break;

            /* skip '"' */
            *ptr = '\0'; ptr ++; position ++;
        }
        else
        {
            argv[argc] = ptr;
            argc ++;
            while ((*ptr != ' ' && *ptr != '\t') && position < length)
            {
                ptr ++; position ++;
            }
            if (position >= length) break;
        }
    }

    return argc;
}

static cmd_function_t msh_get_cmd(char *cmd, int size)
{
    struct finsh_syscall *index;
    cmd_function_t cmd_func = RT_NULL;

    for (index = _syscall_table_begin;
        index < _syscall_table_end;
        FINSH_NEXT_SYSCALL(index))
    {
        if (strncmp(index->name, "__cmd_", 6) != 0) continue;
        
        if (strncmp(&index->name[6], cmd, size) == 0 &&
			index->name[6 + size] == '\0')
        {
            cmd_func = (cmd_function_t)index->func;
            break;
        }
    }

    return cmd_func;
}

#if defined(RT_USING_MODULE) && defined(RT_USING_DFS)
/* Return 0 on module executed. Other value indicate error.
 */
int msh_exec_module(const char* cmd_line, int size)
{
    int ret;
    int fd = -1;
    char *pg_name;
    int length, cmd_length = 0;

    if (size == 0)
        return -RT_ERROR;
    /* get the length of command0 */
    while ((cmd_line[cmd_length] != ' ' && cmd_line[cmd_length] != '\t') && cmd_length < size)
        cmd_length ++;

    /* get name length */
    length = cmd_length + 32;

    /* allocate program name memory */
    pg_name = (char*) rt_malloc(length);
    if (pg_name == RT_NULL)
        return -RT_ENOMEM;

    /* copy command0 */
    memcpy(pg_name, cmd_line, cmd_length);
    pg_name[cmd_length] = '\0';

    if (strstr(pg_name, ".mo") != RT_NULL || strstr(pg_name, ".MO") != RT_NULL)
    {
        /* try to open program */
        fd = open(pg_name, O_RDONLY, 0);

        /* search in /bin path */
        if (fd < 0)
        {
            rt_snprintf(pg_name, length - 1, "/bin/%.*s", cmd_length, cmd_line);
            fd = open(pg_name, O_RDONLY, 0);
        }
    }
    else
    {
        /* add .mo and open program */

        /* try to open program */
        strcat(pg_name, ".mo");
        fd = open(pg_name, O_RDONLY, 0);

        /* search in /bin path */
        if (fd < 0)
        {
            rt_snprintf(pg_name, length - 1, "/bin/%.*s.mo", cmd_length, cmd_line);
            fd = open(pg_name, O_RDONLY, 0);
        }
    }

    if (fd >= 0)
    {
        /* found program */
        close(fd);
        rt_module_exec_cmd(pg_name, cmd_line, size);
        ret = 0;
    }
    else
    {
        ret = -1;
    }

    rt_free(pg_name);
    return ret;
}

int system(const char *command)
{
    return msh_exec_module(command, rt_strlen(command));
}
RTM_EXPORT(system);
#endif

static int _msh_exec_cmd(char* cmd, rt_size_t length, int *retp)
{
    int argc;
    int cmd0_size = 0;
    cmd_function_t cmd_func;
    char *argv[RT_FINSH_ARG_MAX];

    RT_ASSERT(cmd);
    RT_ASSERT(retp);

    /* find the size of first command */
    while ((cmd[cmd0_size] != ' ' && cmd[cmd0_size] != '\t') && cmd0_size < length)
        cmd0_size ++;
    if (cmd0_size == 0)
        return -RT_ERROR;

    cmd_func = msh_get_cmd(cmd, cmd0_size);
    if (cmd_func == RT_NULL)
        return -RT_ERROR;

    /* split arguments */
    memset(argv, 0x00, sizeof(argv));
    argc = msh_split(cmd, length, argv);
    if (argc == 0)
        return -RT_ERROR;

    /* exec this command */
    *retp = cmd_func(argc, argv);
    return 0;
}

int msh_exec(char* cmd, rt_size_t length)
{
    int cmd_ret;

	/* strim the beginning of command */
    while(*cmd  == ' ' || *cmd == '\t')
    {
        cmd++;
        length--;
    }

    if (length == 0)
        return 0;

    /* Exec sequence:
     * 1. built-in command
     * 2. module(if enabled)
     * 3. chdir to the directry(if possible)
     */
    if (_msh_exec_cmd(cmd, length, &cmd_ret) == 0)
    {
        return cmd_ret;
    }
#ifdef RT_USING_MODULE
    if (msh_exec_module(cmd, length) == 0)
    {
        return 0;
    }
#endif

#if defined(RT_USING_DFS) && defined(DFS_USING_WORKDIR)
	/* change to this directory */
    if (chdir(cmd) == 0)
    {
        return 0;
    }
#endif

    /* truncate the cmd at the first space. */
    {
        char *tcmd;
        tcmd = cmd;
        while(*tcmd != ' ' && *tcmd != '\0')
        {
            tcmd++;
        }
        *tcmd = '\0';
    }
    rt_kprintf("%s: command not found.\n", cmd);
    return -1;
}

static int str_common(const char *str1, const char *str2)
{
    const char *str = str1;

    while ((*str != 0) && (*str2 != 0) && (*str == *str2))
    {
        str ++;
        str2 ++;
    }

    return (str - str1);
}

#ifdef RT_USING_DFS
void msh_auto_complete_path(char *path)
{
    DIR* dir = RT_NULL;
    struct dirent *dirent = RT_NULL;
    char *full_path, *ptr, *index;

    if (!path)
        return;

    full_path = (char*)rt_malloc(256);
    if (full_path == RT_NULL) return; /* out of memory */

    if (*path != '/')
    {
        getcwd(full_path, 256);
        if (full_path[rt_strlen(full_path) - 1]  != '/')
            strcat(full_path, "/");
    }
    else *full_path = '\0';

    index = RT_NULL;
    ptr = path;
    for (;;)
    {
        if (*ptr == '/') index = ptr + 1; if (!*ptr) break; ptr ++;
    }
    if (index == RT_NULL) index = path;

    if (index != RT_NULL)
    {
        char *dest = index;

        /* fill the parent path */
        ptr = full_path;
        while (*ptr) ptr ++;

        for (index = path; index != dest;)
            *ptr++ = *index++;
        *ptr = '\0';

        dir = opendir(full_path);
        if (dir == RT_NULL) /* open directory failed! */
        {
            rt_free(full_path);
            return;
        }

        /* restore the index position */
        index = dest;
    }

    /* auto complete the file or directory name */
    if (*index == '\0') /* display all of files and directories */
    {
        for (;;)
        {
            dirent = readdir(dir);
            if (dirent == RT_NULL) break;

            rt_kprintf("%s\n", dirent->d_name);
        }
    }
    else
    {
        int length, min_length;

        min_length = 0;
        for (;;)
        {
            dirent = readdir(dir);
            if (dirent == RT_NULL) break;

            /* matched the prefix string */
            if (strncmp(index, dirent->d_name, rt_strlen(index)) == 0)
            {
                if (min_length == 0)
                {
                    min_length = rt_strlen(dirent->d_name);
                    /* save dirent name */
                    strcpy(full_path, dirent->d_name);
                }
                
                length = str_common(dirent->d_name, full_path);
                
                if (length < min_length)
                {
                    min_length = length;
                }
            }
        }

        if (min_length)
        {
            if (min_length < rt_strlen(full_path))
            {
                /* list the candidate */
                rewinddir(dir);

                for (;;)
                {
                    dirent = readdir(dir);
                    if (dirent == RT_NULL) break;

                    if (strncmp(index, dirent->d_name, rt_strlen(index)) == 0)
                        rt_kprintf("%s\n", dirent->d_name);
                }
            }
            
            length = index - path;
            memcpy(index, full_path, min_length);
            path[length + min_length] = '\0';
        }
    }

    closedir(dir);
    rt_free(full_path);
}
#endif

void msh_auto_complete(char *prefix)
{
    int length, min_length;
    const char *name_ptr, *cmd_name;
    struct finsh_syscall *index;

    min_length = 0;
    name_ptr = RT_NULL;

    if (*prefix == '\0') 
    {
        msh_help(0, RT_NULL);
        return;
    }

#ifdef RT_USING_DFS
    /* check whether a spare in the command */
    {
        char *ptr;

        ptr = prefix + rt_strlen(prefix);
        while (ptr != prefix)
        {
            if (*ptr == ' ')
            {
                msh_auto_complete_path(ptr + 1);
                break;
            }

            ptr --;
        }
#ifdef RT_USING_MODULE
        /* There is a chance that the user want to run the module directly. So
         * try to complete the file names. If the completed path is not a
         * module, the system won't crash anyway. */
        if (ptr == prefix)
        {
            msh_auto_complete_path(ptr);
        }
#endif
    }
#endif

    /* checks in internal command */
    {
        for (index = _syscall_table_begin; index < _syscall_table_end; FINSH_NEXT_SYSCALL(index))
        {
            /* skip finsh shell function */
            if (strncmp(index->name, "__cmd_", 6) != 0) continue;

            cmd_name = (const char*) &index->name[6];
            if (strncmp(prefix, cmd_name, strlen(prefix)) == 0)
            {
                if (min_length == 0)
                {
                    /* set name_ptr */
                    name_ptr = cmd_name;
                    /* set initial length */
                    min_length = strlen(name_ptr);
                }

                length = str_common(name_ptr, cmd_name);
                if (length < min_length)
                    min_length = length;

                rt_kprintf("%s\n", cmd_name);
            }
        }
    }

    /* auto complete string */
    if (name_ptr != NULL)
    {
        rt_strncpy(prefix, name_ptr, min_length);
    }

    return ;
}
#endif