/*
 * Copyright (c) 2006-2022, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2013-03-30     Bernard      the first verion for finsh
 * 2014-01-03     Bernard      msh can execute module.
 * 2017-07-19     Aubr.Cool    limit argc to RT_FINSH_ARG_MAX
 */
#include <rtthread.h>
#include <string.h>
#include <errno.h>

#ifdef RT_USING_FINSH

#ifndef FINSH_ARG_MAX
#define FINSH_ARG_MAX    8
#endif /* FINSH_ARG_MAX */

#include "msh.h"
#include "shell.h"
#ifdef DFS_USING_POSIX
#include <dfs_file.h>
#include <unistd.h>
#include <fcntl.h>
#endif /* DFS_USING_POSIX */
#ifdef RT_USING_MODULE
#include <dlmodule.h>
#endif /* RT_USING_MODULE */

typedef int (*cmd_function_t)(int argc, char **argv);

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 defined(FINSH_USING_DESCRIPTION) && defined(FINSH_USING_SYMTAB)
            rt_kprintf("%-16s - %s\n", index->name, index->desc);
#else
            rt_kprintf("%s ", index->name);
#endif
        }
    }
    rt_kprintf("\n");

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

#ifdef MSH_USING_BUILT_IN_COMMANDS
int cmd_ps(int argc, char **argv)
{
    extern long list_thread(void);
    extern int list_module(void);

#ifdef RT_USING_MODULE
    if ((argc == 2) && (strcmp(argv[1], "-m") == 0))
        list_module();
    else
#endif
        list_thread();
    return 0;
}
MSH_CMD_EXPORT_ALIAS(cmd_ps, ps, List threads in the system.);

#ifdef RT_USING_HEAP
int cmd_free(int argc, char **argv)
{
#ifdef RT_USING_MEMHEAP_AS_HEAP
    extern void list_memheap(void);
    list_memheap();
#else
    rt_size_t total = 0, used = 0, max_used = 0;

    rt_memory_info(&total, &used, &max_used);
    rt_kprintf("total    : %d\n", total);
    rt_kprintf("used     : %d\n", used);
    rt_kprintf("maximum  : %d\n", max_used);
    rt_kprintf("available: %d\n", total - used);
#endif
    return 0;
}
MSH_CMD_EXPORT_ALIAS(cmd_free, free, Show the memory usage in the system.);
#endif /* RT_USING_HEAP */
#endif /* MSH_USING_BUILT_IN_COMMANDS */

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

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

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

        if (argc >= FINSH_ARG_MAX)
        {
            rt_kprintf("Too many args ! We only Use:\n");
            for (i = 0; i < argc; i++)
            {
                rt_kprintf("%s ", argv[i]);
            }
            rt_kprintf("\n");
            break;
        }

        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, size) == 0 &&
                index->name[size] == '\0')
        {
            cmd_func = (cmd_function_t)index->func;
            break;
        }
    }

    return cmd_func;
}

#if defined(RT_USING_MODULE) && defined(DFS_USING_POSIX)
/* 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 + 3);
    if (pg_name == RT_NULL)
        return -RT_ENOMEM;

    /* copy command0 */
    rt_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);
        dlmodule_exec(pg_name, cmd_line, size);
        ret = 0;
    }
    else
    {
        ret = -1;
    }

    rt_free(pg_name);
    return ret;
}
#endif

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

    RT_ASSERT(cmd);
    RT_ASSERT(retp);

    /* find the size of first command */
    while (cmd0_size < length && (cmd[cmd0_size] != ' ' && cmd[cmd0_size] != '\t'))
        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 */
    rt_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;
}

#if defined(RT_USING_SMART) && defined(DFS_USING_POSIX)
pid_t exec(char*, int, int, char**);

/* check whether a file of the given path exits */
static rt_bool_t _msh_lwp_cmd_exists(const char *path)
{
    int fd = -1;
    fd = open(path, O_RDONLY, 0);
    if (fd < 0)
    {
        return RT_FALSE;
    }
    close(fd);
    return RT_TRUE;
}

/*
 * search for the file named "pg_name" or "pg_name.elf" at the given directory,
 * and return its path. return NULL when not found.
 */
static char *_msh_exec_search_path(const char *path, const char *pg_name)
{
    char *path_buffer = RT_NULL;
    ssize_t pg_len = strlen(pg_name);
    ssize_t base_len = 0;

    if (path)
    {
        base_len = strlen(path);
    }

    path_buffer = rt_malloc(base_len + pg_len + 6);
    if (path_buffer == RT_NULL)
    {
        return RT_NULL; /* no mem */
    }

    if (base_len > 0)
    {
        memcpy(path_buffer, path, base_len);
        path_buffer[base_len] = '/';
        path_buffer[base_len + 1] = '\0';
    }
    else
    {
        *path_buffer = '\0';
    }
    strcat(path_buffer, pg_name);

    if (_msh_lwp_cmd_exists(path_buffer))
    {
        return path_buffer;
    }

    if (strstr(path_buffer, ".elf") != NULL)
    {
        goto not_found;
    }

    strcat(path_buffer, ".elf");
    if (_msh_lwp_cmd_exists(path_buffer))
    {
        return path_buffer;
    }

not_found:
    rt_free(path_buffer);
    return RT_NULL;
}

/*
 * search for the file named "pg_name" or "pg_name.elf" at each env path,
 * and return its path. return NULL when not found.
 */
static char *_msh_exec_search_env(const char *pg_name)
{
    char *result = RT_NULL;
    char *exec_path = RT_NULL;
    char *search_path = RT_NULL;
    char *pos = RT_NULL;
    char tmp_ch = '\0';

    if (!(exec_path = getenv("PATH")))
    {
        return RT_NULL;
    }

    /* exec path may need to be modified */
    if (!(exec_path = strdup(exec_path)))
    {
        return RT_NULL;
    }

    pos = exec_path;
    search_path = exec_path;

    /* walk through the entire exec_path until finding the program wanted
       or hitting its end */
    while (1)
    {
        /* env paths are seperated by ':' */
        if (*pos == ':' || *pos == '\0')
        {
            tmp_ch = *pos;
            *pos = '\0';

            result = _msh_exec_search_path(search_path, pg_name);
            if (result || tmp_ch == '\0')
            {
                goto ret;
            }

            pos++;
            search_path = pos;
            continue;
        }

        pos++;
    }

    /* release the duplicated exec_path and return */
ret:
    rt_free(exec_path);
    return result;
}

int _msh_exec_lwp(int debug, char *cmd, rt_size_t length)
{
    int argc;
    int cmd0_size = 0;
    char *argv[FINSH_ARG_MAX];
    char *pg_name;
    int ret;

    /* find the size of first command */
    while ((cmd[cmd0_size] != ' ' && cmd[cmd0_size] != '\t') && cmd0_size < length)
        cmd0_size ++;
    if (cmd0_size == 0)
        return -1;

    /* split arguments */
    rt_memset(argv, 0x00, sizeof(argv));
    argc = msh_split(cmd, length, argv);
    if (argc == 0)
        return -1;

    /* try to find program in working directory */
    pg_name = _msh_exec_search_path("", argv[0]);
    if (pg_name)
    {
        goto found_program;
    }

    /* only check these paths when the first argument doesn't contain path
       seperator */
    if (strstr(argv[0], "/"))
    {
        return -1;
    }

    /* try to find program in /bin */
    pg_name = _msh_exec_search_path("/bin", argv[0]);
    if (pg_name)
    {
        goto found_program;
    }

    /* try to find program in dirs registered to env path */
    pg_name = _msh_exec_search_env(argv[0]);
    if (pg_name)
    {
        goto found_program;
    }

    /* not found in anywhere */
    return -1;

    /* found program */
found_program:
    ret = exec(pg_name, debug, argc, argv);
    rt_free(pg_name);

    return ret;
}
#endif


int msh_exec(char *cmd, rt_size_t length)
{
    int cmd_ret = 0;

    /* strim the beginning of command */
    while ((length > 0) && (*cmd  == ' ' || *cmd == '\t'))
    {
        cmd++;
        length--;
    }

    if (length == 0)
        return 0;

    /* Exec sequence:
     * 1. built-in command
     * 2. module(if enabled)
     */
    if (_msh_exec_cmd(cmd, length, &cmd_ret) == 0)
    {
        return cmd_ret;
    }
#ifdef DFS_USING_POSIX
#ifdef DFS_USING_WORKDIR
    if (msh_exec_script(cmd, length) == 0)
    {
        return 0;
    }
#endif

#ifdef RT_USING_MODULE
    if (msh_exec_module(cmd, length) == 0)
    {
        return 0;
    }
#endif /* RT_USING_MODULE */

#ifdef RT_USING_SMART
    /* exec from msh_exec , debug = 0*/
    /* _msh_exec_lwp return is pid , <= 0 means failed */
    cmd_ret = _msh_exec_lwp(0, cmd, length);
    if (cmd_ret > 0)
    {
        return 0;
    }
#endif /* RT_USING_SMART */
#endif /* DFS_USING_POSIX */

    /* truncate the cmd at the first space. */
    {
        char *tcmd;
        tcmd = cmd;
        while (*tcmd != ' ' && *tcmd != '\0')
        {
            tcmd++;
        }
        *tcmd = '\0';
    }
#ifdef RT_USING_SMART
    if (cmd_ret == -EACCES)
    {
        rt_kprintf("%s: Permission denied.\n", cmd);
    }
    else
#endif
    {
        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 DFS_USING_POSIX
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 multi = 0;
        rt_size_t 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)
            {
                multi ++;
                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 (multi > 1)
            {
                /* 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;
            rt_memcpy(index, full_path, min_length);
            path[length + min_length] = '\0';

            /* try to locate folder */
            if (multi == 1)
            {
                struct stat buffer = {0};
                if ((stat(path, &buffer) == 0))
                {
                    if (S_ISDIR(buffer.st_mode))
                    {
                        strcat(path, "/");
                    }
                    else if (S_ISLNK(buffer.st_mode))
                    {
                        DIR *dir = opendir(path);
                        if (dir)
                        {
                            closedir(dir);
                            strcat(path, "/");
                        }
                    }
                }
            }
        }
    }

    closedir(dir);
    rt_free(full_path);
}
#endif /* DFS_USING_POSIX */

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 DFS_USING_POSIX
    /* 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 --;
        }
#if defined(RT_USING_MODULE) || defined(RT_USING_SMART)
        /* 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 /* RT_USING_MODULE */
    }
#endif /* DFS_USING_POSIX */

    /* checks in internal command */
    {
        for (index = _syscall_table_begin; index < _syscall_table_end; FINSH_NEXT_SYSCALL(index))
        {
            /* skip finsh shell function */
            cmd_name = (const char *) index->name;
            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 /* RT_USING_FINSH */