/* Jimsh - An interactive shell for Jim
 * Copyright 2005 Salvatore Sanfilippo <antirez@invece.org>
 * Copyright 2009 Steve Bennett <steveb@workware.net.au>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * A copy of the license is also included in the source distribution
 * of Jim, as a TXT file name called LICENSE.
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

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

#include "jim.h"

/* JimGetExePath try to get the absolute path of the directory
 * of the jim binary, in order to add this path to the library path.
 * Likely shipped libraries are in the same path too. */
#ifndef JIM_ANSIC

/* A bit complex on POSIX */
#include <unistd.h>
static Jim_Obj *JimGetExePath(Jim_Interp *interp, const char *argv0)
{
    char *p;

    /* Check if the executable was called with an absolute pathname */
    if (argv0[0] == '/') {
        p = strrchr(argv0, '/');
        return Jim_NewStringObj(interp, argv0, (p == argv0) ? 1 : p - argv0);
    }
    else {
        int l;
        char *path = Jim_Alloc(JIM_PATH_LEN + 1);

        if (getcwd(path, JIM_PATH_LEN) == NULL) {
default_path:
            Jim_Free(path);
            return Jim_NewStringObj(interp, "/usr/local/lib/jim/", -1);
        }

        /* Need to add the directory component of argv0 to pwd (path) */

        /* Strip any leading "./" off argv0 for cleanliness */
        while (argv0[0] == '.' && argv0[1] == '/') {
            argv0 += 2;
        }

        l = strlen(path);

        /* Strip the last component from argv0 */
        p = strrchr(argv0, '/');
        if (p) {
            int argv0len = p - argv0;

            /* Need a trailing / on pwd */
            if (l > 0 && path[l - 1] != '/')
                path[l++] = '/';

            /* And append it to 'path' */
            if (l + argv0len > JIM_PATH_LEN) {
                /* It won't fit. Don't both trying to realloc. */
                goto default_path;
            }
            memcpy(path + l, argv0, argv0len);
            l += argv0len;
            path[l] = '\0';
        }

        return Jim_NewStringObjNoAlloc(interp, path, l);
    }
}
#else /* JIM_ANSIC */

/* ... and impossible with just ANSI C */
static Jim_Obj *JimGetExePath(Jim_Interp *interp, const char *argv0)
{
    JIM_NOTUSED(argv0);
    return Jim_NewStringObj(interp, "/usr/local/lib/jim/", -1);
}
#endif /* JIM_ANSIC */

static void JimLoadJimRc(Jim_Interp *interp)
{
    const char *home;
    /* XXX: Move off stack */
    char buf[JIM_PATH_LEN + 1];
    const char *names[] = { ".jimrc", "jimrc.tcl", NULL };
    int i;
    FILE *fp;

    if ((home = getenv("HOME")) == NULL)
        return;
    for (i = 0; names[i] != NULL; i++) {
        if (strlen(home) + strlen(names[i]) + 1 > JIM_PATH_LEN)
            continue;
        sprintf(buf, "%s/%s", home, names[i]);
        if ((fp = fopen(buf, "r")) != NULL) {
            fclose(fp);
            if (Jim_EvalFile(interp, buf) != JIM_OK) {
                Jim_PrintErrorMessage(interp);
            }
            return;
        }
    }
}

static void JimSetArgv(Jim_Interp *interp, int argc, char *const argv[])
{
    int n;
    Jim_Obj *listObj = Jim_NewListObj(interp, NULL, 0);

    /* Populate argv global var */
    for (n = 0; n < argc; n++) {
        Jim_Obj *obj = Jim_NewStringObj(interp, argv[n], -1);

        Jim_ListAppendElement(interp, listObj, obj);
    }

    Jim_SetVariableStr(interp, "argv", listObj);
}

int main(int argc, char *const argv[])
{
    int retcode;
    Jim_Interp *interp;
    Jim_Obj *listObj;

    /* Create and initialize the interpreter */
    interp = Jim_CreateInterp();
    Jim_RegisterCoreCommands(interp);

    /* Register static extensions */
    if (Jim_InitStaticExtensions(interp) != JIM_OK) {
        Jim_PrintErrorMessage(interp);
    }

    /* Append the path where the executed Jim binary is contained
     * in the jim_libpath list. */
    listObj = Jim_GetVariableStr(interp, JIM_LIBPATH, JIM_NONE);
    if (Jim_IsShared(listObj))
        listObj = Jim_DuplicateObj(interp, listObj);
    Jim_ListAppendElement(interp, listObj, JimGetExePath(interp, argv[0]));
    Jim_SetVariableStr(interp, JIM_LIBPATH, listObj);

    Jim_SetVariableStrWithStr(interp, "jim_argv0", argv[0]);

    if (argc == 1) {
        Jim_SetVariableStrWithStr(interp, JIM_INTERACTIVE, "1");
        JimSetArgv(interp, 0, NULL);
        JimLoadJimRc(interp);
        retcode = Jim_InteractivePrompt(interp);
    }
    else {
        Jim_SetVariableStrWithStr(interp, JIM_INTERACTIVE, "0");
        if (argc > 2 && strcmp(argv[1], "-e") == 0) {
            JimSetArgv(interp, argc - 3, argv + 3);
            retcode = Jim_Eval(interp, argv[2]);
        }
        else {
            Jim_SetVariableStr(interp, "argv0", Jim_NewStringObj(interp, argv[1], -1));
            JimSetArgv(interp, argc - 2, argv + 2);
            retcode = Jim_EvalFile(interp, argv[1]);
        }
        if (retcode == JIM_ERR) {
            Jim_PrintErrorMessage(interp);
        }
    }
    if (retcode == JIM_OK) {
        retcode = 0;
    }
    else if (retcode == JIM_EXIT) {
        retcode = interp->exitCode;
    }
    else {
        retcode = 1;
    }
    Jim_FreeInterp(interp);
    return retcode;
}