#define CHAZ_USE_SHORT_NAMES

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

#include "Charmonizer/Core/Util.h"
#include "Charmonizer/Core/OperSys.h"

static void
probe_devnull(OperSys *self);

static void
destroy(OperSys *self);

static void
remove_exe(OperSys *self, char *name);

static void
remove_obj(OperSys *self, char *name);

static void
run_local(OperSys *self, ...);

chaz_OperSys*
chaz_OS_new(const char *name) 
{
    OperSys *self = (OperSys*)malloc(sizeof(OperSys));

    if (verbosity)
        printf("Creating os object...\n");

    /* assign */
    self->name = strdup(name);

    /* init */
    self->buf        = NULL;
    self->buf_len    = 0;
    self->remove_obj = remove_obj;
    self->remove_exe = remove_exe;
    self->run_local  = run_local;
    self->destroy    = destroy;

    /* derive */
    if (strcmp(name, "mswin32") == 0) {
        self->obj_ext = strdup(".obj");
        self->exe_ext = strdup(".exe");
        self->local_command_start = strdup(".\\");
        self->devnull = strdup("nul");
    }
    else {
        self->obj_ext = strdup("");
        self->exe_ext = strdup("");
        self->local_command_start = strdup("./");
        probe_devnull(self);
    }

    return self;
}

static void
probe_devnull(OperSys *self)
{
    char *const devnull_options[] = {
        "/dev/null", 
        "/dev/nul", 
        NULL
    };
    int i;

    if (verbosity)
        printf("Trying to find a bit-bucket a la /dev/null...\n");

    /* iterate through names of possible devnulls trying to open them */
    for (i = 0; devnull_options[i] != NULL; i++) {
        if (can_open_file(devnull_options[i])) {
            self->devnull = strdup(devnull_options[i]);
            return;
        }
    }

    /* bail out we couldn't find a devnull */
    die("Couldn't find anything like /dev/null");
}

static void
destroy(OperSys *self)
{
    free(self->buf);
    free(self->name);
    free(self->obj_ext);
    free(self->exe_ext);
    free(self->local_command_start);
    free(self->devnull);
    free(self);
}

static void
remove_exe(OperSys *self, char *name)
{
    self->buf_len = join_strings(&(self->buf), self->buf_len, name, 
        self->exe_ext, NULL);
    remove(self->buf);
}

static void
remove_obj(OperSys *self, char *name)
{
    self->buf_len = join_strings(&(self->buf), self->buf_len, name, 
        self->obj_ext, NULL);
    remove(self->buf);
}

static void
run_local(OperSys *self, ...)
{
    va_list args;

    /* start with "./", ".\", or whatever */
    self->buf_len = join_strings(&(self->buf), self->buf_len,
        self->local_command_start, NULL);

    /* append all supplied texts */ 
    va_start(args, self);
    self->buf_len = vappend_strings(&(self->buf), self->buf_len, args);
    va_end(args);

    /* run the command */
    system(self->buf);
}


/**
 * Copyright 2006 The Apache Software Foundation
 *
 * 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
 *
 * 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.
 */