/* main.c
 *
 * Copyright 2024 axtlos <axtlos@disroot.org>
 *
 * 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, version 3.
 *
 * 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, see <https://www.gnu.org/licenses/>.
 *
 * SPDX-License-Identifier: GPL-3.0-only
 */

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

#define _XOPEN_SOURCE 500
#include <extlib.h>
#include "config.h"

struct compile_cmd_t *find_cmd(char *file_extension, struct compile_cmd_t **ccmds, size_t ccmds_len) {
  for (int i = 0; i < ccmds_len; i++) {
    if (strcmp (ccmds[i]->fileext, file_extension) == 0) {
      return ccmds[i];
    }
  }
  return NULL;
}

void remove_shebang(char **file, char *tmpdir, char *file_extension) {
  char *new_file_path = malloc (strlen (tmpdir)+strlen ("/source.")+strlen(file_extension)+1);
  sprintf (new_file_path, "%s/source.%s", tmpdir, file_extension);
  FILE *new_file = fopen (new_file_path, "w");
  FILE *old_file = fopen (*file, "r");
  char buffer[1024];
  fgets (buffer, 1024, old_file);
  fcopy (old_file, new_file);
  fclose (new_file);
  fclose (old_file);
  free (*file);
  *file = strdup (new_file_path);
  free (new_file_path);
}

int main (int argc, char *argv[]) {
  int errno = 0;
  size_t parts_len = 0;
  size_t ccmds_len = 0;
  struct compile_cmd_t **ccmds = NULL;
  struct compile_cmd_t *matching_cmd = NULL;
  char *tmpdir = strdup ("/tmp/XXXXXX");;
  char *compile_file = NULL;
  char *ap = NULL;
  char *cmd = NULL;
  char *excmd = NULL;
  char *fileparts[strlen (argv[argc-1])];

  if (argc < 2) {
    fprintf (stderr, "usage: %s <source file>", argv[0]);
    errno = 1;
    goto EXIT;
  }
  compile_file = strdup(argv[argc-1]);
  ccmds_len = get_commands(&ccmds);

  tmpdir = mkdtemp(tmpdir);
  if (!tmpdir) {
    errno = 1;
    goto EXIT;
  }

  for (int i = 0; (ap = strsep (&argv[argc-1], ".")); i++) {
    fileparts[i] = ap;
    parts_len += 1;
  }
  if (parts_len == 0) {
    fprintf (stderr, "error: no file extension found\n");
    errno = 1;
    goto EXIT;
  }

  matching_cmd = find_cmd(fileparts[parts_len-1], ccmds, ccmds_len);
  if (!matching_cmd) {
    fprintf (stderr, "error: no complier for file extension '%s' found\n", fileparts[parts_len-1]);
    errno = 1;
    goto EXIT;
  }

  FILE *source = fopen (compile_file, "r");
  //  char *is_shebang = malloc (strlen ("#!")+1);
  char is_shebang[3];
  fread (&is_shebang, 1, 2, source);
  fclose (source);
  if (strcmp (is_shebang, "#!") == 0)
    remove_shebang (&compile_file, tmpdir, fileparts[parts_len-1]);

  cmd = malloc (strlen (matching_cmd->cmd)+
		      strlen (matching_cmd->args)+
		      strlen (compile_file)+
		      strlen ("   -o   ")+
		      strlen (tmpdir)+
		      strlen ("/exec")+1);
  if (!cmd) {
    errno = 1;
    goto EXIT;
  }
  excmd = malloc (strlen (tmpdir)+strlen ("/exec")+1);
  if (!excmd) {
    errno = 1;
    goto EXIT;
  };
  sprintf (cmd, "%s %s  %s -o %s/exec", matching_cmd->cmd, matching_cmd->args, compile_file, tmpdir);
  if ((errno = system (cmd), errno != 0)) {
    fprintf(stderr, "error: compiler failed with code %d\n", errno);
    goto EXIT;
  }

  sprintf (excmd, "%s/exec", tmpdir);
  if ((errno = system (excmd), errno != 0)) {
    fprintf (stderr, "error: binary failed with code %d\n", errno);
    goto EXIT;
  }

  if ((errno = rrmdir(tmpdir)), errno != 0)
    fprintf (stderr, "error: failed to remove temporary directory %s\n", tmpdir);

 EXIT:
  for (int i = 0; i < ccmds_len; i++)
    compile_cmd_free (ccmds[i]);
  free (excmd);
  free (ccmds);
  free (tmpdir);
  free (cmd);
  free (compile_file);
  exit(errno % 255);
}