/*
 * @(#) $Header: /tmp/cvs/mysql-admutils/mysql-dbadm.c,v 1.9 2003-04-03 22:37:44 lkarsten Exp $
 *
 * mysql-dbadm.c
 *
 */ 

#include <config.h>
#include <stdio.h>
#include <string.h>
#include <mysql.h>
#include <assert.h>
#include <stdarg.h>
#include <stdlib.h>
#include <pwd.h>
#include <grp.h>
#include <sys/types.h>
#include <unistd.h>
#include "mysql-admutils.h"

char *
strchr_whitespace(const char *s)
{
  char *sp, *tab;
  sp = strchr(s, ' ');
  tab = strchr(s, '\t');
  if (sp == NULL)
    return tab;
  if (tab == NULL)
    return sp;
  return sp < tab ? sp : tab; /* if both are found, return the first one */
}

char *
strtok_whitespace(char *s)
{
  static char *cp;
  char *r; 

  r = s ? s : cp;
  if (r == NULL)
    return NULL;
  cp = strchr_whitespace(r);
  if (cp == NULL)
    return r;
  while ((*cp == ' ') || (*cp == '\t'))
    {
      *cp++ = '\0';
      }
  return r;
}


int
valid_priv(const char *s)
{
  #define ACCEPT(x) if (strcmp(s, x) == 0) return 1
  ACCEPT("Y");
  ACCEPT("N");
  ACCEPT("y");
  ACCEPT("n");
  #undef ACCEPT
  return 0; /* not a valid priv */
}


int
usage()
{
  printf("Usage: %s COMMAND [DATABASE]...\n", program_name);
  printf("Create, drop og edit permission for the DATABASE(s),\n");
  printf("as determined by the COMMAND.  Valid COMMANDs:\n");
  printf("\n");
  printf("  create     create the DATABASE(s).\n");
  printf("  drop       delete the DATABASE(s).\n");
  printf("  show       give information about the DATABASE(s), or, if\n");
  printf("             none are given, all the ones you own.\n");
  printf("  editperm   change permissions for the DATABASE(s).  Your\n");
  printf("             favorite editor will be started, allowing you\n");
  printf("             to make changes to the permission table.\n");
  printf("\n");
  printf("Report bugs to drift@stud.ntnu.no\n");
  return 0;
}


int
create(MYSQL *pmysql, char *db)
{
  if (mysql_create_db(pmysql, db))
    return dberror(pmysql, "Cannot create database '%s'.", db);

  fprintf(stderr, "Database '%s' created.\n", db);
  return 0;
}


int
drop(MYSQL *pmysql, char *db)
{
  char query[1024];

  sprintf(query, "delete from db where db = '%s'", db);
  if (mysql_query(pmysql, query))
    dberror(pmysql, "Failed to delete permissions for database '%s'.", db);

  if (mysql_drop_db(pmysql, db))
    return dberror(pmysql, "Cannot drop database '%s'.", db);

  fprintf(stderr, "Database '%s' dropped.\n", db);
  return 0;
}

/* return a list of the user's databases */
char **
list(MYSQL *pmysql)
{
  char *wild;
  char **usr_groups, **cp;  /* holds all group names this dude is a member of [tlan]*/
  MYSQL_RES *res;
  int rows, numgroups, numgroupdbs;
  MYSQL_ROW row;
  char **dblist;
  int i, counter;
  struct passwd *p;

  p = getpwuid(getuid());
  if (!p)
    {
      dberror(NULL, "Failed to lookup your UNIX username.");
      exit(1);
    }

  dblist = malloc(2 * sizeof(char*)); /* one for username (if used), rest is done below */

  numgroupdbs = 0;
  counter = 0;

  usr_groups = get_group_names(&numgroups);
  cp = usr_groups;
  while (*cp) {
    if (*cp == NULL)
	break;

    wild = malloc(strlen(*cp)+3);
    sprintf(wild, "%s\\_%%", *cp);

#ifdef DEBUG
    printf("dbadm: wildcard: %s\n", wild);
#endif
    res = mysql_list_dbs(pmysql, wild);
    rows = mysql_num_rows(res);

    if (rows > 0) {
      numgroupdbs += rows;

      dblist = realloc(dblist, (numgroupdbs+2) * sizeof(char *));

      for (i = 0; i < rows; i++)
	if ((row = mysql_fetch_row(res))) {
	  dblist[counter++] = strdup(row[0]);
	}
    }

    
    free(wild);    
    cp++;
  }

  wild = malloc(strlen(p->pw_name) + 3);
  sprintf(wild, "%s_%%", p->pw_name);

  res = mysql_list_dbs(pmysql, wild);
  rows = mysql_num_rows(res);
  dblist = realloc(dblist, (numgroupdbs+rows+2) * sizeof(char *)); 

  if (!dblist)
    {
      dberror(NULL, "Out of memory.\n");
      free(wild);
      return NULL;
    }

  for (i = 0; i < rows; i++)
    if ((row = mysql_fetch_row(res)))
      {
	dblist[counter++] = strdup(row[0]);
      }

  res = mysql_list_dbs(pmysql, p->pw_name);
  rows = mysql_num_rows(res);
  if (rows == 1)
      dblist[counter++] = strdup(p->pw_name);

  dblist[counter] = NULL;

  return dblist;
}


int
writeperm(FILE *f, MYSQL *pmysql, const char *db)
{
  char query[1024];
  MYSQL_RES *res;
  int rows, i;
  MYSQL_ROW row;

  sprintf(query, "select user,select_priv,insert_priv,update_priv,"
	  "delete_priv,create_priv,drop_priv,alter_priv,index_priv from db where db='%s'", db);

  if (mysql_query(pmysql, query))
    return dberror(pmysql, "Query for permissions failed.");
  res = mysql_store_result(pmysql);
  rows = mysql_num_rows(res);
  fprintf(f, "# User                " 
	  "Select  Insert  Update  Delete  Create   Drop   Alter  Index\n");
  fprintf(f, "# ----------------    "
	  "------  ------  ------  ------  ------   ----   -----  -----\n");

  if (rows == 0)
      fprintf(f, "# (no permissions currently granted to any users)\n");
  else
    for (i = 0; i < rows; i++)
      {
	row = mysql_fetch_row(res);
	fprintf(f, "  %-16s      %-7s %-7s %-7s %-7s %-7s %-7s %-7s %s\n",
	       row[0], row[1],  row[2], row[3], row[4], row[5], row[6], row[7], row[8]);
      }
  return 0;
}


/* show information about the database */
int
show(MYSQL *pmysql, const char *db)
{
  printf("Database '%s':\n", db);

  writeperm(stdout, pmysql, db);
  return 0;
}


#define MAX_GRANTS 1024


int
editperm(MYSQL *pmysql, const char *db)
{
  char fn[] = "/tmp/mysql-dbadm.tmp.XXXXXX";
  FILE *f;
  char *editor;
  char cmd[1024]; /* shell command for editing the file */
  char line[1024]; /* buffer to hold one line */
  char *cp; /* used to interate through a line */
  char *user, *select_priv, *insert_priv, *update_priv, *delete_priv, 
    *create_priv, *drop_priv, *alter_priv, *index_priv;
  char query[1024]; /* used to build a query */
  char *queries[MAX_GRANTS]; /* insert queries */
  int lines; /* number of grant lines processed */
  int i; /* iterate through lines[] */

  mktemp(fn);
  if (strcmp(fn, "") == 0)
    return dberror(NULL, "Cannot create a unique temporary file name.");

  f = fopen(fn, "w");
  if (f == NULL)
    return dberror(NULL, "Failed to open temporary file %s.", fn);
  writeperm(f, pmysql, db);
  fclose(f);

  editor = getenv("EDITOR");
  if (!editor)
    editor = "pico"; /* OK since editor won't be freed */
  strcpy(cmd, editor);
  strcat(cmd, " ");
  strcat(cmd, fn);
  if (system(cmd) == -1)
    {
      dberror(NULL, "Failed to execute '%s'\n", cmd);
      perror("system");
      return 1;
    }

  /* parse */
  f = fopen(fn, "r");
  lines = 0;
  while (fgets(line, sizeof(line), f))
    {
      cp = strchr(line, '\n');
      if (cp)
	*cp = '\0';

      cp = line;
      while (*cp && ((*cp == ' ') || (*cp == '\t'))) cp++;
      if (*cp == '\0') continue;
      if (*cp == '#') continue;
      if (*cp == '\n') continue;

      #define STRTOK_WHITESPACE(res, start) \
      {	if (!(res = strtok_whitespace(start))) continue; }

      STRTOK_WHITESPACE(user, cp);
      if (strlen(user) < 1)
	return dberror(NULL, "Invalid user '%s' in grant line %d.", user, 
		       lines + 1);
      if (strcmp(user, "%") == 0)
	*user = '\0'; /* ugly, but it works... */

      #define CHECK_PRIV(PRIV) \
      if (!valid_priv(PRIV)) return dberror(NULL, "Invalid value '%s' " \
      "in grant line %d.", PRIV, lines + 1)

      STRTOK_WHITESPACE(select_priv, NULL);
      CHECK_PRIV(select_priv);
      STRTOK_WHITESPACE(insert_priv, NULL);
      CHECK_PRIV(insert_priv);
      STRTOK_WHITESPACE(update_priv, NULL);
      CHECK_PRIV(update_priv);
      STRTOK_WHITESPACE(delete_priv, NULL);
      CHECK_PRIV(delete_priv);
      STRTOK_WHITESPACE(create_priv, NULL);
      CHECK_PRIV(create_priv);
      STRTOK_WHITESPACE(drop_priv, NULL);
      CHECK_PRIV(drop_priv);
      STRTOK_WHITESPACE(alter_priv, NULL);
      CHECK_PRIV(alter_priv);
      STRTOK_WHITESPACE(index_priv, NULL);
      CHECK_PRIV(index_priv);

      #undef STRTOK_WHITESPACE
      #undef CHECK_PRIV

      sprintf(query, "insert into db (host, db, user, select_priv, insert_priv, "
	      "update_priv, delete_priv, create_priv, drop_priv, alter_priv, index_priv) values "
              "('%%', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s', '%s')",
              db, user, select_priv, insert_priv, update_priv, delete_priv, 
	      create_priv, drop_priv, alter_priv, index_priv);
      queries[lines] = strdup(query);
      lines++;
      if (lines >= MAX_GRANTS)
	{
	  dberror(NULL, "Warning: Maximum of %d grants reached.\n", 
		  MAX_GRANTS);
	  continue;
	}
    } /* while fgets ... */
  
  unlink(fn);
  fclose(f);

  /* now that we have checked the input for errors, we can safely
     delete the old grants from the database and insert the new ones. */

  sprintf(query, "delete from db where db='%s'", db);
  if (mysql_query(pmysql, query))
    dberror(pmysql, "Failed to delete old grants for '%s'.", db);

  for (i = 0; i < lines; i++)
    {
      #ifdef DEBUG
      puts(queries[i]);
      putchar('\n');
      #endif
      if (mysql_query(pmysql, queries[i]))
	dberror(pmysql, "Failed to insert grant line %d.", i + 1);
    }

  return 0;
}


int
main(int argc, char *argv[])
{
  int i;
  enum { c_create, c_drop, c_editperm, c_show } command;
  MYSQL mysql;
  char **dblist, **p;

  program_name = argv[0];

  for (i = 1; i < argc; i++)
    if (strcmp(argv[i], "--help") == 0)
      return usage();
  for (i = 1; i < argc; i++)
    if (strcmp(argv[i], "--version") == 0)
      return version();
  
  if (argc < 2)
    return wrong_use(NULL);

  /* check that the supplied command is valid */

  if (strcmp(argv[1], "create") == 0)
    command = c_create;
  else if (strcmp(argv[1], "drop") == 0)
    command = c_drop;
  else if (strcmp(argv[1], "editperm") == 0)
    command = c_editperm;
  else if (strcmp(argv[1], "show") == 0)
    command = c_show;
  else
    return wrong_use("unrecognized command"); /* XXX */

  /* all other than show requires at lease one DATABASE argument. */
  if ((command != c_show) && (argc < 3))
    return wrong_use(NULL);

  read_config_file();

  /* connect to the database server and select the mysql database */
  if (!mysql_connect(&mysql, db_server, db_user, db_passwd))
    return dberror(&mysql, "Cannot connect to database server '%s'.", 
		   db_server);
  if (mysql_select_db(&mysql, db_name))
    return dberror(&mysql, "Cannot select database '%s'.", db_name);

  if ((command == c_show) && (argc == 2))
    {
      dblist = list(&mysql);
      p = dblist;
      while (*p)
	{
	  show(&mysql, *p);
	  free(*p);
	  p++;
	}
      free(dblist);
    }
  else
    {
      /* for each supplied database name, perform the requested action */
      for (i = 2; i < argc; i++)
	{
	  if (! (owner(argv[i]) || member(argv[i]))) 
	    {
	      dberror(NULL, "You are not the owner of '%s'.  Skipping.",
		      argv[i]);
	      continue;
	    }

	  switch (command)
	    {
	    case c_create:
	      create(&mysql, argv[i]);
	      break;
	    case c_drop:
	      drop(&mysql, argv[i]);
	      break;
	    case c_editperm:
	      editperm(&mysql, argv[i]);
	      break;
	    case c_show:
	      show(&mysql, argv[i]);
	      break;
	    default:
	      return dberror(NULL, "This point should never be reached!");
	    }
	}
    } 

  mysql_reload(&mysql);
  mysql_close(&mysql);

  return 0;
}