/**

 * @file

 * Pgp functions

 *

 * @authors

 * Copyright (C) 2022 Richard Russon <rich@flatcap.org>

 *

 * @copyright

 * 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, either version 2 of the License, or (at your option) any later

 * version.

 *

 * 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 <http://www.gnu.org/licenses/>.

 */

/**

 * @page pgp_functions Pgp functions

 *

 * Pgp functions

 */

#include "config.h"

#include <stdio.h>

#include <unistd.h>

#include "mutt/lib.h"

#include "config/lib.h"

#include "core/lib.h"

#include "gui/lib.h"

#include "pgp_functions.h"

#include "lib.h"

#include "menu/lib.h"

#include "pager/lib.h"

#include "question/lib.h"

#include "globals.h"

#include "mutt_logging.h"

#include "pgp.h"

#include "pgpinvoke.h"

#include "pgpkey.h"

#include "pgplib.h"

/**

 * op_exit - Exit this menu - Implements ::pgp_function_t - @ingroup pgp_function_api

 */

static int op_exit(struct PgpData *pd, int op)

{

  pd->done = true;

  return FR_SUCCESS;

}

/**

 * op_generic_select_entry - Select the current entry - Implements ::pgp_function_t - @ingroup pgp_function_api

 */

static int op_generic_select_entry(struct PgpData *pd, int op)

{

  /* XXX make error reporting more verbose */

  const int index = menu_get_index(pd->menu);

  struct PgpUid *cur_key = pd->key_table[index];

  if (OptPgpCheckTrust)

  {

    if (!pgp_key_is_valid(cur_key->parent))

    {

      mutt_error(_("This key can't be used: expired/disabled/revoked"));

      return FR_ERROR;

    }

  }

  if (OptPgpCheckTrust && (!pgp_id_is_valid(cur_key) || !pgp_id_is_strong(cur_key)))

  {

    const char *str = "";

    char buf2[1024];

    if (cur_key->flags & KEYFLAG_CANTUSE)

    {

      str = _("ID is expired/disabled/revoked. Do you really want to use the key?");

    }

    else

    {

      switch (cur_key->trust & 0x03)

      {

        case 0:

          str = _("ID has undefined validity. Do you really want to use the key?");

          break;

        case 1:

          str = _("ID is not valid. Do you really want to use the key?");

          break;

        case 2:

          str = _("ID is only marginally valid. Do you really want to use the key?");

          break;

      }

    }

    snprintf(buf2, sizeof(buf2), "%s", str);

    if (query_yesorno(buf2, MUTT_NO) != MUTT_YES)

    {

      mutt_clear_error();

      return FR_NO_ACTION;

    }

  }

  pd->key = cur_key->parent;

  pd->done = true;

  return FR_SUCCESS;

}

/**

 * op_verify_key - Verify a PGP public key - Implements ::pgp_function_t - @ingroup pgp_function_api

 */

static int op_verify_key(struct PgpData *pd, int op)

{

  FILE *fp_null = fopen("/dev/null", "w");

  if (!fp_null)

  {

    mutt_perror(_("Can't open /dev/null"));

    return FR_ERROR;

  }

  struct Buffer *tempfile = NULL;

  tempfile = buf_pool_get();

  buf_mktemp(tempfile);

  FILE *fp_tmp = mutt_file_fopen(buf_string(tempfile), "w");

  if (!fp_tmp)

  {

    mutt_perror(_("Can't create temporary file"));

    mutt_file_fclose(&fp_null);

    buf_pool_release(&tempfile);

    return FR_ERROR;

  }

  mutt_message(_("Invoking PGP..."));

  const int index = menu_get_index(pd->menu);

  struct PgpUid *cur_key = pd->key_table[index];

  char tmpbuf[256] = { 0 };

  snprintf(tmpbuf, sizeof(tmpbuf), "0x%s",

           pgp_fpr_or_lkeyid(pgp_principal_key(cur_key->parent)));

  pid_t pid = pgp_invoke_verify_key(NULL, NULL, NULL, -1, fileno(fp_tmp),

                                    fileno(fp_null), tmpbuf);

  if (pid == -1)

  {

    mutt_perror(_("Can't create filter"));

    unlink(buf_string(tempfile));

    mutt_file_fclose(&fp_tmp);

    mutt_file_fclose(&fp_null);

  }

  filter_wait(pid);

  mutt_file_fclose(&fp_tmp);

  mutt_file_fclose(&fp_null);

  mutt_clear_error();

  char title[1024] = { 0 };

  snprintf(title, sizeof(title), _("Key ID: 0x%s"),

           pgp_keyid(pgp_principal_key(cur_key->parent)));

  struct PagerData pdata = { 0 };

  struct PagerView pview = { &pdata };

  pdata.fname = buf_string(tempfile);

  pview.banner = title;

  pview.flags = MUTT_PAGER_NO_FLAGS;

  pview.mode = PAGER_MODE_OTHER;

  mutt_do_pager(&pview, NULL);

  buf_pool_release(&tempfile);

  menu_queue_redraw(pd->menu, MENU_REDRAW_FULL);

  return FR_SUCCESS;

}

/**

 * op_view_id - View the key's user id - Implements ::pgp_function_t - @ingroup pgp_function_api

 */

static int op_view_id(struct PgpData *pd, int op)

{

  const int index = menu_get_index(pd->menu);

  struct PgpUid *cur_key = pd->key_table[index];

  mutt_message("%s", NONULL(cur_key->addr));

  return FR_SUCCESS;

}

// -----------------------------------------------------------------------------

/**

 * PgpFunctions - All the NeoMutt functions that the Pgp supports

 */

static const struct PgpFunction PgpFunctions[] = {

  // clang-format off

  { OP_EXIT,                   op_exit },

  { OP_GENERIC_SELECT_ENTRY,   op_generic_select_entry },

  { OP_VERIFY_KEY,             op_verify_key },

  { OP_VIEW_ID,                op_view_id },

  { 0, NULL },

  // clang-format on

};

/**

 * pgp_function_dispatcher - Perform a Pgp function - Implements ::function_dispatcher_t - @ingroup dispatcher_api

 */

int pgp_function_dispatcher(struct MuttWindow *win, int op)

{

  if (!win || !win->wdata)

    return FR_UNKNOWN;

  struct MuttWindow *dlg = dialog_find(win);

  if (!dlg)

    return FR_ERROR;

  struct PgpData *pd = dlg->wdata;

  int rc = FR_UNKNOWN;

  for (size_t i = 0; PgpFunctions[i].op != OP_NULL; i++)

  {

    const struct PgpFunction *fn = &PgpFunctions[i];

    if (fn->op == op)

    {

      rc = fn->function(pd, op);

      break;

    }

  }

  if (rc == FR_UNKNOWN) // Not our function

    return rc;

  const char *result = dispatcher_get_retval_name(rc);

  mutt_debug(LL_DEBUG1, "Handled %s (%d) -> %s\n", opcodes_get_name(op), op, NONULL(result));

  return rc;

}