/*
 * hlogin(1)
 *
 * Copyleft (C) 2022 ~keith <keith@keithhacks.cyou>
 *
 * This file is part of hlogin.
 *
 * hlogin 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.
 *
 * hlogin 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 hlogin. If not, see <https://www.gnu.org/licenses/>.
 */
#include "config.h"

#include <security/_pam_types.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

#include <locale.h>
#include "gettext.h"

#include <unistd.h>
#include <security/pam_appl.h>
#include <security/pam_misc.h>

#include "ui.h"

#define VAR_(x) #x
#define VAR(x) VAR_(x)
#pragma message "LOCALEDIR=" VAR(LOCALEDIR)

int pam_conv_handler(int msgc, const struct pam_message *msgv[], struct pam_response **resp, void *appdata_ptr)
{
	if (msgc <= 0)
		return PAM_CONV_ERR;

	struct pam_response *result = calloc(msgc, sizeof(struct pam_response));
	if (!result)
		return PAM_CONV_ERR;

	for (int i = 0; i < msgc; i++) {
		int r;
		char *text;
		switch (msgv[i]->msg_style) {
			case PAM_PROMPT_ECHO_OFF:
			case PAM_PROMPT_ECHO_ON:
				ui_setup_dialog((char *) msgv[i]->msg, msgv[i]->msg_style == PAM_PROMPT_ECHO_OFF);
				r = ui_run();
				text = ui_get_text();
				if (r != 0) {
					_pam_overwrite(text);
					free(text);
					text = NULL;
				}
				result[i].resp_retcode = 0;
				result[i].resp = text;
				break;
			case PAM_ERROR_MSG:
			case PAM_TEXT_INFO:
				goto FAILURE; // TODO implement info/error dialog
			default:
				goto FAILURE;
		}
	}

	*resp = result;
	return PAM_SUCCESS;

FAILURE:
	if (result) {
		for (int i = 0; i < msgc; i++) {
			if (result[i].resp) {
				_pam_overwrite(result[i].resp);
				free(result[i].resp);
			}
		}
		free(result);
		result = NULL;
	}
	return PAM_CONV_ERR;
}

int main(int argc, char* argv[])
{
	setlocale(LC_ALL, "");
	bindtextdomain(PACKAGE, LOCALEDIR);
	textdomain(PACKAGE);

	pam_handle_t *pam = NULL;
	struct pam_conv conv = { .conv = pam_conv_handler, .appdata_ptr = NULL };
	if (pam_start("login", NULL, &conv, &pam) != PAM_SUCCESS) {
		// TODO log error & pause before exiting
		return EXIT_FAILURE;
	}

	ui_init();

	// prompt for username
	ui_setup_dialog(_("Login name:"), false);
	int result = ui_run();
	char *login_name = ui_get_text();
	if (result != 0)
		goto END;

	result = pam_set_item(pam, PAM_USER, login_name);
	if (result != PAM_SUCCESS) {
		endwin();
		printf("pam_set_item error: %s\n", pam_strerror(pam, result));
		return EXIT_FAILURE;
	}

	result = pam_authenticate(pam, 0);
	if (result != PAM_SUCCESS) {
		endwin();
		printf("pam_authenticate error: %s\n", pam_strerror(pam, result));
		return EXIT_FAILURE;
	}

END:
	endwin();
	return EXIT_SUCCESS;
}