/*
 * mobilebackup.c 
 * Contains functions for the built-in MobileBackup client.
 * 
 * Copyright (c) 2009 Martin Szulecki All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
 */

#include <plist/plist.h>
#include <string.h>
#include <stdlib.h>
#include <arpa/inet.h>

#include "mobilebackup.h"
#include "device_link_service.h"
#include "debug.h"

#define MBACKUP_VERSION_INT1 100
#define MBACKUP_VERSION_INT2 0

/**
 * Convert an device_link_service_error_t value to an mobilebackup_error_t value.
 * Used internally to get correct error codes when using device_link_service stuff.
 *
 * @param err An device_link_service_error_t error code
 *
 * @return A matching mobilebackup_error_t error code,
 *     MOBILEBACKUP_E_UNKNOWN_ERROR otherwise.
 */
static mobilebackup_error_t mobilebackup_error(device_link_service_error_t err)
{
	switch (err) {
		case DEVICE_LINK_SERVICE_E_SUCCESS:
			return MOBILEBACKUP_E_SUCCESS;
		case DEVICE_LINK_SERVICE_E_INVALID_ARG:
			return MOBILEBACKUP_E_INVALID_ARG;
		case DEVICE_LINK_SERVICE_E_PLIST_ERROR:
			return MOBILEBACKUP_E_PLIST_ERROR;
		case DEVICE_LINK_SERVICE_E_MUX_ERROR:
			return MOBILEBACKUP_E_MUX_ERROR;
		case DEVICE_LINK_SERVICE_E_BAD_VERSION:
			return MOBILEBACKUP_E_BAD_VERSION;
		default:
			break;
	}
	return MOBILEBACKUP_E_UNKNOWN_ERROR;
}

/**
 * Connects to the mobilebackup service on the specified device.
 *
 * @param device The device to connect to.
 * @param port Destination port (usually given by lockdownd_start_service).
 * @param client Pointer that will be set to a newly allocated
 *     mobilebackup_client_t upon successful return.
 *
 * @return MOBILEBACKUP_E_SUCCESS on success, MOBILEBACKUP_E_INVALID ARG if one
 *     or more parameters are invalid, or DEVICE_LINK_SERVICE_E_BAD_VERSION if
 *     the mobilebackup version on the device is newer.
 */
mobilebackup_error_t mobilebackup_client_new(idevice_t device, uint16_t port,
						   mobilebackup_client_t * client)
{
	if (!device || port == 0 || !client || *client)
		return MOBILEBACKUP_E_INVALID_ARG;

	device_link_service_client_t dlclient = NULL;
	mobilebackup_error_t ret = mobilebackup_error(device_link_service_client_new(device, port, &dlclient));
	if (ret != MOBILEBACKUP_E_SUCCESS) {
		return ret;
	}

	mobilebackup_client_t client_loc = (mobilebackup_client_t) malloc(sizeof(struct mobilebackup_client_private));
	client_loc->parent = dlclient;

	/* perform handshake */
	ret = mobilebackup_error(device_link_service_version_exchange(dlclient, MBACKUP_VERSION_INT1, MBACKUP_VERSION_INT2));
	if (ret != MOBILEBACKUP_E_SUCCESS) {
		debug_info("version exchange failed, error %d", ret);
		mobilebackup_client_free(client_loc);
		return ret;
	}

	*client = client_loc;

	return ret;
}

/**
 * Disconnects a mobilebackup client from the device and frees up the
 * mobilebackup client data.
 *
 * @param client The mobilebackup client to disconnect and free.
 *
 * @return MOBILEBACKUP_E_SUCCESS on success, or MOBILEBACKUP_E_INVALID_ARG
 *     if client is NULL.
 */
mobilebackup_error_t mobilebackup_client_free(mobilebackup_client_t client)
{
	if (!client)
		return MOBILEBACKUP_E_INVALID_ARG;
	device_link_service_disconnect(client->parent);
	mobilebackup_error_t err = mobilebackup_error(device_link_service_client_free(client->parent));
	free(client);
	return err;
}

/**
 * Polls the device for mobilebackup data.
 *
 * @param client The mobilebackup client
 * @param plist A pointer to the location where the plist should be stored
 *
 * @return an error code
 */
mobilebackup_error_t mobilebackup_receive(mobilebackup_client_t client, plist_t * plist)
{
	if (!client)
		return MOBILEBACKUP_E_INVALID_ARG;
	mobilebackup_error_t ret = mobilebackup_error(device_link_service_receive(client->parent, plist));
	return ret;
}

/**
 * Sends mobilebackup data to the device
 * 
 * @note This function is low-level and should only be used if you need to send
 *        a new type of message.
 *
 * @param client The mobilebackup client
 * @param plist The location of the plist to send
 *
 * @return an error code
 */
mobilebackup_error_t mobilebackup_send(mobilebackup_client_t client, plist_t plist)
{
	if (!client || !plist)
		return MOBILEBACKUP_E_INVALID_ARG;
	return mobilebackup_error(device_link_service_send(client->parent, plist));
}

/**
 * Request a backup from the connected device.
 *
 * @param client The connected MobileBackup client to use.
 * @param backup_manifest The backup manifest, a plist_t of type PLIST_DICT
 *    containing the backup state of the last backup. For a first-time backup
 *    set this parameter to NULL.
 * @param base_path The base path on the device to use for the backup
 *    operation, usually "/".
 * @param proto_version A string denoting the version of the backup protocol
 *    to use. Latest known version is "1.6"
 *
 * @return MOBILEBACKUP_E_SUCCESS on success, MOBILEBACKUP_E_INVALID_ARG if
 *    one of the parameters is invalid, MOBILEBACKUP_E_PLIST_ERROR if
 *    backup_manifest is not of type PLIST_DICT, MOBILEBACKUP_E_MUX_ERROR
 *    if a communication error occurs, MOBILEBACKUP_E_REPLY_NOT_OK
 */
mobilebackup_error_t mobilebackup_request_backup(mobilebackup_client_t client, plist_t backup_manifest, const char *base_path, const char *proto_version)
{
	if (!client || !client->parent || !base_path || !proto_version)
		return MOBILEBACKUP_E_INVALID_ARG;

	if (backup_manifest && (plist_get_node_type(backup_manifest) != PLIST_DICT))
		return MOBILEBACKUP_E_PLIST_ERROR;

	mobilebackup_error_t err;

	/* construct request plist */
	plist_t dict = plist_new_dict();
	if (backup_manifest)
		plist_dict_insert_item(dict, "BackupManifestKey", plist_copy(backup_manifest));
	plist_dict_insert_item(dict, "BackupComputerBasePathKey", plist_new_string(base_path));
	plist_dict_insert_item(dict, "BackupMessageTypeKey", plist_new_string("BackupMessageBackupRequest"));
	plist_dict_insert_item(dict, "BackupProtocolVersion", plist_new_string(proto_version));

	/* send it as DLMessageProcessMessage */
	err = mobilebackup_error(device_link_service_send_process_message(client->parent, dict));
	plist_free(dict);
	dict = NULL;
	if (err != MOBILEBACKUP_E_SUCCESS) {
		debug_info("ERROR: Could not send backup request message (%d)!", err);
		goto leave;
	}

	/* now receive and hopefully get a BackupMessageBackupReplyOK */
	err = mobilebackup_error(device_link_service_receive_process_message(client->parent, &dict));
	if (err != MOBILEBACKUP_E_SUCCESS) {
		debug_info("ERROR: Could not receive BackupReplyOK message (%d)!", err);
		goto leave;
	}

	plist_t node = plist_dict_get_item(dict, "BackupMessageTypeKey");
	if (!node) {
		debug_info("ERROR: BackupMessageTypeKey not found in BackupReplyOK message!");
		err = MOBILEBACKUP_E_PLIST_ERROR;
		goto leave;
	}

	char *str = NULL;
	plist_get_string_val(node, &str);
	if (!str || (strcmp(str, "BackupMessageBackupReplyOK") != 0)) {
		debug_info("ERROR: BackupMessageTypeKey value does not match 'BackupMessageBackupReplyOK'");
		err = MOBILEBACKUP_E_REPLY_NOT_OK;
		if (str)
			free(str);
		goto leave;
	}
	free(str);
	str = NULL;

	node = plist_dict_get_item(dict, "BackupProtocolVersion");
	if (node) {
		plist_get_string_val(node, &str);
		if (str) {
			if (strcmp(str, proto_version) != 0) {
				err = MOBILEBACKUP_E_BAD_VERSION;
			}
			free(str);
		}
	}
	if (err != MOBILEBACKUP_E_SUCCESS)
		goto leave;

	/* BackupMessageBackupReplyOK received, send it back */
	err = mobilebackup_error(device_link_service_send_process_message(client->parent, dict));
	if (err != MOBILEBACKUP_E_SUCCESS) {
		debug_info("ERROR: Could not send BackupReplyOK ACK (%d)", err);
	}

leave:
	if (dict)
		plist_free(dict);
	return err;
}

/**
 * Sends a confirmation to the device that a backup file has been received.
 *
 * @param client The connected MobileBackup client to use.
 * 
 * @return MOBILEBACKUP_E_SUCCESS on success, MOBILEBACKUP_E_INVALID_ARG if
 *    client is invalid, or MOBILEBACKUP_E_MUX_ERROR if a communication error
 *    occurs.
 */
mobilebackup_error_t mobilebackup_send_backup_file_received(mobilebackup_client_t client)
{
	if (!client || !client->parent)
		return MOBILEBACKUP_E_INVALID_ARG;

	mobilebackup_error_t err;

	/* construct ACK plist */
	plist_t dict = plist_new_dict();
	plist_dict_insert_item(dict, "BackupMessageTypeKey", plist_new_string("kBackupMessageBackupFileReceived"));

	/* send it as DLMessageProcessMessage */
	err = mobilebackup_error(device_link_service_send_process_message(client->parent, dict));
	plist_free(dict);

	return err;
}

/**
 * Sends a backup error message to the device.
 *
 * @param client The connected MobileBackup client to use.
 * @param reason A string describing the reason for the error message.
 * 
 * @return MOBILEBACKUP_E_SUCCESS on success, MOBILEBACKUP_E_INVALID_ARG if
 *    one of the parameters is invalid, or MOBILEBACKUP_E_MUX_ERROR if a
 *    communication error occurs.
 */
mobilebackup_error_t mobilebackup_send_error(mobilebackup_client_t client, const char *reason)
{
	if (!client || !client->parent || !reason)
		return MOBILEBACKUP_E_INVALID_ARG;

	mobilebackup_error_t err;

	/* construct error plist */
	plist_t dict = plist_new_dict();
	plist_dict_insert_item(dict, "BackupMessageTypeKey", plist_new_string("BackupMessageError"));
	plist_dict_insert_item(dict, "BackupErrorReasonKey", plist_new_string(reason));

	/* send it as DLMessageProcessMessage */
	err = mobilebackup_error(device_link_service_send_process_message(client->parent, dict));
	plist_free(dict);

	return err;
}