/*
 * libdivecomputer
 *
 * Copyright (C) 2013 Jef Driesen
 *
 * 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
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h> // malloc, free
#include <stdio.h>

#include "socket.h"

#ifdef _WIN32
#ifdef HAVE_WS2BTH_H
#define BLUETOOTH
#include <initguid.h>
#include <ws2bth.h>
#endif
#else
#ifdef HAVE_BLUEZ
#define BLUETOOTH
#include <bluetooth/bluetooth.h>
#include <bluetooth/rfcomm.h>
#include <bluetooth/hci.h>
#include <bluetooth/hci_lib.h>
#include <bluetooth/sdp.h>
#include <bluetooth/sdp_lib.h>
#endif
#endif

#include <libdivecomputer/bluetooth.h>

#include "common-private.h"
#include "context-private.h"
#include "iostream-private.h"
#include "iterator-private.h"
#include "descriptor-private.h"
#include "platform.h"

#ifdef _WIN32
#define DC_ADDRESS_FORMAT "%012I64X"
#else
#define DC_ADDRESS_FORMAT "%012llX"
#endif

#define C_ARRAY_SIZE(array) (sizeof (array) / sizeof *(array))

#define MAX_DEVICES 255
#define MAX_PERIODS 8

#define ISINSTANCE(device) dc_iostream_isinstance((device), &dc_bluetooth_vtable)

struct dc_bluetooth_device_t {
	dc_bluetooth_address_t address;
	char name[248];
};

#ifdef BLUETOOTH
static dc_status_t dc_bluetooth_iterator_next (dc_iterator_t *iterator, void *item);
static dc_status_t dc_bluetooth_iterator_free (dc_iterator_t *iterator);

typedef struct dc_bluetooth_iterator_t {
	dc_iterator_t base;
	dc_filter_t filter;
#ifdef _WIN32
	HANDLE hLookup;
#else
	int fd;
	inquiry_info *devices;
	size_t count;
	size_t current;
#endif
} dc_bluetooth_iterator_t;

static const dc_iterator_vtable_t dc_bluetooth_iterator_vtable = {
	sizeof(dc_bluetooth_iterator_t),
	dc_bluetooth_iterator_next,
	dc_bluetooth_iterator_free,
};

static const dc_iostream_vtable_t dc_bluetooth_vtable = {
	sizeof(dc_socket_t),
	dc_socket_set_timeout, /* set_timeout */
	NULL, /* set_latency */
	NULL, /* set_break */
	NULL, /* set_dtr */
	NULL, /* set_rts */
	NULL, /* get_lines */
	dc_socket_get_available, /* get_available */
	NULL, /* configure */
	dc_socket_poll, /* poll */
	dc_socket_read, /* read */
	dc_socket_write, /* write */
	dc_socket_ioctl, /* ioctl */
	NULL, /* flush */
	NULL, /* purge */
	dc_socket_sleep, /* sleep */
	dc_socket_close, /* close */
};

#ifdef HAVE_BLUEZ
static dc_bluetooth_address_t
dc_address_get (const bdaddr_t *ba)
{
	dc_bluetooth_address_t address = 0;

	size_t shift = 0;
	for (size_t i = 0; i < C_ARRAY_SIZE(ba->b); ++i) {
		address |= (dc_bluetooth_address_t) ba->b[i] << shift;
		shift += 8;
	}

	return address;
}

static void
dc_address_set (bdaddr_t *ba, dc_bluetooth_address_t address)
{
	size_t shift = 0;
	for (size_t i = 0; i < C_ARRAY_SIZE(ba->b); ++i) {
		ba->b[i] = (address >> shift) & 0xFF;
		shift += 8;
	}
}

static dc_status_t
dc_bluetooth_sdp (uint8_t *port, dc_context_t *context, const bdaddr_t *ba)
{
	dc_status_t status = DC_STATUS_SUCCESS;
	sdp_session_t *session = NULL;
	sdp_list_t *search = NULL, *attrid = NULL;
	sdp_list_t *records = NULL;
	uint8_t channel = 0;

	// Connect to the SDP server on the remote device.
	session = sdp_connect (BDADDR_ANY, ba, SDP_RETRY_IF_BUSY);
	if (session == NULL) {
		s_errcode_t errcode = S_ERRNO;
		SYSERROR (context, errcode);
		status = dc_socket_syserror(errcode);
		goto error;
	}

	// Specify the UUID of the serial port service with all attributes.
	uuid_t uuid = {0};
	uint32_t range = 0x0000FFFF;
	sdp_uuid16_create (&uuid, SERIAL_PORT_SVCLASS_ID);
	search = sdp_list_append (NULL, &uuid);
	attrid = sdp_list_append (NULL, &range);
	if (search == NULL || attrid == NULL) {
		s_errcode_t errcode = S_ERRNO;
		SYSERROR (context, errcode);
		status = dc_socket_syserror(errcode);
		goto error;
	}

	// Get a list of the service records with their attributes.
	if (sdp_service_search_attr_req (session, search, SDP_ATTR_REQ_RANGE, attrid, &records) != 0) {
		s_errcode_t errcode = S_ERRNO;
		SYSERROR (context, errcode);
		status = dc_socket_syserror(errcode);
		goto error;
	}

	// Go through each of the service records.
	for (sdp_list_t *r = records; r; r = r->next ) {
		sdp_record_t *record = (sdp_record_t *) r->data;

		// Get a list of the protocol sequences.
		sdp_list_t *protos = NULL;
		if (sdp_get_access_protos (record, &protos) != 0 ) {
			s_errcode_t errcode = S_ERRNO;
			SYSERROR (context, errcode);
			status = dc_socket_syserror(errcode);
			goto error;
		}

		// Get the rfcomm port number.
		int ch = sdp_get_proto_port (protos, RFCOMM_UUID);

		sdp_list_foreach (protos, (sdp_list_func_t) sdp_list_free, NULL);
		sdp_list_free (protos, NULL);

		if (ch > 0) {
			channel = ch;
			break;
		}
	}

	if (channel == 0) {
		ERROR (context, "No serial port service found!");
		status = DC_STATUS_IO;
		goto error;
	}

	INFO (context, "SDP: channel=%u", channel);

	*port = channel;

error:
	sdp_list_free (records, (sdp_free_func_t) sdp_record_free);
	sdp_list_free (attrid, NULL);
	sdp_list_free (search, NULL);
	sdp_close (session);

	return status;
}
#endif
#endif

char *
dc_bluetooth_addr2str(dc_bluetooth_address_t address, char *str, size_t size)
{
	if (str == NULL || size < DC_BLUETOOTH_SIZE)
		return NULL;

	int n = snprintf(str, size, "%02X:%02X:%02X:%02X:%02X:%02X",
		(unsigned char)((address >> 40) & 0xFF),
		(unsigned char)((address >> 32) & 0xFF),
		(unsigned char)((address >> 24) & 0xFF),
		(unsigned char)((address >> 16) & 0xFF),
		(unsigned char)((address >>  8) & 0xFF),
		(unsigned char)((address >>  0) & 0xFF));
	if (n < 0 || (size_t) n >= size)
		return NULL;

	return str;
}

dc_bluetooth_address_t
dc_bluetooth_str2addr(const char *str)
{
	dc_bluetooth_address_t address = 0;

	if (str == NULL)
		return 0;

	unsigned char c = 0;
	while ((c = *str++) != '\0') {
		if (c == ':') {
			continue;
		} else if (c >= '0' && c <= '9') {
			c -= '0';
		} else if (c >= 'A' && c <= 'F') {
			c -= 'A' - 10;
		} else if (c >= 'a' && c <= 'f') {
			c -= 'a' - 10;
		} else {
			return 0; /* Invalid character! */
		}

		address <<= 4;
		address |= c;
	}

	return address;
}

dc_bluetooth_address_t
dc_bluetooth_device_get_address (dc_bluetooth_device_t *device)
{
	if (device == NULL)
		return 0;

	return device->address;
}

const char *
dc_bluetooth_device_get_name (dc_bluetooth_device_t *device)
{
	if (device == NULL || device->name[0] == '\0')
		return NULL;

	return device->name;
}

void
dc_bluetooth_device_free (dc_bluetooth_device_t *device)
{
	free (device);
}

dc_status_t
dc_bluetooth_iterator_new (dc_iterator_t **out, dc_context_t *context, dc_descriptor_t *descriptor)
{
#ifdef BLUETOOTH
	dc_status_t status = DC_STATUS_SUCCESS;
	dc_bluetooth_iterator_t *iterator = NULL;

	if (out == NULL)
		return DC_STATUS_INVALIDARGS;

	iterator = (dc_bluetooth_iterator_t *) dc_iterator_allocate (context, &dc_bluetooth_iterator_vtable);
	if (iterator == NULL) {
		SYSERROR (context, S_ENOMEM);
		return DC_STATUS_NOMEMORY;
	}

	// Initialize the socket library.
	status = dc_socket_init (context);
	if (status != DC_STATUS_SUCCESS) {
		goto error_free;
	}

#ifdef _WIN32
	WSAQUERYSET wsaq;
	memset(&wsaq, 0, sizeof (wsaq));
	wsaq.dwSize = sizeof (wsaq);
	wsaq.dwNameSpace = NS_BTH;
	wsaq.lpcsaBuffer = NULL;

	HANDLE hLookup = NULL;
	if (WSALookupServiceBegin(&wsaq, LUP_CONTAINERS | LUP_FLUSHCACHE, &hLookup) != 0) {
		s_errcode_t errcode = S_ERRNO;
		if (errcode == WSASERVICE_NOT_FOUND) {
			// No remote bluetooth devices found.
			hLookup = NULL;
		} else {
			SYSERROR (context, errcode);
			status = dc_socket_syserror(errcode);
			goto error_socket_exit;
		}
	}

	iterator->hLookup = hLookup;
#else
	// Get the resource number for the first available bluetooth adapter.
	int dev = hci_get_route (NULL);
	if (dev < 0) {
		s_errcode_t errcode = S_ERRNO;
		SYSERROR (context, errcode);
		status = dc_socket_syserror(errcode);
		goto error_socket_exit;
	}

	// Open a socket to the bluetooth adapter.
	int fd = hci_open_dev (dev);
	if (fd < 0) {
		s_errcode_t errcode = S_ERRNO;
		SYSERROR (context, errcode);
		status = dc_socket_syserror(errcode);
		goto error_socket_exit;
	}

	// Perform the bluetooth device discovery. The inquiry lasts for at
	// most MAX_PERIODS * 1.28 seconds, and at most MAX_DEVICES devices
	// will be returned.
	inquiry_info *devices = NULL;
	int ndevices = hci_inquiry (dev, MAX_PERIODS, MAX_DEVICES, NULL, &devices, IREQ_CACHE_FLUSH);
	if (ndevices < 0) {
		s_errcode_t errcode = S_ERRNO;
		SYSERROR (context, errcode);
		status = dc_socket_syserror(errcode);
		goto error_close;
	}

	iterator->fd = fd;
	iterator->devices = devices;
	iterator->count = ndevices;
	iterator->current = 0;
#endif
	iterator->filter = dc_descriptor_get_filter (descriptor);

	*out = (dc_iterator_t *) iterator;

	return DC_STATUS_SUCCESS;

#ifndef _WIN32
error_close:
	hci_close_dev(fd);
#endif
error_socket_exit:
	dc_socket_exit (context);
error_free:
	dc_iterator_deallocate ((dc_iterator_t *) iterator);
	return status;
#else
	return DC_STATUS_UNSUPPORTED;
#endif
}

#ifdef BLUETOOTH
static dc_status_t
dc_bluetooth_iterator_next (dc_iterator_t *abstract, void *out)
{
	dc_bluetooth_iterator_t *iterator = (dc_bluetooth_iterator_t *) abstract;
	dc_bluetooth_device_t *device = NULL;

#ifdef _WIN32
	if (iterator->hLookup == NULL) {
		return DC_STATUS_DONE;
	}

	unsigned char buf[4096];
	LPWSAQUERYSET pwsaResults = (LPWSAQUERYSET) buf;
	memset(pwsaResults, 0, sizeof(WSAQUERYSET));
	pwsaResults->dwSize = sizeof(WSAQUERYSET);
	pwsaResults->dwNameSpace = NS_BTH;
	pwsaResults->lpBlob = NULL;

	while (1) {
		DWORD dwSize = sizeof(buf);
		if (WSALookupServiceNext (iterator->hLookup, LUP_RETURN_NAME | LUP_RETURN_ADDR, &dwSize, pwsaResults) != 0) {
			s_errcode_t errcode = S_ERRNO;
			if (errcode == WSA_E_NO_MORE || errcode == WSAENOMORE) {
				break; // No more results.
			}
			SYSERROR (abstract->context, errcode);
			return dc_socket_syserror(errcode);
		}

		if (pwsaResults->dwNumberOfCsAddrs == 0 ||
			pwsaResults->lpcsaBuffer == NULL ||
			pwsaResults->lpcsaBuffer->RemoteAddr.lpSockaddr == NULL) {
			ERROR (abstract->context, "Invalid results returned");
			return DC_STATUS_IO;
		}

		SOCKADDR_BTH *sa = (SOCKADDR_BTH *) pwsaResults->lpcsaBuffer->RemoteAddr.lpSockaddr;
		dc_bluetooth_address_t address = sa->btAddr;
		const char *name = (char *) pwsaResults->lpszServiceInstanceName;
#else
	while (iterator->current < iterator->count) {
		inquiry_info *dev = &iterator->devices[iterator->current++];

		dc_bluetooth_address_t address = dc_address_get (&dev->bdaddr);

		// Get the user friendly name.
		char buf[HCI_MAX_NAME_LENGTH], *name = buf;
		int rc = hci_read_remote_name (iterator->fd, &dev->bdaddr, sizeof(buf), buf, 0);
		if (rc < 0) {
			name = NULL;
		}

		// Null terminate the string.
		buf[sizeof(buf) - 1] = '\0';
#endif

		INFO (abstract->context, "Discover: address=" DC_ADDRESS_FORMAT ", name=%s",
			address, name ? name : "");

		if (iterator->filter && !iterator->filter (DC_TRANSPORT_BLUETOOTH, name)) {
			continue;
		}

		device = (dc_bluetooth_device_t *) malloc (sizeof(dc_bluetooth_device_t));
		if (device == NULL) {
			SYSERROR (abstract->context, S_ENOMEM);
			return DC_STATUS_NOMEMORY;
		}

		device->address = address;
		if (name) {
			strncpy(device->name, name, sizeof(device->name) - 1);
			device->name[sizeof(device->name) - 1] = '\0';
		} else {
			memset(device->name, 0, sizeof(device->name));
		}

		*(dc_bluetooth_device_t **) out = device;

		return DC_STATUS_SUCCESS;
	}

	return DC_STATUS_DONE;
}

static dc_status_t
dc_bluetooth_iterator_free (dc_iterator_t *abstract)
{
	dc_bluetooth_iterator_t *iterator = (dc_bluetooth_iterator_t *) abstract;

#ifdef _WIN32
	if (iterator->hLookup) {
		WSALookupServiceEnd (iterator->hLookup);
	}
#else
	bt_free(iterator->devices);
	hci_close_dev(iterator->fd);
#endif
	dc_socket_exit (abstract->context);

	return DC_STATUS_SUCCESS;
}
#endif

dc_status_t
dc_bluetooth_open (dc_iostream_t **out, dc_context_t *context, dc_bluetooth_address_t address, unsigned int port)
{
#ifdef BLUETOOTH
	dc_status_t status = DC_STATUS_SUCCESS;
	dc_socket_t *device = NULL;

	if (out == NULL)
		return DC_STATUS_INVALIDARGS;

	INFO (context, "Open: address=" DC_ADDRESS_FORMAT ", port=%u", address, port);

	// Allocate memory.
	device = (dc_socket_t *) dc_iostream_allocate (context, &dc_bluetooth_vtable, DC_TRANSPORT_BLUETOOTH);
	if (device == NULL) {
		SYSERROR (context, S_ENOMEM);
		return DC_STATUS_NOMEMORY;
	}

	// Open the socket.
#ifdef _WIN32
	status = dc_socket_open (&device->base, AF_BTH, SOCK_STREAM, BTHPROTO_RFCOMM);
#else
	status = dc_socket_open (&device->base, AF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM);
#endif
	if (status != DC_STATUS_SUCCESS) {
		goto error_free;
	}

#ifdef _WIN32
	SOCKADDR_BTH sa;
	sa.addressFamily = AF_BTH;
	sa.btAddr = address;
	sa.port = port;
	if (port == 0) {
		sa.serviceClassId = SerialPortServiceClass_UUID;
	} else {
		memset(&sa.serviceClassId, 0, sizeof(sa.serviceClassId));
	}
#else
	struct sockaddr_rc sa;
	sa.rc_family = AF_BLUETOOTH;
	dc_address_set (&sa.rc_bdaddr, address);
	if (port == 0) {
		status = dc_bluetooth_sdp (&sa.rc_channel, context, &sa.rc_bdaddr);
		if (status != DC_STATUS_SUCCESS) {
			goto error_close;
		}
	} else {
		sa.rc_channel = port;
	}
#endif

	status = dc_socket_connect (&device->base, (struct sockaddr *) &sa, sizeof (sa));
	if (status != DC_STATUS_SUCCESS) {
		goto error_close;
	}

	*out = (dc_iostream_t *) device;

	return DC_STATUS_SUCCESS;

error_close:
	dc_socket_close (&device->base);
error_free:
	dc_iostream_deallocate ((dc_iostream_t *) device);
	return status;
#else
	return DC_STATUS_UNSUPPORTED;
#endif
}