#!/usr/bin/env python3
# encoding: utf-8
"""
broadcast.py
Created by kueblc on 2019-01-25.
Encode data for Tuya smartconfig via broadcast
broadcast strategy ported from https://github.com/tuyapi/link
"""

from crc import crc_8

broadcast_head = [1, 3, 6, 10]

def encode_broadcast_body( password, ssid, token_group ):
	r = []
	r.append( len(password) )
	r.extend([ ord(l) for l in password ])
	r.append( len(token_group) )
	r.extend([ ord(l) for l in token_group ])
	r.extend([ ord(l) for l in ssid ])
	e = []
	length = len(r)
	length_crc = crc_8([ length ])
	e.append( length >> 4 | 16 )
	e.append( length & 0xF | 32 )
	e.append( length_crc >> 4 | 48 )
	e.append( length_crc & 0xF | 64 )
	sequence = 0
	for i in range(0, length, 4):
		group = []
		group.append( sequence )
		group.extend( r[ i : i+4 ] )
		group.extend( [0] * (5 - len(group)) )
		group_crc = crc_8(group)
		e.append( group_crc & 0x7F | 128 )
		e.append( sequence | 128 )
		e.extend([ b | 256 for b in r[ i : i+4 ] ])
		sequence += 1
	e.extend( [256] * (length - i) )
	return e