#
# buildroot/share/PlatformIO/scripts/marlin.py
# Helper module with some commonly-used functions
#
import os,shutil

from SCons.Script import DefaultEnvironment
env = DefaultEnvironment()

def copytree(src, dst, symlinks=False, ignore=None):
   for item in os.listdir(src):
        s = os.path.join(src, item)
        d = os.path.join(dst, item)
        if os.path.isdir(s):
            shutil.copytree(s, d, symlinks, ignore)
        else:
            shutil.copy2(s, d)

def replace_define(field, value):
	envdefs = env['CPPDEFINES'].copy()
	for define in envdefs:
		if define[0] == field:
			env['CPPDEFINES'].remove(define)
	env['CPPDEFINES'].append((field, value))

# Relocate the firmware to a new address, such as "0x08005000"
def relocate_firmware(address):
	replace_define("VECT_TAB_ADDR", address)

# Relocate the vector table with a new offset
def relocate_vtab(address):
	replace_define("VECT_TAB_OFFSET", address)

# Replace the existing -Wl,-T with the given ldscript path
def custom_ld_script(ldname):
	apath = os.path.abspath("buildroot/share/PlatformIO/ldscripts/" + ldname)
	for i, flag in enumerate(env["LINKFLAGS"]):
		if "-Wl,-T" in flag:
			env["LINKFLAGS"][i] = "-Wl,-T" + apath
		elif flag == "-T":
			env["LINKFLAGS"][i + 1] = apath

# Encrypt ${PROGNAME}.bin and save it with a new name
# Called by specific encrypt() functions, mostly for MKS boards
def encrypt_mks(source, target, env, new_name):
	import sys

	key = [0xA3, 0xBD, 0xAD, 0x0D, 0x41, 0x11, 0xBB, 0x8D, 0xDC, 0x80, 0x2D, 0xD0, 0xD2, 0xC4, 0x9B, 0x1E, 0x26, 0xEB, 0xE3, 0x33, 0x4A, 0x15, 0xE4, 0x0A, 0xB3, 0xB1, 0x3C, 0x93, 0xBB, 0xAF, 0xF7, 0x3E]

	firmware = open(target[0].path, "rb")
	renamed = open(target[0].dir.path + "/" + new_name, "wb")
	length = os.path.getsize(target[0].path)
	position = 0
	try:
		while position < length:
			byte = firmware.read(1)
			if position >= 320 and position < 31040:
				byte = chr(ord(byte) ^ key[position & 31])
				if sys.version_info[0] > 2:
					byte = bytes(byte, 'latin1')
			renamed.write(byte)
			position += 1
	finally:
		firmware.close()
		renamed.close()

def add_post_action(action):
	env.AddPostAction("$BUILD_DIR/${PROGNAME}.bin", action);

# Apply customizations for a MKS Robin
def prepare_robin(address, ldname, fwname):
	def encrypt(source, target, env):
		encrypt_mks(source, target, env, fwname)
	relocate_firmware(address)
	custom_ld_script(ldname)
	add_post_action(encrypt);
