import re, sys, traceback, json
import phys

file_format_version = 1

def save_system(path, system):
	ser = dict()
	ser["version"] = file_format_version

	ser["ignore"] = system.ignore
	ser["elements"] = []
	for pol in system.elements:
		el = {
			"type": pol.type,
			"angle": pol.angle,
			"delta": pol.delta,
			"ref": pol.ref
		}

		ser["elements"].append(el)

	with open(path, "w") as fd:
		fd.write(json.dumps(ser))

def open_system(path):
	system = phys.System()

	with open(path, "r") as fd:
		ser = json.loads(fd.read())

	if ser["version"] != file_format_version:
		raise ValueError("Bad file version: expected %d, found %d" \
		                 %  (file_format_version, ser["version"]))

	system.ignore = ser["ignore"]

	for el in ser["elements"]:
		pol = phys.Polarizer(str(el["type"]))
		pol.angle = float(el["angle"])
		pol.delta = float(el["delta"])
		pol.ref = el["ref"]
		system.elements.append(pol)

	return system