import helpers.misc as __misc


def sshconf_decode_bool(
	value
):
	return (value == "yes")
	

def sshconf_decode(
	sshconf
):
	state = {
		"name": "initial",
		"entries": {},
		"current_name": None,
		"current_entry": None,
	}
	for line in sshconf.split("\n"):
		line_stripped = line.strip()
		if (line_stripped == ""):
			pass
		else:
			parts = line_stripped.split(" ")
			head = parts[0]
			body = " ".join(parts[1:])
			if (head == "#"):
				state["current_entry"]["extra"] = (
					[body]
					if ("extra" not in state["current_entry"]) else
					(state["current_entry"]["extra"] + [body])
				)
			elif (head.lower() == "host"):
				if ((state["current_name"] is None) or (state["current_entry"] is None)):
					pass
				else:
					state["entries"][state["current_name"]] = state["current_entry"]
				state["current_name"] = body
				state["current_entry"] = {}
			elif (head.lower() == "hostname"):
				state["current_entry"]["host"] = body
			elif (head.lower() == "port"):
				state["current_entry"]["port"] = int(body)
			elif (head.lower() == "user"):
				state["current_entry"]["username"] = body
			elif (head.lower() == "identityfile"):
				state["current_entry"]["key_name"] = body
			elif (head.lower() == "proxyjump"):
				state["current_entry"]["proxy_jump"] = body
			elif (head.lower() == "proxycommand"):
				state["current_entry"]["proxy_command"] = body
			elif (head.lower() == "pubkeyauthentication"):
				state["current_entry"]["pub_key_authentication"] = sshconf_decode_bool(body)
			elif (head.lower() == "identitiesonly"):
				state["current_entry"]["identities_only"] = sshconf_decode_bool(body)
			else:
				raise ValueError("unhandled sshconf thing: " + head)
	state["entries"][state["current_name"]] = state["current_entry"]
	state["current_name"] = None
	state["current_entry"] = None
	return state["entries"]
	

def sshconf_encode_bool(
	value
):
	return ("yes" if value else "no")
	

def sshconf_encode_entry(name, entry, prefix):
	lines = []
	lines.append(__misc.string_coin("Host {{prefix}}{{name}}", {"prefix": prefix, "name": name}))
	if ("host" in entry):
		lines.append(__misc.string_coin("\tHostName {{host}}", {"host": entry["host"]}))
	if ("port" in entry):
		lines.append(__misc.string_coin("\tPort {{port}}", {"port": ("%u" % entry["port"])}))
	if ("username" in entry):
		lines.append(__misc.string_coin("\tUser {{username}}", {"username": entry["username"]}))
	if ("key_name" in entry):
		lines.append(__misc.string_coin("\tIdentityFile {{key_path}}", {"key_path": ("~/.ssh/keypairs/%s%s" % (prefix, entry["key_name"]))}))
	if ("proxy_jump" in entry):
		lines.append(__misc.string_coin("\tProxyJump {{proxy_jump}}", {"proxy_jump": entry["proxy_jump"]}))
	if ("proxy_command" in entry):
		lines.append(__misc.string_coin("\tProxyCommand {{proxy_command}}", {"proxy_command": entry["proxy_command"]}))
	if ("pub_key_authentication" in entry):
		lines.append(__misc.string_coin("\tPubKeyAuthentication {{pub_key_authentication}}", {"pub_key_authentication": sshconf_encode_bool(entry["pub_key_authentication"])}))
	if ("identities_only" in entry):
		lines.append(__misc.string_coin("\tIdentitiesOnly {{identities_only}}", {"identities_only": sshconf_encode_bool(entry["identities_only"])}))
	lines.append("")
	return "\n".join(lines)
	

def sshconf_encode(conf):
	return "\n".join(
		map(
			lambda pair: sshconf_encode_entry(
				pair[0],
				pair[1],
				conf["settings"]["prefix"]
			),
			sorted(
				conf["entries"].items(),
				key = lambda entry: entry[0]
			)
		)
	)