#!/usr/bin/python3

import sys
import re

class StackElem:
	def __init__(self, parent):
		self.parent = parent
		self.methods = set()

def emitOperation(number, command, operation, stack):
	if command in [".prot", ".protect", ".unprot", ".unprotect"]:
		return # Xyce does not support these commands
	elif command == ".option":
		operation = fixOption(number, operation, stack)
	elif command in [".if", ".elif", ".elsif", ".else", ".endif"]:
		pass
	else:
		operation = fixParams(number, operation, stack)

	if len(operation) > 0:
		print("\n".join(operation))

def emitFunction(name, args, definition):
	print(".func " + name + args + " {" + definition + "}")

# s/^include/* include/g

def fixParams(number, operation, stack):
	result = []
	index = []

	for i, line in enumerate(operation):
		if len(line) == 0 or line[0] == "*":
			result.append(line)
			continue
	
		result.append("")
		line = line.replace("$", ";")
		
		for param in re.finditer(r'([^ \t=+\(\)]+|\'[^\']*\'|[\(\)])(?:[ \t]*(\([^\)]*\))?[ \t]*=[ \t]*(\'[^\']*\'|[^ \t]+))?', line):
			name = param.group(1)
			args = param.group(2)
			definition = param.group(3)

			# dev/gauss is an unsupported parameter in xyce
			if name == "dev/gauss":
				continue
			elif name in ["vt", "Vt", "vT", "VT"]:
				name = "local_" + name
			#elif name.lower().endswith("_fc"):
			#	continue

			if definition:
				if ":" in definition:
					definition = definition.replace(":", " :")
					if definition[0] != "'":
						definition = "'" + definition + "'"

			# Convert .param functions to .func commands
			if args and len(args) > 0:
				found = False
				for elem in stack:
					if name in elem.methods:
						found = True
						break
				if not found:
					emitFunction(name, args, definition[1:-1] if definition[0] == "'" else definition)
					stack[-1].methods.add(name)
			# TODO(edward.bingham) other parameter fixes
			elif definition and len(definition) > 0:
				result[-1] += " " + name + "=" + definition
			elif name and len(name) > 0:
				if len(result[-1]) > 0:
					result[-1] += " "
				result[-1] += name

		if len(result[-1]) == 0:
			result.pop()
		else:
			index.append(len(result)-1)

	if len(index) == 1 and result[index[0]] == ".param":
		del result[index[0]]

	for i in index[1:]:
		result[i] = "+ " + result[i]

	return result

def fixOption(number, operation, stack):
	result = []
	for i, line in enumerate(operation):
		if len(line) == 0 or line[0] == "*":
			result.append(line)
			continue

		for param in re.finditer(r'([a-zA-Z_][a-zA-Z0-9_]*)[ \t]*=[ \t]*(\'[^\']*\'|[^ \t]*)', line):
			name = param.group(1)
			definition = param.group(2)
			if name in ["tmiflag", "modmonte", "tmipath", "etmiUsrInput"]:
				# these options load the TSMC Model Interface (TMI) which isn't supported in Xyce
				# TMI is generally used for modelling of silicon, transistor, and wire aging
				continue
			# TODO(edward.bingham) scale and geoshrink ultimately need to be
			# combined, which means keeping track of the values of each in a given
			# scope and generating options that combine those values as needed
			if name == "scale":
				result.append(".options parser " + name + "=" + definition)
			elif name == "geoshrink":
				result.append(".options parser scale=" + definition)
			else:
				# options need to be actively handled individually, all options between hspice and xyce are different
				print("line " + str(number) + ": unhandled option '" + line + "'", file=sys.stderr)
				continue

	return result

def hspice2Xyce(path):
	stack = [StackElem("")]
	operation = []
	command = ""

	devices = "bcdefghijklmopqrstuvwxyz"
	commands = "."
	continuations = "+"

	with open(path, 'r') as fptr:
		for number, line in enumerate(fptr):
			line = line.strip()
			# extraneous include statements
			if line.lower().startswith("include"):
				line = "* " + line

			if len(line) == 0 or line[0] == '*' or line[0] == '#':
				pass
			else:
				if line[0].lower() in continuations:
					pass
				elif line[0].lower() in commands or line[0].lower() in devices:
					# print and clear stored multiline command
					emitOperation(number, command, operation, stack)
					operation = []

					command = re.split("[ \t]+", line)[0].lower().strip()
					if line[0].lower() in commands:
						if command in [".data", ".subckt", ".if", ".control"]:
							stack.append(StackElem(command))
						elif command == ".lib":
							args = re.split("[ \t]+", line)
							if len(args) <= 2:
								stack.append(StackElem(command))
						elif command.startswith(".end"):
							if command == ".endl" and stack[-1].parent == ".lib":
								stack.pop()
							elif command == ".ends" and stack[-1].parent == ".subckt":
								stack.pop()
							elif command == ".enddata" and stack[-1].parent == ".data":
								stack.pop()
							elif command == ".endif" and stack[-1].parent == ".if":
								stack.pop()
							elif command == ".endc" and stack[-1].parent == ".control":
								stack.pop()
							elif command == ".end" and stack[-1].parent == "":
								stack.pop()
							else:
								print("line " + str(number) + ": stack parse error '" + command + "' disagrees with '" + stack[-1].parent + "'", file=sys.stderr)
								return
				else:
					print("line " + str(number) + ": unrecognized command '" + line + "'", file=sys.stderr)
					return

			operation.append(line)	

		emitOperation(-1, command, operation, stack)
		operation = []

if __name__ == "__main__":
	if len(sys.argv) > 1:
		hspice2Xyce(sys.argv[1])
	else:
		print("$ hspice2xyce path")
		print("Converts an HSPICE netlist to a Xyce netlist and emits result to stdout.")