#!/usr/bin/env python3
#
# convert_io_cdl.py ---
#
# This script converts the GF CDL for the I/O pads to turn it into valid
# SPICE syntax, using regular expression parsing.

# This script is a filter to be run by setting the name of this script as
# the value to "filter=" for the model install in the sky130 Makefile.

import re
import os
import sys

def filter(inname, outname):

    # Read input
    try:
        with open(inname, 'r') as inFile:
            spitext = inFile.read()
            # (Don't) unwrap continuation lines
            # spilines = spitext.replace('\n+', ' ').splitlines()
            spilines = spitext.splitlines()
    except:
        print('convert_io_cdl.py: failed to open ' + inname + ' for reading.', file=sys.stderr)
        return 1

    fixedlines = []
    modified = False

    resrex = re.compile('^R', re.IGNORECASE)
    caprex = re.compile('^C', re.IGNORECASE)

    for line in spilines:
        fixedline = line
        isres = resrex.match(fixedline)
        iscap = caprex.match(fixedline)
        # check if resistor or capacitor for parameter name changes
        # regexp substitutions:
        # 1) Lines starting with R, C, or M --> change to X
        fixedline = re.sub('^[RCM]', 'X', fixedline, flags=re.IGNORECASE)
        # 2) Names in $[...] --> remove the delimiter
        fixedline = re.sub(' \$\[', ' ', fixedline, flags=re.IGNORECASE)
        fixedline = re.sub('\] ', ' ', fixedline, flags=re.IGNORECASE)
        # 3) Remove $SUB=
        fixedline = re.sub('\$SUB=', '', fixedline, flags=re.IGNORECASE)
        # 4) Handle $W and $L for resistors
        if isres:
            fixedline = re.sub('\$W', 'r_width', fixedline, flags=re.IGNORECASE)
            fixedline = re.sub('\$L', 'r_length', fixedline, flags=re.IGNORECASE)
        if iscap:
            fixedline = re.sub('w=', 'c_width=', fixedline, flags=re.IGNORECASE)
            fixedline = re.sub('l=', 'c_length=', fixedline, flags=re.IGNORECASE)
        # 5) Lowercase AREA and PJ
        fixedline = re.sub('AREA', 'area', fixedline)
        fixedline = re.sub('PJ', 'pj', fixedline)

        if line != fixedline:
            modified = True
        fixedlines.append(fixedline)

    # Write output
    if outname == None:
        for i in fixedlines:
            print(i)
    else:
        # If the output is a symbolic link but no modifications have been made,
        # then leave it alone.  If it was modified, then remove the symbolic
        # link before writing.
        if os.path.islink(outname):
            if not modified:
                return 0
            else:
                os.unlink(outname)
        try:
            with open(outname, 'w') as outFile:
                for i in fixedlines:
                    print(i, file=outFile)
        except:
            print('convert_io_cdl.py: failed to open ' + outname + ' for writing.', file=sys.stderr)
            return 1


if __name__ == '__main__':

    # This script expects to get one or two arguments.  One argument is
    # mandatory and is the input file.  The other argument is optional and
    # is the output file.  The output file and input file may be the same
    # name, in which case the original input is overwritten.

    options = []
    arguments = []
    for item in sys.argv[1:]:
        if item.find('-', 0) == 0:
            options.append(item[1:])
        else:
            arguments.append(item)

    if len(arguments) > 0:
        infilename = arguments[0]

    if len(arguments) > 1:
        outfilename = arguments[1]
    else:
        outfilename = None

    result = filter(infilename, outfilename)
    sys.exit(result)