#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import sys
import argparse
import re

# parse arguments and return arguments list.
def get_args():
    parser = argparse.ArgumentParser(
    formatter_class=argparse.RawDescriptionHelpFormatter,
    description="""\
Parse meta connect syntax. Default output is stdout.

sample)
    goto code1(arg1, arg2, ...);
    \t|
    \tV
    goto meta_code1(context, arg1, arg2, ..., Code1);
    """)
    parser.add_argument('input_file',\
                        nargs=None,\
                        type=str,\
                        help='input file path.')
    parser.add_argument('-o', dest='output',\
                        nargs=1,\
                        type=str,\
                        metavar='<file>',\
                        help='write output to <file>')
                        
    return parser.parse_args()

# parse input file and create meta connection list
def parse_meta_syntax(lines,file):
    comment_out = False
    target_cs = False
    caller_name = ''
    isMetaOrStub = False
    for i,l in enumerate(lines):

        regexed_l = re.search(r"[a-zA-Z0-9_]+ *\(",l)

        # get caller code segment name
        if re.search(r"^ *__code",l) is not None:
            caller_name = regexed_l.group(0).rstrip('(')
            if re.search(r"^ *meta_*|stub$",caller_name) is not None:
                isMetaOrStub = True
            else:
                isMetaOrStub = False
            file.write(l)
        elif not isMetaOrStub and regexed_l is not None and re.search(r"^ *goto",l):
            callee_name = regexed_l.group(0).rstrip('(')
            if meta_search(lines, callee_name):
                file.write("/*-- connected by script */\n")
                file.write('// '+l)
                file.write("goto {0:s}(context, {1:s}, {2:s});\n".format('meta_'+caller_name,\
                                                                     l.split('(')[1].rsplit(')')[0],\
                                                                     callee_name.capitalize()))
            else:
                file.write(l)
        else:
            file.write(l)

# search meta code segment.
# Find it :  __code meta_'name'
def meta_search(lines, name):
    for l in lines:
        if re.search(r"^ *__code +meta_{0:s}\(".format(name),l) is not None:
            return True
    return False

def main():
    args = get_args()
    output = sys.stdout
    try:
        f = open(args.input_file,'r')
    except IOError:
        print("cannot open file %s" % input_file)
    if args.output is not None:
        try:
            output = open(args.output[0],'w')
        except IOError:
            print("cannot open file %s" % args.output)
        
    lines = f.readlines()
    connect_list = parse_meta_syntax(lines, output)
    
main()