import os
import re

    
def get_entity_declarations(ftxt):
    z = re.compile("\s*entity\s+(?P<entities>\w+)\s+is")
    entities = []
    for m in z.finditer(ftxt):
        entities.extend(m.groupdict().values())
    return entities


def get_entity_instantiations(ftxt):
    z = re.compile("(:\s*entity\s+((?P<library>\w+(?=\.))\.)?(?P<entity>\w+)\s+)|(\s*component\s+(?P<compentity>\w+)\s+)")
    entities = []
    for m in z.finditer(ftxt):
        d = m.groupdict()
        if d['entity'] != None:
            entities.append(d['entity'])
        if d['compentity'] != None:
            entities.append(d['compentity'])
        
    return entities
                                      
def entity_tuple(ftxt):
    return (get_entity_declarations(ftxt),get_entity_instantiations(ftxt))
    
#flist is a list of file paths, txtfun is applied to the text in these files. a list of [(file-path, txtfun(file-text)), ...] is returned
def analyze_files(flist,txtfun):    
    return [(filepath,txtfun(file(filepath).read())) for filepath in flist]
        
        
def get_constants(ftxt):

    start_search_at = 0    
    constant_list = []
    search_results = [res.start() for res in re.finditer("constant\s+\w+\s+:",ftxt)]
 
    for result in search_results:
        colon_after = ftxt.find(":",result)
        constant = ftxt[result+8:colon_after].lstrip("\t ").rstrip("\t ")
        constant_list.append(constant)
        
    return constant_list


def uppercase_constants(filepath):
    f = file(filepath)
    ftxt = f.read()
    constant_list = get_constants(ftxt)
    for constant in constant_list:
        ftxt = re.sub("(?i)"+constant,constant.upper(),ftxt)
    file(filepath+".out","wt").write(ftxt)

def get_vhd_files(startpath):
    filelist = []
    for t in os.walk(startpath):
        for filename in t[2]:
            if filename[-3:].upper() == "VHD":
                filelist.append(t[0]+"\\"+filename)
    return filelist

def main(path):    
    files = get_vhd_files(path)
    print files
    for file in files:
        uppercase_constants(file)    
    return files

def commit(files):
    for file in files:
        os.remove(file)
        os.rename(file+".out",file)

#use this to delete files appended with '.out'        
def delete_output(files): 
    os.remove(file+".out")
        
import sys
if __name__ == "__main__":
    if len(sys.argv) > 1:
        files = main(sys.argv[1])
    else:
        files = main('.')