import sys
import os

def rem_empty(data):
    return [v for v in data if v]

class PreprocessorError(ValueError):
    pass

def open_and_preprocess(path, name, main=False):
    file = open(f"{path}/{name}", "r")
    content = file.read()
    defines = dict()

    #take care of whitespaces
    content_rem = rem_empty(content.split("\n"))
    content = []
    for line in content_rem:
        content += [line.strip()]

    #preprocessing
    for line in content:
        if line[0] == "#": #is process command
            line_argv = rem_empty(line[1:].split(" "))
            command = line_argv[0].lower()
            if command == "name":
                if main:
                    global out_name
                    out_name = line_argv[1]
            elif command == "include":
                open_and_preprocess(path, " ".join(line_argv[1:]))
            elif command == "define":
                defines[line_argv[1]] = " ".join(line_argv[2:])
            else:
                raise PreprocessorError(f"{command} preprocessor unknown")
        else:
            print(line)

temp = open(".temp", "w")
stdout = sys.stdout
sys.stdout = temp
path = "."
name = "main.bc"
out_name = None
open_and_preprocess(path, name, main=True)
sys.stdout = stdout
temp.close()
if not out_name:
    raise PreprocessorError("#name <name> preprocessor missing")
else:
    os.replace(".temp", f"{out_name}.txt")