import sys
import os
import tempfile
import re
import argparse
import time
from userconfig.cfgfile import Conf
from userconfig.tools import Debug
from userconfig.checks import classes_for_host
#FIXME: fill in: from userconfig.tools import ...


class Usage(Exception):
    def __init__(self, msg):
        self.msg = msg


def workconf(directory, depth=2):
    """walks through directory, collecting all filenames, returns list of all filenames"""
    dirs = os.listdir(directory)
    ret = []
    debug.stdout("   ================ workconf ===============", 1)
    debug.stdout("   Finding files in directory %s." % directory, 4)
    for d in dirs:
        name = directory+"/"+d
        if os.path.isdir(name):
            workconf(name, depth+1)
        if name.endswith(".swp"):
            continue
        if d == ".svn":
            continue
        ret.append(name)
        debug.stdout("   +++ Found file %s in directory %s" % (name, directory), 4)
    debug.stdout("   ================ workconf ===============", 1)
    return ret




def build_file(classfiles, destfile, commentstring):
    """open all classfiles, assemble them and write the contents into a tempfile
      returns the name of tempfile
      :param classfiles:
      :param destfile:
      :param commentstring:
      :return: str
      """
    content = []
    debug.stdout("   ================ build_file ===============", 1)
    if commentstring != "":
        debug.stdout("   +++ commentstring found, adding header.", 3)
        content.append(commentstring + " " + cfg.get("Main","stamp") + " " + time.strftime("%+") + "\n")

    for f in classfiles:
        debug.stdout("   +++ Merging %s." % f, 4)
        fp = open(f, "r")
        filecontent = fp.read()
        fp.close()
        if commentstring == "":
            # look for stamp in content, replace with real stamp
            if re.search(re.escape(cfg.get("Main","stampreplace")), filecontent):
                debug.stdout("   +++ commentstring empty, replacing stamp in file", 3)
                filecontent = re.sub(re.escape(cfg.get("Main","stampreplace")), cfg.get("Main","stamp"), filecontent)
        content.append(filecontent)

    (tempfd, tempfilename) = tempfile.mkstemp(prefix=os.path.basename(destfile), dir="/tmp")

    try:
        fp = os.fdopen(tempfd, "w")
    except:
        Tools.error("Cannot write to temporary file %s" % tempfilename)
        os.remove(tempfilename)
        return False
    debug.stdout("   +++ Writing merged files into tempfile %s." % tempfilename, 3)
    for block in content:
        fp.write(block)
        fp.write("\n")
    fp.close()
    debug.stdout("   ================ build_file ===============", 1)
    return tempfilename


def process_all_files(destfiles, dir_config):
    """processes all files in destfiles, generate files from classes, compare and copy if necessary"""
    debug.stdout("   ================ process_all_files ===============", 1)
    for df in destfiles.keys():
        debug.stdout("   ??? Processing source files for %s." % df, 2)
        if not os.path.exists(os.path.dirname(df)):
            debug.stdout("   +++ Directory %s does not exist, creating" % os.path.dirname(df), 1)
            os.mkdir(os.path.dirname(df))
        if not os.path.isdir(os.path.dirname(df)):
            debug.stdout("   --- Destination directory %s does not exist, skipping." % os.path.dirname(df), 1)
            return False
        # assemble file to tmp
        commentstring = ""
        if dir_config.check("Main", "commentstring"):
            commentstring = dir_config.get("Main", "commentstring")
            debug.stdout("   +++ Found commentstring %s in %s" % (commentstring, df), 3)

        tempfilename = build_file(destfiles[df], df, commentstring)
        if not tempfilename:
            debug.stdout("   --- Error while creating temp file for %s, skipping." % df, 1)
            continue
        debug.stdout("   +++ Merged files %s for %s into %s" % (str(destfiles[df]), df, tempfilename), 2)

        # diff assembled file and config file
        if Tools.diff(df, tempfilename, commentstring, debug):
            debug.stdout("File %s has changed" % df, 0)
            if not Tools.user_config_generated(df, cfg):
                debug.stdout("   +++ %s not generated by userconfig, backing up." % df, 2)
                # file not generated from userconfig -> back up
                Tools.backup_file(df, debug)
            # copy tmp file to real location
            debug.stdout("Copy %s to %s." % (tempfilename, df), 0)
            Tools.copy_file(tempfilename, df, debug)
        # remove tmp
        debug.stdout("   +++ Removing temporary file %s." % tempfilename, 2)
        os.remove(tempfilename)
    debug.stdout("   ================ process_all_files ===============", 1)


classchecks = Checks()


def main():
    parser = argparse.ArgumentParser(prog='userconfig',
                                   description='Manages configuration files, usually in the user home directory')

    parser.add_argument('-v',
                      help='Verbosity level (multiple v for higher level)',
                      dest='verbose', action='count', default=0)
    parser.add_argument('-f', '--file',
                      help='userconfig2.cfg config file',
                      dest='file', action='store')
    cmdline = parser.parse_args()
    cfg = Conf(cmdline.file)
    debug = Debug()
    cfg.set_debug(debug)

    cfg.debug(f"Verbose level is {cfg.debug._verbose}", 1)
    cfg.debug("================ main ===============", 1)
    temp_classes = ""
    for h in classes_for_host():
        temp_classes=temp_classes + str(h) + ","
    cfg.debug("+++ Current host is in classes %s" % temp_classes, 1)
    configdir = cfg.get("configdir")
    for d in os.listdir(configdir):
        name = configdir+"/"+d
        cfg.debug("+++ Working in %s" % name, 1)
        if not os.path.isdir(name):
            cfg.debug("--- %s is not a directory, skipping." % name, 3)
            continue
        elif d.startswith(".svn") or d.startswith(".git"):
            cfg.debug("--- %s is .svn or .git, skipping." % name, 3)
            continue
        elif os.path.isfile(name+"/.ignore"):
            cfg.debug("--- %s contains file .ignore, skipping." % name, 3)
            continue
        else:
            cfg.debug("+++ Processing files in %s" % name, 2)
            (destfiles, dirConfig) = workdir(name)
            if isinstance(destfiles, dict):
                if len(destfiles.keys()) > 0:
                    cfg.debug("+++ Building %d files: %s" % (len(destfiles.keys()), destfiles.keys()), 3)
                    process_all_files(destfiles, dirConfig)
            else:
                cfg.debug("--- No files found for %s, skipping." % name, 1)


if __name__ == '__main__':
    main()