"""
Dieses Programm durchlaeuft das angegebene Programmverzeichnis und ermittelt zu jeder Datei den md5-Hash.
Wenn neben diesem Programm eine Datei *md5Hash.txt liegt, werden die Werte gegen diese Datei verglichen.
weitere Feature:
* in Anwendung ueberfuehren, z.B. eine jar
* aufrubar ueber cli und Dialog
* config zu Standardeingaben --path, --work;
* --name mit Aufbauregel Release + Name
* Namensliste hinterlegen mit: unterverzeichnis, repo-name und repo-branch
* Methoden zum Annehmen einer Lieferung (unzip Subzips, pruefen, git-push nach korrekter Pruefung
* Methoden zum Erzeugen einer Lieferung
Definition *_md5protokoll.txt: datei \t md5checksum \n
"""
import argparse
import datetime
import hashlib
import os

def openLog(args):
    startTime = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
    path = os.path.join(getattr(args, "work"), getattr(args, "name") + "_" + startTime + ".txt")
    logfile = open(path, 'w', encoding="utf-8")
    logfile.write("* * * * * * * * * *  PROTOKOLLL MD5-Checksum-Pruefung  * * * * * * * * * * * * * * *\n")
    logfile.write("Name: " + getattr(args, "name") + "\n")
    logfile.write("Path: " + getattr(args, "path") + "\n")
    logfile.write("Dir : " + getattr(args, "dir") + "\n")
    return logfile

def openResult(args, mode, suffix):
    path = os.path.join(getattr(args, "work"), getattr(args, "name") + "_"+suffix+".txt")
    if mode == "r" and not os.path.exists(path):
        return None
    resultfile = open(path, mode, encoding="utf-8")
    return resultfile

def traverseDir(logfile, resultfile, path, rootpath):
    logfile.write("traverse " + path + "\n")
    for f in sorted(os.listdir(path)):
        if f[:1] == ".":
            continue
        if f[:2] == "__":
            continue
        if os.path.isfile(os.path.join(path, f)):
            fname = os.path.join(path, f)
            lname = fname.replace(rootpath, "")
            logfile.write(". " + lname + "\n")
            resultfile.write(lname + "\t" + getMD5Hash(fname) + "\n")
        elif os.path.isdir(os.path.join(path, f)):
            traverseDir(logfile, resultfile, os.path.join(path, f), rootpath)

def getMD5Hash(path):
    hash_md5 = hashlib.md5()
    with open(path, "rb") as f:
        for chunk in iter(lambda: f.read(4096), b""):
            hash_md5.update(chunk)
    return hash_md5.hexdigest()

def compareLists(logfile, args):
    protokollfile = openResult(args, "r", "md5protokoll")
    if protokollfile is None:
        logfile.write("Kein Vergleich, da Protokolldatei fehlt! \n")
        return
    resultfile = openResult(args, "r", "md5result")
    protLines = protokollfile.readlines()
    protokollfile.close()
    resultLines = resultfile.readlines()
    resultfile.close()
    p = 0
    r = 0
    error = False
    while (True):
        # print("p " + str(p) + " r " + str(r))
        if len(protLines) > p:
            protRow = protLines[p].replace("\r","").split("\t")
        else:
            protRow = None
        if len(resultLines) > r:
            resRow = resultLines[r].replace("\r","").split("\t")
        else:
            resRow = None
        if protRow is None and resRow is None:
            break
        elif protRow is None and resRow is not None:
            error = True
            logfile.write("ERROR Result " + resRow[0] + ": ist ueberzaehlig\n")
            r += 1
        elif resRow is not None and resRow is not None and protRow[0] > resRow[0]:
            error = True
            logfile.write("ERROR Result " + resRow[0] + ": ist ueberzaehlig\n")
            r += 1
        elif resRow is None and protRow is not None:
            error = True
            logfile.write("ERROR Protokoll " + protRow[0] + ": ist ueberzaehlig\n")
            p += 1
        elif protRow is not None and resRow is not None and protRow[0] < resRow[0]:
            error = True
            logfile.write("ERROR Protokoll " + protRow[0] + ": ist ueberzaehlig\n")
            p += 1
        elif protRow is not None and resRow is not None and protRow[0] == resRow[0]:
            if protRow[1] != resRow[1]:
                error = True
                logfile.write("ERROR "+protRow[0]+": md5Hash unterscheiden sich (" + protRow[1] + "!=" + resRow[1].strip() + ")\n")
            r += 1
            p += 1
    if error:
        logfile.write("\n+--------------------------------------------------------+\n")
        logfile.write("| Fehler aufgetreten, die Dateien unterscheiden sich     |\n")
        logfile.write("+--------------------------------------------------------+\n")
    else:
        logfile.write("\nDateien unterscheiden sich nicht\n")


def readParameter():
    """
    --dir  das zu durchsuchende Verzeichnis
    --name Namenszusatz fuer das zu untersuchende Programmpaket
    --work Arbeitserzeichnis mit:
     <name>_md5result.txt         erstellte Ergebnisdatei
     <name>_md5protokoll.txt      mitgelieferte Vergleichsdatei
     <name>_JJJJMMTT_hhmmss.txt   Protokolldatei
    """
    parser = argparse.ArgumentParser()
    parser.add_argument('-p', '--path', required=True, action='store')
    parser.add_argument('-d', '--dir', required=True, action='store')
    parser.add_argument('-n', '--name', required=True, action='store')
    parser.add_argument('-w', '--work', required=True, action='store')
    args = parser.parse_args()
    return args

if __name__ == '__main__':
    args = readParameter()
    logfile = openLog(args)
    logfile.write("\n")
    resultfile = openResult(args, "w", "md5result")
    path = os.path.join(getattr(args, "path"))
    traverseDir(logfile, resultfile, path, path)
    resultfile.close()
    logfile.write("\n")
    compareLists(logfile, args)
    logfile.close()