#!/usr/bin/env python3

import sys
import os
import shutil
# import ssl

import re
import logging
import sqlite3

from hashlib import md5
from pathlib import Path
from datetime import datetime

from utils.time import timestamp_fmt as ts
from utils.time import date_refmt as df
from utils.config import set_config as setting

from pyftpdlib.handlers import FTPHandler, TLS_FTPHandler
from pyftpdlib.servers import FTPServer
from pyftpdlib.authorizers import DummyAuthorizer, AuthenticationFailed

class DummyMD5Authorizer(DummyAuthorizer):
    def __init__(self, cfg):
        # Initialize the DummyAuthorizer and add the admin user
        super().__init__()
        self.add_user(
            cfg.adminuser[0], cfg.adminuser[1], cfg.adminuser[2], perm=cfg.adminuser[3])

        # Connect to the SQLite database for virtual users
        con = sqlite3.connect(cfg.virtusersdb)
        cur = con.cursor()
        # Create the virtusers table if it doesn't exist
        cur.execute(
            '''CREATE TABLE IF NOT EXISTS virtusers (user text, hash text, virtpath text, perm text)''')
        # Create an index on the user column for faster lookups
        cur.execute(
            '''CREATE INDEX IF NOT EXISTS user_idx on virtusers(user)''')

        # Load existing virtual users from the database
        for row in cur.execute('SELECT * FROM virtusers'):
            self.add_user(row[0], row[1], row[2], perm=row[3])
        con.close()

    def validate_authentication(self, username, password, handler):
        # Validate the user's password against the stored hash
        hash = md5(password.encode("UTF-8")).hexdigest()
        try:
            if self.user_table[username]["pwd"] != hash:
                raise KeyError
        except KeyError:
            raise AuthenticationFailed


class ASEHandler(FTPHandler):

    def __init__(self, conn, server, ioloop=None):
        # Initialize the FTPHandler and add custom commands
        super().__init__(conn, server, ioloop)
        self.proto_cmds = FTPHandler.proto_cmds.copy()
        # Add custom FTP commands for managing virtual users - command in lowercase
        self.proto_cmds.update(
            {'SITE ADDU': dict(perm='M', auth=True, arg=True,
                               help='Syntax: SITE <SP> ADDU USERNAME PASSWORD (add virtual user).')}
        )
        self.proto_cmds.update(
            {'SITE DELU': dict(perm='M', auth=True, arg=True,
                               help='Syntax: SITE <SP> DELU USERNAME (remove virtual user).')}
        )
        self.proto_cmds.update(
            {'SITE LSTU': dict(perm='M', auth=True, arg=None,
                               help='Syntax: SITE <SP> LSTU (list virtual users).')}
        )

    def on_file_received(self, file):
        # Handle the event when a file is received
        unitType = ""
        unitName = ""
        toolName = ""
        toolType = ""
        fileDate = ""
        fileTime = ""
        queue = ""
        # Check if the file is empty and remove it if so
        if not os.stat(file).st_size:
            os.remove(file)
            logging.info(
                "File {} was empty: removed.".format(file))
        else:
            cfg = self.cfg
            path, filenameExt = os.path.split(file)
            filename, fileExtension = os.path.splitext(filenameExt)
            # Process the file if it has a valid extension
            if (fileExtension.upper() in (cfg.fileext)):
                # Match the filename against a specific pattern
                if m := re.match(
                    r"^(G\d\d\d|GFLOW)_(ID\d\d\d\d)_(DT\d\d\d\d)_(\d\d)(\d\d)(\d\d\d\d|\d\d)(\d\d)(\d\d)(\d\d)$",
                    filename,
                    re.I,
                ):
                    unitType = m.group(1).upper()
                    unitName = m.group(2).upper()
                    toolName = m.group(3).upper()
                    toolType = "N/A"
                    fileDate = m.group(6) + "/" + m.group(5) + "/" + m.group(4)
                    fileTime = m.group(7) + ":" + m.group(8) + ":" + m.group(9)

                # Match against another pattern for different file formats
                elif re.match(
                    r"^(\d\d_\d\d\d\d|)(DT\d\d\d\d|LOC\d\d\d\d|GD\d\d\d\d)$", filename, re.I
                ):
                    with open(file, "r") as fileCsv:
                        try:
                            # Read the CSV file line by line
                            for i, line in enumerate(fileCsv.readlines(4096), 1):
                                # Extract creation date and time
                                if m1 := re.match(
                                    r"^(File Creation Date:\s)?(\d*\/\d*\/\d*)\s(\d*:\d*:\d*)\;*\n?$",
                                    line,
                                    re.I,
                                ):
                                    fileDate = m1.group(2)
                                    fileTime = m1.group(3)

                                # Extract unit type and name
                                elif m2 := re.match(
                                    r"^(\w+\d+)\s(\w+\d+)\;*\n?$",
                                    line,
                                    re.I,
                                ):
                                    unitType = m2.group(1).upper()
                                    unitName = m2.group(2).upper()

                                # Extract tool type and name from the path
                                elif m3 := re.match(
                                    r"^SD path: a:\/\w+\/(\w+)(?:\.\w+)?\/*(\w*)(?:\.\w+)?\;*\n?$",
                                    line,
                                    re.I,
                                ):
                                    if m3.group(2):
                                        toolType = m3.group(1).upper()
                                        toolName = m3.group(2).upper()
                                    else:
                                        toolType = "".join(
                                            re.findall(
                                                "^[a-zA-Z]+", m3.group(1))
                                        ).upper()
                                        toolName = m3.group(1).upper()
                                    break
                        except:
                            logging.error(
                                "Error: {}.".format(sys.exc_info()[1]))
                        fileCsv.close

                # Log the extracted information
                logging.info(
                    "{} - {} - {} - {} - {} {}.".format(
                        unitType,
                        unitName,
                        toolName,
                        toolType,
                        df.dateFmt(fileDate),
                        fileTime,
                    )
                )
                # Prepare the new path for the received file
                newPath = cfg.csvfs + "/" + self.username + "/received/" + \
                    unitName.upper() + "/"
                newFilename = (
                    newPath + filename + "_" +
                    str(ts.timestamp("tms") + fileExtension)
                )
                fileRenamed = file + "_" + str(ts.timestamp("tms"))
                # Rename the original file to avoid conflicts
                os.rename(file, fileRenamed)
                try:
                    # Create the new directory for the user if it doesn't exist
                    os.makedirs(newPath)
                    logging.info("Path {} created.".format(newPath))
                except FileExistsError:
                    logging.info("Path {} already exists.".format(newPath))
                try:
                    # Move the renamed file to the new location
                    shutil.move(fileRenamed, newFilename)
                    logging.info("{} moved into {}.".format(
                        filenameExt, newFilename))
                except OSError:
                    logging.error("Error to move {} into {}.".format(
                        filenameExt, newFilename))
                now = datetime.now()

    def on_incomplete_file_received(self, file):
        # Remove partially uploaded files
        os.remove(file)

    def ftp_SITE_ADDU(self, line):
        """
            Add a virtual user and save the virtuser configuration file.
            Create a directory for the virtual user in the specified virtpath.
        """
        cfg = self.cfg
        parms = line.split()
        user = os.path.basename(parms[0])  # Extract the username
        password = parms[1]  # Get the password
        hash = md5(password.encode("UTF-8")).hexdigest()  # Hash the password

        try:
            # Create the user's directory
            Path(cfg.virtpath + user).mkdir(parents=True, exist_ok=True)
        except:
            self.respond('551 Error in create virtual user path.')
        else:
            try:
                # Add the user to the authorizer
                self.authorizer.add_user(str(user),
                                         hash, cfg.virtpath + "/" + user, perm="lmw")
                # Save the user to the SQLite database
                con = sqlite3.connect(cfg.virtusersdb)
                cur = con.cursor()
                cur.execute("INSERT INTO virtusers VALUES (?,?,?,?)",
                            (user, hash, cfg.virtpath + user, 'elmw'))
                con.commit()
                con.close()
                logging.info("User {} created.".format(user))
                self.respond('200 SITE ADDU successful.')
            except:
                self.respond('501 SITE ADDU failed.')

    def ftp_SITE_DELU(self, line):
        """
            Remove a virtual user and save the virtuser configuration file.
        """
        cfg = self.cfg
        parms = line.split()
        user = os.path.basename(parms[0])  # Extract the username
        try:
            # Remove the user from the authorizer
            self.authorizer.remove_user(str(user))
            # Delete the user from the SQLite database
            con = sqlite3.connect(cfg.virtusersdb)
            cur = con.cursor()
            cur.execute("DELETE FROM virtusers WHERE user = ?", (user,))
            con.commit()
            con.close()
            logging.info("User {} deleted.".format(user))
            self.respond('200 SITE DELU successful.')

        except:
            self.respond('501 SITE DELU failed.')

    def ftp_SITE_LSTU(self, line):
        """
            List all virtual users.
        """
        cfg = self.cfg
        users_list = []
        try:
            # Connect to the SQLite database to fetch users
            con = sqlite3.connect(cfg.virtusersdb)
            cur = con.cursor()
            self.push("214-The following virtual users are defined:\r\n")
            # Fetch and list all virtual users
            for row in cur.execute("SELECT * FROM virtusers").fetchall():
                users_list.append(
                    " Username: " + row[0] + "\tPerms: " + row[3] + "\r\n")
            con.close()
            self.push(''.join(users_list))
            self.respond("214 LSTU SITE command successful.")

        except:
            self.respond('501 list users failed.')


def main():
    # Load the configuration settings
    cfg = setting.config()

    try:
        # Initialize the authorizer and handler
        authorizer = DummyMD5Authorizer(cfg)
        handler = ASEHandler
        handler.cfg = cfg
        handler.authorizer = authorizer
        handler.masquerade_address = cfg.proxyaddr
        # Set the range of passive ports for the FTP server
        _range = list(range(cfg.firstport, cfg.firstport + cfg.portrangewidth))
        handler.passive_ports = _range

        # Configure logging
        logging.basicConfig(
            format="%(asctime)s %(message)s",
            filename=cfg.logfilename,
            level=logging.INFO,
        )

        # Create and start the FTP server
        server = FTPServer(("0.0.0.0", 2121), handler)
        server.serve_forever()
    except KeyboardInterrupt:
        logging.info(
            "Info: {}.".format("Shutdown requested...exiting")
        )
    except Exception:
        print(
            "{} - PID {:>5} >> Error: {}.".format(
                ts.timestamp("log"), os.getpid(), sys.exc_info()[1]
            )
        )


if __name__ == "__main__":
    main()